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Riederer SJ, Borisch EA, Froemming AT, Kawashima A, Takahashi N. Comparison of model-based versus deep learning-based image reconstruction for thin-slice T2-weighted spin-echo prostate MRI. Abdom Radiol (NY) 2024; 49:2921-2931. [PMID: 38520510 PMCID: PMC11300170 DOI: 10.1007/s00261-024-04256-1] [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: 01/02/2024] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 03/25/2024]
Abstract
PURPOSE To compare a previous model-based image reconstruction (MBIR) with a newly developed deep learning (DL)-based image reconstruction for providing improved signal-to-noise ratio (SNR) in high through-plane resolution (1 mm) T2-weighted spin-echo (T2SE) prostate MRI. METHODS Large-area contrast and high-contrast spatial resolution of the reconstruction methods were assessed quantitatively in experimental phantom studies. The methods were next evaluated radiologically in 17 subjects at 3.0 Tesla for whom prostate MRI was clinically indicated. For each subject, the axial T2SE raw data were directed to MBIR and to the DL reconstruction at three vendor-provided levels: (L)ow, (M)edium, and (H)igh. Thin-slice images from the four reconstructions were compared using evaluation criteria related to SNR, sharpness, contrast fidelity, and reviewer preference. Results were compared using the Wilcoxon signed-rank test using Bonferroni correction, and inter-reader comparisons were done using the Cohen and Krippendorf tests. RESULTS Baseline contrast and resolution in phantom studies were equivalent for all four reconstruction pathways as desired. In vivo, all three DL levels (L, M, H) provided improved SNR versus MBIR. For virtually, all other evaluation criteria DL L and M were superior to MBIR. DL L and M were evaluated as superior to DL H in fidelity of contrast. For 44 of the 51 evaluations, the DL M reconstruction was preferred. CONCLUSION The deep learning reconstruction method provides significant SNR improvement in thin-slice (1 mm) T2SE images of the prostate while retaining image contrast. However, if taken to too high a level (DL High), both radiological sharpness and fidelity of contrast diminish.
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Affiliation(s)
| | - Eric A Borisch
- Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | | | | | - Naoki Takahashi
- Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
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Park J, Jang M, Heier L, Limperopoulos C, Zun Z. Rapid anatomical imaging of the neonatal brain using T 2 -prepared 3D balanced steady-state free precession. Magn Reson Med 2023; 89:1456-1468. [PMID: 36420869 PMCID: PMC10208121 DOI: 10.1002/mrm.29537] [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: 07/13/2022] [Revised: 10/18/2022] [Accepted: 11/03/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE To develop a new approach to 3D gradient echo-based anatomical imaging of the neonatal brain with a substantially shorter scan time than standard 3D fast spin echo (FSE) methods, while maintaining a high SNR. METHODS T2 -prepration was employed immediately prior to image acquisition of 3D balanced steady-state free precession (bSSFP) with a single trajectory of center-out k-space view ordering, which requires no magnetization recovery time between imaging segments during the scan. This approach was compared with 3D FSE, 2D single-shot FSE, and product 3D bSSFP imaging in numerical simulations, plus phantom and in vivo experiments. RESULTS T2 -prepared 3D bSSFP generated image contrast of gray matter, white matter, and CSF very similar to that of reference T2 -weighted imaging methods, without major image artifacts. Scan time of T2 -prepared 3D bSSFP was remarkably shorter compared to 3D FSE, whereas SNR was comparable to that of 3D FSE and higher than that of 2D single-shot FSE. Specific absorption rate of T2 -prepared 3D bSSFP remained within the safety limit. Determining an optimal imaging flip angle of T2 -prepared 3D bSSFP was critical to minimizing blurring of images. CONCLUSION T2 -prepared 3D bSSFP offers an alternative method for anatomical imaging of the neonatal brain with dramatically reduced scan time compared to standard 3D FSE and higher SNR than 2D single-shot FSE.
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Affiliation(s)
- Jinho Park
- Department of Cardiology, Yonsei University, Seoul, Korea
| | - MinJung Jang
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Linda Heier
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Catherine Limperopoulos
- Developing Brain Institute, Division of Diagnostic Imaging and Radiology, Children’s National Hospital, Washington, DC, USA
- Division of Fetal and Transitional Medicine, Children’s National Hospital, Washington, DC, USA
- Department of Pediatrics, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
- Department of Radiology, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
| | - Zungho Zun
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
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Borisch EA, Froemming AT, Grimm RC, Kawashima A, Trzasko JD, Riederer SJ. Model-based image reconstruction with wavelet sparsity regularization for through-plane resolution restoration in T 2 -weighted spin-echo prostate MRI. Magn Reson Med 2023; 89:454-468. [PMID: 36093998 PMCID: PMC9617775 DOI: 10.1002/mrm.29447] [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: 06/15/2022] [Revised: 08/18/2022] [Accepted: 08/19/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE The purpose is to develop a model-based image-reconstruction method using wavelet sparsity regularization for maintaining restoration of through-plane resolution but with improved retention of SNR versus linear reconstruction using Tikhonov (TK) regularization in high through-plane resolution (1 mm) T2 -weighted spin-echo (T2SE) images of the prostate. METHODS A wavelet sparsity (WS)-regularized image reconstruction was developed that takes as input a set of ≈80 overlapped 3-mm-thick slices acquired using a T2SE multislice scan and typically 30 coil elements. After testing in contrast and resolution phantoms and calibration in 6 subjects, the WS reconstruction was evaluated in 16 consecutive prostate T2SE MRI exams. Results reconstructed with nominal 1-mm thickness were compared with those from the TK reconstruction with the same raw data. Results were evaluated radiologically. The ratio of magnitude of prostate signal to periprostatic muscle signal was used to assess the presence of noise reduction. Technical performance was also compared with a commercial 3D-T2SE sequence. RESULTS The new WS reconstruction was assessed as superior statistically to TK for overall SNR, contrast, and multiple evaluation criteria related to sharpness while retaining the high (1 mm) through-plane resolution. Wavelet sparsity tended to provide improved overall diagnostic quality versus TK, but not significantly so. In all 16 studies, the prostate-to-muscle signal ratio increased. CONCLUSIONS Model-based WS-regularized reconstruction consistently provides improved SNR in high (1 mm) through-plane resolution images of prostate T2SE MRI versus linear reconstruction using TK regularization.
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Borisch EA, Grimm RC, Kargar S, Kawashima A, Rossman PJ, Riederer SJ. Cross correlation-based misregistration correction for super resolution T 2 -weighted spin-echo images: application to prostate. Magn Reson Med 2021; 85:1350-1363. [PMID: 32970892 PMCID: PMC7718320 DOI: 10.1002/mrm.28518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/12/2020] [Accepted: 08/23/2020] [Indexed: 12/15/2022]
Abstract
PURPOSE The purpose is to develop a retrospective correction for subtle slice-to-slice positional inconsistencies that can occur when overlapped slices are acquired for super resolution in T2 -weighted spin-echo multislice imaging. METHODS Spin-echo acquisition of overlapped slices is typically done using multiple passes. After the passes are assembled into the final slice set, consecutive slices are correlated due to their overlap. Cross correlation was used to measure slice-to-slice displacement. After Z-dependent filtering to preserve true object shape, the displacements were used to correct slice position. The method was tested in a phantom moved slowly (0.16-0.63 mm/pass) under computer control and in vivo in 16 patients having prostate MRI. RESULTS Over the motion range, the correlation method had an accuracy within 0.03 mm/pass and precision ± 0.20 mm (ie, subpixel). Corrected images visually resemble the true object. Over the patient studies, the mean range of motion in the anterior-posterior direction was 1.63 mm. Motion-corrected axial images and the sagittal reformats were evaluated as significantly superior over those formed without motion correction. CONCLUSION The retrospective correlation-based motion-correction method provides significant improvement in the slice-to-slice registration necessary for effective super resolution using overlapped slices.
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Affiliation(s)
| | | | - Soudabeh Kargar
- Department of Radiology, Mayo Clinic, Rochester MN
- Department of Radiology, University of Wisconsin, Madison WI
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Vidya Shankar R, Roccia E, Cruz G, Neji R, Botnar R, Prezzi D, Goh V, Prieto C, Dregely I. Accelerated 3D T 2 w-imaging of the prostate with 1-millimeter isotropic resolution in less than 3 minutes. Magn Reson Med 2019; 82:721-731. [PMID: 31006906 PMCID: PMC6563534 DOI: 10.1002/mrm.27764] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 03/15/2019] [Accepted: 03/16/2019] [Indexed: 12/29/2022]
Abstract
PURPOSE To achieve 3D T2 w imaging of the prostate with 1-mm isotropic resolution in less than 3 min. METHODS We devised and implemented a 3D T2 -prepared multishot balanced steady state free precession (T2 prep-bSSFP) acquisition sequence with a variable density undersampled trajectory combined with a total variation regularized iterative SENSE (TV-SENSE) reconstruction. Prospectively undersampled images of the prostate (acceleration factor R = 3) were acquired in 11 healthy subjects in an institutional review board-approved study. Image quality metrics (subjective signal-to-noise ratio, contrast, sharpness, and overall prostate image quality) were evaluated by 2 radiologists. Scores of the proposed accelerated sequence were compared using the Wilcoxon signed-rank and Kruskal-Wallis non-parametric tests to prostate images acquired using a fully sampled 3D T2 prep-bSSFP acquisition, and with clinical standard 2D and 3D turbo spin echo (TSE) T2 w acquisitions. A P-value < 0.05 was considered significant. RESULTS The 3× accelerated 3D T2 prep-bSSFP images required a scan time (min:s) of 2:45, while the fully sampled 3D T2 prep-bSSFP and clinical standard 3D TSE images were acquired in 8:23 and 7:29, respectively. Image quality scores (contrast, sharpness, and overall prostate image quality) of the accelerated 3D T2 prep-bSSFP, fully sampled T2 prep-bSSFP, and clinical standard 3D TSE acquisitions along all 3 spatial dimensions were not significantly different (P > 0.05). CONCLUSION 3D T2 w images of the prostate with 1-mm isotropic resolution can be acquired in less than 3 min, with image quality that is comparable to a clinical standard 3D TSE sequence but only takes a third of the acquisition time.
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Affiliation(s)
- Rohini Vidya Shankar
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
| | - Elisa Roccia
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
| | - Gastao Cruz
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
- MR Research Collaborations, Siemens Healthcare LimitedFrimleyUnited Kingdom
| | - René Botnar
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
| | - Davide Prezzi
- Department of RadiologyGuy's and St Thomas' Hospitals NHS Foundation TrustLondonUnited Kingdom
| | - Vicky Goh
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
- Department of RadiologyGuy's and St Thomas' Hospitals NHS Foundation TrustLondonUnited Kingdom
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
| | - Isabel Dregely
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUnited Kingdom
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Soliman AS, Owrangi A, Ravi A, Song WY. Metal artefacts in MRI-guided brachytherapy of cervical cancer. J Contemp Brachytherapy 2016; 8:363-9. [PMID: 27648092 PMCID: PMC5018526 DOI: 10.5114/jcb.2016.61817] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/28/2016] [Indexed: 11/29/2022] Open
Abstract
The importance of assessing the metal-induced artefacts in magnetic resonance imaging (MRI)-guided brachytherapy is growing along with the increasing interest of integrating MRI into the treatment procedure of cervical cancer. Examples of metal objects in use include intracavitary cervical applicators and interstitial needles. The induced artefacts increase the uncertainties in the clinical workflow and can be a potential obstacle for the accurate delivery of the treatment. Overcoming this problem necessitates a good understanding of its originating sources. Several efforts are recorded in the literature to quantify the extent of such artefacts, in phantoms and in clinical practice. Here, we elaborate on the origin of metal-induced artefacts in the light of brachytherapy applications, while summarizing recent efforts that have been made to assess and overcome the induced distortions.
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Affiliation(s)
- Abraam S Soliman
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Physical Sciences Platform, Sunnybrook Research Institute, Toronto
| | - Amir Owrangi
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Ananth Ravi
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Physical Sciences Platform, Sunnybrook Research Institute, Toronto; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - William Y Song
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Physical Sciences Platform, Sunnybrook Research Institute, Toronto; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
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