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Stilianu C, Graf C, Huemer M, Diwoky C, Soellradl M, Rund A, Zaiss M, Stollberger R. Enhanced and robust contrast in CEST MRI: Saturation pulse shape design via optimal control. Magn Reson Med 2024; 92:1867-1880. [PMID: 38818538 DOI: 10.1002/mrm.30164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/10/2024] [Accepted: 05/07/2024] [Indexed: 06/01/2024]
Abstract
PURPOSE To employ optimal control for the numerical design of Chemical Exchange Saturation Transfer (CEST) saturation pulses to maximize contrast and stability againstB 0 $$ {\mathrm{B}}_0 $$ inhomogeneities. THEORY AND METHODS We applied an optimal control framework for the design pulse shapes for CEST saturation pulse trains. The cost functional minimized both the pulse energy and the discrepancy between the corresponding CEST spectrum and the target spectrum based on a continuous radiofrequency (RF) pulse. The optimization is subject to hardware limitations. In measurements on a 7 T preclinical scanner, the optimal control pulses were compared to continuous-wave and Gaussian saturation methods. We conducted a comparison of the optimal control pulses with Gaussian, block pulse trains, and adiabatic spin-lock pulses. RESULTS The optimal control pulse train demonstrated saturation levels comparable to continuous-wave saturation and surpassed Gaussian saturation by up to 50 % in phantom measurements. In phantom measurements at 3 T the optimized pulses not only showcased the highest CEST contrast, but also the highest stability against field inhomogeneities. In contrast, block pulse saturation resulted in severe artifacts. Dynamic Bloch-McConnell simulations were employed to identify the source of these artifacts, and underscore theB 0 $$ {\mathrm{B}}_0 $$ robustness of the optimized pulses. CONCLUSION In this work, it was shown that a substantial improvement in pulsed saturation CEST imaging can be achieved by using Optimal Control design principles. It is possible to overcome the sensitivity of saturation to B0 inhomogeneities while achieving CEST contrast close to continuous wave saturation.
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Affiliation(s)
- Clemens Stilianu
- Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
| | - Christina Graf
- Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
| | - Markus Huemer
- Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
| | - Clemens Diwoky
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Martin Soellradl
- Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
- Department of Radiology and Radiological Sciences, Monash University, Melbourne, Australia
| | - Armin Rund
- Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria
| | - Moritz Zaiss
- Institute of Neuroradiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
- High-Field Magnetic Resonance Center, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Rudolf Stollberger
- Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
- BioTechMed Graz, Graz, Austria
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Jin T, Wang J, Chung J, Hitchens TK, Sun D, Mettenburg J, Wang P. Amide proton transfer MRI at 9.4 T for differentiating tissue acidosis in a rodent model of ischemic stroke. Magn Reson Med 2024; 92:2140-2148. [PMID: 38923094 DOI: 10.1002/mrm.30194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 04/08/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024]
Abstract
PURPOSE Differentiating ischemic brain damage is critical for decision making in acute stroke treatment for better outcomes. We examined the sensitivity of amide proton transfer (APT) MRI, a pH-weighted imaging technique, to achieve this differentiation. METHODS In a rat stroke model, the ischemic core, oligemia, and the infarct-growth region (IGR) were identified by tracking the progression of the lesions. APT MRI signals were measured alongside ADC, T1, and T2 maps to evaluate their sensitivity in distinguishing ischemic tissues. Additionally, stroke under hyperglycemic conditions was studied. RESULTS The APT signal in the IGR decreased by about 10% shortly after stroke onset, and further decreased to 35% at 5 h, indicating a progression from mild to severe acidosis as the lesion evolved into infarction. Although ADC, T1, and T2 contrasts can only detect significant differences between the IGR and oligemia for a portion of the stroke duration, APT contrast consistently differentiates between them at all time points. However, the contrast to variation ratio at 1 h is only about 20% of the contrast to variation ratio between the core and normal tissues, indicating limited sensitivity. In the ischemic core, the APT signal decreases to about 45% and 33% of normal tissue level at 1 h for the normoglycemic and hyperglycemic groups, respectively, confirming more severe acidosis under hyperglycemia. CONCLUSION The sensitivity of APT MRI is high in detecting severe acidosis of the ischemic core but is much lower in detecting mild acidosis, which may affect the accuracy of differentiation between the IGR and oligemia.
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Affiliation(s)
- Tao Jin
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jicheng Wang
- Department of Urology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Julius Chung
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - T Kevin Hitchens
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joseph Mettenburg
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ping Wang
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Wang K, Ju L, Song Y, Blair L, Xie K, Liu C, Li A, Zhu D, Xu F, Liu G, Heo HY, Yadav N, Oeltzschner G, Edden RAE, Qin Q, Kamson DO, Xu J. Whole-cerebrum guanidino and amide CEST mapping at 3 T by a 3D stack-of-spirals gradient echo acquisition. Magn Reson Med 2024; 92:1456-1470. [PMID: 38748853 PMCID: PMC11262991 DOI: 10.1002/mrm.30134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/01/2024] [Accepted: 04/09/2024] [Indexed: 05/22/2024]
Abstract
PURPOSE To develop a 3D, high-sensitivity CEST mapping technique based on the 3D stack-of-spirals (SOS) gradient echo readout, the proposed approach was compared with conventional acquisition techniques and evaluated for its efficacy in concurrently mapping of guanidino (Guan) and amide CEST in human brain at 3 T, leveraging the polynomial Lorentzian line-shape fitting (PLOF) method. METHODS Saturation time and recovery delay were optimized to achieve maximum CEST time efficiency. The 3DSOS method was compared with segmented 3D EPI (3DEPI), turbo spin echo, and gradient- and spin-echo techniques. Image quality, temporal SNR (tSNR), and test-retest reliability were assessed. Maps of Guan and amide CEST derived from 3DSOS were demonstrated on a low-grade glioma patient. RESULTS The optimized recovery delay/saturation time was determined to be 1.4/2 s for Guan and amide CEST. In addition to nearly doubling the slice number, the gradient echo techniques also outperformed spin echo sequences in tSNR: 3DEPI (193.8 ± 6.6), 3DSOS (173.9 ± 5.6), and GRASE (141.0 ± 2.7). 3DSOS, compared with 3DEPI, demonstrated comparable GuanCEST signal in gray matter (GM) (3DSOS: [2.14%-2.59%] vs. 3DEPI: [2.15%-2.61%]), and white matter (WM) (3DSOS: [1.49%-2.11%] vs. 3DEPI: [1.64%-2.09%]). 3DSOS also achieves significantly higher amideCEST in both GM (3DSOS: [2.29%-3.00%] vs. 3DEPI: [2.06%-2.92%]) and WM (3DSOS: [2.23%-2.66%] vs. 3DEPI: [1.95%-2.57%]). 3DSOS outperforms 3DEPI in terms of scan-rescan reliability (correlation coefficient: 3DSOS: 0.58-0.96 vs. 3DEPI: -0.02 to 0.75) and robustness to motion as well. CONCLUSION The 3DSOS CEST technique shows promise for whole-cerebrum CEST imaging, offering uniform contrast and robustness against motion artifacts.
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Affiliation(s)
- Kexin Wang
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Licheng Ju
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yulu Song
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lindsay Blair
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, USA
| | - Kevin Xie
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Claire Liu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Anna Li
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Dan Zhu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Feng Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Guanshu Liu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hye-Young Heo
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nirbhay Yadav
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Georg Oeltzschner
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Richard A. E. Edden
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Qin Qin
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David Olayinka Kamson
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jiadi Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Librizzi G, Lombardi G, Bertoldo A, Manara R. Perioperative imaging predictors of tumor progression and pseudoprogression: A systematic review. Crit Rev Oncol Hematol 2024; 202:104445. [PMID: 38992848 DOI: 10.1016/j.critrevonc.2024.104445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 06/26/2024] [Accepted: 07/06/2024] [Indexed: 07/13/2024] Open
Abstract
In high-grade gliomas, pseudoprogression after radiation treatment might dramatically impact patient's management. We searched for perioperative imaging predictors of pseudoprogression in high-grade gliomas according to PRISMA guidelines, using MEDLINE/Pubmed and Embase (until January 2024). Study design, sample size, setting, diagnostic gold standard, imaging modalities and contrasts, and differences among variables or measures of diagnostic accuracy were recorded. Study quality was assessed through the QUADAS-2 tool. Twelve studies (11 with MRI, one with PET; 1058 patients) were reviewed. Most studies used a retrospective design (9/12), and structural MRI (7/12). Studies were heterogeneous in metrics and diagnostic reference standards; patient selection bias was a frequent concern. Pseudoprogression and progression showed some significant group differences in perioperative imaging metrics, although often with substantial overlap. Radiomics showed moderate accuracy but requires further validation. Current literature is scarce and limited by methodological concerns, highlighting the need of new predictors and multiparametric approaches.
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Affiliation(s)
- Giovanni Librizzi
- Padova Neuroscience Center (PNC), University of Padova, Padova, Italy; Neuroradiology Unit, Padova University Hospital, Padova, Italy.
| | - Giuseppe Lombardi
- Department of Oncology, Oncology 1, Veneto Institute of Oncology IOV-IRCCS, Padova, Italy.
| | - Alessandra Bertoldo
- Padova Neuroscience Center (PNC), University of Padova, Padova, Italy; Department of Information Engineering, University of Padova, Padova, Italy.
| | - Renzo Manara
- Neuroradiology Unit, Padova University Hospital, Padova, Italy; DIMED, University of Padova, Padova, Italy.
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Chung JJ, Kim H, Ji Y, Lu D, Zhou IY, Sun PZ. Improving standardization and accuracy of in vivo omega plot exchange parameter determination using rotating-frame model-based fitting of quasi-steady-state Z-spectra. Magn Reson Med 2024. [PMID: 39221563 DOI: 10.1002/mrm.30259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 07/31/2024] [Accepted: 08/01/2024] [Indexed: 09/04/2024]
Abstract
PURPOSE Although Ω-plot-driven quantification of in vivo amide exchange properties has been demonstrated, differences in scan parameters may complicate the fidelity of determination. This work systematically evaluated the use of quasi-steady-state (QUASS) Z-spectra reconstruction to standardize in vivo amide exchange quantification across acquisition conditions and further determined it in vivo. METHODS Simulation and in vivo rodent brain chemical exchange saturation transfer (CEST) data at 4.7 T were fit with and without QUASS reconstruction using both multi-Lorentzian and model-based fitting approaches. pH modulation was accomplished both in simulation and in vivo by inducing global ischemia via cardiac arrest. Amide parameters were determined via Ω-plots and compared across methods. RESULTS Simulation showed that Ω-plots using multi-Lorentzian fitting could underestimate the exchange rate, with error increasing as conditions diverged from the steady state. In comparison, model-based fitting using QUASS estimated the same exchange rate within 2%. These results aligned with in vivo findings where multi-Lorentzian fitting of native Z-spectra resulted in an exchange rate of 64 ± 13 s-1 (38 ± 16 s-1 after cardiac arrest), whereas model-based fitting of QUASS Z-spectra yielded an exchange rate of 126 ± 25 s-1 (49 ± 13 s-1). CONCLUSION The model-based fitting of QUASS CEST Z-spectra enables consistent and accurate quantification of exchange parameters through Ω-plot construction by reducing error due to signal overlap and nonequilibrium CEST effects.
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Affiliation(s)
- Julius Juhyun Chung
- Primate Imaging Center, Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
| | - Hahnsung Kim
- Primate Imaging Center, Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Yang Ji
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Dongshuang Lu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Iris Y Zhou
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Phillip Zhe Sun
- Primate Imaging Center, Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia, USA
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, USA
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Takami Y, Norikane T, Kimura N, Mitamura K, Yamamoto Y, Miyake K, Miyoshi M, Nishiyama Y. Relationship between multi-pool model-based chemical exchange saturation transfer imaging, intravoxel incoherent motion MRI, and 11C-methionine uptake on PET/CT in patients with gliomas. Magn Reson Imaging 2024; 111:148-156. [PMID: 38729226 DOI: 10.1016/j.mri.2024.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/01/2024] [Accepted: 05/07/2024] [Indexed: 05/12/2024]
Abstract
PURPOSE Magnetization transfer ratio asymmetry (MTRasym) analysis is used for chemical exchange saturation transfer (CEST) in patients with gliomas; however, this approach has limitations. CEST imaging using a multi-pool model (MPM) may allow a more detailed assessment of gliomas; however, its mechanism remains unknown. This study aimed to assess the relationship between CEST imaging by MPM, intravoxel incoherent motion (IVIM), and 11C-methionine (11C-MET) uptake on positron emission tomography/computed tomography (PET/CT) to clarify the clinical significance of CEST imaging using MPM in gliomas. METHODS This retrospective study included 17 patients with gliomas who underwent 11C-MET PET/CT at our institution between January 2020 and January 2022. Two-dimensional axial CEST imaging was conducted using single-shot fast-spin echo acquisition at 3 T. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), f, MTRasym (3.5 ppm), parameters of MPM-based CEST imaging, and tumor-to-contralateral normal brain tissue (T/N) ratio were calculated using a region-of-interest analysis. Shapiro-Wilk test, weighted kappa coefficient, and Spearman's rank correlation coefficients were used for statistical analysis. RESULTS Significant correlations were found between APT_T1 and T/N ratio (ρ = 0.87, p < 0.001), APT_T2 and T/N ratio (ρ = 0.47, p < 0.05), MTRasym and T/N ratio (ρ = 0.55, p < 0.01), and T2/T1 and T/N ratio (ρ = -0.36, p < 0.05). Furthermore, significant correlations were observed between APT_T1 and ADC (ρ = -0.67, p < 0.001), APT_T1 and D (ρ = -0.70, p < 0.001), APT_T2 and D* (ρ = -0.45, p < 0.05), and T2/T1 and D (ρ = 0.39, p < 0.05). CONCLUSION These preliminary findings indicate that MPM-based CEST imaging parameters correlate with IVIM and 11C-MET uptake on PET/CT in patients with gliomas. In particular, the new parameter APT_T1 correlated more strongly with 11C-MET uptake compared to the traditional CEST parameter MTRasym.
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Affiliation(s)
- Yasukage Takami
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan.
| | - Takashi Norikane
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Naruhide Kimura
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Katsuya Mitamura
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yuka Yamamoto
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Keisuke Miyake
- Department of Neurological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Mitsuharu Miyoshi
- Global MR Clinical Solution and Research Collaboration, GE HealthCare, Tokyo, Japan
| | - Yoshihiro Nishiyama
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
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Li JL, Xu Y, Xiang YS, Wu P, Shen AJ, Wang PJ, Wang F. The Value of Amide Proton Transfer MRI in the Diagnosis of Malignant and Benign Urinary Bladder Lesions: Comparison With Diffusion-Weighted Imaging. J Magn Reson Imaging 2024; 60:1124-1133. [PMID: 38174777 DOI: 10.1002/jmri.29199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/08/2023] [Accepted: 12/09/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Conventional magnetic resonance imaging (MRI) has certain limitations in distinguishing between malignant and benign urinary bladder (UB) lesions. Amide proton transfer (APT) imaging may provide more diagnostic information than diffusion-weighted imaging (DWI) to distinguish between malignant and benign UB. PURPOSE To investigate the potential of APT imaging in the diagnosis of malignant and benign UB lesions and to compare its diagnostic efficacy with that of conventional DWI. STUDY TYPE Prospective. SUBJECTS Eighty patients with UB lesions. FIELD STRENGTH/SEQUENCE A 3.0 T/turbo spin echo (TSE) T1-weighted and T2-weighted imaging, single-shot echo planar DWI, and three-dimensional TSE APT imaging. ASSESSMENT Patients underwent radical cystectomy or transurethral resection of the bladder lesions within 2 weeks after CT urography and MRI examination. APT signal intensity in UB lesions was quantified by the asymmetric magnetization transfer ratio (MTRasym). MTRasym and apparent diffusion coefficient (ADC) values were measured and compared between malignant and benign UB lesions. STATISTICAL TESTS Kolmogorov-Smirnov test, Student's t test or Mann-Whitney U test, Spearman rank correlation coefficient, area under the receiver operating characteristic (ROC) curve (AUC), Delong test, and intraclass correlation coefficient (ICC). The significance threshold was set at P < 0.05. RESULTS Thirty-two patients had pathologically confirmed benign UB lesions, including 2 bladder leiomyomas, 1 submucosal amyloidosis, 1 inflammatory myofibroblastic tumor, and 28 inflammatory lesions, and 48 patients had pathologically confirmed urothelial carcinoma. Urothelial carcinomas showed significantly higher MTRasym values (1.53% [0.74%] vs. 0.85% [0.23%]) and significantly lower ADC values (1.24 ± 0.34 × 10-3 mm2/s vs. 1.43 ± 0.22 × 10-3 mm2/s) than benign UB lesions. The MTRasym value (AUC = 0.928) was significantly better in differentiating urothelial carcinoma from benign UB lesions than the ADC value (AUC = 0.722). DATA CONCLUSION APT imaging may have value in discriminating malignant from benign UB lesions and has better diagnostic performance than DWI. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Jing-Lu Li
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai, China
| | - Yun Xu
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai, China
| | - Yong-Sheng Xiang
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai, China
| | - Peng Wu
- Clinical and Technical Support, Philips Healthcare, Shanghai, China
| | - Ai-Jun Shen
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai, China
| | - Pei-Jun Wang
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai, China
| | - Fang Wang
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai, China
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Yu FF, Rathnakar J, Ryder B, Hitt B, Kashmer OM, Sherry AD, Vinogradov E. Differentiation and characterization of healthy versus pathological tau using chemical exchange saturation transfer. NMR IN BIOMEDICINE 2024; 37:e5160. [PMID: 38646677 DOI: 10.1002/nbm.5160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 02/29/2024] [Accepted: 03/17/2024] [Indexed: 04/23/2024]
Abstract
Neurofibrillary tangles of tau constitute one of the key biological hallmarks of Alzheimer's disease. Currently, the assessment of regional tau accumulation requires intravenous administration of radioactive tracers for PET imaging. A noninvasive MRI-based solution would have significant clinical implications. Herein, we utilized an MRI technique known as chemical exchange saturation transfer (CEST) to determine the imaging signature of tau in both its monomeric and pathologic fibrillated conformations. Three sets of purified recombinant full-length (4R) tau protein were prepared for collection of CEST spectra using a 9.4 T NMR spectrometer at varying temperatures (25, 37, and 42 °C) and RF intensities (0.7, 1.0, 1.5, and 2.2 μT). Monomeric and fibrillated tau were readily distinguished based on their Z-spectrum profiles. Fibrillated tau demonstrated a less prominent peak at 3.5 ppm with additional peaks near 0.5 and 1.5 ppm. No significant differences were identified between fibrillated tau prepared using heparin versus seed-competent tau. In conclusion, monomeric and fibrillated tau can be readily detected and distinguished based on their CEST-derived Z-spectra, pointing to the potential utility of CEST-MRI as a noninvasive biomarker of regional pathologic tau accumulation in the brain. Further testing and validation in vitro and in vivo will be necessary before this can be applied clinically.
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Affiliation(s)
- Fang Frank Yu
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - James Rathnakar
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Bryan Ryder
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Brian Hitt
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, UCI Medical Center, Orange, California, USA
| | - Omar M Kashmer
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - A Dean Sherry
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Chemistry & Biochemistry, University of Texas at Dallas, Dallas, Texas, USA
| | - Elena Vinogradov
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Cai Z, Zhong Q, Zhang D, Feng Y, Wang Q, Yang Y, Xu Y, Liang C, Liu Z, Cai K. Z-Spectral MRI Quantifies the Mass and Metabolic Activity of Adipose Tissues With Fat-Water-Fraction and Amide-Proton-Transfer Contrasts. J Magn Reson Imaging 2024. [PMID: 39215496 DOI: 10.1002/jmri.29598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 08/20/2024] [Accepted: 08/20/2024] [Indexed: 09/04/2024] Open
Abstract
BACKGROUND Brown adipose tissue (BAT) is metabolically activatable and plays an important role in obesity and metabolic diseases. With reduced fat-water-fraction (FWF) compared with white adipose tissue (WAT), BAT mass and its functional activation may be quantified with Z-spectra MRI, with built-in FWF and the metabolic amide proton transfer (APT) contrasts. PURPOSE To investigate if Z-spectral MRI can quantify the mass and metabolic activity of adipose tissues. STUDY TYPE Prospective. SUBJECTS Seven groups of 8-week-old male rats, including two groups (n = 7 per group) for in vivo MRI study and five groups (n = 5 per group) for ex vivo validation; 12 young and healthy volunteers with 6 male and 6 female. FIELD STRENGTH/SEQUENCE The 7 T small animal and 3 T clinical systems, T2-weighted imaging, Rapid Acquisition with Relaxation Enhancement (RARE) readout based chemical exchange saturation transfer (CEST) Z-spectral MRI sequence. ASSESSMENT Quantified FWF and APT from Z-spectra in rats before and after norepinephrine (NE) stimulation and in healthy human subjects; ex vivo measurements of total proteins in BAT from rats. STATISTICAL TESTS Two-tailed unpaired Student's t-tests and repeated measures ANOVA. P-value <0.05 was considered significant. RESULTS Decreased FWF (from 39.6% ± 7.2% before NE injection to 16.4% ± 7.2% 120 minutes after NE injection, P < 0.0001) and elevated APT (from 1.1% ± 0.5% before NE injection to 2.9% ± 0.5% 120 minutes after NE injection, P < 0.0001) signals in BAT were observed with in vivo Z-spectral MRI in rats injected with NE at 7 T MRI. At clinical 3 T, Z-spectral MRI was used to quantify the FWF (58.5% ± 7.2% in BAT and 73.7% ± 6.5% in WAT with P < 0.0001) and APT (2.6% ± 0.8% in BAT and 0.9% ± 0.3% in WAT with P < 0.0001) signals in healthy volunteers. APT signals of BAT were negatively correlated with the BMI in humans (r = 0.71). DATA CONCLUSION Endogenous Z-spectral MRI was demonstrated to simultaneously quantify BAT mass and function based on its FWF and APT contrasts. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE 1.
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Affiliation(s)
- Zimeng Cai
- School of Medicine, South China University of Technology, Guangzhou, China
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangzhou, China
| | - Qiaoling Zhong
- Department of Radiology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Daming Zhang
- State Key Laboratory of Bioactive Molecules and Draggability Assessment, The Biomedical Translational Research Institute, Health Science Center, School of Medicine, Jinan University, Guangzhou, China
- Key Laboratory of Viral Pathogenesis & Infection Prevention and Control, Jinan University, Ministry of Education, Guangzhou, China
| | - Yanqiu Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Medical Image Processing & Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China
- Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence & Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, China
- Department of Radiology, Shunde Hospital, Southern Medical University, The First People's Hospital of Shunde, Foshan, China
| | - Qian Wang
- State Key Laboratory of Bioactive Molecules and Draggability Assessment, The Biomedical Translational Research Institute, Health Science Center, School of Medicine, Jinan University, Guangzhou, China
- Key Laboratory of Viral Pathogenesis & Infection Prevention and Control, Jinan University, Ministry of Education, Guangzhou, China
| | - Yuanbo Yang
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangzhou, China
| | | | - Changhong Liang
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangzhou, China
| | - Zaiyi Liu
- School of Medicine, South China University of Technology, Guangzhou, China
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangzhou, China
| | - Kejia Cai
- Radiology Department, University of Illinois at Chicago, Chicago, Illinois, USA
- Biomedical Engineering Department, University of Illinois at Chicago, Chicago, Illinois, USA
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10
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Agarwal N, Fan A, Huang X, Dehkharghani S, van der Kolk A. ISMRM Clinical Focus Meeting 2023: "Imaging the Fire in the Brain". J Magn Reson Imaging 2024. [PMID: 39193867 DOI: 10.1002/jmri.29587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 08/09/2024] [Accepted: 08/11/2024] [Indexed: 08/29/2024] Open
Abstract
Set during the Annual Meeting of the International Society for Magnetic Resonance in Medicine (ISMRM), the "Clinical Focus Meeting" (CFM) aims to bridge the gap between innovative magnetic resonance imaging (MRI) scientific research and daily patient care. This initiative is dedicated to maximizing the impact of MRI technology on healthcare outcomes for patients. At the 2023 Annual Meeting, clinicians and scientists from across the globe were invited to discuss neuroinflammation from various angles (entitled "Imaging the Fire in the Brain"). Topics ranged from fundamental mechanisms and biomarkers of neuroinflammation to the role of different contrast mechanisms, including both proton and non-proton techniques, in brain tumors, autoimmune disorders, and pediatric neuroinflammatory diseases. Discussions also delved into how systemic inflammation can trigger neuroinflammation and the role of the gut-brain axis in causing brain inflammation. Neuroinflammation arises from various external and internal factors and serves as a vital mechanism to mitigate tissue damage and provide neuroprotection. Nonetheless, excessive neuroinflammatory responses can lead to significant tissue injury and subsequent neurological impairments. Prolonged neuroinflammation can result in cellular apoptosis and neurodegeneration, posing severe consequences. MRI can be used to visualize these consequences, by detecting blood-brain barrier damage, characterizing brain lesions, quantifying edema, and identifying specific metabolites. It also facilitates monitoring of chronic changes in both the brain and spinal cord over time, potentially leading to better patient outcomes. This paper represents a summary of the 2023 CFM, and is intended to guide the enthusiastic MR user to several key and novel sequences that MRI offers to image pathophysiologic processes underlying acute and chronic neuroinflammation. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 3.
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Affiliation(s)
- Nivedita Agarwal
- Diagnostic Imaging and Neuroradiology Unit, IRCCS Scientific Institute E. Medea, Bosisio Parini, Lecco, Italy
| | - Audrey Fan
- Department of Neurology, University of California Davis Health, Sacramento, California, USA
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Xiaoqi Huang
- Department of Radiology and Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, China
| | - Seena Dehkharghani
- Department of Radiology, Albert Einstein College of Medicine-Montefiore Health, New York, New York, USA
| | - Anja van der Kolk
- Department of Medical Imaging, Radboudumc, Nijmegen, The Netherlands
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Mahmud SZ, Singh M, van Zijl P, Heo HY. Fast and motion-robust saturation transfer MRI with inherent B 0 correction using rosette trajectories and compressed sensing. Magn Reson Med 2024. [PMID: 39129199 DOI: 10.1002/mrm.30249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 08/13/2024]
Abstract
PURPOSE To implement rosette readout trajectories with compressed sensing reconstruction for fast and motion-robust CEST and magnetization transfer contrast imaging with inherent correction of B0 inhomogeneity. METHODS A pulse sequence was developed for fast saturation transfer imaging using a stack of rosette trajectories with a higher sampling density near the k-space center. Each rosette lobe was segmented into two halves to generate dual-echo images. B0 inhomogeneities were estimated using the phase difference between the images and corrected subsequently. The rosette-based imaging was evaluated in comparison to a fully sampled Cartesian trajectory and demonstrated on CEST phantoms (creatine solutions and egg white) and healthy volunteers at 3 T. RESULTS Compared with the conventional Cartesian acquisition, compressed sensing reconstructed rosette images provided image quality with overall higher contrast-to-noise ratio and significantly faster readout time. Accurate B0 map estimation was achieved from the rosette acquisition with a negligible bias of 0.01 Hz between the rosette and dual-echo Cartesian gradient echo B0 maps, using the latter as ground truth. The water-saturation spectra (Z-spectra) and amide proton transfer weighted signals obtained from the rosette-based sequence were well preserved compared with the fully sampled data, both in the phantom and human studies. CONCLUSIONS Fast, motion-robust, and inherent B0-corrected CEST and magnetization transfer contrast imaging using rosette trajectories could improve subject comfort and compliance, contrast-to-noise ratio, and provide inherent B0 homogeneity information. This work is expected to significantly accelerate the translation of CEST-MRI into a robust, clinically viable approach.
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Affiliation(s)
- Sultan Z Mahmud
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Munendra Singh
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Peter van Zijl
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Hye-Young Heo
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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12
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Zhang C, Chen J, Liu Y, Yang Y, Xu Y, You R, Li Y, Liu L, Yang L, Li H, Wang G, Li W, Li Z. Amide proton transfer-weighted MRI for assessing rectal adenocarcinoma T-staging and perineural invasion: a prospective study. Eur Radiol 2024:10.1007/s00330-024-11000-2. [PMID: 39122854 DOI: 10.1007/s00330-024-11000-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 06/19/2024] [Accepted: 07/20/2024] [Indexed: 08/12/2024]
Abstract
OBJECTIVE To investigate the value of the pre-operative amide proton transfer-weighted (APTw) MRI to assess the prognostic factors in rectal adenocarcinoma (RA). METHODS This prospective study ran from January 2022 to September 2023 and consecutively enrolled participants with RA who underwent pre-operative MRI and radical surgery. The APTw signal intensity (SI) values of RA with various tumor (T), node (N) stages, perineural invasion (PNI), and tumor grade were compared by Mann-Whitney U-test or t-test. The receiver operating characteristic curve was used to evaluate the diagnostic performance of the APTw SI values. RESULTS A total of 51 participants were enrolled (mean age, 58 years ± 10 [standard deviation], 26 men). There were 24 in the T1-T2 stage and 9 with positive PNI. The APTw SI max, 99th, and 95th values were significantly higher in T3-T4 stage tumor than in T1-T2; the median (interquartile range) (M (IQR)) was (4.0% (3.6-4.9%) vs 3.4% (2.9- 4.3%), p = 0.017), (3.7% (3.2-4.1%) vs 3.2% (2.8-3.8%), p = 0.013), and (3.3% (2.8-3.8%) vs 2.9% (2.3-3.5%), p = 0.033), respectively. These indicators also differed significantly between the PNI groups, with the M (IQR) (4.5% (3.6-5.7%) vs 3.7% (3.2-4.2%), p = 0.017), (4.1% (3.4-4.8%) vs 3.3% (3.0-3.9%), p = 0.022), and (3.7% (2.7-4.2%) vs 2.9% (2.6-3.5%), p = 0.045), respectively. CONCLUSION Pre-operative APTw MRI has potential value in the assessment of T-staging and PNI determination in RA. CLINICAL RELEVANCE STATEMENT Pre-operative amide proton transfer-weighted MRI provides a quantitative method for noninvasive assessment of T-staging and PNI in RA aiding in precision treatment planning. KEY POINTS The efficacy of APTw MRI in RA needs further investigation. T3-T4 stage and PNI positive APTw signal intensities were higher than T1-T2 and non-PNI, respectively. APTw MRI provides a quantitative method for assessment of T staging and PNI in RA.
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Affiliation(s)
- Caixia Zhang
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Jianyou Chen
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Yifan Liu
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Yinrui Yang
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | | | - Ruimin You
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Yanli Li
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Lizhu Liu
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Ling Yang
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Huaxiu Li
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China
| | - Guanshun Wang
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China.
| | - Wenliang Li
- Department of Colorectal Surgery, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China.
| | - Zhenhui Li
- Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Yunnan Cancer Center, Kunming, China.
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Yang Z, Shen D, Chan KWY, Huang J. Attention-Based MultiOffset Deep Learning Reconstruction of Chemical Exchange Saturation Transfer (AMO-CEST) MRI. IEEE J Biomed Health Inform 2024; 28:4636-4647. [PMID: 38776205 DOI: 10.1109/jbhi.2024.3404225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2024]
Abstract
One challenge of chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is the long scan time due to multiple acquisitions of images at different saturation frequency offsets. k-space under-sampling strategy is commonly used to accelerate MRI acquisition, while this could introduce artifacts and reduce signal-to-noise ratio (SNR). To accelerate CEST-MRI acquisition while maintaining suitable image quality, we proposed an attention-based multioffset deep learning reconstruction network (AMO-CEST) with a multiple radial k-space sampling strategy for CEST-MRI. The AMO-CEST also contains dilated convolution to enlarge the receptive field and data consistency module to preserve the sampled k-space data. We evaluated the proposed method on a mouse brain dataset containing 5760 CEST images acquired at a pre-clinical 3 T MRI scanner. Quantitative results demonstrated that AMO-CEST showed obvious improvement over zero-filling method with a PSNR enhancement of 11 dB, a SSIM enhancement of 0.15, and a NMSE decrease of [Formula: see text] in three acquisition orientations. Compared with other deep learning-based models, AMO-CEST showed visual and quantitative improvements in images from three different orientations. We also extracted molecular contrast maps, including the amide proton transfer (APT) and the relayed nuclear Overhauser enhancement (rNOE). The results demonstrated that the CEST contrast maps derived from the CEST images of AMO-CEST were comparable to those derived from the original high-resolution CEST images. The proposed AMO-CEST can efficiently reconstruct high-quality CEST images from under-sampled k-space data and thus has the potential to accelerate CEST-MRI acquisition.
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14
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Wu Q, Gong P, Liu S, Li Y, Liang D, Zheng H, Wu Y. B 1 inhomogeneity corrected CEST MRI based on direct saturation removed omega plot model at 5T. Magn Reson Med 2024; 92:532-542. [PMID: 38650080 DOI: 10.1002/mrm.30112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 02/23/2024] [Accepted: 03/25/2024] [Indexed: 04/25/2024]
Abstract
PURPOSE CEST can image macromolecules/compounds via detecting chemical exchange between labile protons and bulk water. B1 field inhomogeneity impairs CEST quantification. Conventional B1 inhomogeneity correction methods depend on interpolation algorithms, B1 choices, acquisition number or calibration curves, making reliable correction challenging. This study proposed a novel B1 inhomogeneity correction method based on a direct saturation (DS) removed omega plot model. METHODS Four healthy volunteers underwent B1 field mapping and CEST imaging under four nominal B1 levels of 0.75, 1.0, 1.5, and 2.0 μT at 5T. DS was resolved using a multi-pool Lorentzian model and removed from respective Z spectrum. Residual spectral signals were used to construct the omega plot as a linear function of 1/B 1 2 $$ {B}_1^2 $$ , from which corrected signals at nominal B1 levels were calculated. Routine asymmetry analysis was conducted to quantify amide proton transfer (APT) effect. Its distribution across white matter was compared before and after B1 inhomogeneity correction and also with the conventional interpolation approach. RESULTS B1 inhomogeneity yielded conspicuous artifact on APT images. Such artifact was mitigated by the proposed method. Homogeneous APT maps were shown with SD consistently smaller than that before B1 inhomogeneity correction and the interpolation method. Moreover, B1 inhomogeneity correction from two and four CEST acquisitions yielded similar results, superior over the interpolation method that derived inconsistent APT contrasts among different B1 choices. CONCLUSION The proposed method enables reliable B1 inhomogeneity correction from at least two CEST acquisitions, providing an effective way to improve quantitative CEST MRI.
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Affiliation(s)
- Qiting Wu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Pengcheng Gong
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Department of Biomedical Engineering, Chongqing University of Technology, Chongqing, China
| | - Shengping Liu
- Department of Biomedical Engineering, Chongqing University of Technology, Chongqing, China
| | - Ye Li
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Dong Liang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hairong Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yin Wu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Pemmasani Prabakaran RS, Park SW, Lai JHC, Wang K, Xu J, Chen Z, Ilyas AMO, Liu H, Huang J, Chan KWY. Deep-learning-based super-resolution for accelerating chemical exchange saturation transfer MRI. NMR IN BIOMEDICINE 2024; 37:e5130. [PMID: 38491754 DOI: 10.1002/nbm.5130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 03/18/2024]
Abstract
Chemical exchange saturation transfer (CEST) MRI is a molecular imaging tool that provides physiological information about tissues, making it an invaluable tool for disease diagnosis and guided treatment. Its clinical application requires the acquisition of high-resolution images capable of accurately identifying subtle regional changes in vivo, while simultaneously maintaining a high level of spectral resolution. However, the acquisition of such high-resolution images is time consuming, presenting a challenge for practical implementation in clinical settings. Among several techniques that have been explored to reduce the acquisition time in MRI, deep-learning-based super-resolution (DLSR) is a promising approach to address this problem due to its adaptability to any acquisition sequence and hardware. However, its translation to CEST MRI has been hindered by the lack of the large CEST datasets required for network development. Thus, we aim to develop a DLSR method, named DLSR-CEST, to reduce the acquisition time for CEST MRI by reconstructing high-resolution images from fast low-resolution acquisitions. This is achieved by first pretraining the DLSR-CEST on human brain T1w and T2w images to initialize the weights of the network and then training the network on very small human and mouse brain CEST datasets to fine-tune the weights. Using the trained DLSR-CEST network, the reconstructed CEST source images exhibited improved spatial resolution in both peak signal-to-noise ratio and structural similarity index measure metrics at all downsampling factors (2-8). Moreover, amide CEST and relayed nuclear Overhauser effect maps extrapolated from the DLSR-CEST source images exhibited high spatial resolution and low normalized root mean square error, indicating a negligible loss in Z-spectrum information. Therefore, our DLSR-CEST demonstrated a robust reconstruction of high-resolution CEST source images from fast low-resolution acquisitions, thereby improving the spatial resolution and preserving most Z-spectrum information.
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Affiliation(s)
- Rohith Saai Pemmasani Prabakaran
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering, Hong Kong, China
| | - Se Weon Park
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering, Hong Kong, China
| | - Joseph H C Lai
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Kexin Wang
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jiadi Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Zilin Chen
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | | | - Huabing Liu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Jianpan Huang
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China
| | - Kannie W Y Chan
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering, Hong Kong, China
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Tung Biomedical Sciences Centre, Hong Kong, China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
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Heo HY, Singh M, Mahmud SZ, Blair L, Kamson DO, Zhou J. Unraveling contributions to the Z-spectrum signal at 3.5 ppm of human brain tumors. Magn Reson Med 2024. [PMID: 39086185 DOI: 10.1002/mrm.30241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/26/2024] [Accepted: 07/17/2024] [Indexed: 08/02/2024]
Abstract
PURPOSE To evaluate the influence of the confounding factors, direct water saturation (DWS), and magnetization transfer contrast (MTC) effects on measured Z-spectra and amide proton transfer (APT) contrast in brain tumors. METHODS High-grade glioma patients were scanned using an RF saturation-encoded 3D MR fingerprinting (MRF) sequence at 3 T. For MRF reconstruction, a recurrent neural network was designed to learn free water and semisolid macromolecule parameter mappings of the underlying multiple tissue properties from saturation-transfer MRF signals. The DWS spectra and MTC spectra were synthesized by solving Bloch-McConnell equations and evaluated in brain tumors. RESULTS The dominant contribution to the saturation effect at 3.5 ppm was from DWS and MTC effects, but 25%-33% of the saturated signal in the gadolinium-enhancing tumor (13%-20% for normal tissue) was due to the APT effect. The APT# signal of the gadolinium-enhancing tumor was significantly higher than that of the normal-appearing white matter (10.1% vs. 8.3% at 1 μT and 11.2% vs. 7.8% at 1.5 μT). CONCLUSION The RF saturation-encoded MRF allowed us to separate contributions to the saturation signal at 3.5 ppm in the Z-spectrum. Although free water and semisolid MTC are the main contributors, significant APT contrast between tumor and normal tissues was observed.
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Affiliation(s)
- Hye-Young Heo
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Munendra Singh
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
| | - Sultan Z Mahmud
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
| | - Lindsay Blair
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - David Olayinka Kamson
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Oncology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jinyuan Zhou
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
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Hu X, Ye K, Bo S, Xiao Z, Ma M, Pan J, Zhong X, Zhang D, Mo X, Yu X, Chen M, Luo L, Shi C. Monitoring imatinib decreasing pericyte coverage and HIF-1α level in a colorectal cancer model by an ultrahigh-field multiparametric MRI approach. J Transl Med 2024; 22:712. [PMID: 39085929 PMCID: PMC11293104 DOI: 10.1186/s12967-024-05497-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 07/10/2024] [Indexed: 08/02/2024] Open
Abstract
BACKGROUND Excessive pericyte coverage promotes tumor growth, and a downregulation may solve this dilemma. Due to the double-edged sword role of vascular pericytes in tumor microenvironment (TME), indiscriminately decreasing pericyte coverage by imatinib causes poor treatment outcomes. Here, we optimized the use of imatinib in a colorectal cancer (CRC) model in high pericyte-coverage status, and revealed the value of multiparametric magnetic resonance imaging (mpMRI) at 9.4T in monitoring treatment-related changes in pericyte coverage and the TME. METHODS CRC xenograft models were evaluated by histological vascular characterizations and mpMRI. Mice with the highest pericyte coverage were treated with imatinib or saline; then, vascular characterizations, tumor apoptosis and HIF-1α level were analyzed histologically, and alterations in the expression of Bcl-2/bax pathway were assessed through qPCR. The effects of imatinib were monitored by dynamic contrast-enhanced (DCE)-, diffusion-weighted imaging (DWI)- and amide proton transfer chemical exchange saturation transfer (APT CEST)-MRI at 9.4T. RESULTS The DCE- parameters provided a good histologic match the tumor vascular characterizations. In the high pericyte coverage status, imatinib exhibited significant tumor growth inhibition, necrosis increase and pericyte coverage downregulation, and these changes were accompanied by increased vessel permeability, decreased microvessel density (MVD), increased tumor apoptosis and altered gene expression of apoptosis-related Bcl-2/bax pathway. Strategically, a 4-day imatinib effectively decreased pericyte coverage and HIF-1α level, and continuous treatment led to a less marked decrease in pericyte coverage and re-elevated HIF-1α level. Correlation analysis confirmed the feasibility of using mpMRI parameters to monitor imatinib treatment, with DCE-derived Ve and Ktrans being most correlated with pericyte coverage, Ve with vessel permeability, AUC with microvessel density (MVD), DWI-derived ADC with tumor apoptosis, and APT CEST-derived MTRasym at 1 µT with HIF-1α. CONCLUSIONS These results provided an optimized imatinib regimen to achieve decreasing pericyte coverage and HIF-1α level in the high pericyte-coverage CRC model, and offered an ultrahigh-field multiparametric MRI approach for monitoring pericyte coverage and dynamics response of the TME to treatment.
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Affiliation(s)
- Xinpeng Hu
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Kunlin Ye
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Shaowei Bo
- Department of Medical Imaging, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Xingang Middle Road No. 466, Guangzhou, 510317, China
| | - Zeyu Xiao
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
- Engineering Research Center of Medical Imaging Artificial Intelligence for Precision Diagnosis and Treatment, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Mengjie Ma
- Department of Radiology, Guangzhou First People's Hospital, Panfu Road No. 1, Guangzhou, 510080, China
| | - Jinghua Pan
- Department of General Surgery, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Xing Zhong
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Dong Zhang
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Xukai Mo
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Xiaojun Yu
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China
| | - Minfeng Chen
- College of Pharmacy, Jinan University, West Huangpu Avenue No.601, Guangzhou, 510632, China.
| | - Liangping Luo
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China.
- Engineering Research Center of Medical Imaging Artificial Intelligence for Precision Diagnosis and Treatment, West Huangpu Avenue No. 613, Guangzhou, 510630, China.
| | - Changzheng Shi
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, West Huangpu Avenue No. 613, Guangzhou, 510630, China.
- Engineering Research Center of Medical Imaging Artificial Intelligence for Precision Diagnosis and Treatment, West Huangpu Avenue No. 613, Guangzhou, 510630, China.
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18
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Kurmi Y, Viswanathan M, Zu Z. Enhancing SNR in CEST imaging: A deep learning approach with a denoising convolutional autoencoder. Magn Reson Med 2024. [PMID: 39030953 DOI: 10.1002/mrm.30228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 05/28/2024] [Accepted: 07/01/2024] [Indexed: 07/22/2024]
Abstract
PURPOSE To develop a SNR enhancement method for CEST imaging using a denoising convolutional autoencoder (DCAE) and compare its performance with state-of-the-art denoising methods. METHOD The DCAE-CEST model encompasses an encoder and a decoder network. The encoder learns features from the input CEST Z-spectrum via a series of one-dimensional convolutions, nonlinearity applications, and pooling. Subsequently, the decoder reconstructs an output denoised Z-spectrum using a series of up-sampling and convolution layers. The DCAE-CEST model underwent multistage training in an environment constrained by Kullback-Leibler divergence, while ensuring data adaptability through context learning using Principal Component Analysis-processed Z-spectrum as a reference. The model was trained using simulated Z-spectra, and its performance was evaluated using both simulated data and in vivo data from an animal tumor model. Maps of amide proton transfer (APT) and nuclear Overhauser enhancement (NOE) effects were quantified using the multiple-pool Lorentzian fit, along with an apparent exchange-dependent relaxation metric. RESULTS In digital phantom experiments, the DCAE-CEST method exhibited superior performance, surpassing existing denoising techniques, as indicated by the peak SNR and Structural Similarity Index. Additionally, in vivo data further confirm the effectiveness of the DCAE-CEST in denoising the APT and NOE maps when compared with other methods. Although no significant difference was observed in APT between tumors and normal tissues, there was a significant difference in NOE, consistent with previous findings. CONCLUSION The DCAE-CEST can learn the most important features of the CEST Z-spectrum and provide the most effective denoising solution compared with other methods.
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Affiliation(s)
- Yashwant Kurmi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Malvika Viswanathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
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19
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Sun PZ. Quasi-steady-state (QUASS) reconstruction enhances T 1 normalization in apparent exchange-dependent relaxation (AREX) analysis: A reevaluation of T 1 correction in quantitative CEST MRI of rodent brain tumor models. Magn Reson Med 2024; 92:236-245. [PMID: 38380727 PMCID: PMC11055669 DOI: 10.1002/mrm.30056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/26/2024] [Accepted: 02/04/2024] [Indexed: 02/22/2024]
Abstract
PURPOSE The apparent exchange-dependent relaxation (AREX) analysis has been proposed as an effective means to correct T1 contribution in CEST quantification. However, it has been recognized that AREX T1 correction is not straightforward if CEST scans are not performed under the equilibrium condition. Our study aimed to test if quasi-steady-state (QUASS) reconstruction could boost the accuracy of the AREX metric under common non-equilibrium scan conditions. THEORY AND METHODS Numerical simulation and in vivo scans were performed to assess the AREX metric accuracy. The CEST signal was simulated under different relaxation delays, RF saturation amplitudes, and durations. The AREX was evaluated as a function of the bulk water T1 and labile proton concentration using the multiple linear regression model. AREX MRI was also assessed in brain tumor rodent models, with both apparent CEST scans and QUASS reconstruction. RESULTS Simulation showed that the AREX calculation from apparent CEST scans, under non-equilibrium conditions, had significant dependence on labile proton fraction ratio, RF saturation time, and T1. In comparison, QUASS-boosted AREX depended on the labile proton fraction ratio without significant dependence on T1 and RF saturation time. Whereas the apparent (2.7 ± 0.8%) and QUASS MTR asymmetry (2.8 ± 0.8%) contrast between normal and tumor regions of interest (ROIs) were significant, the difference was small. In comparison, AREX contrast between normal and tumor ROIs calculated from the apparent CEST scan and QUASS reconstruction was 3.8 ± 1.1%/s and 4.4 ± 1.2%/s, respectively, statistically different from each other. CONCLUSIONS AREX analysis benefits from the QUASS-reconstructed equilibrium CEST effect for improved T1 correction and quantitative CEST analysis.
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Affiliation(s)
- Phillip Zhe Sun
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
- Winship Cancer Institute, Emory University, Atlanta, GA
- Primate Imaging Center, Emory National Primate Research Center, Emory University, Atlanta, GA
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20
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Tokunaga C, Wada T, Togao O, Kobayashi K, Kato T. Amide proton transfer-weighted imaging with a short acquisition time based on a self B0 correction using the turbo spin echo-Dixon method: A phantom study. Magn Reson Imaging 2024; 110:69-77. [PMID: 38614223 DOI: 10.1016/j.mri.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/06/2024] [Accepted: 04/07/2024] [Indexed: 04/15/2024]
Abstract
PURPOSE Conventional amide proton transfer (APT)-weighted imaging requires a chemical exchange saturation transfer (CEST) sequence with multiple saturation frequency offsets and a B0 correction sequence, plus a long acquisition time that can be reduced by applying the conventional method using CEST images with seven radiation pulses (i.e., the seven-points method). For a further reduction of acquisition times, we propose fast two-dimensional (2D) APT-weighted imaging based on a self B0 correction using the turbo spin echo (TSE)-Dixon method. We conducted a phantom study to investigate the accuracy of TSE-Dixon APT-weighted imaging. METHODS We prepared two types of phantoms with six samples for a concentrationdependent evaluation and a pH-dependent evaluation. APT-weighted images were acquired by the conventional, seven-points, and TSE-Dixon methods. Linear regression analyses assessed the dependence between each method's APT signal intensities (SIs) and the concentration or pH. We performed a one-way analysis of variance with Tukey's honestly significant difference post hoc test to compare the APT SIs among the three methods. The agreement of the APT SIs between the conventional and seven-points or TSE-Dixon methods was assessed by a Bland- Altman plot analysis. RESULTS The APT SIs of all three acquisition methods showed positive concentration dependence and pH dependence. No significant differences were observed in the APT SIs between the conventional and TSE-Dixon methods at each concentration. The Bland-Altman plot analyses showed that the APT SIs measured with the seven-points method resulted in 0.42% bias and narrow 95% limits of agreement (LOA) (0.93%-0.09%) compared to the conventional method. The APT SIs measured using the TSE-Dixon method showed 0.14% bias and similar 95% LOA (-0.33% to 0.61%) compared with the seven-points method. The APT SIs of all three methods showed positive pH dependence. At each pH, no significant differences in the APT SIs were observed among the methods. Bland-Altman plot analyses showed that the APT SIs measured with the seven-points method resulted in low bias (0.03%) and narrow 95% LOA (-0.30% to 0.36%) compared to the conventional method. The APT SIs measured by the TSE-Dixon method showed slightly larger bias (0.29%) and similar 95% LOA (from -0.15% to 0.72%) compared to those measured by the seven-points method. CONCLUSION These results demonstrated that our proposed method has the same concentration dependence and pH dependence as the conventional method and the seven-points method. We thus expect that APT-weighted imaging with less influence of motion can be obtained in clinical examinations.
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Affiliation(s)
- Chiaki Tokunaga
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Tatsuhiro Wada
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Osamu Togao
- Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kouji Kobayashi
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Toyoyuki Kato
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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21
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Wang X, Cao YY, Jiang Y, Jia M, Tian G, Bu CQ, Zhao N, Yue XZ, Shen ZW, Ji Y, Han YD. Effects of Breathing Patterns on Amide Proton Transfer MRI in the Kidney: A Preliminary Comparative Study in Healthy Volunteers and Patients With Tumors. J Magn Reson Imaging 2024; 60:222-230. [PMID: 37888865 DOI: 10.1002/jmri.29099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/16/2023] [Accepted: 10/16/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND The amide proton transfer-weighted (APTw) imaging for kidney diseases is important. However, the breathing patterns on APTw imaging remains unexplored. PURPOSE This study aimed to investigate the effects of intermittent breath-hold (IBH) and free breathing (FB) on renal 3D-APTw imaging. STUDY TYPE Healthy volunteers were enrolled prospectively, and renal clear cell carcinoma (RCCC) patients were included retrospectively. POPULATION 58 healthy volunteers and 10 RCCC patients. FIELD STRENGTH/SEQUENCE 3-T, turbo spin echo, and fast field echo. ASSESSMENT 3D-APTw imaging was scanned using the IBH and FB methods in volunteers and using the IBH method in RCCC patients. The image quality was evaluated by three observers according to the 5-point Likert scale. Optimal images rated at three points or higher were used to measure the APT values. STATISTICAL ANALYSIS The measurement repeatability was assessed using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. The APT values were analyzed using McNemar's test, one-way analysis of variance, and t test. RESULTS 50 healthy volunteers and 8 RCCC patients were enrolled. Renal 3D-APTw imaging using the IBH method revealed a higher success rate (88% vs 78%). The ICCs were excellent in the IBH group (ICCs > 0.74) and were good in the FB group (ICCs < 0.74). No significant differences in the APT values among various zones using the IBH (P = 0.263) or FB method (P = 0.506). The mean APT value using the IBH method (2.091% ± 0.388%) was slightly lower than the FB method (2.176% ± 0.292%), but no significant difference (P = 0.233). The APT value of RCCC (4.832% ± 1.361%) was considerably higher than normal renal using the IBH method. CONCLUSIONS The study demonstrated that the IBH method substantially increased the image quality of renal 3D-APTw imaging. Furthermore, APT values may vary between normal and tumor tissues. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- X Wang
- Department of Radiology, Xi'an GaoXin Hospital, Xi'an Jiao Tong University, Xi'an, Shaanxi, China
| | - Y Y Cao
- Department of Imaging Center, First Affiliated Hospital, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Y Jiang
- Department of Radiology, Xi'an GaoXin Hospital, Xi'an Jiao Tong University, Xi'an, Shaanxi, China
| | - M Jia
- Department of Radiology, Xi'an GaoXin Hospital, Xi'an Jiao Tong University, Xi'an, Shaanxi, China
| | - G Tian
- Department of Radiology, Xi'an GaoXin Hospital, Xi'an Jiao Tong University, Xi'an, Shaanxi, China
| | - C Q Bu
- Department of Radiology, Xi'an GaoXin Hospital, Xi'an Jiao Tong University, Xi'an, Shaanxi, China
| | - N Zhao
- Department of Radiology, Xi'an GaoXin Hospital, Xi'an Jiao Tong University, Xi'an, Shaanxi, China
| | - X Z Yue
- Philips Healthcare, Beijing, China
| | - Z W Shen
- Philips Healthcare, Beijing, China
| | - Y Ji
- Department of Imaging Center, First Affiliated Hospital, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Y D Han
- Department of Radiology, Xi'an GaoXin Hospital, Xi'an Jiao Tong University, Xi'an, Shaanxi, China
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22
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Kurmi Y, Viswanathan M, Zu Z. A Denoising Convolutional Autoencoder for SNR Enhancement in Chemical Exchange Saturation Transfer imaging: (DCAE-CEST). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597818. [PMID: 38895366 PMCID: PMC11185751 DOI: 10.1101/2024.06.07.597818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Purpose To develop a SNR enhancement method for chemical exchange saturation transfer (CEST) imaging using a denoising convolutional autoencoder (DCAE), and compare its performance with state-of-the-art denoising methods. Method The DCAE-CEST model encompasses an encoder and a decoder network. The encoder learns features from the input CEST Z-spectrum via a series of 1D convolutions, nonlinearity applications and pooling. Subsequently, the decoder reconstructs an output denoised Z-spectrum using a series of up-sampling and convolution layers. The DCAE-CEST model underwent multistage training in an environment constrained by Kullback-Leibler divergence, while ensuring data adaptability through context learning using Principal Component Analysis processed Z-spectrum as a reference. The model was trained using simulated Z-spectra, and its performance was evaluated using both simulated data and in-vivo data from an animal tumor model. Maps of amide proton transfer (APT) and nuclear Overhauser enhancement (NOE) effects were quantified using the multiple-pool Lorentzian fit, along with an apparent exchange-dependent relaxation metric. Results In digital phantom experiments, the DCAE-CEST method exhibited superior performance, surpassing existing denoising techniques, as indicated by the peak SNR and Structural Similarity Index. Additionally, in vivo data further confirms the effectiveness of the DCAE-CEST in denoising the APT and NOE maps when compared to other methods. While no significant difference was observed in APT between tumors and normal tissues, there was a significant difference in NOE, consistent with previous findings. Conclusion The DCAE-CEST can learn the most important features of the CEST Z-spectrum and provide the most effective denoising solution compared to other methods.
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Affiliation(s)
- Yashwant Kurmi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, USA
| | - Malvika Viswanathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, USA
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, USA
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23
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Kanematsu Y, Kanazawa Y, Shimada K, Korai M, Miyamoto T, Sogabe S, Ishihara M, Yamaguchi I, Oya T, Yamamoto N, Yamamoto Y, Miyoshi M, Harada M, Takagi Y. Characterization of carotid plaques using chemical exchange saturation transfer imaging. Neuroradiology 2024:10.1007/s00234-024-03401-3. [PMID: 38866959 DOI: 10.1007/s00234-024-03401-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 06/06/2024] [Indexed: 06/14/2024]
Abstract
PURPOSE The preoperative assessment of carotid plaques is necessary to render revascularization safe and effective. The aim of this study is to evaluate the usefulness of chemical exchange saturation transfer (CEST)-MRI, particularly amide proton transfer (APT) imaging as a preoperative carotid plaque diagnostic tool. METHODS We recorded the APT signal intensity on concentration maps of 34 patients scheduled for carotid endarterectomy. Plaques were categorized into group A (APT signal intensity ≥ 1.90 E-04; n = 12) and group B (APT signal intensity < 1.90 E-04; n = 22). Excised plaques were subjected to histopathological assessment and, using the classification promulgated by the American Heart Association, they were classified as intraplaque hemorrhage-positive [type VI-positive (tVI+)] and -negative [no intraplaque hemorrhage (tVI-)]. RESULTS Of the 34 patients, 22 (64.7%) harbored tVI+- and 12 (35.3%) had tVI- plaques. The median APT signals were significantly higher in tVI+- than tIVI- patients (2.43 E-04 (IQR = 0.98-4.00 E-04) vs 0.54 E-04 (IQR = 0.14-1.09 E-04), p < .001). Histopathologically, the number of patients with tVI+ plaques was significantly greater in group A (100%, n = 12) than group B (45%, n = 22) (p < .01). The number of symptomatic patients or asymptomatic patients with worsening stenosis was also significantly greater in group A than group B (75% vs 36%, p < .01). CONCLUSION In unstable plaques with intraplaque hemorrhage and in patients with symptoms or progressive stenosis, the ATP signals were significantly elevated. CEST-MRI studies has the potential for the preoperative assessment of the plaques' characteristics.
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Affiliation(s)
- Yasuhisa Kanematsu
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan.
| | - Yuki Kanazawa
- Department of Medical Imaging and Physics, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Kenji Shimada
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan
| | - Masaaki Korai
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan
| | - Takeshi Miyamoto
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan
| | - Shu Sogabe
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan
| | - Manabu Ishihara
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan
| | - Izumi Yamaguchi
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan
| | - Takeshi Oya
- Department of Molecular Pathology, Tokushima University Graduate School of Biomedical Sciences, Japan, Tokushima
| | - Nobuaki Yamamoto
- Department of Clinical Neuroscience, Tokushima University Graduate School of Biomedical Sciences, Japan, Tokushima
| | - Yuki Yamamoto
- Department of Clinical Neuroscience, Tokushima University Graduate School of Biomedical Sciences, Japan, Tokushima
| | - Mitsuharu Miyoshi
- Global MR Clinical Solutions and Research Collaborations, GE HealthCare, Japan, Hino
| | - Masafumi Harada
- Department of Radiology, Tokushima University Graduate School of Biomedical Sciences, Japan, Tokushima
| | - Yasushi Takagi
- Department of Neurosurgery, Tokushima University Graduate School of Biomedical Sciences, 3-18-15 Kuramoto-Cho, Tokushima, 770-8503, Japan
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24
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Tanaka F, Maeda M, Nakayama R, Inoue K, Kishi S, Kogue R, Umino M, Kitano Y, Obara M, Sakuma H. A Combination of Amide Proton Transfer, Tumor Blood Flow, and Apparent Diffusion Coefficient Histogram Analysis Is Useful for Differentiating Malignant from Benign Intracranial Tumors in Young Patients: A Preliminary Study. Diagnostics (Basel) 2024; 14:1236. [PMID: 38928651 PMCID: PMC11202847 DOI: 10.3390/diagnostics14121236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/06/2024] [Accepted: 06/08/2024] [Indexed: 06/28/2024] Open
Abstract
PURPOSE To evaluate the amide proton transfer (APT), tumor blood flow (TBF), and apparent diffusion coefficient (ADC) combined diagnostic value for differentiating intracranial malignant tumors (MTs) from benign tumors (BTs) in young patients, as defined by the 2021 World Health Organization classification of central nervous system tumors. METHODS Fifteen patients with intracranial MTs and 10 patients with BTs aged 0-30 years underwent MRI with APT, pseudocontinuous arterial spin labeling (pCASL), and diffusion-weighted imaging. All tumors were evaluated through the use of histogram analysis and the Mann-Whitney U test to compare 10 parameters for each sequence between the groups. The diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS The APT maximum, mean, 10th, 25th, 50th, 75th, and 90th percentiles were significantly higher in MTs than in BTs; the TBF minimum (min) was significantly lower in MTs than in BTs; TBF kurtosis was significantly higher in MTs than in BTs; the ADC min, 10th, and 25th percentiles were significantly lower in MTs than in BTs (all p < 0.05). The APT 50th percentile (0.900), TBF min (0.813), and ADC min (0.900) had the highest area under the curve (AUC) values of the parameters in each sequence. The AUC for the combination of these three parameters was 0.933. CONCLUSIONS The combination of APT, TBF, and ADC evaluated through histogram analysis may be useful for differentiating intracranial MTs from BTs in young patients.
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Affiliation(s)
- Fumine Tanaka
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu 5148507, Mie, Japan
| | - Masayuki Maeda
- Department of Neuroradiology, Mie University School of Medicine, 2-174 Edobashi, Tsu 5148507, Mie, Japan
| | - Ryohei Nakayama
- Department of Electronic and Computer Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu 5250058, Shiga, Japan
| | - Katsuhiro Inoue
- Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu 5148507, Mie, Japan
| | - Seiya Kishi
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu 5148507, Mie, Japan
| | - Ryota Kogue
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu 5148507, Mie, Japan
| | - Maki Umino
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu 5148507, Mie, Japan
| | - Yotaro Kitano
- Department of Neurosurgery, Mie University School of Medicine, 2-174 Edobashi, Tsu 5148507, Mie, Japan
| | - Makoto Obara
- MR Clinical Science, Philips Japan, 2-13-37 Konan, Minato 1088507, Tokyo, Japan
| | - Hajime Sakuma
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu 5148507, Mie, Japan
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Wang Y, Sun YX, Yang QY, Gao JH. A generalized QUCESOP method with evaluating CEST peak overlap. NMR IN BIOMEDICINE 2024; 37:e5098. [PMID: 38224670 DOI: 10.1002/nbm.5098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/26/2023] [Accepted: 12/04/2023] [Indexed: 01/17/2024]
Abstract
The overlapping peaks of the target chemical exchange saturation transfer (CEST) solutes and other unknown CEST solutes affect the quantification results and accuracy of the chemical exchange parameters-the fractional concentration, f b , exchange rate, k b , and transverse relaxation rate, R 2 b -for the target solutes. However, to date, no method has been established for assessing the overlapping peaks. This study aimed to develop a method for quantifying the f b , k b , and R 2 b values of a specific CEST solute, as well as assessing the overlap between the CEST peaks of the specific solute(s) and other unknown solutes. A simplified R 1 ρ model was proposed, assuming linear approximation of the other solutes' contributions to R 1 ρ . A CEST data acquisition scheme was applied with various saturation offsets and saturation powers. In addition to fitting the f b , k b , and R 2 b values of the specific solute, the overlapping condition was evaluated based on the root mean square error (RMSE) between the trajectories of the acquired and synthesized data. Single-solute and multi-solute phantoms with various phosphocreatine (PCr) concentrations and pH values were used to calculate the f b and k b of PCr and the corresponding RMSE. The feasibility of RMSE for evaluating the overlapping condition, and the accurate fitting of f b and k b in weak overlapping conditions, were verified. Furthermore, the method was employed to quantify the nuclear Overhauser effect signal in rat brains and the PCr signal in rat skeletal muscles, providing results that were consistent with those reported in previous studies. In summary, the proposed approach can be applied to evaluate the overlapping condition of CEST peaks and quantify the f b , k b , and R 2 b values of specific solutes, if the weak overlapping condition is satisfied.
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Affiliation(s)
- Yi Wang
- Public Health Science and Engineering College, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yi-Xuan Sun
- School of Medical Technology, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Qiu-Yu Yang
- Public Health Science and Engineering College, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Jia-Hong Gao
- Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Beijing City Key Lab for Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China
- McGovern Institute for Brain Research, Peking University, Beijing, China
- National Biomedical Imaging Center, Peking University, Beijing, China
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Viswanathan M, Yin L, Kurmi Y, Zu Z. Machine learning-based amide proton transfer imaging using partially synthetic training data. Magn Reson Med 2024; 91:1908-1922. [PMID: 38098340 PMCID: PMC10955622 DOI: 10.1002/mrm.29970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 10/30/2023] [Accepted: 11/26/2023] [Indexed: 12/20/2023]
Abstract
PURPOSE Machine learning (ML) has been increasingly used to quantify CEST effect. ML models are typically trained using either measured data or fully simulated data. However, training with measured data often lacks sufficient training data, whereas training with fully simulated data may introduce bias because of limited simulations pools. This study introduces a new platform that combines simulated and measured components to generate partially synthetic CEST data, and to evaluate its feasibility for training ML models to predict amide proton transfer (APT) effect. METHODS Partially synthetic CEST signals were created using an inverse summation of APT effects from simulations and the other components from measurements. Training data were generated by varying APT simulation parameters and applying scaling factors to adjust the measured components, achieving a balance between simulation flexibility and fidelity. First, tissue-mimicking CEST signals along with ground truth information were created using multiple-pool model simulations to validate this method. Second, an ML model was trained individually on partially synthetic data, in vivo data, and fully simulated data, to predict APT effect in rat brains bearing 9 L tumors. RESULTS Experiments on tissue-mimicking data suggest that the ML method using the partially synthetic data is accurate in predicting APT. In vivo experiments suggest that our method provides more accurate and robust prediction than the training using in vivo data and fully synthetic data. CONCLUSION Partially synthetic CEST data can address the challenges in conventional ML methods.
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Affiliation(s)
- Malvika Viswanathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Biomedical Engineering, Vanderbilt University, Nashville, US
| | - Leqi Yin
- School of Engineering, Vanderbilt University, Nashville, US
| | - Yashwant Kurmi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Biomedical Engineering, Vanderbilt University, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
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Cronin AE, Liebig P, Detombe SA, Duggal N, Bartha R. Reproducibility of 3D pH-weighted chemical exchange saturation transfer contrast in the healthy cervical spinal cord. NMR IN BIOMEDICINE 2024; 37:e5103. [PMID: 38243648 DOI: 10.1002/nbm.5103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/01/2023] [Accepted: 12/20/2023] [Indexed: 01/21/2024]
Abstract
Spinal cord ischemia and hypoxia can be caused by compression, injury, and vascular alterations. Measuring ischemia and hypoxia directly in the spinal cord noninvasively remains challenging. Ischemia and hypoxia alter tissue pH, providing a physiologic parameter that may be more directly related to tissue viability. Chemical exchange saturation transfer (CEST) is an MRI contrast mechanism that can be made sensitive to pH. More specifically, amine/amide concentration independent detection (AACID) is a recently developed endogenous CEST contrast that has demonstrated sensitivity to intracellular pH at 9.4 T. The goal of this study was to evaluate the reproducibility of AACID CEST measurements at different levels of the healthy cervical spinal cord at 3.0 T incorporating B1 correction. Using a 3.0 T MRI scanner, two 3D CEST scans (saturation pulse train followed by a 3D snapshot gradient-echo readout) were performed on 12 healthy subjects approximately 10 days apart, with the CEST volume centered at the C4 level for all subjects. Scan-rescan reproducibility was evaluated by examining between and within-subject coefficients of variation (CVs) and absolute AACID value differences. The C4 level of the spinal cord demonstrated the lowest within-subject CVs (4.1%-4.3%), between-subject CVs (5.6%-6.3%), and absolute AACID percent difference (5.8-6.1%). The B1 correction scheme significantly improved reproducibility (adjusted p-value = 0.002) compared with the noncorrected data, suggesting that implementing B1 corrections in the spinal cord is beneficial. It was concluded that pH-weighted AACID measurements, incorporating B1-inhomogeneity correction, were reproducible within subjects along the healthy cervical spinal cord and that optimal image quality was achieved at the center of the 3D CEST volume.
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Affiliation(s)
- Alicia E Cronin
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | | | - Sarah A Detombe
- Department of Clinical Neurological Sciences, London Health Sciences Centre, London, Ontario, Canada
| | - Neil Duggal
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Department of Clinical Neurological Sciences, London Health Sciences Centre, London, Ontario, Canada
| | - Robert Bartha
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Centre for Functional and Metabolic Mapping, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
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Fabian MS, Rajput JR, Schüre JR, Weinmüller S, Mennecke A, Möhle TA, Rampp S, Schmidt M, Dörfler A, Zaiss M. Comprehensive 7 T CEST: A clinical MRI protocol covering multiple exchange rate regimes. NMR IN BIOMEDICINE 2024; 37:e5096. [PMID: 38343093 DOI: 10.1002/nbm.5096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 04/04/2024]
Abstract
Chemical exchange saturation transfer (CEST) is a magnetic resonance (MR) imaging method providing molecular image contrasts based on indirect detection of low concentrated solutes. Previous CEST studies focused predominantly on the imaging of single CEST exchange regimes (e.g., slow, intermediate or fast exchanging groups). In this work, we aim to establish a so-called comprehensive CEST protocol for 7 T, covering the different exchange regimes by three saturation B1 amplitude regimes: low, intermediate and high. We used the results of previous publications and our own simulations in pulseq-CEST to produce a 7 T CEST protocol that has sensitivity to these three B1 regimes. With postprocessing optimization (simultaneous mapping of water shift and B1, B0-fitting, multiple interleaved mode saturation B1 correction, neural network employment (deepCEST) and analytical input feature reduction), we are able to shorten our initially 40 min protocol to 15 min and generate six CEST contrast maps simultaneously. With this protocol, we measured four healthy subjects and one patient with a brain tumor. We established a comprehensive CEST protocol for clinical 7 T MRI, covering three different B1 amplitude regimes. We were able to reduce the acquisition time significantly by more than 50%, while still maintaining decent image quality and contrast in healthy subjects and one patient with a tumor. Our protocol paves the way to perform comprehensive CEST studies in clinical scan times for hypothesis generation regarding molecular properties of certain pathologies, for example, ischemic stroke or high-grade brain tumours.
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Affiliation(s)
- Moritz Simon Fabian
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Junaid Rasool Rajput
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Jan-Rüdiger Schüre
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Simon Weinmüller
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Angelika Mennecke
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Tim Alexius Möhle
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Stefan Rampp
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
- Department of Neurosurgery, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Manuel Schmidt
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Arnd Dörfler
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Moritz Zaiss
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany
- High-field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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Ma A, Yan X, Qu Y, Wen H, Zou X, Liu X, Lu M, Mo J, Wen Z. Amide proton transfer weighted and diffusion weighted imaging based radiomics classification algorithm for predicting 1p/19q co-deletion status in low grade gliomas. BMC Med Imaging 2024; 24:85. [PMID: 38600452 PMCID: PMC11005152 DOI: 10.1186/s12880-024-01262-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 03/27/2024] [Indexed: 04/12/2024] Open
Abstract
BACKGROUND 1p/19q co-deletion in low-grade gliomas (LGG, World Health Organization grade II and III) is of great significance in clinical decision making. We aim to use radiomics analysis to predict 1p/19q co-deletion in LGG based on amide proton transfer weighted (APTw), diffusion weighted imaging (DWI), and conventional MRI. METHODS This retrospective study included 90 patients histopathologically diagnosed with LGG. We performed a radiomics analysis by extracting 8454 MRI-based features form APTw, DWI and conventional MR images and applied a least absolute shrinkage and selection operator (LASSO) algorithm to select radiomics signature. A radiomics score (Rad-score) was generated using a linear combination of the values of the selected features weighted for each of the patients. Three neuroradiologists, including one experienced neuroradiologist and two resident physicians, independently evaluated the MR features of LGG and provided predictions on whether the tumor had 1p/19q co-deletion or 1p/19q intact status. A clinical model was then constructed based on the significant variables identified in this analysis. A combined model incorporating both the Rad-score and clinical factors was also constructed. The predictive performance was validated by receiver operating characteristic curve analysis, DeLong analysis and decision curve analysis. P < 0.05 was statistically significant. RESULTS The radiomics model and the combined model both exhibited excellent performance on both the training and test sets, achieving areas under the curve (AUCs) of 0.948 and 0.966, as well as 0.909 and 0.896, respectively. These results surpassed the performance of the clinical model, which achieved AUCs of 0.760 and 0.766 on the training and test sets, respectively. After performing Delong analysis, the clinical model did not significantly differ in predictive performance from three neuroradiologists. In the training set, both the radiomic and combined models performed better than all neuroradiologists. In the test set, the models exhibited higher AUCs than the neuroradiologists, with the radiomics model significantly outperforming resident physicians B and C, but not differing significantly from experienced neuroradiologist. CONCLUSIONS Our results suggest that our algorithm can noninvasively predict the 1p/19q co-deletion status of LGG. The predictive performance of radiomics model was comparable to that of experienced neuroradiologist, significantly outperforming the diagnostic accuracy of resident physicians, thereby offering the potential to facilitate non-invasive 1p/19q co-deletion prediction of LGG.
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Affiliation(s)
- Andong Ma
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Xinran Yan
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Yaoming Qu
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Haitao Wen
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Xia Zou
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Xinzi Liu
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Mingjun Lu
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Jianhua Mo
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China
| | - Zhibo Wen
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Haizhu District, 253 Gongye Middle Avenue, Guangzhou, Guangdong, 510282, China.
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Sheng L, Yuan E, Yuan F, Song B. Amide proton transfer-weighted imaging of the abdomen: Current progress and future directions. Magn Reson Imaging 2024; 107:88-99. [PMID: 38242255 DOI: 10.1016/j.mri.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/13/2024] [Accepted: 01/14/2024] [Indexed: 01/21/2024]
Abstract
The chemical exchange saturation transfer technique serves as a valuable tool for generating in vivo image contrast based on the content of various proton groups, including amide protons, amine protons, and aliphatic protons. Among these, amide proton transfer-weighted (APTw) imaging has seen extensive development as a means to assess the biochemical status of lesions. The exchange from saturated amide protons to bulk water protons during and following the saturation ratio frequency pulse contributes to detectable APT signals. While APTw imaging has garnered significant attention in the central nervous system, demonstrating noteworthy findings in cerebral neoplasia, stroke, and Alzheimer's disease over the past decade, its application in the abdomen has been a relatively recent progression. Notably, studies have explored its utility in hepatocellular carcinoma, prostate cancer, and cervical carcinoma within the abdominal context. Despite these advancements, there is a paucity of reviews on APTw imaging in abdominal applications. This paper aims to fill this gap by providing a concise overview of the fundamental theories underpinning APTw imaging. Additionally, we systematically summarize its diverse clinical applications in the abdomen, with a particular focus on the digestive and urogenital systems. Finally, the manuscript concludes by discussing technical limitations and factors influencing APTw imaging in abdominal applications, along with prospects for future research.
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Affiliation(s)
- Liuji Sheng
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Enyu Yuan
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Fang Yuan
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Bin Song
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Functional and Molecular Imaging Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Department of Radiology, Sanya People's Hospital, Sanya, Hainan, China.
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31
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Zhou IY, Ji Y, Zhao Y, Malvika V, Sun PZ, Zu Z. Specific and rapid guanidinium CEST imaging using double saturation power and QUASS analysis in a rodent model of global ischemia. Magn Reson Med 2024; 91:1512-1527. [PMID: 38098305 PMCID: PMC10872646 DOI: 10.1002/mrm.29960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 10/17/2023] [Accepted: 11/20/2023] [Indexed: 02/03/2024]
Abstract
PURPOSE Guanidinium CEST is sensitive to metabolic changes and pH variation in ischemia, and it can offer advantages over conventional pH-sensitive amide proton transfer (APT) imaging by providing hyperintense contrast in stroke lesions. However, quantifying guanidinium CEST is challenging due to multiple overlapping components and a close frequency offset from water. This study aims to evaluate the applicability of a new rapid and model-free CEST quantification method using double saturation power, termed DSP-CEST, for isolating the guanidinium CEST effect from confounding factors in ischemia. To further reduce acquisition time, the DSP-CEST was combined with a quasi-steady state (QUASS) CEST technique to process non-steady-state CEST signals. METHODS The specificity and accuracy of the DSP-CEST method in quantifying the guanidinium CEST effect were assessed by comparing simulated CEST signals with/without the contribution from confounding factors. The feasibility of this method for quantifying guanidinium CEST was evaluated in a rat model of global ischemia induced by cardiac arrest and compared to a conventional multiple-pool Lorentzian fit method. RESULTS The DSP-CEST method was successful in removing all confounding components and quantifying the guanidinium CEST signal increase in ischemia. This suggests that the DSP-CEST has the potential to provide hyperintense contrast in stroke lesions. Additionally, the DSP-CEST was shown to be a rapid method that does not require the acquisition of the entire or a portion of the CEST Z-spectrum that is required in conventional model-based fitting approaches. CONCLUSION This study highlights the potential of DSP-CEST as a valuable tool for rapid and specific detection of viable tissues.
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Affiliation(s)
- Iris Y. Zhou
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, US
| | - Yang Ji
- Wellcome Centre for Integrative Neuroimaging, FMRIB Division, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Yu Zhao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Viswanathan Malvika
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, US
- Primate Imaging Center, Emory National Primate Research Center, Emory University, Atlanta, GA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
- Department of Biomedical Engineering, Vanderbilt University, Nashville, US
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Schüre JR, Casagranda S, Sedykh M, Liebig P, Papageorgakis C, Mancini L, Bisdas S, Nichelli L, Pinter N, Mechtler L, Jafari R, Boddaert N, Dangouloff-Ros V, Poujol J, Schmidt M, Doerfler A, Zaiss M. Fluid suppression in amide proton transfer-weighted (APTw) CEST imaging: New theoretical insights and clinical benefits. Magn Reson Med 2024; 91:1354-1367. [PMID: 38073061 DOI: 10.1002/mrm.29915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 02/03/2024]
Abstract
PURPOSE Amide proton transfer-weighted (APTw) MRI at 3T provides a unique contrast for brain tumor imaging. However, APTw imaging suffers from hyperintensities in liquid compartments such as cystic or necrotic structures and provides a distorted APTw signal intensity. Recently, it has been shown that heuristically motivated fluid suppression can remove such artifacts and significantly improve the readability of APTw imaging. THEORY AND METHODS In this work, we show that the fluid suppression can actually be understood by the known concept of spillover dilution, which itself can be derived from the Bloch-McConnell equations in comparison to the heuristic approach. Therefore, we derive a novel post-processing formula that efficiently removes fluid artifact, and explains previous approaches. We demonstrate the utility of this APTw assessment in silico, in vitro, and in vivo in brain tumor patients acquired at MR scanners from different vendors. RESULTS Our results show a reduction of the CEST signals from fluid environments while keeping the APTw-CEST signal intensity almost unchanged for semi-solid tissue structures such as the contralateral normal appearing white matter. This further allows us to use the same color bar settings as for conventional APTw imaging. CONCLUSION Fluid suppression has considerable value in improving the readability of APTw maps in the neuro-oncological field. In this work, we derive a novel post-processing formula from the underlying Bloch-McConnell equations that efficiently removes fluid artifact, and explains previous approaches which justify the derivation of this metric from a theoretical point of view, to reassure the scientific and medical field about its use.
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Affiliation(s)
- Jan-Rüdiger Schüre
- Institute of Neuroradiology, University Clinic Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Stefano Casagranda
- Department of R&D Advanced Applications, Olea Medical, La Ciotat, France
| | - Maria Sedykh
- Institute of Neuroradiology, University Clinic Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | | | | | - Laura Mancini
- Lysholm Department of Neuroradiology, University College of London Hospitals NHS Foundation Trus, London, UK
- Institute of Neurology UCL, London, UK
| | - Sotirios Bisdas
- Lysholm Department of Neuroradiology, University College of London Hospitals NHS Foundation Trus, London, UK
- Institute of Neurology UCL, London, UK
| | - Lucia Nichelli
- Department of Neuroradiology, Sorbonne Université, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière-Charles Foix, Paris, France
| | - Nandor Pinter
- DENT Neurologic Institute, Buffalo, New York, USA
- Department of Radiology, Jacobs School of Medicine and Biomedical Sciences, State University of New York, Buffalo, New York, USA
| | | | - Ramin Jafari
- Philips Healthcare, Cambridge, Massachusetts, USA
| | - Nathalie Boddaert
- Necker-Enfants Malades Hospital, AP-HP, Pediatric Radiology Department, Université Paris, Paris, France
- Imagine Institute, INSERM U1163, Université Paris cité, Paris, France
| | - Volodia Dangouloff-Ros
- Necker-Enfants Malades Hospital, AP-HP, Pediatric Radiology Department, Université Paris, Paris, France
- Imagine Institute, INSERM U1163, Université Paris cité, Paris, France
| | | | - Manuel Schmidt
- Institute of Neuroradiology, University Clinic Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Arnd Doerfler
- Institute of Neuroradiology, University Clinic Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Moritz Zaiss
- Institute of Neuroradiology, University Clinic Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
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Viswanathan M, Kurmi Y, Zu Z. A rapid method for phosphocreatine-weighted imaging in muscle using double saturation power-chemical exchange saturation transfer. NMR IN BIOMEDICINE 2024; 37:e5089. [PMID: 38114069 DOI: 10.1002/nbm.5089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/21/2023]
Abstract
Monitoring the variation in phosphocreatine (PCr) levels following exercise provides valuable insights into muscle function. Chemical exchange saturation transfer (CEST) has emerged as a sensitive method with which to measure PCr levels in muscle, surpassing conventional MR spectroscopy. However, existing approaches for quantifying PCr CEST signals rely on time-consuming fitting methods that require the acquisition of the entire or a section of the CEST Z-spectrum. Additionally, traditional fitting methods often necessitate clear CEST peaks, which may be challenging to obtain at low magnetic fields. This paper evaluated the application of a new model-free method using double saturation power (DSP), termed DSP-CEST, to estimate the PCr CEST signal in muscle. The DSP-CEST method requires the acquisition of only two or a few CEST signals at the PCr frequency offset with two different saturation powers, enabling rapid dynamic imaging. Additionally, the DSP-CEST approach inherently eliminates confounding signals, offering enhanced robustness compared with fitting methods. Furthermore, DSP-CEST does not demand clear CEST peaks, making it suitable for low-field applications. We evaluated the capability of DSP-CEST to enhance the specificity of PCr CEST imaging through simulations and experiments on muscle tissue phantoms at 4.7 T. Furthermore, we applied DSP-CEST to animal leg muscle both before and after euthanasia and observed successful reduction of confounding signals. The DSP-CEST signal still has contaminations from a residual magnetization transfer (MT) effect and an aromatic nuclear Overhauser enhancement effect, and thus only provides a PCr-weighted imaging. The residual MT effect can be reduced by a subtraction of DSP-CEST signals at 2.6 and 5 ppm. Results show that the residual MT-corrected DSP-CEST signal at 2.6 ppm has significant variation in postmortem tissues. By contrast, both the CEST signal at 2.6 ppm and a conventional Lorentzian difference analysis of CEST signal at 2.6 ppm demonstrate no significant variation in postmortem tissues.
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Affiliation(s)
- Malvika Viswanathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Yashwant Kurmi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Lu S, Tian J, Zhao S, Song X, Meng X, Ma G, Liu D, Shen Z, Chang B. Amide proton transfer weighted contrast has diagnostic capacity in detecting diabetic foot: an MRI-based case-control study. Front Endocrinol (Lausanne) 2024; 15:1287930. [PMID: 38577572 PMCID: PMC10991844 DOI: 10.3389/fendo.2024.1287930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 03/06/2024] [Indexed: 04/06/2024] Open
Abstract
Objective To evaluate the role of foot muscle amide proton transfer weighted (APTw) contrast and tissue rest perfusion in quantifying diabetic foot (DF) infection and its correlation with blood parameters. Materials and methods With approval from an ethical review board, this study included 40 diabetes mellitus (DM) patients with DF and 31 DM patients without DF or other lower extremity arterial disease. All subjects underwent MRI, which included foot sagittal APTw and coronal arterial spin labeling (ASL) imaging. The normalized MTRasym (3.5 ppm) and the ratio of blood flow (rBF) in rest status of the affected side lesions to the non-affected contralateral side were determined. The inter-group differences of these variables were evaluated. Furthermore, the association between normalized MTRasym (3.5 ppm), rBF, and blood parameters [fasting blood glucose (FBG), glycosylated hemoglobin content, C-reactive protein, neutrophil percentage, and white blood cell count] was explored. Using an ROC curve, the diagnostic capacity of normalized MTRasym (3.5 ppm), BF, and blood biochemical markers in differentiating with or without DF in DM was assessed. Results In the DF group, MTRasym (3.5 ppm) and BF in lesion and normalized MTRasym (3.5 ppm) were higher than those in the control group (p < 0.05). In addition, correlations were identified between normalized MTRasym (3.5 ppm) and blood parameters, such as C-reactive protein, glycosylated hemoglobin content, FBG, neutrophil ratio, and white blood cell (p < 0.001). Meanwhile, association between BF in lesion and blood parameters, such as C-reactive protein, neutrophil percentage, and FBG (p < 0.01). AUC of normalized MTRasym (3.5 ppm) in identifying with/without DF in patients with DM is 0.986 (95% CI, 0.918-1.00) with the sensitivity of 97.22% and the specificity of 100%. Conclusion Normalized MTRasym (3.5 ppm) and the BF in lesion may be treated as a safer and more convenient new indicator to evaluate the tissue infection without using a contrast agent, which may be useful in monitoring and preoperatively assessing DF patients with renal insufficiency.
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Affiliation(s)
- Shan Lu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
| | - Jiwei Tian
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
| | - Shiyu Zhao
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
| | - Xueyan Song
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
| | - Xianglu Meng
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
| | - Guangyang Ma
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
| | - Dengping Liu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
| | - Zhiwei Shen
- Clinical Science, Philips Healthcare, Beijing, China
| | - Baocheng Chang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Department of Radiology, Tianjin Medical University, Tianjin, China
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Meng N, Song C, Sun J, Liu X, Shen L, Zhou Y, Dai B, Yu X, Wu Y, Yuan J, Yang Y, Wang Z, Wang M. Amide proton transfer-weighted imaging and stretch-exponential model DWI based 18F-FDG PET/MRI for differentiation of benign and malignant solitary pulmonary lesions. Cancer Imaging 2024; 24:33. [PMID: 38439101 PMCID: PMC10910843 DOI: 10.1186/s40644-024-00677-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 02/20/2024] [Indexed: 03/06/2024] Open
Abstract
OBJECTIVES To differentiate benign and malignant solitary pulmonary lesions (SPLs) by amide proton transfer-weighted imaging (APTWI), mono-exponential model DWI (MEM-DWI), stretched exponential model DWI (SEM-DWI), and 18F-FDG PET-derived parameters. METHODS A total of 120 SPLs patients underwent chest 18F-FDG PET/MRI were enrolled, including 84 in the training set (28 benign and 56 malignant) and 36 in the test set (13 benign and 23 malignant). MTRasym(3.5 ppm), ADC, DDC, α, SUVmax, MTV, and TLG were compared. The area under receiver-operator characteristic curve (AUC) was used to assess diagnostic efficacy. The Logistic regression analysis was used to identify independent predictors and establish prediction model. RESULTS SUVmax, MTV, TLG, α, and MTRasym(3.5 ppm) values were significantly lower and ADC, DDC values were significantly higher in benign SPLs than malignant SPLs (all P < 0.01). SUVmax, ADC, and MTRasym(3.5 ppm) were independent predictors. Within the training set, the prediction model based on these independent predictors demonstrated optimal diagnostic efficacy (AUC, 0.976; sensitivity, 94.64%; specificity, 92.86%), surpassing any single parameter with statistical significance. Similarly, within the test set, the prediction model exhibited optimal diagnostic efficacy. The calibration curves and DCA revealed that the prediction model not only had good consistency but was also able to provide a significant benefit to the related patients, both in the training and test sets. CONCLUSION The SUVmax, ADC, and MTRasym(3.5 ppm) were independent predictors for differentiation of benign and malignant SPLs, and the prediction model based on them had an optimal diagnostic efficacy.
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Affiliation(s)
- Nan Meng
- Department of Medical Imaging, Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou, China.
- Laboratory of Brain Science and Brain-Like Intelligence Technology, Institute for Integrated Medical Science and Engineering, Henan Academy of Sciences, Zhengzhou, China.
- Biomedical Research Institute, Henan Academy of Sciences, Zhengzhou, China.
| | - Chen Song
- Hematology Laboratory, the First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Jing Sun
- Department of Pediatrics, Zhengzhou Central Hospital Affiliated to Zhengzhou University & Zhengzhou Central Hospital, Zhengzhou, China
| | - Xue Liu
- Department of Medical Imaging, Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou, China
| | - Lei Shen
- Department of Medical Imaging, Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou, China
| | - Yihang Zhou
- Department of Medical Imaging, Xinxiang Medical University People's Hospital & Henan Provincial People's Hospital, Zhengzhou, China
| | - Bo Dai
- Department of Medical Imaging, Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou, China
| | - Xuan Yu
- Department of Medical Imaging, Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou, China
| | - Yaping Wu
- Department of Medical Imaging, Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou, China
| | - Jianmin Yuan
- Central Research Institute, United Imaging Healthcare Group, Shanghai, China
| | - Yang Yang
- Beijing United Imaging Research Institute of Intelligent Imaging, United Imaging Healthcare Group, Beijing, China
| | - Zhe Wang
- Central Research Institute, United Imaging Healthcare Group, Shanghai, China
| | - Meiyun Wang
- Department of Medical Imaging, Henan Provincial People's Hospital & Zhengzhou University People's Hospital, Zhengzhou, China.
- Laboratory of Brain Science and Brain-Like Intelligence Technology, Institute for Integrated Medical Science and Engineering, Henan Academy of Sciences, Zhengzhou, China.
- Biomedical Research Institute, Henan Academy of Sciences, Zhengzhou, China.
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Jin T, Chung JJ. Adjustment of rotation and saturation effects (AROSE) for CEST imaging. Magn Reson Med 2024; 91:1016-1029. [PMID: 38009992 PMCID: PMC10841829 DOI: 10.1002/mrm.29938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 10/09/2023] [Accepted: 11/06/2023] [Indexed: 11/29/2023]
Abstract
PURPOSE Endogenous CEST signal usually has low specificity due to contaminations from the magnetization transfer contrast (MTC) and other labile protons with overlapping or close Larmor frequencies. We propose to improve CEST signal specificity with adjustment of rotation and saturation effects (AROSE). METHODS The AROSE approach measures the difference between CEST signals acquired with the same average irradiation power but largely different duty cycles, for example, a continuous wave or a high duty cycle pulse train versus a low duty cycle pulse train with a flip angle φ. Simulation, phantom, and in vivo rodent studies were performed to evaluate the characteristics of the AROSEφ signal. RESULTS Simulation and experimental results show that AROSE2π is a low-pass filter that can suppress fast exchanging processes (e.g., >3000 s-1 ), whereas AROSEπ is a band-pass filter suppressing both fast and slow exchange (e.g., <30 s-1 ) rates. For other φ angles, the sensitivity and the exchange-rate filtering effect of AROSEφ falls between AROSEπ and AROSE2π . AROSE can also minimize MTC and improve the Larmor frequency selectivity of the CEST signal. The linewidth of the AROSE1.5π spectrum is about 60% to 65% when compared to the CEST spectrum measured by continuous wave. Depending on the needs of an application, the sensitivity, exchange-rate filtering, and Larmor frequency selectivity can be adjusted by varying the flip angle, duty cycle, and average irradiation power. CONCLUSION Compared to conventional CEST signals, AROSE can minimize MTC and improve exchange rate filtering and Larmor frequency specificity.
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Affiliation(s)
- Tao Jin
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Julius Juhyun Chung
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Zhou L, Pan W, Huang R, Wang T, Wei Z, Wang H, Zhang Y, Li Y. Amide Proton Transfer-Weighted MRI, Associations with Clinical Severity and Prognosis in Ischemic Strokes. J Magn Reson Imaging 2024. [PMID: 38426606 DOI: 10.1002/jmri.29333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 02/21/2024] [Accepted: 02/21/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND The National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin scale (mRS) scores have important shortcomings. Amide proton transfer-weighted (APTw) imaging might offer more valuable information in ischemic strokes assessment. PURPOSE To utilize APTw, apparent diffusion coefficient (ADC), and computed tomography perfusion (CTP) for the assessment of clinical symptom severity and 90-day prognosis in patients diagnosed with ischemic stroke. STUDY TYPE Prospective. SUBJECTS 61 patients (mean age 63.2 ± 9.7 years; 46 males, 15 females) with ischemic strokes were included in the study. FIELD STRENGTH/SEQUENCE 3T/turbo spin echo (TSE) T1 -weighted imaging, T2 -weighted imaging, T2 -fluid attenuated inversion recovery (T2 -FLAIR), diffusion-weighted imaging (DWI), and single-shot TSE APTw imaging. ASSESSMENT APTw, ADC, and CTP were used to compare patient subgroups and construct a prognostic nomogram model. STATISTICAL TESTS Kolmogorov-Smirnov test, t-test, Mann-Whitney U test, chi-square test, Pearson correlation analysis, multivariate logistic regression analysis, decision curve analysis (DCA), receiver operating characteristic curves (ROCs). The significance threshold was set at P < 0.05. RESULTS Correlation analysis revealed that APTw and NIHSS exhibit the highest correlation (r = -0.634, 95% confidence interval [CI] -0.418 to -0.782), surpassing that of ADC and lesion size. Multivariable analysis revealed APTw (odds ratio [OR] 0.905, 95% CI 0.845-0.970), ADC (OR 0.745, 95% CI 0.609-0.911), and infarct core-cerebral blood volume (IC-CBV) (OR 0.547, 95% CI 0.310-0.964) as potential risk factors associated with a poor prognosis. The nomogram model demonstrated the highest predictive efficacy, with an area under the curve (AUC) of 0.960 (95% CI 0.911-0.988), exceeding that of APTw, ADC, and IC-CBV individually. DATA CONCLUSION The APTw technique holds potential value in categorizing and managing patients with ischemic stroke, offering guidance for the implementation of clinical treatment strategies. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Le Zhou
- Department of Radiology, The First Affiliated Hospital of Soochow University, Suzhou city, Jiangsu Province, China
| | - Wanqian Pan
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Renjun Huang
- Department of Radiology, The First Affiliated Hospital of Soochow University, Suzhou city, Jiangsu Province, China
| | - Tianye Wang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Zifan Wei
- Suzhou Medical College of Soochow University, Suzhou, China
| | - Hui Wang
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Yi Zhang
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yonggang Li
- Department of Radiology, The First Affiliated Hospital of Soochow University, Suzhou city, Jiangsu Province, China
- Institute of Medical Imaging, Soochow University, Suzhou city, Jiangsu Province, China
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Wu J, Huang Q, Shen Y, Guo P, Zhou J, Jiang S. Radiomic feature reliability of amide proton transfer-weighted MR images acquired with compressed sensing at 3T. INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY 2024; 34:e23027. [PMID: 39185083 PMCID: PMC11343505 DOI: 10.1002/ima.23027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 01/08/2024] [Indexed: 08/27/2024]
Abstract
Compressed sensing (CS) is a novel technique for MRI acceleration. The purpose of this paper was to assess the effects of CS on the radiomic features extracted from amide proton transfer-weighted (APTw) images. Brain tumor MRI data of 40 scans were studied. Standard images using sensitivity encoding (SENSE) with an acceleration factor (AF) of 2 were used as the gold standard, and APTw images using SENSE with CS (CS-SENSE) with an AF of 4 were assessed. Regions of interest (ROIs), including normal tissue, edema, liquefactive necrosis, and tumor, were manually drawn, and the effects of CS-SENSE on radiomics were assessed for each ROI category. An intraclass correlation coefficient (ICC) was first calculated for each feature extracted from APTw images with SENSE and CS-SENSE for all ROIs. Different filters were applied to the original images, and the effects of these filters on the ICCs were further compared between APTw images with SENSE and CS-SENSE. Feature deviations were also provided for a more comprehensive evaluation of the effects of CS-SENSE on radiomic features. The ROI-based comparison showed that most radiomic features extracted from CS-SENSE-APTw images and SENSE-APTw images had moderate or greater reliabilities (ICC ≥ 0.5) for all four ROIs and all eight image sets with different filters. Tumor showed significantly higher ICCs than normal tissue, edema, and liquefactive necrosis. Compared to the original images, filters (such as Exponential or Square) may improve the reliability of radiomic features extracted from CS-SENSE-APTw and SENSE-APTw images.
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Affiliation(s)
- Jingpu Wu
- Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Applied Mathematics and Statistics, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Qianqi Huang
- Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Biomedical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yiqing Shen
- Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Computer Science, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Pengfei Guo
- Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
- Department of Computer Science, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jinyuan Zhou
- Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Shanshan Jiang
- Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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Zeng Q, Machado M, Bie C, van Zijl PCM, Malvar S, Li Y, D’souza V, Poon KA, Grimm A, Yadav NN. In vivo characterization of glycogen storage disease type III in a mouse model using glycoNOE MRI. Magn Reson Med 2024; 91:1115-1121. [PMID: 38009988 PMCID: PMC10842402 DOI: 10.1002/mrm.29923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/28/2023] [Accepted: 10/24/2023] [Indexed: 11/29/2023]
Abstract
PURPOSE Glycogen storage disease type III (GSD III) is a rare inherited metabolic disease characterized by excessive accumulation of glycogen in liver, skeletal muscle, and heart. Currently, there are no widely available noninvasive methods to assess tissue glycogen levels and disease load. Here, we use glycogen nuclear Overhauser effect (glycoNOE) MRI to quantify hepatic glycogen levels in a mouse model of GSD III. METHODS Agl knockout mice (n = 13) and wild-type controls (n = 10) were scanned for liver glycogen content using glycoNOE MRI. All mice were fasted for 12 to 16 h before MRI scans. GlycoNOE signal was quantified by fitting the Z-spectrum using a four-pool Voigt lineshape model. Next, the fitted direct water saturation pool was removed and glycoNOE signal was estimated from the integral of the residual Z spectrum within -0.6 to -1.4 ppm. Glycogen concentration was also measured ex vivo using a biochemical assay. RESULTS GlycoNOE MRI clearly distinguished Agl knockout mice from wild-type controls, showing a statistically significant difference in glycoNOE signals in the livers across genotypes. There was a linear correlation between glycoNOE signal and glycogen concentration determined by the biochemical assay. The obtained glycoNOE maps of mouse livers also showed higher glycogen levels in Agl knockout mice compared to wild-type mice. CONCLUSION GlycoNOE MRI was used successfully as a noninvasive method to detect liver glycogen levels in mice, suggesting the potential of this method to be applied to assess glycogen storage diseases.
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Affiliation(s)
- Qing Zeng
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | | | - Chongxue Bie
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Peter C. M. van Zijl
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Sofi Malvar
- Ultragenyx Pharmaceutical Inc., Novato, CA, United States
| | - Yuguo Li
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Valentina D’souza
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | | | - Andrew Grimm
- Ultragenyx Pharmaceutical Inc., Novato, CA, United States
| | - Nirbhay N. Yadav
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
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Chiba D, Kanazawa Y, Miyati T, Harada M, Miyoshi M, Hayashi H, Haga A. Simplified assessment for chemical exchanged saturation transfer (CEST) imaging: local offset frequency and CEST effect. Radiol Phys Technol 2024; 17:93-102. [PMID: 37897684 DOI: 10.1007/s12194-023-00752-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/27/2023] [Accepted: 10/09/2023] [Indexed: 10/30/2023]
Abstract
The aim of this study is to develop a novel phantom for the evaluation of clinical CEST imaging settings, e.g., B0 and B1 field inhomogeneities, CEST contrast, and post-processing. We made a phantom composed of two slice sections: a grid section for local offset frequency evaluation and a sample section for CEST effect evaluation using different concentrations of an egg white albumin solution. On a 3 Tesla MR scanner, a phantom study was performed using CEST imaging; the mean B1 amplitudes were set at 1.2 and 1.9 µT, and CEST images with and without B0 corrections were acquired. Next, region of interest (ROI) analysis was performed for each slice. Then, CEST images with and without B0 corrections were compared at each B1 amplitude. The B0 corrected Z-spectrums at each local region in the grid section showed a shifting of the curve bottom to 0 ppm. Z-spectrum at B1 = 1.9 µT showed a broader curve shape than that at 1.2 µT. Moreover, MTRasym values at 3.5 ppm for each albumin sample at B1 = 1.9 µT were about two times higher than those at 1.2 µT. Our phantom enabled us to evaluate and optimize B0 inhomogeneity and the CEST effect at the B1 amplitude.
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Affiliation(s)
- Daiki Chiba
- Brain Attack Center Ota Memorial Hospital, 3-6-28 Okinogami, Fukuyama, Hiroshima, 7200825, Japan
| | - Yuki Kanazawa
- Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-Cyo, Toksuhima, 7708503, Japan.
| | - Tosiaki Miyati
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5‑11‑80 Kodatsuno, Kanazawa, Ishikawa, 9200942, Japan
| | - Masafumi Harada
- Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-Cyo, Toksuhima, 7708503, Japan
| | - Mitsuharu Miyoshi
- Global MR Clinical Solutions and Research Collaborations, GE HealthCare, 4-7-127 Asahigaoka, Hino, Tokyo, 1918503, Japan
| | - Hiroaki Hayashi
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5‑11‑80 Kodatsuno, Kanazawa, Ishikawa, 9200942, Japan
| | - Akihiro Haga
- Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-Cyo, Toksuhima, 7708503, Japan
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Heo HY, Singh M, Yedavalli V, Jiang S, Zhou J. CEST and nuclear Overhauser enhancement imaging with deep learning-extrapolated semisolid magnetization transfer reference: Scan-rescan reproducibility and reliability studies. Magn Reson Med 2024; 91:1002-1015. [PMID: 38009996 PMCID: PMC10842109 DOI: 10.1002/mrm.29937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 10/18/2023] [Accepted: 11/04/2023] [Indexed: 11/29/2023]
Abstract
PURPOSE To develop a novel MR physics-driven, deep-learning, extrapolated semisolid magnetization transfer reference (DeepEMR) framework to provide fast, reliable magnetization transfer contrast (MTC) and CEST signal estimations, and to determine the reproducibility and reliability of the estimates from the DeepEMR. METHODS A neural network was designed to predict a direct water saturation and MTC-dominated signal at a certain CEST frequency offset using a few high-frequency offset features in the Z-spectrum. The accuracy, scan-rescan reproducibility, and reliability of MTC, CEST, and relayed nuclear Overhauser enhancement (rNOE) signals estimated from the DeepEMR were evaluated on numerical phantoms and in heathy volunteers at 3 T. In addition, we applied the DeepEMR method to brain tumor patients and compared tissue contrast with other CEST calculation metrics. RESULTS The DeepEMR method demonstrated a high degree of accuracy in the estimation of reference MTC signals at ±3.5 ppm for APT and rNOE imaging, and computational efficiency (˜190-fold) compared with a conventional fitting approach. In addition, the DeepEMR method achieved high reproducibility and reliability (intraclass correlation coefficient = 0.97, intersubject coefficient of variation = 3.5%, and intrasubject coefficient of variation = 1.3%) of the estimation of MTC signals at ±3.5 ppm. In tumor patients, DeepEMR-based amide proton transfer images provided higher tumor contrast than a conventional MT ratio asymmetry image, particularly at higher B1 strengths (>1.5 μT), with a distinct delineation of the tumor core from normal tissue or peritumoral edema. CONCLUSION The DeepEMR approach is feasible for measuring clean APT and rNOE effects in longitudinal and cross-sectional studies with low scan-rescan variability.
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Affiliation(s)
- Hye-Young Heo
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
| | - Munendra Singh
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
| | - Vivek Yedavalli
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
| | - Shanshan Jiang
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jinyuan Zhou
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
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Wu X, Su T, Chen Y, Xu Z, Wang X, Hu G, Wang Y, Wong LM, Zhang Z, Zhang T, Jin Z. B1 Power Modification for Amide Proton Transfer Imaging in Parotid Glands: A Strategy for Image Quality Accommodation and Evaluation of Tumor Detection Feasibility. Cancers (Basel) 2024; 16:888. [PMID: 38473250 DOI: 10.3390/cancers16050888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/17/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
BACKGROUND In the application of APTw protocols for evaluating tumors and parotid glands, inhomogeneity and hyperintensity artifacts have remained an obstacle. This study aimed to improve APTw imaging quality and evaluate the feasibility of difference B1 values to detect parotid tumors. METHODS A total of 31 patients received three APTw sequences to acquire 32 lesions and 30 parotid glands (one patient had lesions on both sides). Patients received T2WI and 3D turbo-spin-echo (TSE) APTw imaging on a 3.0 T scanner for three sequences (B1 = 2 μT, 1 μT, and 0.7 μT in APTw 1, 2, and 3, respectively). APTw image quality was evaluated using four-point Likert scales in terms of integrity and hyperintensity artifacts. Image quality was compared between the three sequences. An evaluable group and a trustable group were obtained for APTmean value comparison. RESULTS Tumors in both APT2 and APT3 had fewer hyperintensity artifacts than in APT1. With B1 values decreasing, tumors had less integrity in APTw imaging. APTmean values of tumors were higher than parotid glands in traditional APT1 sequence though not significant, while the APTmean subtraction value was significantly different. CONCLUSIONS Applying a lower B1 value could remove hyperintensity but could also compromise its integrity. Combing different APTw sequences might increase the feasibility of tumor detection.
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Affiliation(s)
- Xiaoqian Wu
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Tong Su
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Yu Chen
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Zhentan Xu
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Xiaoqi Wang
- Yangtze Delta Region Institute of Tsinghua University, Jiaxing 314006, China
| | - Geli Hu
- Department of Clinical and Technical Support, Philips Healthcare, Beijing 100600, China
| | - Yunting Wang
- Department of Stomatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Lun M Wong
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong 999077, China
| | - Zhuhua Zhang
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Tao Zhang
- Department of Stomatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Zhengyu Jin
- Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
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Xu Y, Wan Q, Ren X, Jiang Y, Wang F, Yao J, Wu P, Shen A, Wang P. Amide proton transfer-weighted MRI for renal tumors: Comparison with diffusion-weighted imaging. Magn Reson Imaging 2024; 106:104-109. [PMID: 38135260 DOI: 10.1016/j.mri.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/07/2023] [Accepted: 12/10/2023] [Indexed: 12/24/2023]
Abstract
OBJECTIVE To investigate the potential of amide proton transfer-weighted (APTw) MRI in identifying benign and malignant renal tumors and to evaluate whether APTw MRI can add diagnostic value to diffusion-weighted imaging (DWI). MATERIALS AND METHODS Participants with renal tumor underwent preoperative multiparametric MRI, including APTw MRI and DWI. The APTw and apparent diffusion coefficient (ADC) of malignant tumors and benign tumors were calculated independently by two radiologists and compared. The value of the mean APTw and the mean ADC for differentiating malignant and benign tumors was evaluated by receiver operating characteristic analysis. RESULTS In total, 65 participants (mean age, 59 years ±14; 41 men) were evaluated: 54 with malignant and 11 with benign renal tumors. Malignant renal tumors showed higher mean APTw values [2.03% (1.63) vs 1.00% (1.60); P < 0.01] and lower mean ADC values (1.22 × 10-3 mm2/s ± 0.37 vs 1.51 × 10-3 mm2/s ± 0.37; P < 0.05) than benign renal tumors. The area under the receiver operating characteristic curve (AUC) of APTw, ADC and the combination of them for the identification of benign and malignant renal tumors was 0.78(95% CI: 0.66, 0.87; P < 0.001),0.70(95% CI: 0.54, 0.86; P < 0.05) and 0.79 (95% CI: 0.67, 0.88; P < 0.001). The optimal cutoff value for mean APTw was 2.14% (sensitivity, 74%; specificity, 73%). There was no difference between these three parameters for differentiating malignant from benign renal tumors (P > 0.05). CONCLUSION The APTw MRI has the potential use as an imaging biomarker for renal malignant and benign tumors.
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Affiliation(s)
- Yun Xu
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China
| | - Qingxuan Wan
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China
| | - Xihui Ren
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China
| | - Yutao Jiang
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China
| | - Fang Wang
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China
| | - Jing Yao
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China
| | - Peng Wu
- Philips Healthcare, Shanghai 200072, China
| | - Aijun Shen
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China.
| | - Peijun Wang
- Department of Medical Imaging, Tongji Hospital, School of Medicine, Tongji University, Shanghai 200065, China; Institute of Medical Imaging Artificial Intelligence, Tongji University School of Medicine, Shanghai 200065, China.
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Teng M, Wang M, He F, Liang W, Zhang G. Arterial Spin Labeling and Amide Proton Transfer Imaging can Differentiate Glioblastoma from Brain Metastasis: A Systematic Review and Meta-Analysis. World Neurosurg 2024; 182:e702-e711. [PMID: 38072160 DOI: 10.1016/j.wneu.2023.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 12/04/2023] [Indexed: 01/06/2024]
Abstract
BACKGROUND Currently, arterial spin labeling (ASL) and amide proton transfer (APT) imaging have shown potential for distinguishing glioblastoma from brain metastases. Thus, a meta-analysis was conducted to investigate this further. METHODS An extensive and comprehensive search was conducted in 6 English and Chinese databases according to predefined inclusion and exclusion criteria, encompassing data up to July 2023. Data from eligible literature were extracted, and bivariate models were employed to calculate pooled sensitivities, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) of the summary receiver operating characteristic curve. RESULTS The meta-analysis included 11 articles. For ASL, the pooled sensitivity was 0.77 (95% confidence interval [CI], 0.63-0.87), and the pooled specificity was 0.87 (95% CI, 0.77-0.93). The pooled PLR was 5.89 (95% CI, 2.97-11.69), the pooled NLR was 0.26 (95% CI, 0.15-0.47), the pooled DOR was 22.33 (95% CI, 6.89-72.34), and AUC was 0.90 (95% CI, 0.87-0.92). For APT imaging, the pooled sensitivity was 0.78 (95% CI, 0.70-0.85), and the pooled specificity was 0.86 (95% CI, 0.77-0.92). The pooled PLR was 5.51 (95% CI, 3.24-9.37), the pooled NLR was 0.25 (95% CI, 0.17-0.37), the pooled DOR was 21.99 (95% CI, 10.28-47.03), and the AUC was 0.90 (95% CI, 0.87-0.92). CONCLUSIONS This meta-analysis suggest that both ASL and APT imaging exhibit high accuracy in distinguishing between glioblastoma and brain metastasis.
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Affiliation(s)
- Minghao Teng
- Department of Neurosurgery, Minda Hospital of Hubei Minzu University, Enshi, Hubei, China; Hubei Provincial Key Laboratory of Occurrence and Intervention of Rheumatic Diseases, Enshi, Hubei, China; Hubei Provincial Clinical Medical Research Center for Nephropathy, Enshi, Hubei, China
| | - Minshu Wang
- Department of Neurosurgery, Minda Hospital of Hubei Minzu University, Enshi, Hubei, China; Hubei Provincial Key Laboratory of Occurrence and Intervention of Rheumatic Diseases, Enshi, Hubei, China; Hubei Provincial Clinical Medical Research Center for Nephropathy, Enshi, Hubei, China
| | - Feng He
- Department of Neurosurgery, Minda Hospital of Hubei Minzu University, Enshi, Hubei, China; Hubei Provincial Key Laboratory of Occurrence and Intervention of Rheumatic Diseases, Enshi, Hubei, China; Hubei Provincial Clinical Medical Research Center for Nephropathy, Enshi, Hubei, China
| | - Wu Liang
- Department of Neurosurgery, Minda Hospital of Hubei Minzu University, Enshi, Hubei, China; Hubei Provincial Key Laboratory of Occurrence and Intervention of Rheumatic Diseases, Enshi, Hubei, China; Hubei Provincial Clinical Medical Research Center for Nephropathy, Enshi, Hubei, China
| | - Guisheng Zhang
- Department of Neurosurgery, Minda Hospital of Hubei Minzu University, Enshi, Hubei, China; Hubei Provincial Key Laboratory of Occurrence and Intervention of Rheumatic Diseases, Enshi, Hubei, China; Hubei Provincial Clinical Medical Research Center for Nephropathy, Enshi, Hubei, China.
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Sun C, Zhao Y, Zu Z. Evaluation of the molecular origin of amide proton transfer-weighted imaging. Magn Reson Med 2024; 91:716-734. [PMID: 37749854 PMCID: PMC10841347 DOI: 10.1002/mrm.29878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/15/2023] [Accepted: 09/08/2023] [Indexed: 09/27/2023]
Abstract
PURPOSE To evaluate the assumption in amide proton transfer weighted (APTw) imaging that the APT dominates over the relayed nuclear Overhauser enhancement (rNOE) and other CEST effects such as those from amines/guanidines, thereby providing imaging of mobile proteins/peptides. METHODS We introduced two auxiliary asymmetric analysis metrics that can vary the relative contributions from amine/guanidinium CEST and other effects. By comparing these metrics with the conventional asymmetric analysis metric on healthy rat brains, we can approximately assess the contribution from amines/guanidines to APTw and determine whether the APT dominates over the rNOE effect. To further investigate the molecular origin of APTw, we used samples of dialyzed tissue homogenates to eliminate small metabolites and supernatants of homogenates to separate lipids from other components. RESULTS When the APTw signal is positive using high saturation amplitudes (e.g., 2-3 μT), the contributions from amines/guanidines are significant and cannot be ignored. The APTw signal from the dialyzed homogenates and the controls has negligible changes, indicating that it primarily originates from macromolecules rather than small metabolites. Additionally, the APTw signals with low saturation amplitudes (e.g., 1 μT) were negative in tissue homogenates but positive in their supernatants, suggesting that proteins contribute positively to APTw signals, whereas lipids contribute negatively to it. CONCLUSION The positive APTw signal using high saturation amplitudes could have significant contributions from soluble proteins through CEST, including amide/amine/guanidine proton transfer effects. In contrast, the negative APTw signal using low saturation amplitudes has significant contribution from lipids through rNOE.
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Affiliation(s)
- Casey Sun
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Chemistry, University of Florida, Gainesville, US
| | - Yu Zhao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, US
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, US
- Department of Biomedical Engineering, Vanderbilt University, Nashville, US
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Viswanathan M, Kurmi Y, Zu Z. Nuclear Overhauser enhancement imaging at -1.6 ppm in rat brain at 4.7T. Magn Reson Med 2024; 91:615-629. [PMID: 37867419 DOI: 10.1002/mrm.29896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/21/2023] [Accepted: 10/04/2023] [Indexed: 10/24/2023]
Abstract
PURPOSE A new nuclear Overhauser enhancement (NOE)-mediated saturation transfer signal at around -1.6 ppm, termed NOE(-1.6), has been reported at high fields of 7T and 9.4T previously. This study aims to validate the presence of this signal at a relatively low field of 4.7T and evaluate its variations in different brain regions and tumors. METHODS Rats were injected with monocrystalline iron oxide nanoparticles to reduce the NOE(-1.6) signal. CEST signals were measured using different saturation powers before and after injection to assess the presence of this signal. Multiple-pool Lorentzian fits, with/without inclusion of the NOE(-1.6) pool, were performed on CEST Z-spectra obtained from healthy rat brains and rats with 9L tumors. These fits aimed to further validate the presence of the NOE(-1.6) signal and quantify its amplitude. RESULTS The NOE(-1.6) signal exhibited a dramatic change following the injection of monocrystalline iron oxide nanoparticles, confirming its presence at 4.7T. The NOE(-1.6) signal reached its peak at a saturation power of ∼0.75 μT, indicating an optimized power level. The multiple-pool Lorentzian fit without the NOE(-1.6) pool showed higher residuals around -1.6 ppm compared to the fit with this pool, further supporting the presence of this signal. The NOE(-1.6) signal did not exhibit significant variation in the corpus callosum and caudate putamen regions, but it showed a significant decrease in tumors, which aligns with previous findings at 9.4T. CONCLUSION This study successfully demonstrated the presence of the NOE(-1.6) signal at 4.7T, which provides valuable insights into its potential applications at lower field strengths.
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Affiliation(s)
- Malvika Viswanathan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Yashwant Kurmi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Park SW, Lai JHC, Han X, Leung VWM, Xiao P, Huang J, Chan KWY. Preclinical Application of CEST MRI to Detect Early and Regional Tumor Response to Local Brain Tumor Treatment. Pharmaceutics 2024; 16:101. [PMID: 38258112 PMCID: PMC10820766 DOI: 10.3390/pharmaceutics16010101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Treating glioblastoma and monitoring treatment response non-invasively remain challenging. Here, we developed a robust approach using a drug-loaded liposomal hydrogel that is mechanically compatible with the brain, and, simultaneously, we successfully monitored early tumor response using Chemical Exchange Saturation Transfer (CEST) MRI. This CEST-detectable liposomal hydrogel was optimized based on a sustainable drug release and a soft hydrogel for the brain tumor, which is unfavorable for tumor cell proliferation. After injecting the hydrogel next to the tumor, three distinctive CEST contrasts enabled the monitoring of tumor response and drug release longitudinally at 3T. As a result, a continuous tumor volume decrease was observed in the treatment group along with a significant decrease in CEST contrasts relating to the tumor response at 3.5 ppm (Amide Proton Transfer; APT) and at -3.5 ppm (relayed Nuclear Overhauser Effect; rNOE) when compared to the control group (p < 0.05). Interestingly, the molecular change at 3.5 ppm on day 3 (p < 0.05) was found to be prior to the significant decrease in tumor volume on day 5. An APT signal also showed a strong correlation with the number of proliferating cells in the tumors. This demonstrated that APT detected a distinctive decrease in mobile proteins and peptides in tumors before the change in tumor morphology. Moreover, the APT signal showed a regional response to the treatment, associated with proliferating and apoptotic cells, which allowed an in-depth evaluation and prediction of the tumor treatment response. This newly developed liposomal hydrogel allows image-guided brain tumor treatment to address clinical needs using CEST MRI.
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Affiliation(s)
- Se-Weon Park
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (S.-W.P.); (J.H.C.L.); (X.H.); (P.X.)
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Joseph H. C. Lai
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (S.-W.P.); (J.H.C.L.); (X.H.); (P.X.)
| | - Xiongqi Han
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (S.-W.P.); (J.H.C.L.); (X.H.); (P.X.)
| | - Vivian W. M. Leung
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (S.-W.P.); (J.H.C.L.); (X.H.); (P.X.)
| | - Peng Xiao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (S.-W.P.); (J.H.C.L.); (X.H.); (P.X.)
| | - Jianpan Huang
- Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China;
| | - Kannie W. Y. Chan
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China; (S.-W.P.); (J.H.C.L.); (X.H.); (P.X.)
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China
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Xiao G, Zhang X, Tang H, Huang W, Chen Y, Zhuang C, Chen B, Yang L, Chen Y, Yan G, Wu R. Deep learning for dense Z-spectra reconstruction from CEST images at sparse frequency offsets. Front Neurosci 2024; 17:1323131. [PMID: 38249588 PMCID: PMC10796656 DOI: 10.3389/fnins.2023.1323131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/13/2023] [Indexed: 01/23/2024] Open
Abstract
A direct way to reduce scan time for chemical exchange saturation transfer (CEST)-magnetic resonance imaging (MRI) is to reduce the number of CEST images acquired in experiments. In some scenarios, a sufficient number of CEST images acquired in experiments was needed to estimate parameters for quantitative analysis, and this prolonged the scan time. For that, we aim to develop a general deep-learning framework to reconstruct dense CEST Z-spectra from experimentally acquired images at sparse frequency offsets so as to reduce the number of experimentally acquired CEST images and achieve scan time reduction. The main innovation works are outlined as follows: (1) a general sequence-to-sequence (seq2seq) framework is proposed to reconstruct dense CEST Z-spectra from experimentally acquired images at sparse frequency offsets; (2) we create a training set from wide-ranging simulated Z-spectra instead of experimentally acquired CEST data, overcoming the limitation of the time and labor consumption in manual annotation; (3) a new seq2seq network that is capable of utilizing information from both short-range and long-range is developed to improve reconstruction ability. One of our intentions is to establish a simple and efficient framework, i.e., traditional seq2seq can solve the reconstruction task and obtain satisfactory results. In addition, we propose a new seq2seq network that includes the short- and long-range ability to boost dense CEST Z-spectra reconstruction. The experimental results demonstrate that the considered seq2seq models can accurately reconstruct dense CEST images from experimentally acquired images at 11 frequency offsets so as to reduce the scan time by at least 2/3, and our new seq2seq network contributes to competitive advantage.
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Affiliation(s)
- Gang Xiao
- School of Mathematics and Statistics, Hanshan Normal University, Chaozhou, China
| | - Xiaolei Zhang
- Department of Radiology, Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Hanjing Tang
- College of Engineering, Shantou University, Shantou, China
| | - Weipeng Huang
- Medical Imaging Center, Jieyang People's Hospital, Jieyang, China
| | - Yaowen Chen
- College of Engineering, Shantou University, Shantou, China
| | - Caiyu Zhuang
- Department of Radiology, Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Beibei Chen
- Department of Radiology, Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Lin Yang
- Department of Radiology, Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yue Chen
- Department of Radiology, Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Gen Yan
- Department of Radiology, Second Affiliated Hospital of Xiamen Medical College, Xiamen, China
| | - Renhua Wu
- Department of Radiology, Second Affiliated Hospital of Shantou University Medical College, Shantou, China
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Han M, Li Q, Yang T, Li J. Amide proton transfer imaging in rats after heatstroke. Neuroreport 2024; 35:37-41. [PMID: 37983618 DOI: 10.1097/wnr.0000000000001974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Metabolic acidosis is the most common acid-base change following heatstroke. This study aimed to evaluate the internal environment changes caused by heatstroke using amide proton transfer (APT) imaging. Nineteen male Sprague-Dawley rats were randomly divided into the control group (CTRL, n = 7) and the heatstroke group (HS, n = 12). All the rats underwent a 7.0-T MRI, which included T2-weighted imaging (T2WI) and APT imaging. Subsequently, the surviving HS group rats repeated the same magnetic resonance scanning after 25 days and were designated as the follow-up group (FU, n = 7). APT values were measured in the hippocampus, thalamus, and corpus callosum. The APT values of the three groups were statistically analyzed and found in the hippocampus (CTRL vs. HS, P = 0.011; CTRL vs. FU, P = 0.078; HS vs. FU, P = 0.484; η ² = 0.276), left thalamus (CTRL vs. HS, P = 0.004; CTRL vs. FU, P = 0.014; HS vs. FU, P = 0.822; η ² = 0.331), right thalamus (CTRL vs. HS, P = 0.003; CTRL vs. FU, P = 0.015; HS vs. FU P = 0.769; η ² = 0.336), and corpus callosum (CTRL vs. HS, P < 0.001; CTRL vs. FU, P = 0.005; HS vs. FU, P = 0.523; η ² = 0.437). APT imaging can be a viable and practical tool for diagnosing heatstroke and monitoring its progression.
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Affiliation(s)
- Mingxing Han
- Department of Radiology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai
| | - Qinglong Li
- Department of Radiology, Henan Provincial Hospital of Traditional Chinese Medicine (The Second Affiliated Hospital of Henan University of Traditional Chinese Medicine), Zhengzhou, People's Republic of China
| | - Ting Yang
- Department of Radiology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai
| | - Jun Li
- Department of Radiology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai
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Chung J, Sun D, Hitchens TK, Modo M, Bandos A, Mettenburg J, Wang P, Jin T. Dual contrast CEST MRI for pH-weighted imaging in stroke. Magn Reson Med 2024; 91:357-367. [PMID: 37798945 PMCID: PMC10872804 DOI: 10.1002/mrm.29842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/30/2023] [Accepted: 08/05/2023] [Indexed: 10/07/2023]
Abstract
PURPOSE pH enhanced (pHenh ) CEST imaging combines the pH sensitivity from amide and guanidino signals, but the saturation parameters have not been optimized. We propose pHdual as a variant of pHenh that suppresses background signal variations, while enhancing pH sensitivity and potential for imaging ischemic brain injury of stroke. METHODS Simulation and in vivo rodent stroke experiments of pHenh MRI were performed with varied RF saturation powers for both amide and guanidino protons to optimize the contrast between lesion/normal tissues, while simultaneously minimizing signal variations across different types of normal tissues. In acute stroke, contrast and volume ratio measured by pHdual imaging were compared with an amide-CEST approach, and perfusion and diffusion MRI. RESULTS Simulation experiments indicated that amide and guanidino CEST signals exhibit unique sensitivities across different pH ranges, with pHenh producing greater sensitivity over a broader pH regime. The pHenh data of rodent stroke brain demonstrated that the lesion/normal tissue contrast was maximized for an RF saturation power pair of 0.5 μT at 2.0 ppm and 1.0 μT at 3.6 ppm, whereas an optimal contrast-to-variation ratio (CVR) was obtained with a 0.7 μT saturation at 2.0 ppm and 0.8 μT at 3.6 ppm. In acute stroke, CVR optimized pHenh (i.e., pHdual ) achieved a higher sensitivity than the three-point amide-CEST approach, and distinct patterns of lesion tissue compared to diffusion and perfusion MRI. CONCLUSION pHdual MRI improves the sensitivity of pH-weighted imaging and will be a valuable tool for assessing tissue viability in stroke.
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Affiliation(s)
- Julius Chung
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - T. Kevin Hitchens
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michel Modo
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andriy Bandos
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Joseph Mettenburg
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Ping Wang
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Tao Jin
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania
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