1
|
Li XM, Ma FZ, Quan XY, Zhang XC, Xiao BH, Wáng YXJ. Repeatability and reproducibility comparisons of liver IVIM imaging with free-breathing or respiratory-triggered sequences. NMR Biomed 2024; 37:e5080. [PMID: 38113878 DOI: 10.1002/nbm.5080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 10/26/2023] [Accepted: 11/07/2023] [Indexed: 12/21/2023]
Abstract
For liver intravoxel incoherent motion (IVIM) data acquisition, respiratory-triggering (RT) MRI is commonly used, and there are strong motivations to shorten the scan duration. For the same scan duration, more b values or higher numbers of excitations can be allowed for free-breathing (FB) imaging than for RT. We studied whether FB can be used to replace RT when careful IVIM image acquisition and image processing are conducted. MRI data of 22 healthy participants were acquired using a 3.0 T scanner. Diffusion imaging was based on a single-shot spin-echo-type echo-planar sequence and 16 b values of 0, 2, 4, 7, 10, 15, 20, 30, 46, 60, 72, 100, 150, 200, 400, and 600 s/mm2 . Each subject attended two scan sessions with an interval of 10-20 days. For each scan session, a subject was scanned twice, first with RT and then with FB. The mean image acquisition time was 5.4 min for FB and 10.8 min for RT. IVIM parameters were calculated with bi-exponential model segmented fitting with a threshold b value of 60 s/mm2 , and fitting started from b = 2 s/mm2 . There was no statistically significant difference between IVIM parameters measured with FB imaging or RT imaging. Perfusion fraction ICC (intraclass correlation coefficient) for FB imaging and RT imaging in the same scan session was 0.824. For perfusion fraction, wSD (within-subject standard deviation), BA (Bland-Altman) difference, BA 95% limit, and ICC were 0.022, 0.0001, -0.0635~0.0637, and 0.687 for FB and 0.031, 0.0122, -0.0723~0.0967, and 0.611 for RT. For Dslow (×10-3 s/mm2 ), wSD, BA difference, BA 95% limit, and ICC were 0.057, 0.0268, -0.1258~0.1793, and 0.471 for FB and 0.073, -0.0078, -0.2170-0.2014, and <0.4 for RT. The Dfast coefficient of variation was 0.20 for FB imaging and 0.28 for RT imaging. All reproducibility indicators slightly favored FB imaging.
Collapse
Affiliation(s)
- Xin-Ming Li
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Fu-Zhao Ma
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Xian-Yue Quan
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Xu-Chang Zhang
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Ben-Heng Xiao
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Yì Xiáng J Wáng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| |
Collapse
|
2
|
Monteuuis D, Bouzerar R, Dantoing C, Poujol J, Bohbot Y, Renard C. Prospective Comparison of Free-Breathing Accelerated Cine Deep Learning Reconstruction Versus Standard Breath-Hold Cardiac MRI Sequences in Patients With Ischemic Heart Disease. AJR Am J Roentgenol 2024:1-9. [PMID: 38323784 DOI: 10.2214/ajr.23.30272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
BACKGROUND. Cine cardiac MRI sequences require repeated breath-holds, which can be difficult for patients with ischemic heart disease (IHD). OBJECTIVE. The purpose of the study was to compare a free-breathing accelerated cine sequence using deep learning (DL) reconstruction and a standard breath-hold cine sequence in terms of image quality and left ventricular (LV) measurements in patients with IHD undergoing cardiac MRI. METHODS. This prospective study included patients undergoing 1.5- or 3-T cardiac MRI for evaluation of IHD between March 15, 2023, and June 21, 2023. Examinations included an investigational free-breathing cine short-axis sequence with DL reconstruction (hereafter, cine-DL sequence). Two radiologists (reader 1 [R1] and reader 2 [R2]), in blinded fashion, independently assessed left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and subjective image quality for the cine-DL sequence and a standard breath-hold balanced SSFP sequence; R1 assessed artifacts. RESULTS. The analysis included 26 patients (mean age, 64.3 ± 11.7 [SD] years; 14 men, 12 women). Acquisition was shorter for the cine-DL sequence than the standard sequence (mean ± SD, 0.6 ± 0.1 vs 2.4 ± 0.6 minutes; p < .001). The cine-DL sequence, in comparison with the standard sequence, showed no significant difference for LVEF for R1 (mean ± SD, 51.7% ± 14.3% vs 51.3% ± 14.7%; p = .56) or R2 (53.4% ± 14.9% vs 52.8% ± 14.6%; p = .53); significantly greater LVEDV for R2 (mean ± SD, 171.9 ± 51.9 vs 160.6 ± 49.4 mL; p = .01) but not R1 (171.8 ± 53.7 vs 165.5 ± 52.4 mL; p = .16); and no significant difference in LVESV for R1 (mean ± SD, 88.1 ± 49.3 vs 86.0 ± 50.5 mL; p = .45) or R2 (85.2 ± 48.1 vs 81.3 ± 48.2 mL; p = .10). The mean bias between the cine-DL and standard sequences by LV measurement was as follows: LVEF, 0.4% for R1 and 0.7% for R2; LVEDV, 6.3 mL for R1 and 11.3 mL for R2; and LVESV, 2.1 mL for R1 and 3.9 mL for R2. Subjective image quality was better for cine-DL sequence than the standard sequence for R1 (mean ± SD, 2.3 ± 0.5 vs 1.9 ± 0.8; p = .02) and R2 (2.2 ± 0.4 vs 1.9 ± 0.7; p = .02). R1 reported no significant difference between the cine-DL and standard sequences for off-resonance artifacts (3.8% vs 23.1% examinations; p = .10) and parallel imaging artifacts (3.8% vs 19.2%; p = .19); blurring artifacts were more frequent for the cine-DL sequence than the standard sequence (42.3% vs 7.7% examinations; p = .008). CONCLUSION. A free-breathing cine-DL sequence, in comparison with a standard breath-hold cine sequence, showed very small bias for LVEF measurements and better subjective quality. The cine-DL sequence yielded greater LV volumes than the standard sequence. CLINICAL IMPACT. A free-breathing cine-DL sequence may yield reliable LVEF measurements in patients with IHD unable to repeatedly breath-hold. TRIAL REGISTRATION. ClinicalTrials.gov NCT05105984.
Collapse
Affiliation(s)
- David Monteuuis
- Department of Radiology, Amiens University Hospital, 1 Rond-Point du Professeur Christian Cabrol, Amiens 80054 Cedex 01, France
| | - Roger Bouzerar
- Biophysics and Image Processing Unit, Amiens University Hospital, Amiens, France
| | - Charlotte Dantoing
- Department of Radiology, Amiens University Hospital, 1 Rond-Point du Professeur Christian Cabrol, Amiens 80054 Cedex 01, France
| | | | - Yohann Bohbot
- Department of Cardiology, Amiens University Hospital, Amiens, France
| | - Cédric Renard
- Department of Radiology, Amiens University Hospital, 1 Rond-Point du Professeur Christian Cabrol, Amiens 80054 Cedex 01, France
| |
Collapse
|
3
|
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 2023. [PMID: 37888865 DOI: 10.1002/jmri.29099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [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.
Collapse
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
| |
Collapse
|
4
|
Fyrdahl A, Ullvin A, Ramos JG, Seiberlich N, Ugander M, Sigfridsson A. Three-dimensional sector-wise golden angle-improved k-space uniformity after electrocardiogram binning. Magn Reson Med 2023; 90:1041-1052. [PMID: 37183485 DOI: 10.1002/mrm.29698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 04/17/2023] [Accepted: 04/21/2023] [Indexed: 05/16/2023]
Abstract
PURPOSE To develop and evaluate a 3D sector-wise golden-angle (3D-SWIG) profile ordering scheme for cardiovascular MR cine imaging that maintains high k-space uniformity after electrocardiogram (ECG) binning. METHOD Cardiovascular MR (CMR) was performed at 1.5 T. A balanced SSFP pulse sequence was implemented with a novel 3D-SWIG radial ordering, where k-space was divided into wedges, and each wedge was acquired in a separate heartbeat. The high uniformity of k-space coverage after physiological binning can be used to perform functional imaging using a very short acquisition. The 3D-SWIG was compared with two commonly used 3D radial trajectories for CMR (i.e., double golden angle and spiral phyllotaxis) in numerical simulations. Free-breathing 3D-SWIG and conventional breath-held 2D cine were compared in patients (n = 17) referred clinically for CMR. Quantitative comparison was performed based on left ventricular segmentation. RESULTS Numerical simulations showed that 3D-SWIG both required smaller steps between successive readouts and achieved better k-space sampling uniformity after binning than either the double golden angle or spiral phyllotaxis trajectories. In vivo evaluation showed that measurements of left ventricular ejection fraction calculated from a 48 heart-beat free-breathing 3D-SWIG acquisition were highly reproducible and agreed with breath-held 2D-Cartesian cine (mean ± SD difference of -3.1 ± 3.5% points). CONCLUSIONS The 3D-SWIG acquisition offers a simple solution for highly improved k-space uniformity after physiological binning. The feasibility of the 3D-SWIG method is demonstrated in this study through whole-heart cine imaging during free breathing with an acquisition time of less than 1 min.
Collapse
Affiliation(s)
- Alexander Fyrdahl
- Department of Clinical Physiology, Karolinska University Hospital, and Karolinska Institutet, Stockholm, Sweden
| | - Amanda Ullvin
- Department of Clinical Physiology, Karolinska University Hospital, and Karolinska Institutet, Stockholm, Sweden
| | - Joao G Ramos
- Department of Clinical Physiology, Karolinska University Hospital, and Karolinska Institutet, Stockholm, Sweden
| | - Nicole Seiberlich
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Martin Ugander
- Department of Clinical Physiology, Karolinska University Hospital, and Karolinska Institutet, Stockholm, Sweden
- The Kolling Institute, Royal North Shore Hospital, and University of Sydney, Sydney, Australia
| | - Andreas Sigfridsson
- Department of Clinical Physiology, Karolinska University Hospital, and Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
5
|
Cruz G, Hua A, Munoz C, Ismail TF, Chiribiri A, Botnar RM, Prieto C. Low-rank motion correction for accelerated free-breathing first-pass myocardial perfusion imaging. Magn Reson Med 2023; 90:64-78. [PMID: 36861454 PMCID: PMC10952238 DOI: 10.1002/mrm.29626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 12/29/2022] [Accepted: 02/10/2023] [Indexed: 03/03/2023]
Abstract
PURPOSE Develop a novel approach for accelerated 2D free-breathing myocardial perfusion via low-rank motion-corrected (LRMC) reconstructions. METHODS Myocardial perfusion imaging requires high spatial and temporal resolution, despite scan time constraints. Here, we incorporate LRMC models into the reconstruction-encoding operator, together with high-dimensionality patch-based regularization, to produce high quality, motion-corrected myocardial perfusion series from free-breathing acquisitions. The proposed framework estimates beat-to-beat nonrigid respiratory (and any other incidental) motion and the dynamic contrast subspace from the actual acquired data, which are then incorporated into the proposed LRMC reconstruction. LRMC was compared with iterative SENSitivity Encoding (SENSE) (itSENSE) and low-rank plus sparse (LpS) reconstruction in 10 patients based on image-quality scoring and ranking by two clinical expert readers. RESULTS LRMC achieved significantly improved results relative to itSENSE and LpS in terms of image sharpness, temporal coefficient of variation, and expert reader evaluation. Left ventricle image sharpness was approximately 75%, 79%, and 86% for itSENSE, LpS and LRMC, respectively, indicating improved image sharpness for the proposed approach. Corresponding temporal coefficient of variation results were 23%, 11% and 7%, demonstrating improved temporal fidelity of the perfusion signal with the proposed LRMC. Corresponding clinical expert reader scores (1-5, from poor to excellent image quality) were 3.3, 3.9 and 4.9, demonstrating improved image quality with the proposed LRMC, in agreement with the automated metrics. CONCLUSION LRMC produces motion-corrected myocardial perfusion in free-breathing acquisitions with substantially improved image quality when compared with iterative SENSE and LpS reconstructions.
Collapse
Affiliation(s)
- Gastao Cruz
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Alina Hua
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Camila Munoz
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Tevfik Fehmi Ismail
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Amedeo Chiribiri
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - René Michael Botnar
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
- Escuela de Ingeniería, Pontificia Universidad Católica de ChileSantiagoChile
- Millenium Institute for Intelligent Healthcare Engineering iHEALTHSantiagoChile
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
- Escuela de Ingeniería, Pontificia Universidad Católica de ChileSantiagoChile
- Millenium Institute for Intelligent Healthcare Engineering iHEALTHSantiagoChile
| |
Collapse
|
6
|
Katano A, Noyama T, Morishima K, Nozawa Y, Yamashita H. Dosimetric Comparison Study Between Free Breathing and Breath Hold Techniques in Patients Treated by Liver-Directed Stereotactic Body Radiation Therapy. Cureus 2023; 15:e40382. [PMID: 37456453 PMCID: PMC10344598 DOI: 10.7759/cureus.40382] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/18/2023] Open
Abstract
Background Breathing motion management is the key to delivering stereotactic body radiation therapy (SBRT) for liver lesions. This study aimed to compare the dosimetric parameters of liver SBRT using two different techniques: free breathing and breath hold. Method The study included 11 patients with liver metastases or hepatocellular carcinoma who underwent liver-directed SBRT. A dosimetric comparison was performed using dose-volume histogram analysis, evaluating parameters such as the maximum dose to 5 cc of bowel volume, mean liver dose (MLD), and liver V20 and V30. Statistical analyses were performed to compare results. Results The findings revealed that the breath hold technique resulted in significantly lower doses to the bowel and smaller volumes of normal liver tissue receiving 20 Gy (V20) and 30 Gy (V30) than the free breathing. Although there was no statistically significant difference in the MLD between the two techniques, the breath hold technique resulted in a lower MLD. Conclusion This dosimetric comparison study suggests that the breath hold technique is associated with lower radiation exposure to the bowel and normal liver tissues. Although this may not be feasible for all patients, it may be an appropriate procedure for selected individuals. Further research is needed to validate these findings in different patient populations and explore their impact on clinical outcomes and patient-reported quality of life.
Collapse
Affiliation(s)
- Atsuto Katano
- Radiology, The University of Tokyo Hospital, Tokyo, JPN
| | | | | | - Yuki Nozawa
- Radiology, The University of Tokyo Hospital, Tokyo, JPN
| | | |
Collapse
|
7
|
Chung SH, Huynh KM, Goralski JL, Chen Y, Yap PT, Ceppe AS, Powell MZ, Donaldson SH, Lee YZ. Feasibility of free-breathing 19 F MRI image acquisition to characterize ventilation defects in CF and healthy volunteers at wash-in. Magn Reson Med 2023; 90:79-89. [PMID: 36912481 PMCID: PMC10149612 DOI: 10.1002/mrm.29630] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 01/27/2023] [Accepted: 02/15/2023] [Indexed: 03/14/2023]
Abstract
PURPOSE To explore the feasibility of measuring ventilation defect percentage (VDP) using 19 F MRI during free-breathing wash-in of fluorinated gas mixture with postacquisition denoising and to compare these results with those obtained through traditional Cartesian breath-hold acquisitions. METHODS Eight adults with cystic fibrosis and 5 healthy volunteers completed a single MR session on a Siemens 3T Prisma. 1 H Ultrashort-TE MRI sequences were used for registration and masking, and ventilation images with 19 F MRI were obtained while the subjects breathed a normoxic mixture of 79% perfluoropropane and 21% oxygen (O2 ). 19 F MRI was performed during breath holds and while free breathing with one overlapping spiral scan at breath hold for VDP value comparison. The 19 F spiral data were denoised using a low-rank matrix recovery approach. RESULTS VDP measured using 19 F VIBE and 19 F spiral images were highly correlated (r = 0.84) at 10 wash-in breaths. Second-breath VDPs were also highly correlated (r = 0.88). Denoising greatly increased SNR (pre-denoising spiral SNR, 2.46 ± 0.21; post-denoising spiral SNR, 33.91 ± 6.12; and breath-hold SNR, 17.52 ± 2.08). CONCLUSION Free-breathing 19 F lung MRI VDP analysis was feasible and highly correlated with breath-hold measurements. Free-breathing methods are expected to increase patient comfort and extend ventilation MRI use to patients who are unable to perform breath holds, including younger subjects and those with more severe lung disease.
Collapse
Affiliation(s)
- Sang Hun Chung
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Khoi Minh Huynh
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jennifer L Goralski
- Division of Pulmonary and Critical Care Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Marsico Lung Institute/UNC Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Division of Pediatric Pulmonology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yong Chen
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Pew-Thian Yap
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Agathe S Ceppe
- Division of Pulmonary and Critical Care Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Marsico Lung Institute/UNC Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Margret Z Powell
- Marsico Lung Institute/UNC Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Scott H Donaldson
- Division of Pulmonary and Critical Care Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Marsico Lung Institute/UNC Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yueh Z Lee
- Division of Pulmonary and Critical Care Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
8
|
Xu X, Hu J, Zheng Y, Liu Y, Cui Z, Liang D, Zhu Y. Slice-specific tracking for free-breathing diffusion tensor cardiac MRI. NMR Biomed 2023:e4922. [PMID: 36914257 DOI: 10.1002/nbm.4922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Diffusion tensor cardiac magnetic resonance (DT-CMR) imaging has great potential to characterize myocardial microarchitecture. However, its accuracy is limited by respiratory and cardiac motion and long scan times. Here, we develop and evaluate a slice-specific tracking method to improve the efficiency and accuracy of DT-CMR acquisition during free breathing. METHODS Coronal images were obtained along with signals from a diaphragmatic navigator. Respiratory and slice displacements were obtained from the navigator signals and coronal images, respectively, and these displacements were fitted with a linear model to obtain the slice-specific tracking factors. This method was evaluated in DT-CMR examinations of 17 healthy subjects, and the results were compared with those obtained using a fixed tracking factor of 0.6. DT-CMR with breath-holding was used for reference. Quantitative and qualitative evaluation methods were used to analyze the performance of the slice-specific tracking method and the consistency between the obtained diffusion parameters. RESULTS In the study, the slice-specific tracking factors showed an upward trend from the basal to the apical slice. Residual in-plane movements were lower in slice-specific tracking than in fixed-factor tracking (RMSE: 2.748 ± 1.171 versus 5.983 ± 2.623, P < 0.001). The diffusion parameters obtained using slice-specific tracking were not significantly different from those obtained from breath-holding acquisition (P > 0.05). CONCLUSION In free-breathing DT-CMR imaging, the slice-specific tracking method reduced misalignment of the acquired slices. The diffusion parameters obtained using this approach were consistent with those obtained with the breath-holding technique.
Collapse
Affiliation(s)
- Xi Xu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
| | - Junpu Hu
- United Imaging Healthcare, Shanghai, China
| | - Yijia Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yuanyuan Liu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Zhuoxu Cui
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Dong Liang
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
- Research Center for Medical AI, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yanjie Zhu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| |
Collapse
|
9
|
Jafari R, Do RKG, LaGratta MD, Fung M, Bayram E, Cashen T, Otazo R. GRASPNET: Fast spatiotemporal deep learning reconstruction of golden-angle radial data for free-breathing dynamic contrast-enhanced magnetic resonance imaging. NMR Biomed 2023; 36:e4861. [PMID: 36305619 PMCID: PMC9898111 DOI: 10.1002/nbm.4861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 10/23/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
The purpose of the current study was to develop a deep learning technique called Golden-angle RAdial Sparse Parallel Network (GRASPnet) for fast reconstruction of dynamic contrast-enhanced 4D MRI acquired with golden-angle radial k-space trajectories. GRASPnet operates in the image-time space and does not use explicit data consistency to minimize the reconstruction time. Three different network architectures were developed: (1) GRASPnet-2D: 2D convolutional kernels (x,y) and coil and contrast dimensions collapsed into a single combined dimension; (2) GRASPnet-3D: 3D kernels (x,y,t); and (3) GRASPnet-2D + time: two 3D kernels to first exploit spatial correlations (x,y,1) followed by temporal correlations (1,1,t). The networks were trained using iterative GRASP reconstruction as the reference. Free-breathing 3D abdominal imaging with contrast injection was performed on 33 patients with liver lesions using a T1-weighted golden-angle stack-of-stars pulse sequence. Ten datasets were used for testing. The three GRASPnet architectures were compared with iterative GRASP results using quantitative and qualitative analysis, including impressions from two body radiologists. The three GRASPnet techniques reduced the reconstruction time to about 13 s with similar results with respect to iterative GRASP. Among the GRASPnet techniques, GRASPnet-2D + time compared favorably in the quantitative analysis. Spatiotemporal deep learning enables reconstruction of dynamic 4D contrast-enhanced images in a few seconds, which would facilitate translation to clinical practice of compressed sensing methods that are currently limited by long reconstruction times.
Collapse
Affiliation(s)
- Ramin Jafari
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
| | | | | | | | | | | | - Ricardo Otazo
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY
| |
Collapse
|
10
|
Shahzadeh S, Barough MS, Ganjoorian H, Gholami S. Comparison of normal tissue doses in deep inspiration breath-hold and free breathing methods for radiotherapy of left-sided breast cancer using 4D-XCAT digital phantom. J Cancer Res Ther 2022; 18:S335-S340. [PMID: 36510985 DOI: 10.4103/jcrt.jcrt_1681_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Purpose To evaluate normal lung and heart tissue doses for treatment of left-sided breast cancer in deep inspiration breath-hold (DIBH) and free breathing (FB) as a function of breast size and diaphragm displacement using 4D-XCAT digital phantom in a simulation study. Materials and Methods 4D-XCAT digital phantom was used to create 36 left-sided breast cancer digital phantom datasets with different breast height (BH) of 40, 50, and 60 mm, breast length (BL) of 16, 17, and 18 mm, and diaphragm excursion of 20, 25, 30, and 35 mm. For each dataset, DIBH and FB treatment plans were prepared using planning computerized radiotherapy-three dimensional (PCRT-3D) treatment planning system (TPS) with superposition computational algorithm. Dose differences in DIBH and FB plans were assessed in terms of mean lung dose (MLD), the lung volume receiving ≤20 Gy (V20), normal tissue complication probability (NTCP) of the lung, mean heart dose (MHD), and the heart volume receiving ≤30 (V30). Results DIBH reduced mean dose and V20 and NTCP of the lung in all cases, by up to 4.37 Gy, 7.62%, and 18.95%. Mean dose and V30 of the heart were also significantly reduced by 5.02 Gy and 8.23%. Conclusions The use of DIBH for left-sided breast cancer radiotherapy offers excellent possibilities for sparing critical normal tissue without compromising radiation dose to the target.
Collapse
Affiliation(s)
- Sara Shahzadeh
- Department of Medical Radiation Engineering, Shahid Beheshti University, Tehran, Iran
| | - Mehdi Salehi Barough
- Department of Medical Radiation Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Hamed Ganjoorian
- Department of Medical Radiation Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Somayeh Gholami
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| |
Collapse
|
11
|
Mørkeset ST, Lervåg C, Lund JÅ, Jensen C. Clinical experience of volumetric-modulated flattening filter free stereotactic body radiation therapy of lesions in the lung with deep inspiration breath-hold. J Appl Clin Med Phys 2022; 23:e13733. [PMID: 35867387 PMCID: PMC9512343 DOI: 10.1002/acm2.13733] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 05/19/2022] [Accepted: 06/23/2022] [Indexed: 11/05/2022] Open
Abstract
This clinical study aimed to evaluate lung cancer patients' ability to perform deep inspiration breath-hold (DIBH) during CT simulation and throughout the treatment course of stereotactic body radiation therapy (SBRT). In addition, target sizes, organ at risk (OAR) sizes, and doses to the respective volumes in filter-free volumetric-modulated arc therapy plans performed under free-breathing (FB) and DIBH conditions were evaluated. Twenty-one patients with peripheral lesions were included, of which 13 were eligible for SBRT. All patients underwent training for breath-hold during CT, and if they complied with the requirements, two CT scans were obtained: CT scan in DIBH and a four-dimensional CT scan in FB. The treatment plans in FB and DIBH were generated, and the dose parameters and volume sizes were compared. The endpoints for evaluation were patient compliance, target dose coverage, and doses to the OARs. This clinical study showed high patient DIBH compliance during both CT simulation and treatment for patients with lung cancer. A significant reduction in target volumes was achieved with SBRT in DIBH, in addition to significantly decreased doses to the heart, chest wall, and lungs. DIBH in SBRT of lung lesions is feasible, and a routine to manage intra-fractional deviation should be established upon implementation.
Collapse
Affiliation(s)
- Siri T Mørkeset
- Department of Oncology and Rehabilitation, Møre and Romsdal Hospital Trust, Ålesund Hospital, Ålesund, Norway
| | - Christoffer Lervåg
- Department of Oncology and Rehabilitation, Møre and Romsdal Hospital Trust, Ålesund Hospital, Ålesund, Norway
| | - Jo-Åsmund Lund
- Department of Oncology and Rehabilitation, Møre and Romsdal Hospital Trust, Ålesund Hospital, Ålesund, Norway.,Department of Health Sciences in Ålesund, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Ålesund, Norway
| | - Christer Jensen
- Department of Health Sciences in Ålesund, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Ålesund, Norway.,Department of Medicine and Healthcare, Møre and Romsdal Hospital Trust, Ålesund Hospital, Ålesund, Norway
| |
Collapse
|
12
|
Rohani SC, Morin CE, Zhong X, Kannengiesser S, Shrestha U, Goode C, Holtrop J, Khan A, Loeffler RB, Hankins JS, Hillenbrand CM, Tipirneni-Sajja A. Hepatic Iron Quantification Using a Free-Breathing 3D Radial Gradient Echo Technique and Validation With a 2D Biopsy-Calibrated R 2* Relaxometry Method. J Magn Reson Imaging 2022; 55:1407-1416. [PMID: 34545639 PMCID: PMC10424632 DOI: 10.1002/jmri.27921] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Hepatic iron content (HIC) is an important parameter for the management of iron overload. Non-invasive HIC assessment is often performed using biopsy-calibrated two-dimensional breath-hold Cartesian gradient echo (2D BH GRE) R2* -MRI. However, breath-holding is not possible in most pediatric patients or those with respiratory problems, and three-dimensional free-breathing radial GRE (3D FB rGRE) has emerged as a viable alternative. PURPOSE To evaluate the performance of a 3D FB rGRE and validate its R2* and fat fraction (FF) quantification with 3D breath-hold Cartesian GRE (3D BH cGRE) and biopsy-calibrated 2D BH GRE across a wide range of HICs. STUDY TYPE Retrospective. SUBJECTS Twenty-nine patients with hepatic iron overload (22 females, median age: 15 [5-25] years). FIELD STRENGTH/SEQUENCE Three-dimensional radial and 2D and 3D Cartesian multi-echo GRE at 1.5 T. ASSESSMENT R2* and FF maps were computed for 3D GREs using a multi-spectral fat model and 2D GRE R2* maps were calculated using a mono-exponential model. Mean R2* and FF values were calculated via whole-liver contouring and T2* -thresholding by three operators. STATISTICAL TESTS Inter- and intra-observer reproducibility was assessed using Bland-Altman and intraclass correlation coefficient (ICC). Linear regression and Bland-Altman analysis were performed to compare R2* and FF values among the three acquisitions. One-way repeated-measures ANOVA and Wilcoxon signed-rank tests, respectively, were used to test for significant differences between R2* and FF values obtained with different acquisitions. Statistical significance was assumed at P < 0.05. RESULTS The mean biases and ICC for inter- and intra-observer reproducibility were close to 0% and >0.99, respectively for both R2* and FF. The 3D FB rGRE R2* and FF values were not significantly different (P > 0.44) and highly correlated (R2 ≥ 0.98) with breath-hold Cartesian GREs, with mean biases ≤ ±2.5% and slopes 0.90-1.12. In non-breath-holding patients, Cartesian GREs showed motion artifacts, whereas 3D FB rGRE exhibited only minimal streaking artifacts. DATA CONCLUSION Free-breathing 3D radial GRE is a viable alternative in non-breath-hold patients for accurate HIC estimation. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 2.
Collapse
Affiliation(s)
- Shawyon Chase Rohani
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Cara E. Morin
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Xiaodong Zhong
- MR R&D Collaborations, Siemens Medical Solutions USA, Inc., Los Angeles, CA, USA
| | | | - Utsav Shrestha
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA
| | - Chris Goode
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Joseph Holtrop
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Ayaz Khan
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Ralf B. Loeffler
- Research Imaging NSW, University of New South Wales, Sydney, Australia
| | - Jane S. Hankins
- Department of Hematology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | | | - Aaryani Tipirneni-Sajja
- Department of Biomedical Engineering, The University of Memphis, Memphis, TN, USA
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN, USA
| |
Collapse
|
13
|
Ding Z, Cheng Z, She H, Liu B, Yin Y, Du YP. Dynamic pulmonary MRI using motion-state weighted motion-compensation (MostMoCo) reconstruction with ultrashort TE: A structural and functional study. Magn Reson Med 2022; 88:224-238. [PMID: 35388914 DOI: 10.1002/mrm.29204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/24/2021] [Accepted: 02/01/2022] [Indexed: 11/11/2022]
Abstract
PURPOSE To improve the quality of structural images and the quantification of ventilation in free-breathing dynamic pulmonary MRI. METHODS A 3D radial ultrashort TE (UTE) sequence with superior-inferior navigators was used to acquire pulmonary data during free breathing. All acquired data were binned into different motion states according to the respiratory signal extracted from superior-inferior navigators. Motion-resolved images were reconstructed using eXtra-Dimensional (XD) UTE reconstruction. The initial motion fields were generated by registering images at each motion state to other motion states in motion-resolved images. A motion-state weighted motion-compensation (MostMoCo) reconstruction algorithm was proposed to reconstruct the dynamic UTE images. This technique, termed as MostMoCo-UTE, was compared with XD-UTE and iterative motion-compensation (iMoCo) on a porcine lung and 10 subjects. RESULTS MostMoCo reconstruction provides higher peak SNR (37.0 vs. 35.4 and 34.2) and structural similarity (0.964 vs. 0.931 and 0.947) compared to XD-UTE and iMoCo in the porcine lung experiment. Higher apparent SNR and contrast-to-noise ratio are achieved using MostMoCo in the human experiment. MostMoCo reconstruction better preserves the temporal variations of signal intensity of parenchyma compared to iMoCo, shows reduced random noise and improved sharpness of anatomical structures compared to XD-UTE. In the porcine lung experiment, the quantification of ventilation using MostMoCo images is more accurate than that using XD-UTE and iMoCo images. CONCLUSION The proposed MostMoCo-UTE provides improved quality of structural images and quantification of ventilation for free-breathing pulmonary MRI. It has the potential for the detection of structural and functional disorders of the lung in clinical settings.
Collapse
Affiliation(s)
- Zekang Ding
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.,Central Research Institute, United Imaging Healthcare, Shanghai, China
| | - Zenghui Cheng
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China
| | - Huajun She
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Bei Liu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yongfang Yin
- Department of Radiology, People's Hospital of Jilin Province, Changchun, China
| | - Yiping P Du
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
14
|
Yatsushiro S, Sunohara S, Matsumae M, Atsumi H, Horie T, Kajihara N, Kuroda K. Evaluation of Cardiac- and Respiratory-driven Cerebrospinal Fluid Motions by Applying the S-transform to Steady-state Free Precession Phase Contrast Imaging. Magn Reson Med Sci 2022; 21:372-379. [PMID: 35173115 DOI: 10.2463/mrms.mp.2021-0126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To extract the status of hydrocephalus and other cerebrospinal fluid (CSF)-related diseases, a technique to characterize the cardiac- and respiratory-driven CSF motions separately under free breathing was developed. This technique is based on steady-state free precession phase contrast (SSFP-PC) imaging in combination with a Stockwell transform (S-transform). METHODS 2D SSFP-PC at 3 T was applied to measure the CSF velocity in the caudal-cranial direction within a sagittal slice at the midline (N = 3) under 6-, 10-, and 16-s respiratory cycles and free breathing. The frequency-dependent window width of the S-transform was controlled by a particular scaling factor, which then converted the CSF velocity waveform into a spectrogram. Based on the frequency bands of the cardiac pulsation and respiration, as determined by the electrocardiogram (ECG) and respirator pressure sensors, Gaussian bandpass filters were applied to the CSF spectrogram to extract the time-domain cardiac- and respiratory-driven waveforms. RESULTS The cardiac-driven CSF velocity component appeared in the spectrogram clearly under all respiratory conditions. The respiratory-driven velocity under the controlled respiratory cycles was observed as constant frequency signals, compared to a time-varying frequency signal under free breathing. When the widow width was optimized using the scale factor, the temporal change in the respiratory-driven CSF component was even more apparent under free breathing. CONCLUSION Velocity amplitude variations and transient frequency changes of both cardiac- and respiratory-driven components were successfully characterized. These findings indicated that the proposed technique is useful for evaluating CSF motions driven by different cyclic forces.
Collapse
Affiliation(s)
- Satoshi Yatsushiro
- Department of Human and Information Science, School of Information Science and Technology, Tokai University.,BioView, Inc
| | | | | | - Hideki Atsumi
- Department of Neurosurgery, School of Medicine, Tokai University
| | - Tomohiko Horie
- Department of Radiological Technology, Tokai University Hospital
| | - Nao Kajihara
- Department of Radiological Technology, Tokai University Hospital
| | - Kagayaki Kuroda
- Department of Human and Information Science, School of Information Science and Technology, Tokai University
| |
Collapse
|
15
|
Thaper D, Yadav HP, Sharma D, Kamal R, Singh G, Oinam AS, Kumar V. Degree of reduction in normal liver complication probability from free-breathing to breath-hold liver SBRT: a dose-escalation strategy using radiation dose-volume effect. Biomed Phys Eng Express 2021; 8. [PMID: 34874286 DOI: 10.1088/2057-1976/ac3fe5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/03/2021] [Indexed: 11/12/2022]
Abstract
Introduction. This study aimed to analyze the degree of reduction in normal liver complication probability (NTCP) from free-breathing (FB) to breath-hold (BH) liver SBRT. The effect of the radiation dose-volume on the mean liver dose (MLD) was also analyzed due to dose prescription, normal liver volume (NLV), and PTV.Materials and Methods. Thirty-three stereotactic body radiation therapy (SBRT) cases of hepatocellular carcinoma were selected, retrospectively. For FB, the treatments were planned on average intensity projection scan (CTavg), and patient-specific internal target volume (ITV) margins were applied. To simulate the BH treatment, computed tomography (CT) scan correspond to the 40%-50% of the respiratory cycle (CT40%-50%) was chosen, and an appropriate intrafraction margin of 2 mm, 1.5 mm, and 1.5 mm were given in craniocaudal (CC), superior-inferior (SI), and lateral direction to generate the final iGTV. As per RTOG 1112, all organs at risk (OAR's) were considered during the optimization of treatment plans. NTCP was calculated using LKB fractionated model. Multivariate regression analysis was performed to see the effect of EQD2Gy, NLV, and PTV on MLD2Gy.Results.A significant dosimetric difference was observed in the normal liver (liver-ITV/iGTV). A reduction of 1.7% in NTCP was observed from FB to BH technique. The leverage of dose escalation is more in BH because MLD2Gycorresponds to 5%, 10%, 20%, and 50% NTCP was 0.099 Gy, 0.41 Gy, 1.21 Gy, and 3.432 Gy more in BH as compared to FB technique. In MVRA, the major factor which was attributed to a change in MLD2Gyis EQD2Gy. Conclusion. From FB to BH technique, a significant reduction in NTCP was observed. The dose prescription is a major factor attributed to the change in MLD2Gy. Advances in knowledge: If feasible, prefer BH treatment either for tumor dose escalation or for the reduction in NTCP.
Collapse
Affiliation(s)
- Deepak Thaper
- Centre for Medical Physics, Panjab University, Chandigarh, India.,Radiation Oncology Department, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Hanuman P Yadav
- Radiation Oncology Department, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Deepti Sharma
- Radiation Oncology Department, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Rose Kamal
- Centre for Medical Physics, Panjab University, Chandigarh, India.,Radiation Oncology Department, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Gaganpreet Singh
- Centre for Medical Physics, Panjab University, Chandigarh, India.,Radiotherapy Department, PGIMER, Regional Cancer Centre, Chandigarh, India
| | - Arun S Oinam
- Radiotherapy Department, PGIMER, Regional Cancer Centre, Chandigarh, India
| | - Vivek Kumar
- Centre for Medical Physics, Panjab University, Chandigarh, India
| |
Collapse
|
16
|
Choi ES, Kim JS, Nickel MD, Sung JK, Lee JK. Free-breathing contrast-enhanced multiphase MRI of the liver in patients with a high risk of breath-holding failure: comparison of compressed sensing-accelerated radial and Cartesian acquisition techniques. Acta Radiol 2021; 63:1453-1462. [PMID: 34839679 DOI: 10.1177/02841851211052988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Knowing the advantages and disadvantages of each magnetic resonance (MR) technique, would allow us to choose a sequence better suited in patients with a high risk of breath-holding failure. PURPOSE To compare the image quality of free-breathing contrast-enhanced multiphase MR imaging (MRI) using incoherent Cartesian k-space sampling combined with a motion-resolved compressed sensing reconstruction (XD-VIBE) and Golden-Angle Radial Sparse Parallel MRI (GRASP). MATERIAL AND METHODS A total of 67 patients were included. Overall image quality, motion artifacts, and liver edge sharpness on arterial and portal-venous phase were evaluated by two radiologists. We evaluated the signal intensity ratio between liver in the late arterial phase to aorta at peak enhancement and the detection rate of hypervascular lesions. RESULTS Overall image quality, artifact, and liver edge sharpness scores of XD-VIBE and GRASP were not significantly different (P = 0.070-0.397). Four (reviewer 1, 12.1%) and seven patients (reviewer 2, 21.2%) received non-diagnostic quality in the XD-VIBE group whereas one patient (reviewer 2, 2.9%) received non-diagnostic quality in the GRASP group. The ratio between the aorta and liver signal for GRASP was significantly higher than that of XD-VIBE (0.32 ± 0.10 vs. 0.47 ± 0.13; P < 0.001). The hypervascular lesion detection rate of XD-VIBE (86.7%) was higher than that of GRASP (57.1%) in the arterial phase without a statistically significant difference (P = 0.081). CONCLUSION Overall image quality of XD-VIBE and GRASP were not significantly different. More XD-VIBE examinations were rated non-diagnostic. On the other hand, the relative liver parenchymal enhancement to the aorta in the late arterial phase of GRASP was higher than that of XD-VIBE, which potentially leads to lower detectability of hypervascular lesions on arterial phase images.
Collapse
Affiliation(s)
- Eun Sun Choi
- Department of Radiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Jin Sil Kim
- Department of Radiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | | | - Jae Kon Sung
- Siemens Healthineers Ltd, Seoul, Republic of Korea
| | - Jeong Kyong Lee
- Department of Radiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| |
Collapse
|
17
|
Sclocco R, Nguyen C, Staley R, Fisher H, Mendez A, Velez C, Kettner NW, Kuo B, Napadow V. Non-uniform gastric wall kinematics revealed by 4D Cine magnetic resonance imaging in humans. Neurogastroenterol Motil 2021; 33:e14146. [PMID: 33797166 DOI: 10.1111/nmo.14146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 02/24/2021] [Accepted: 03/16/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Assessment of gastric function in humans has relied on modalities with varying degrees of invasiveness, which are usually limited to the evaluation of single aspects of gastric function, thus requiring patients to undergo a number of often invasive tests for a full clinical understanding. Therefore, the development of a non-invasive tool able to concurrently assess multiple aspects of gastric function is highly desirable for both research and clinical assessments of gastrointestinal (GI) function. Recently, technological advances in magnetic resonance imaging (MRI) have provided new tools for dynamic (or "cine") body imaging. Such approaches can be extended to GI applications. METHODS In the present work, we propose a non-invasive assessment of gastric function using a four-dimensional (4D, volumetric cine imaging), free-breathing MRI sequence with gadolinium-free contrast enhancement achieved through a food-based meal. In healthy subjects, we successfully estimated multiple parameters describing gastric emptying, motility, and peristalsis propagation patterns. KEY RESULTS Our data demonstrated non-uniform kinematics of the gastric wall during peristaltic contraction, highlighting the importance of using volumetric data to derive motility measures. CONCLUSIONS & INFERENCES MRI has the potential of becoming an important clinical and gastric physiology research tool, providing objective parameters for the evaluation of impaired gastric function.
Collapse
Affiliation(s)
- Roberta Sclocco
- Department of Radiology, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Gastroenterology, Harvard Medical School, Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA, USA.,Department of Radiology, Logan University, Chesterfield, MO, USA
| | - Christopher Nguyen
- Department of Radiology, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.,Harvard Medical School, Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Rowan Staley
- Department of Radiology, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Gastroenterology, Harvard Medical School, Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA, USA
| | - Harrison Fisher
- Department of Radiology, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - April Mendez
- Department of Gastroenterology, Harvard Medical School, Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA, USA
| | - Christopher Velez
- Department of Gastroenterology, Harvard Medical School, Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA, USA
| | - Norman W Kettner
- Department of Radiology, Logan University, Chesterfield, MO, USA
| | - Braden Kuo
- Department of Gastroenterology, Harvard Medical School, Center for Neurointestinal Health, Massachusetts General Hospital, Boston, MA, USA
| | - Vitaly Napadow
- Department of Radiology, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Radiology, Logan University, Chesterfield, MO, USA
| |
Collapse
|
18
|
Jensen CA, Funderud M, Lervåg C. Free breathing VMAT versus deep inspiration breath-hold 3D conformal radiation therapy for early stage left-sided breast cancer. J Appl Clin Med Phys 2021; 22:44-51. [PMID: 33638600 PMCID: PMC8035549 DOI: 10.1002/acm2.13208] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 12/15/2020] [Accepted: 02/01/2021] [Indexed: 12/25/2022] Open
Abstract
The purpose of the in silico study was to compare free breathing volumetric modulated arc therapy (VMAT) to standard deep inspiration breath‐hold (DIBH) three‐dimensional conformal radiotherapy (3DCRT) and determine whether the former is a viable option for elderly patients with left‐sided early stage breast cancer. Data from 22 patients with early‐stage left breast carcinoma requiring breast‐only radiation therapy were used for this planning study. The robustness of VMAT plans when using the free breathing method was compared to that of standard 3DCRT plans using the DIBH method. The endpoints for evaluation were the target dose coverage as well as doses to the organs‐at‐risk. The free breathing VMAT plans produced a significantly higher mean dose to the heart and right breast than the DIBH‐3DCRT plans. Free breathing VMAT plans resulted in significantly better target coverage than did 3DCRT using DIBH. The external volume that received more than 40 Gy was significantly smaller in the VMAT plans. Free breathing VMAT is a viable alternative to DIBH 3DCRT in elderly patients with a limited life expectancy and in subjects who are unable to perform DIBH. The choice of treatment should be individualized, and all relevant risks ought to be considered.
Collapse
Affiliation(s)
- Christer A Jensen
- Department of Medicine and Healthcare, Møre & Romsdal Hospital Trust, Ålesund Hospital, Ålesund, Norway.,Department of Health Sciences in Ålesund, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Ålesund, Norway
| | - Marit Funderud
- Department of Oncology, Møre & Romsdal Hospital Trust, Ålesund Hospital, Ålesund, Norway
| | - Christoffer Lervåg
- Department of Oncology, Møre & Romsdal Hospital Trust, Ålesund Hospital, Ålesund, Norway
| |
Collapse
|
19
|
Kim K, Lee J, So J, Jang YS, Jung M, Kang K, Choi M, Yoon J. Feasibility and Reliability of Two-Dimensional Shear-Wave Elastography of the Liver of Clinically Healthy Cats. Front Vet Sci 2020; 7:614750. [PMID: 33426033 PMCID: PMC7785986 DOI: 10.3389/fvets.2020.614750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/20/2020] [Indexed: 12/26/2022] Open
Abstract
Given the broad overlap of normal and abnormal liver tissue in the subjective evaluation of the liver in conventional B-mode ultrasonography, there is a need for a non-invasive and quantitative method for the diagnosis of liver disease. Novel two-dimensional shear-wave elastography (2-D SWE) can measure tissue stiffness by propagation of the shear wave induced using acoustic radiation force impulse in real time. To the best of our knowledge, two-dimensional shear-wave measurement of the liver in cats has not been reported to date. This study assessed the feasibility, reliability, normal values, and related influencing factors of 2-D SWE for assessment of the feline liver without anesthesia and breath-holding. Two-dimensional shear-wave ultrasonography was performed by two evaluators at the right and left sides of the liver. Twenty-nine client-owned clinically healthy adult cats were included. The means and standard deviations for the shear-wave speed and stiffness in the right liver were 1.52 ± 0.13 m/s and 6.94 ± 1.26 kPa, respectively, and those for the left liver were 1.61 ± 0.15 m/s and 7.90 ± 1.47 kPa, respectively. Shear-wave speed (P = 0.005) and stiffness (P = 0.002) were significantly lower in the right liver when compared to the left. The intraclass correlation value for liver stiffness was 0.835 and 0.901 for the right and left liver, respectively, indicating high interobserver agreement. Age, weight, body condition score (BCS), gabapentin administration, and measurement depths were not significantly correlated with liver stiffness or elastography measurements (P > 0.05). Our findings suggest that 2-D SWE measurements of the liver are not influenced significantly by age, weight, or BCS and can be reliably performed without anesthesia and breath-holding in cats. The values determined here can help form the basis for reference elastography values for evaluation of the feline liver.
Collapse
Affiliation(s)
- Kyeonga Kim
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Jieun Lee
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Jaebeom So
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Yong-Seok Jang
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Mingyu Jung
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Kyuyong Kang
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Mincheol Choi
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| | - Junghee Yoon
- College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
| |
Collapse
|
20
|
Kaireit TF, Kern A, Voskrebenzev A, Pöhler GH, Klimes F, Behrendt L, Gutberlet M, Moher-Alsady T, Dittrich AM, Wacker F, Hohlfeld J, Vogel-Claussen J. Flow Volume Loop and Regional Ventilation Assessment Using Phase-Resolved Functional Lung (PREFUL) MRI: Comparison With 129 Xenon Ventilation MRI and Lung Function Testing. J Magn Reson Imaging 2020; 53:1092-1105. [PMID: 33247456 DOI: 10.1002/jmri.27452] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/09/2020] [Accepted: 11/12/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Regional flow volume loop ventilation-weighted noncontrast-enhanced proton lung MRI in free breathing has emerged as a novel technique for assessment of regional lung ventilation, but has yet not been validated with 129 Xenon MRI (129 Xe-MRI), a direct visualization of ventilation in healthy volunteers, cystic fibrosis (CF), and chronic obstructive pulmonary disease (COPD) patients. PURPOSE To compare regional ventilation and regional flow volume loops measured by noncontrast-enhanced ventilation-weighted phase-resolved functional lung MRI (PREFUL-MRI) with 129 Xe-MRI ventilation imaging and with lung function test parameters. STUDY TYPE Retrospective study. POPULATION Twenty patients with COPD, eight patients with CF, and six healthy volunteers. FIELD STRENGTH/SEQUENCE PREFUL and 129 Xe-MRI gradient echo sequences were acquired at 1.5T. ASSESSMENT Coronal slices of PREFUL-MRI (free breathing) and 129 Xe-MRI (single breath-hold) were acquired on the same day, matched by their ventrodorsal position and coregistered for evaluation. Ventilation defect percentage (VDP) was calculated based on regional ventilation (RV), regional flow volume loops (RFVL), or 129 Xe-MRI with two different threshold methods. A combined VDP was calculated for RV and RFVL. Additionally, lung function testing was performed (such as the forced expiratory volume in 1 second [FEV1 ]) was used. STATISTICAL TESTS The obtained parameters were compared using Wilcoxon tests, correlated using Spearman's correlation coefficient (r), and agreement between PREFUL and 129 Xe-MRI parameters was assessed using Bland-Altman analysis and Dice coefficients. RESULTS VDP measured by PREFUL and 129 Xe were significantly correlated with both thresholding techniques (r = 0.62-0.69, P < 0.05 for all) and with lung function test parameters. Combined RV and RFVL PREFUL defect maps correlated with lung function testing (eg, with FEV1 r = -0.87 P < 0.05), and showed better regional agreement to 129 Xe-MRI ventilation defects (Dice coefficient defect 0.413) with significantly higher VDP values (10.2 ± 27.3, P = 0.04) than either PREFUL defect map alone. DATA CONCLUSION Combined RV and RFVL PREFUL defect maps likely increase sensitivity to mild airway obstruction with increased VDP values compared to 129 Xe-MRI, and correlate strongly with lung function test parameters. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY STAGE: 2.
Collapse
Affiliation(s)
- Till F Kaireit
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Agilo Kern
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Andreas Voskrebenzev
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Gesa H Pöhler
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Filip Klimes
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Lea Behrendt
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Marcel Gutberlet
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Tawfik Moher-Alsady
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Anna-Maria Dittrich
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany.,Department for Paediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Frank Wacker
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Jens Hohlfeld
- Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany.,Clinic of Pneumology, Hannover Medical School, Hannover, Germany.,Fraunhofer Institute for T oxicology and Experimental Medicine, Hannover, Germany
| | - Jens Vogel-Claussen
- Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| |
Collapse
|
21
|
Guo R, Cai X, Kucukseymen S, Rodriguez J, Paskavitz A, Pierce P, Goddu B, Thompson RB, Nezafat R. Free-breathing simultaneous myocardial T 1 and T 2 mapping with whole left ventricle coverage. Magn Reson Med 2020; 85:1308-1321. [PMID: 33078443 DOI: 10.1002/mrm.28506] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 01/20/2023]
Abstract
PURPOSE To develop a free-breathing sequence, that is, Multislice Joint T1 -T2 , for simultaneous measurement of myocardial T1 and T2 for multiple slices to achieve whole left-ventricular coverage. METHODS Multislice Joint T1 -T2 adopts slice-interleaved acquisition to collect 10 single-shot electrocardiogram-triggered images for each slice prepared by saturation and T2 preparation to simultaneously estimate myocardial T1 and T2 and achieve whole left-ventricular coverage. Prospective slice-tracking using a respiratory navigator and retrospective image registration are used to reduce through-plane and in-plane motion, respectively. Multislice Joint T1 -T2 was validated through numerical simulations and phantom and in vivo experiments, and compared with saturation-recovery single-shot acquisition and T2 -prepared balanced Steady-State Free Precession (T2 -prep SSFP) sequences. RESULTS Phantom T1 and T2 from Multislice Joint T1 -T2 had good accuracy and precision, and were insensitive to heart rate. Multislice Joint T1 -T2 yielded T1 and T2 maps of nine left-ventricular slices in 1.4 minutes. The mean left-ventricular T1 difference between saturation-recovery single-shot acquisition and Multislice Joint T1 -T2 across healthy subjects and patients was 191 ms (1564 ± 60 ms versus 1373 ± 50 ms; P < .05) and 111 ms (1535 ± 49 ms vs 1423 ± 49 ms; P < .05), respectively. The mean difference in left-ventricular T2 between T2 -prep SSFP and Multislice Joint T1 -T2 across healthy subjects and patients was -6.3 ms (42.4 ± 1.4 ms vs 48.7 ± 2.5; P < .05) and -5.7 ms (41.6 ± 2.5 ms vs 47.3 ± 2.7; P < .05), respectively. CONCLUSION Multislice Joint T1 -T2 enables quantification of whole left-ventricular T1 and T2 during free breathing within a clinically feasible scan time of less than 2 minutes.
Collapse
Affiliation(s)
- Rui Guo
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Xiaoying Cai
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.,Siemens Medical Solutions USA, Inc., Boston, Massachusetts, USA
| | - Selcuk Kucukseymen
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Jennifer Rodriguez
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Amanda Paskavitz
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Patrick Pierce
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Beth Goddu
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Richard B Thompson
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
22
|
Guo R, Cai X, Kucukseymen S, Rodriguez J, Paskavitz A, Pierce P, Goddu B, Nezafat R. Free-breathing whole-heart multi-slice myocardial T 1 mapping in 2 minutes. Magn Reson Med 2020; 85:89-102. [PMID: 32662908 DOI: 10.1002/mrm.28402] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/13/2020] [Accepted: 06/08/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE To develop and validate a saturation-delay-inversion recovery preparation, slice tracking and multi-slice based sequence for measuring whole-heart native T1 . METHOD The proposed free-breathing sequence performs T1 mapping of multiple left-ventricular slices by slice-interleaved acquisition to collect 10 electrocardiogram-triggered single-shot slice-selective images for each slice. A saturation-delay-inversion recovery pulse is used for T1 preparation. Prospective slice tracking by the diaphragm navigator and retrospective registration are used to reduce through-plane and in-plane motion, respectively. The proposed sequence was validated in both phantom and human subjects (12 healthy subjects and 15 patients who were referred for a clinical cardiac MR exam) and compared with saturation recovery single-shot acquisition (SASHA) and modified Look-Locker inversion recovery (MOLLI). RESULTS Phantom T1 measured by the proposed sequence had excellent agreement (R2 = 0.99) with the ground-truth T1 and was insensitive to heart rate. In both healthy subjects and patients, the proposed sequence yielded nine left-ventricular T1 maps per volume in less than 2 minutes (healthy volunteers: 1.8 ± 0.4 minutes; patients: 1.9 ± 0.2 minutes). The average T1 of whole left ventricle for all healthy subjects and patients were 1560 ± 61 and 1535 ± 49 ms by SASHA, 1208 ± 42 and 1233 ± 56 ms by MOLLI5(3)3, and 1397 ± 34 and 1433 ± 56 ms by the proposed sequence, respectively. The corresponding coefficient of variation of T1 were 6.2 ± 1.4% and 5.8 ± 1.6%, 5.3 ± 1.1% and 5.1 ± 0.8%, and 4.9 ± 0.8% and 4.5 ± 0.8%, respectively. CONCLUSION The proposed sequence enables quantification of whole heart T1 with good accuracy and precision in less than 2 minutes during free breathing.
Collapse
Affiliation(s)
- Rui Guo
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Xiaoying Cai
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.,Siemens Medical Solutions USA, Inc., Boston, MA, USA
| | - Selcuk Kucukseymen
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Jennifer Rodriguez
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Amanda Paskavitz
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Patrick Pierce
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Beth Goddu
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
23
|
den Otter LA, Anakotta RM, Weessies M, Roos CTG, Sijtsema NM, Muijs CT, Dieters M, Wijsman R, Troost EGC, Richter C, Meijers A, Langendijk JA, Both S, Knopf AC. Investigation of inter-fraction target motion variations in the context of pencil beam scanned proton therapy in non-small cell lung cancer patients. Med Phys 2020; 47:3835-3844. [PMID: 32573792 PMCID: PMC7586844 DOI: 10.1002/mp.14345] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/01/2020] [Accepted: 06/14/2020] [Indexed: 12/25/2022] Open
Abstract
Purpose For locally advanced‐stage non‐small cell lung cancer (NSCLC), inter‐fraction target motion variations during the whole time span of a fractionated treatment course are assessed in a large and representative patient cohort. The primary objective is to develop a suitable motion monitoring strategy for pencil beam scanning proton therapy (PBS‐PT) treatments of NSCLC patients during free breathing. Methods Weekly 4D computed tomography (4DCT; 41 patients) and daily 4D cone beam computed tomography (4DCBCT; 10 of 41 patients) scans were analyzed for a fully fractionated treatment course. Gross tumor volumes (GTVs) were contoured and the 3D displacement vectors of the centroid positions were compared for all scans. Furthermore, motion amplitude variations in different lung segments were statistically analyzed. The dosimetric impact of target motion variations and target motion assessment was investigated in exemplary patient cases. Results The median observed centroid motion was 3.4 mm (range: 0.2–12.4 mm) with an average variation of 2.2 mm (range: 0.1–8.8 mm). Ten of 32 patients (31.3%) with an initial motion <5 mm increased beyond a 5‐mm motion amplitude during the treatment course. Motion observed in the 4DCBCT scans deviated on average 1.5 mm (range: 0.0–6.0 mm) from the motion observed in the 4DCTs. Larger motion variations for one example patient compromised treatment plan robustness while no dosimetric influence was seen due to motion assessment biases in another example case. Conclusions Target motion variations were investigated during the course of radiotherapy for NSCLC patients. Patients with initial GTV motion amplitudes of < 2 mm can be assumed to be stable in motion during the treatment course. For treatments of NSCLC patients who exhibit motion amplitudes of > 2 mm, 4DCBCT should be considered for motion monitoring due to substantial motion variations observed.
Collapse
Affiliation(s)
- Lydia A den Otter
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Renske M Anakotta
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Menkedina Weessies
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Catharina T G Roos
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Nanna M Sijtsema
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Christina T Muijs
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Margriet Dieters
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Robin Wijsman
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Esther G C Troost
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden, Rossendorf, Germany.,Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology, OncoRay, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Partner Site Dresden, and German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
| | - Christian Richter
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden, Rossendorf, Germany.,Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology, OncoRay, Germany.,Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Partner Site Dresden, and German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Arturs Meijers
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Johannes A Langendijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Stefan Both
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| | - Antje-Christin Knopf
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, 9713 GZ, The Netherlands
| |
Collapse
|
24
|
Zhao R, Zhang Y, Wang X, Colgan TJ, Rehm JL, Reeder SB, Johnson KM, Hernando D. Motion-robust, high-SNR liver fat quantification using a 2D sequential acquisition with a variable flip angle approach. Magn Reson Med 2020; 84:2004-2017. [PMID: 32243665 DOI: 10.1002/mrm.28263] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 02/24/2020] [Accepted: 03/02/2020] [Indexed: 01/18/2023]
Abstract
PURPOSE Chemical shift encoded (CSE)-MRI enables quantification of proton-density fat fraction (PDFF) as a biomarker of liver fat content. However, conventional 3D Cartesian CSE-MRI methods require breath-holding. A motion-robust 2D Cartesian sequential method addresses this limitation but suffers from low SNR. In this work, a novel free breathing 2D Cartesian sequential CSE-MRI method using a variable flip angle approach with centric phase encoding (VFA-centric) is developed to achieve fat quantification with low T 1 bias, high SNR, and minimal blurring. METHODS Numerical simulation was performed for variable flip angle schedule design and preliminary evaluation of VFA-centric method, along with several alternative flip angle designs. Phantom, adults (n = 8), and children (n = 27) were imaged at 3T. Multi-echo images were acquired and PDFF maps were estimated. PDFF standard deviation was used as a surrogate for SNR. RESULTS In both simulation and phantom experiments, the VFA-centric method enabled higher SNR imaging with minimal T 1 bias and blurring artifacts. High correlation (slope = 1.00, intercept = 0.04, R 2 = 0.998) was observed in vivo between the proposed VFA-centric method obtained PDFF and reference PDFF (free breathing low-flip angle 2D sequential acquisition). Further, the proposed VFA-centric method (PDFF standard deviation = 1.5%) had a better SNR performance than the reference acquisition (PDFF standard deviation = 3.3%) with P < .001. CONCLUSIONS The proposed free breathing 2D Cartesian sequential CSE-MRI method with variable flip angle approach and centric-ordered phase encoding achieved motion robustness, low T 1 bias, high SNR compared to previous 2D sequential methods, and low blurring in liver fat quantification.
Collapse
Affiliation(s)
- Ruiyang Zhao
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Yuxin Zhang
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Xiaoke Wang
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Timothy J Colgan
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Jennifer L Rehm
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, USA
| | - Scott B Reeder
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA.,Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.,Department of Emergency Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Kevin M Johnson
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Diego Hernando
- Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA
| |
Collapse
|
25
|
Zhu X, Chan M, Lustig M, Johnson KM, Larson PEZ. Iterative motion-compensation reconstruction ultra-short TE (iMoCo UTE) for high-resolution free-breathing pulmonary MRI. Magn Reson Med 2019; 83:1208-1221. [PMID: 31565817 DOI: 10.1002/mrm.27998] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/19/2019] [Accepted: 08/26/2019] [Indexed: 12/24/2022]
Abstract
PURPOSE To develop a high-scanning efficiency, motion-corrected imaging strategy for free-breathing pulmonary MRI by combining an iterative motion-compensation reconstruction with a ultrashort echo time (UTE) acquisition called iMoCo UTE. METHODS An optimized golden-angle ordering radial UTE sequence was used to continuously acquire data for 5 minutes. All readouts were grouped to different respiratory motion states based on self-navigator signals, and then motion-resolved data was reconstructed by XD golden-angle radial sparse parallel reconstruction. One state from the motion-resolved images was selected as a reference, and then motion fields from the other states to the reference were derived via nonrigid registration. Finally, all motion-resolved data and motion fields were reconstructed by using an iterative motion-compensation (MoCo) reconstruction with a total generalized variation sparse constraint. RESULTS The iMoCo UTE strategy was evaluated in volunteers and nonsedated pediatric patient (4-6 years old) studies. Images reconstructed with iMoCo UTE provided sharper anatomical lung structures and higher apparent SNR and contrast-to-noise ratio compared to using other motion-correction strategies, such as soft-gating, motion-resolved reconstruction, and nonrigid MoCo. iMoCo UTE also showed promising results in an infant study. CONCLUSION The proposed iMoCo UTE combines self-navigation, motion modeling, and a compressed sensing reconstruction to increase scan efficiency and SNR and to reduce respiratory motion in lung MRI. This proposed strategy shows improvements in free-breathing lung MRI scans, especially in very challenging application situations such as pediatric MRI studies.
Collapse
Affiliation(s)
- Xucheng Zhu
- UCSF/UC Berkeley Graduate Program in Bioengineering, University of California, San Francisco, California.,Department of Radiology and Biomedical Imaging, University of California, San Francisco, California
| | - Marilynn Chan
- Department of Pediatrics, Division of Pediatric Pulmonology, University of California, San Francisco, California
| | - Michael Lustig
- UCSF/UC Berkeley Graduate Program in Bioengineering, University of California, San Francisco, California.,Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California
| | - Kevin M Johnson
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin.,Department of Radiology, University of Wisconsin, Madison, Wisconsin
| | - Peder E Z Larson
- UCSF/UC Berkeley Graduate Program in Bioengineering, University of California, San Francisco, California.,Department of Radiology and Biomedical Imaging, University of California, San Francisco, California
| |
Collapse
|
26
|
Aramendía-Vidaurreta V, García-Osés A, Vidorreta M, Bastarrika G, Fernández-Seara MA. Optimal repetition time for free breathing myocardial arterial spin labeling. NMR Biomed 2019; 32:e4077. [PMID: 30811728 DOI: 10.1002/nbm.4077] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 12/21/2018] [Accepted: 01/15/2019] [Indexed: 06/09/2023]
Abstract
The aim of this study was to improve the scan efficiency of ASL in the myocardium. Free breathing FAIR-ASL scans with different TRs were compared, while keeping the acquisition time constant. Scans were named by the trigger pulse that started each acquisition: every two (TP1), four (TP2) and six (TP3) cardiac cycles. TP2 offered the best alternative with a coefficient of variation of 17.15% intrasession and 36.85% intersession. Mean MBF increased by 0.22 ± 0.41 ml/g/min with mild stress.
Collapse
Affiliation(s)
| | | | | | - Gorka Bastarrika
- Radiology Department, Clínica Universidad de Navarra, Pamplona, Spain
| | | |
Collapse
|
27
|
Zhang X, Xie G, Lu N, Zhu Y, Wei Z, Su S, Shi C, Yan F, Liu X, Qiu B, Fan Z. 3D self-gated cardiac cine imaging at 3 Tesla using stack-of-stars bSSFP with tiny golden angles and compressed sensing. Magn Reson Med 2018; 81:3234-3244. [PMID: 30474151 DOI: 10.1002/mrm.27612] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 10/25/2018] [Accepted: 10/29/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE To develop and evaluate an accelerated 3D self-gated cardiac cine imaging technique at 3 Tesla without the use of external electrocardiogram triggering or respiratory gating. METHODS A 3D stack-of-stars balanced steady-state free precession sequence with a tiny golden angle sampling scheme was developed to reduced eddy current effect-related artefacts at 3 Tesla. Respiratory and cardiac motion were derived from a central 5-point self-gating signal extraction approach. The data acquired around the end-expiration phases were then sorted into individual cardiac bins and used for reconstruction with compressed sensing. To evaluate the performance of the proposed method, image quality (1: the best; 4: the worst) was quantitatively compared using both the proposed method and the conventional 3D golden-angle self-gated method. Linear regression and Bland-Altman analysis were used to assess the functional measurements agreement between the proposed method and the routine 2D breath-hold multi-slice technique. RESULTS Compared to the conventional 3D golden-angle self-gated method, the proposed method yielded images with much less streaking artifact and higher myocardium edge sharpness (0.50 ± 0.06 vs. 0.45 ± 0.05, P = 0.004). The proposed method provided an inferior image quality score to the routine 2D technique (2.13 ± 0.35 vs. 1.38 ± 0.52, P = 0.063) but a superior one to the conventional self-gated method (2.13 ± 0.35 vs. 3.13 ± 0.64, P = 0.031). Left ventricular functional measurements between the proposed method and routine 2D technique were all well in agreement. CONCLUSION This study presents a novel self-gating approach to realize rapid 3D cardiac cine imaging at 3 Tesla.
Collapse
Affiliation(s)
- Xiaoyong Zhang
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, People's Republic of China.,MR Collaborations NE Asia, Siemens Healthcare, Shenzhen, People's Republic of China
| | - Guoxi Xie
- Paul C. Lauterber Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China.,Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Na Lu
- Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Yanchun Zhu
- Paul C. Lauterber Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Zijun Wei
- Paul C. Lauterber Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Shi Su
- Paul C. Lauterber Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Caiyun Shi
- Paul C. Lauterber Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Fei Yan
- Paul C. Lauterber Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Xin Liu
- Paul C. Lauterber Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Bensheng Qiu
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, People's Republic of China
| | - Zhaoyang Fan
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Departments of Medicine and Bioengineering, University of California, Los Angeles, California
| |
Collapse
|
28
|
Lo WC, Chen Y, Jiang Y, Hamilton J, Grimm R, Griswold M, Gulani V, Seiberlich N. Realistic 4D MRI abdominal phantom for the evaluation and comparison of acquisition and reconstruction techniques. Magn Reson Med 2018; 81:1863-1875. [PMID: 30394573 DOI: 10.1002/mrm.27545] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/24/2018] [Accepted: 08/30/2018] [Indexed: 12/22/2022]
Abstract
PURPOSE This work presents a 4D numerical abdominal phantom, which includes T1 and T2 relaxation times, proton density fat fraction, perfusion, and diffusion, as well as respiratory motion for the evaluation and comparison of acquisition and reconstruction techniques. METHODS The 3D anatomical mesh models were non-rigidly scaled and shifted by respiratory motion derived from an in vivo scan. A time series of voxelized 3D abdominal phantom images were obtained with contrast determined by the tissue properties and pulse sequence parameters. Two example simulations: (1) 3D T1 mapping under breath-hold and free-breathing acquisition conditions and (2) two different reconstruction techniques for accelerated 3D dynamic contrast-enhanced MRI, are presented. The source codes can be found at https://github.com/SeiberlichLab/Abdominal_MR_Phantom. RESULTS The proposed 4D abdominal phantom can successfully simulate images and MRI data with nonrigid respiratory motion and specific contrast settings and data sampling schemes. In example 1, the use of a numerical 4D abdominal phantom was demonstrated to aid in the comparison between different approaches for volumetric T1 mapping. In example 2, the average arterial fraction over the healthy hepatic parenchyma as calculated with spiral generalized autocalibrating partial parallel acquisition was closer to that from the fully sampled data than the arterial fraction from conjugate gradient sensitivity encoding, although both are elevated compared to the gold-standard reference. CONCLUSION This realistic abdominal MR phantom can be used to simulate different pulse sequences and data sampling schemes for the comparison of acquisition and reconstruction methods under controlled conditions that are impossible or prohibitively difficult to perform in vivo.
Collapse
Affiliation(s)
- Wei-Ching Lo
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Yong Chen
- Department of Radiology, UH Cleveland Medical Center, Cleveland, Ohio
| | - Yun Jiang
- Department of Radiology, UH Cleveland Medical Center, Cleveland, Ohio
| | - Jesse Hamilton
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | | | - Mark Griswold
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio.,Department of Radiology, UH Cleveland Medical Center, Cleveland, Ohio
| | - Vikas Gulani
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio.,Department of Radiology, UH Cleveland Medical Center, Cleveland, Ohio
| | - Nicole Seiberlich
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio.,Department of Radiology, UH Cleveland Medical Center, Cleveland, Ohio
| |
Collapse
|
29
|
Kowalik GT, Steeden JA, Atkinson D, Montalt-Tordera J, Mortensen KH, Muthurangu V. Golden ratio stack of spirals for flexible angiographic imaging: Proof of concept in congenital heart disease. Magn Reson Med 2018; 81:90-101. [PMID: 29802643 DOI: 10.1002/mrm.27353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 04/19/2018] [Accepted: 04/19/2018] [Indexed: 11/11/2022]
Abstract
PURPOSE In this study, a golden ratio stack of spiral (GRASS) sequence that used both golden step and golden angle ordering was implemented. The aim was to demonstrate that GRASS acquisitions could be flexibly reconstructed as both cardiac-gated and time-resolved angiograms. METHODS Image quality of time-resolved and cardiac-gated reconstructions of the GRASS sequence were compared to 3 conventional stack of spirals (SoS) acquisitions in an in silico model. In 10 patients, the GRASS sequence was compared to conventional breath hold angiography (BH-MRA) in terms of image quality and for vessel measurement. Vessel measurements were also compared to cine images. RESULTS In the cardiac-gated in silico model, the image quality of GRASS was superior to regular and golden-angle with regular step SoS approaches. In the time-resolved model, GRASS image quality was comparable to the golden-angle with regular step technique and superior to regular SoS acquisitions. In patients, there was no difference in qualitative image scores between GRASS and BH-MRA, but SNR was lower. There was good agreement in vessel measurements between the GRASS reconstructions and conventional MR techniques (BH-MRA: 29.8 ± 5.6 mm, time-resolved GRASS-MRA: 29.9 ± 5.4 mm, SSFP diastolic: 29.4 ± 5.8 mm, cardiac-gated GRASS-MRA diastolic: 29.5 ± 5.5 mm, P > 0.87). CONCLUSION We have demonstrated that the GRASS acquisition enables flexible reconstruction of the same raw data as both time-resolved and cardiac-gated volumes. This may enable better interrogation of anatomy in congenital heart disease.
Collapse
Affiliation(s)
- Grzegorz Tomasz Kowalik
- UCL Institute of Cardiovascular Science, Centre for Cardiovascular Imaging, London, United Kingdom
| | - Jennifer Anne Steeden
- UCL Institute of Cardiovascular Science, Centre for Cardiovascular Imaging, London, United Kingdom
| | - David Atkinson
- University College London, Centre for Medical Imaging, Wolfson House, London, United Kingdom
| | - Javier Montalt-Tordera
- UCL Institute of Cardiovascular Science, Centre for Cardiovascular Imaging, London, United Kingdom
| | | | - Vivek Muthurangu
- UCL Institute of Cardiovascular Science, Centre for Cardiovascular Imaging, London, United Kingdom.,Great Ormond Street Hospital for Children, Great Ormond Street, London, United Kingdom
| |
Collapse
|
30
|
Lv J, Chen K, Yang M, Zhang J, Wang X. Reconstruction of undersampled radial free-breathing 3D abdominal MRI using stacked convolutional auto-encoders. Med Phys 2018; 45:2023-2032. [PMID: 29574939 DOI: 10.1002/mp.12870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 02/21/2018] [Accepted: 03/06/2018] [Indexed: 01/22/2023] Open
Abstract
PURPOSE Free-breathing three-dimensional (3D) abdominal imaging is a challenging task for MRI, as respiratory motion severely degrades image quality. One of the most promising self-navigation techniques is the 3D golden-angle radial stack-of-stars (SOS) sequence, which has advantages in terms of speed, resolution, and allowing free breathing. However, streaking artifacts are still clearly observed in reconstructed images when undersampling is applied. This work presents a novel reconstruction approach based on a stacked convolutional auto-encoder (SCAE) network to solve this problem. METHODS Thirty healthy volunteers participated in our experiment. To build the dataset, reference and artifact-affected images were reconstructed using 451 golden-angle spokes and the first 20, 40, or 90 golden-angle spokes corresponding to acceleration rates of 31.4, 15.7, and 6.98, respectively. In the training step, we trained the SCAE by feeding it with patches from artifact-affected images. The SCAE outputs patches in the corresponding reference images. In the testing step, we applied the trained SCAE to map each input artifact-affected patch to the corresponding reference image patch. RESULT The SCAE-based reconstruction images with acceleration rates of 6.98 and 15.7 show nearly similar quality as the reference images. Additionally, the calculation time is below 1 s. Moreover, the proposed approach preserves important features, such as lesions not presented in the training set. CONCLUSION The preliminary results demonstrate the feasibility of the proposed SCAE-based strategy for correcting the streaking artifacts of undersampled free-breathing 3D abdominal MRI with a negligible reconstruction time.
Collapse
Affiliation(s)
- Jun Lv
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Kun Chen
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Ming Yang
- Vusion Tech Ltd. Co, Hefei, 230031, China
| | - Jue Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.,College of Engineering, Peking University, Beijing, 100871, China
| | - Xiaoying Wang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.,Department of Radiology, Peking University First Hospital, Beijing, 100034, China
| |
Collapse
|
31
|
Fyrdahl A, Vargas Paris R, Nyrén S, Holst K, Ugander M, Lindholm P, Sigfridsson A. Pulmonary artery imaging under free-breathing using golden-angle radial bSSFP MRI: a proof of concept. Magn Reson Med 2018. [PMID: 29542200 DOI: 10.1002/mrm.27177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE To evaluate the feasibility of an improved motion and flow robust methodology for imaging the pulmonary vasculature using non-contrast-enhanced, free-breathing, golden-angle radial MRI. METHODS Healthy volunteers (n = 10, age 46 ± 11 years, 50% female) and patients (n = 2, ages 27 and 84, both female) were imaged at 1.5 T using a Cartesian and golden-angle radial 2D balanced SSFP pulse sequence. The acquisitions were made under free breathing without contrast agent enhancement. The radial acquisitions were reconstructed at 3 temporal footprints. All series were scored from 1 to 5 for perceived diagnostic quality, artifact level, and vessel sharpness in multiple anatomical locations. In addition, vessel sharpness and blood-to-blood clot contrast were measured. RESULTS Quantitative measurements showed higher vessel sharpness for golden-angle radial (n = 76, 0.79 ± 0.11 versus 0.71 ± 0.16, p < .05). Blood-to-blood clot contrast was found to be 23% higher in golden-angle radial in the 2 patients. At comparable temporal footprints, golden-angle radial was scored higher for diagnostic quality (mean ± SD, 2.3 ± 0.7 versus 2.2 ± 0.6, p < .01) and vessel sharpness (2.2 ± 0.8 versus 2.1 ± 0.5, p < .01), whereas the artifact level did not differ (3.0 ± 0.9 versus 3.0 ± 1.0, p = .80). The ability to retrospectively choose a temporal resolution and perform sliding-window reconstructions was demonstrated in patients. CONCLUSION In pulmonary artery imaging, the motion and flow robustness of a radial trajectory does both improve image quality over Cartesian trajectory in healthy volunteers, and allows for flexible selection of temporal footprints and the ability to perform real-time sliding window reconstructions, which could potentially provide further diagnostic insight.
Collapse
Affiliation(s)
- Alexander Fyrdahl
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Roberto Vargas Paris
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Department of Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Sven Nyrén
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Thoracic Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Karen Holst
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Martin Ugander
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Peter Lindholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Department of Thoracic Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Andreas Sigfridsson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
32
|
Kim B, Seo H, Kim D, Park H. Retrospective motion gating in cardiac MRI using a simultaneously acquired navigator. NMR Biomed 2018; 31:e3874. [PMID: 29266452 DOI: 10.1002/nbm.3874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/03/2017] [Accepted: 11/06/2017] [Indexed: 06/07/2023]
Abstract
A simultaneous acquisition technique of image and navigator signals (simultaneously acquired navigator, SIMNAV) is proposed for cardiac magnetic resonance imaging (CMRI) in Cartesian coordinates. To simultaneously acquire both image and navigator signals, a conventional balanced steady-state free precession (bSSFP) pulse sequence is modified by adding a radiofrequency (RF) pulse, which excites a supplementary slice for the navigator signal. Alternating phases of the RF pulses make it easy to separate the simultaneously acquired magnetic resonance data into image and navigator signals. The navigator signals of the proposed SIMNAV were compared with those of current gating devices and self-gating techniques for seven healthy subjects. In vivo experiments demonstrated that SIMNAV could provide cardiac cine images with sufficient image quality, similar to those from electrocardiogram (ECG) gating with breath-hold. SIMNAV can be used to acquire a cardiac cine image without requiring an ECG device and breath-hold, whilst maintaining feasible imaging time efficiency.
Collapse
Affiliation(s)
- Byungjai Kim
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Guseong-dong, Yuseong-gu, Daejeon, South Korea
| | - Hyunseok Seo
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Guseong-dong, Yuseong-gu, Daejeon, South Korea
| | - Dongchan Kim
- College of Medicine, Gachon University, Hambakmoero 191, Yeonsu-gu, Incheon, South Korea
| | - HyunWook Park
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Guseong-dong, Yuseong-gu, Daejeon, South Korea
| |
Collapse
|
33
|
Feng L, Huang C, Shanbhogue K, Sodickson DK, Chandarana H, Otazo R. RACER-GRASP: Respiratory-weighted, aortic contrast enhancement-guided and coil-unstreaking golden-angle radial sparse MRI. Magn Reson Med 2017; 80:77-89. [PMID: 29193260 DOI: 10.1002/mrm.27002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 12/25/2022]
Abstract
PURPOSE To develop and evaluate a novel dynamic contrast-enhanced imaging technique called RACER-GRASP (Respiratory-weighted, Aortic Contrast Enhancement-guided and coil-unstReaking Golden-angle RAdial Sparse Parallel) MRI that extends GRASP to include automatic contrast bolus timing, respiratory motion compensation, and coil-weighted unstreaking for improved imaging performance in liver MRI. METHODS In RACER-GRASP, aortic contrast enhancement (ACE) guided k-space sorting and respiratory-weighted sparse reconstruction are performed using aortic contrast enhancement and respiratory motion signals extracted directly from the acquired data. Coil unstreaking aims to weight multicoil k-space according to streaking artifact level calculated for each individual coil during image reconstruction, so that coil elements containing a high level of streaking artifacts contribute less to the final results. Self-calibrating GRAPPA operator gridding was applied as a pre-reconstruction step to reduce computational burden in the subsequent iterative reconstruction. The RACER-GRASP technique was compared with standard GRASP reconstruction in a group of healthy volunteers and patients referred for clinical liver MR examination. RESULTS Compared with standard GRASP, RACER-GRASP significantly improved overall image quality (average score: 3.25 versus 3.85) and hepatic vessel sharpness/clarity (average score: 3.58 versus 4.0), and reduced residual streaking artifact level (average score: 3.23 versus 3.94) in different contrast phases. RACER-GRASP also enabled automatic timing of the arterial phases. CONCLUSIONS The aortic contrast enhancement-guided sorting, respiratory motion suppression and coil unstreaking introduced by RACER-GRASP improve upon the imaging performance of standard GRASP for free-breathing dynamic contrast-enhanced MRI of the liver. Magn Reson Med 80:77-89, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Li Feng
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Chenchan Huang
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Krishna Shanbhogue
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Daniel K Sodickson
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Hersh Chandarana
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Ricardo Otazo
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| |
Collapse
|
34
|
Hess AT, Tunnicliffe EM, Rodgers CT, Robson MD. Diaphragm position can be accurately estimated from the scattering of a parallel transmit RF coil at 7 T. Magn Reson Med 2017; 79:2164-2169. [PMID: 28771792 PMCID: PMC5836958 DOI: 10.1002/mrm.26866] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/12/2017] [Accepted: 07/19/2017] [Indexed: 11/10/2022]
Abstract
Purpose To evaluate the use of radiofrequency scattering of a parallel transmit coil to track diaphragm motion. Methods Measurements made during radiofrequency excitation on an 8‐channel parallel transmit coil by the directional couplers of the radiofrequency safety monitor were combined and converted into diaphragm position. A 30‐s subject‐specific calibration with an MRI navigator was used to determine a diaphragm estimate from each directional‐coupler measure. Seven healthy volunteers were scanned at 7 T, in which images of the diaphragm were continuously acquired and directional couplers were monitored during excitation radiofrequency pulses. The ability to detect coughing was evaluated in one subject. The method was implemented on the scanner and evaluated for diaphragm gating of a free‐breathing cardiac cine. Results Six of the seven scans were successful. In these subjects, the root mean square difference between MRI and scattering estimation of the superior–inferior diaphragm position was 1.4 ± 0.5 mm. On the scanner, the position was calculated less than 2 ms after every radiofrequency pulse. A prospectively gated (echocardiogram and respiration) high‐resolution free‐breathing cine showed no respiratory artifact and sharp blood‐myocardium definition. Conclusions Transmit coil scattering is sensitive to diaphragm motion and provides rapid, quantitative, and accurate monitoring of respiration. Magn Reson Med 79:2164–2169, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Collapse
Affiliation(s)
- Aaron T Hess
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford, United Kingdom
| | - Elizabeth M Tunnicliffe
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford, United Kingdom
| | - Christopher T Rodgers
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford, United Kingdom
| | - Matthew D Robson
- University of Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford, United Kingdom
| |
Collapse
|
35
|
Tipirneni-Sajja A, Krafft AJ, McCarville MB, Loeffler RB, Song R, Hankins JS, Hillenbrand CM. Radial Ultrashort TE Imaging Removes the Need for Breath-Holding in Hepatic Iron Overload Quantification by R2* MRI. AJR Am J Roentgenol 2017; 209:187-94. [PMID: 28504544 DOI: 10.2214/AJR.16.17183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The objective of this study is to evaluate radial free-breathing (FB) multiecho ultrashort TE (UTE) imaging as an alternative to Cartesian FB multiecho gradient-recalled echo (GRE) imaging for quantitative assessment of hepatic iron content (HIC) in sedated patients and subjects unable to perform breath-hold (BH) maneuvers. MATERIALS AND METHODS FB multiecho GRE imaging and FB multiecho UTE imaging were conducted for 46 test group patients with iron overload who could not complete BH maneuvers (38 patients were sedated, and eight were not sedated) and 16 control patients who could complete BH maneuvers. Control patients also underwent standard BH multiecho GRE imaging. Quantitative R2* maps were calculated, and mean liver R2* values and coefficients of variation (CVs) for different acquisitions and patient groups were compared using statistical analysis. RESULTS FB multiecho GRE images displayed motion artifacts and significantly lower R2* values, compared with standard BH multiecho GRE images and FB multiecho UTE images in the control cohort and FB multiecho UTE images in the test cohort. In contrast, FB multiecho UTE images produced artifact-free R2* maps, and mean R2* values were not significantly different from those measured by BH multiecho GRE imaging. Motion artifacts on FB multiecho GRE images resulted in an R2* CV that was approximately twofold higher than the R2* CV from BH multiecho GRE imaging and FB multiecho UTE imaging. The R2* CV was relatively constant over the range of R2* values for FB multiecho UTE, but it increased with increases in R2* for FB multiecho GRE imaging, reflecting that motion artifacts had a stronger impact on R2* estimation with increasing iron burden. CONCLUSION FB multiecho UTE imaging was less motion sensitive because of radial sampling, produced excellent image quality, and yielded accurate R2* estimates within the same acquisition time used for multiaveraged FB multiecho GRE imaging. Thus, FB multiecho UTE imaging is a viable alternative for accurate HIC assessment in sedated children and patients who cannot complete BH maneuvers.
Collapse
|
36
|
Piccini D, Feng L, Bonanno G, Coppo S, Yerly J, Lim RP, Schwitter J, Sodickson DK, Otazo R, Stuber M. Four-dimensional respiratory motion-resolved whole heart coronary MR angiography. Magn Reson Med 2016; 77:1473-1484. [PMID: 27052418 DOI: 10.1002/mrm.26221] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/25/2016] [Accepted: 02/24/2016] [Indexed: 12/27/2022]
Abstract
PURPOSE Free-breathing whole-heart coronary MR angiography (MRA) commonly uses navigators to gate respiratory motion, resulting in lengthy and unpredictable acquisition times. Conversely, self-navigation has 100% scan efficiency, but requires motion correction over a broad range of respiratory displacements, which may introduce image artifacts. We propose replacing navigators and self-navigation with a respiratory motion-resolved reconstruction approach. METHODS Using a respiratory signal extracted directly from the imaging data, individual signal-readouts are binned according to their respiratory states. The resultant series of undersampled images are reconstructed using an extradimensional golden-angle radial sparse parallel imaging (XD-GRASP) algorithm, which exploits sparsity along the respiratory dimension. Whole-heart coronary MRA was performed in 11 volunteers and four patients with the proposed methodology. Image quality was compared with that obtained with one-dimensional respiratory self-navigation. RESULTS Respiratory-resolved reconstruction effectively suppressed respiratory motion artifacts. The quality score for XD-GRASP reconstructions was greater than or equal to self-navigation in 80/88 coronary segments, reaching diagnostic quality in 61/88 segments versus 41/88. Coronary sharpness and length were always superior for the respiratory-resolved datasets, reaching statistical significance (P < 0.05) in most cases. CONCLUSION XD-GRASP represents an attractive alternative for handling respiratory motion in free-breathing whole heart MRI and provides an effective alternative to self-navigation. Magn Reson Med 77:1473-1484, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Davide Piccini
- Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland.,Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Li Feng
- Center for Advanced Imaging Innovation and Research, and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Gabriele Bonanno
- Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Simone Coppo
- Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jérôme Yerly
- Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland.,Center for Biomedical Imaging, Lausanne, Switzerland
| | - Ruth P Lim
- Department of Radiology, Austin Health and The University of Melbourne, Melbourne, Victoria, Australia
| | - Juerg Schwitter
- Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne, Lausanne, Switzerland
| | - Daniel K Sodickson
- Center for Advanced Imaging Innovation and Research, and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Ricardo Otazo
- Center for Advanced Imaging Innovation and Research, and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Matthias Stuber
- Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland.,Center for Biomedical Imaging, Lausanne, Switzerland
| |
Collapse
|
37
|
Abstract
BACKGROUND One disadvantage of magnetic resonance imaging (MRI) is the inability to adequately image the lungs. Recent advances in hyperpolarized gas technology [e.g., helium-3 ((3)He) and xenon-129 ((129)Xe)] have changed this. However, the required technology is expensive and often needing extra physics or engineering staff. Hence there is considerable interest in developing (1)H (proton)-based MRI approaches that can be readily implemented on standard clinical systems. Thus, the purpose of this work was to compare a newly developed free breathing proton-based MR lung imaging method to that of a standard gadolinium (Gd) based perfusion approach. METHODS Healthy volunteers [10] were scanned using a 3-T MRI with 8 parallel receivers, and a cardiac gated fast spin echo (FSE) sequence. Acquisition was cardiac triggered, with different time delays incremented to cover the entire cardiac cycle. Image k-space was filled rectilinearly. But to reduce motion artefacts k-space was retrospectively sorted using the minimal variance algorithm (MVA), based on physiologic data recorded from both the respiratory bellows and electrocardiogram (ECG). Resorted and reconstructed FSE images were compared to contrast enhanced lung images, obtained following intravenous injection of Gd-DTPA-BMA. RESULTS Biphasic variation in FSE lung signal intensity was observed across the cardiac cycle with a maximal signal change following rapid cardiac ejection (between S and T waves), and following rapid isovolumetric relaxation. A difference image between systolic and diastolic states in the cardiac cycle resulted in images with improved lung contrast to noise ratio (CNR). FSE image intensity was uniform over lung parenchyma while Gd-based enhancement of spoiled gradient recalled echo (SPGR) images showed gravitational dependence. CONCLUSIONS Here we show how 1H-MR images of lung can be obtained during free breathing. The image contrast obtained during this approach is likely the result of flow and oxygen modulation during the cardiac cycle. This free breathing method provides lung images comparable to those obtained using Gd-enhancement. Besides having the advantage of free breathing, this approach doesn't require any Gd-contrast or suffer from methodological problems associated with perfusion (e.g., poor bolus timing). However, as gravitational differences typically observed in lung perfusion are not visible with this method it is not providing exclusive microvascular perfusion information.
Collapse
Affiliation(s)
- Sergei I Obruchkov
- 1 Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada ; 2 Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada ; 3 Department of Electrical and Computer Engineering, 4 McMaster School of Biomedical Engineering, 5 Department of Radiology, McMaster University, Hamilton, Ontario, Canada
| | - Michael D Noseworthy
- 1 Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada ; 2 Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada ; 3 Department of Electrical and Computer Engineering, 4 McMaster School of Biomedical Engineering, 5 Department of Radiology, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
38
|
Taron J, Martirosian P, Erb M, Kuestner T, Schwenzer NF, Schmidt H, Honndorf VS, Weiβ J, Notohamiprodjo M, Nikolaou K, Schraml C. Simultaneous multislice diffusion-weighted MRI of the liver: Analysis of different breathing schemes in comparison to standard sequences. J Magn Reson Imaging 2016; 44:865-79. [PMID: 26919580 DOI: 10.1002/jmri.25204] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To systematically evaluate image characteristics of simultaneous-multislice (SMS)-accelerated diffusion-weighted imaging (DWI) of the liver using different breathing schemes in comparison to standard sequences. MATERIALS AND METHODS DWI of the liver was performed in 10 healthy volunteers and 12 patients at 1.5T using an SMS-accelerated echo planar imaging sequence performed with respiratory-triggering and free breathing (SMS-RT, SMS-FB). Standard DWI sequences served as reference (STD-RT, STD-FB). Reduction of scan time by SMS-acceleration was measured. Image characteristics of SMS-DWI and STD-DWI with both breathing schemes were analyzed quantitatively (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR]) and qualitatively (5-point Likert scale, 5 = excellent). Qualitative and quantitative parameters were compared using Friedman test and Dunn-Bonferroni post-hoc method with P-values < 0.05 considered statistically significant. RESULTS SMS-DWI provided diagnostic image quality in volunteers and patients both with RT and FB with a reduction of scan time of 70% (0:56 vs. 3:20 min in FB). Overall image quality did not significantly differ between FB and RT acquisition in both STD and SMS sequences (median STD-RT 5.0, STD-FB 4.5, SMS-RT: 4.75; SMS-FB: 4.5; P = 0.294). SNR in the right hepatic lobe was comparable between the four tested sequences. ADC values were significantly lower in SMS-DWI compared to STD-DWI irrespective of the breathing scheme (1.2 ± 0.2 × 10(-3) mm(2) /s vs. 1.0 ± 0.2 × 10(-3) mm(2) /s; P < 0.001). CONCLUSION SMS-acceleration provides considerable scan time reduction for hepatic DWI with equivalent image quality compared to the STD technique both using RT and FB. Discrepancies in ADC between STD-DWI and SMS-DWI need to be considered when transferring the SMS technique to clinical routine reading. J. MAGN. RESON. IMAGING 2016;44:865-879.
Collapse
Affiliation(s)
- Jana Taron
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Petros Martirosian
- Section on Experimental Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Michael Erb
- Department of Biomedical Magnetic Resonance, University Hospital of Tuebingen, Tuebingen, Germany
| | - Thomas Kuestner
- Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany
| | - Nina F Schwenzer
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Holger Schmidt
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Valerie S Honndorf
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Jakob Weiβ
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Mike Notohamiprodjo
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Konstantin Nikolaou
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany
| | - Christina Schraml
- Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
| |
Collapse
|
39
|
Chan RW, Von Deuster C, Stoeck CT, Harmer J, Punwani S, Ramachandran N, Kozerke S, Atkinson D. High-resolution diffusion tensor imaging of the human kidneys using a free-breathing, multi-slice, targeted field of view approach. NMR Biomed 2014; 27:1300-12. [PMID: 25219683 PMCID: PMC4265306 DOI: 10.1002/nbm.3190] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 07/22/2014] [Accepted: 07/24/2014] [Indexed: 05/28/2023]
Abstract
Fractional anisotropy (FA) obtained by diffusion tensor imaging (DTI) can be used to image the kidneys without any contrast media. FA of the medulla has been shown to correlate with kidney function. It is expected that higher spatial resolution would improve the depiction of small structures within the kidney. However, the achievement of high spatial resolution in renal DTI remains challenging as a result of respiratory motion and susceptibility to diffusion imaging artefacts. In this study, a targeted field of view (TFOV) method was used to obtain high-resolution FA maps and colour-coded diffusion tensor orientations, together with measures of the medullary and cortical FA, in 12 healthy subjects. Subjects were scanned with two implementations (dual and single kidney) of a TFOV DTI method. DTI scans were performed during free breathing with a navigator-triggered sequence. Results showed high consistency in the greyscale FA, colour-coded FA and diffusion tensors across subjects and between dual- and single-kidney scans, which have in-plane voxel sizes of 2 × 2 mm(2) and 1.2 × 1.2 mm(2) , respectively. The ability to acquire multiple contiguous slices allowed the medulla and cortical FA to be quantified over the entire kidney volume. The mean medulla and cortical FA values were 0.38 ± 0.017 and 0.21 ± 0.019, respectively, for the dual-kidney scan, and 0.35 ± 0.032 and 0.20 ± 0.014, respectively, for the single-kidney scan. The mean FA between the medulla and cortex was significantly different (p < 0.001) for both dual- and single-kidney implementations. High-spatial-resolution DTI shows promise for improving the characterization and non-invasive assessment of kidney function.
Collapse
Affiliation(s)
- Rachel W Chan
- Centre for Medical Imaging, University College LondonLondon, UK
| | - Constantin Von Deuster
- Institute for Biomedical Engineering, University and ETH ZurichZurich, Switzerland
- Division of Imaging Sciences, King's College LondonLondon, UK
| | - Christian T Stoeck
- Institute for Biomedical Engineering, University and ETH ZurichZurich, Switzerland
| | - Jack Harmer
- Division of Imaging Sciences, King's College LondonLondon, UK
| | - Shonit Punwani
- Centre for Medical Imaging, University College LondonLondon, UK
- Radiology Department, University College London HospitalsLondon, UK
| | - Navin Ramachandran
- Centre for Medical Imaging, University College LondonLondon, UK
- Radiology Department, University College London HospitalsLondon, UK
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH ZurichZurich, Switzerland
- Division of Imaging Sciences, King's College LondonLondon, UK
| | - David Atkinson
- Centre for Medical Imaging, University College LondonLondon, UK
| |
Collapse
|
40
|
Ding H, Fernandez-de-Manuel L, Schär M, Schuleri KH, Halperin H, He L, Zviman MM, Beinart R, Herzka DA. Three-dimensional whole-heart T2 mapping at 3T. Magn Reson Med 2014; 74:803-16. [PMID: 25242141 DOI: 10.1002/mrm.25458] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/23/2014] [Accepted: 08/25/2014] [Indexed: 01/28/2023]
Abstract
PURPOSE Detecting variations in myocardial water content with T2 mapping is superior to conventional T2 -weighted MRI since quantification enables direct observation of complicated pathology. Most commonly used T2 mapping techniques are limited in achievable spatial and/or temporal resolution, both of which reduce accuracy due to partial-volume averaging and misregistration between images. The goal of this study was to validate a novel free breathing T2 mapping sequence that overcomes these limitations. METHODS The proposed technique was made insensitive to heart rate variability through the use of a saturation prepulse to reset magnetization every heartbeat. Respiratory navigator-gated, differentially T2 -weighted volumes were interleaved per heartbeat, guaranteeing registered images and robust voxel-by-voxel T2 maps. Free breathing acquisitions removed limits on spatial resolution and allowed short diastolic windows. Accuracy was quantified with simulations and phantoms. RESULTS Homogeneous three-dimensional (3D) T2 maps were obtained from normal human subjects and swine. Normal human and swine left ventricular T2 values were 42.3 ± 4.0 and 43.5 ± 4.3 ms, respectively. The T2 value for edematous myocardium obtained from a swine model of acute myocardial infarction was 59.1 ± 7.1 ms. CONCLUSION Free-breathing accurate 3D T2 mapping is feasible and may be applicable in myocardial assessment in lieu of current clinical black blood, T2 -weighted techniques.
Collapse
Affiliation(s)
- Haiyan Ding
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China.,Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Laura Fernandez-de-Manuel
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.,Biomedical Image Technologies Laboratory, ETSI Telecomunicación, Universidad Politécnica de Madrid, and CIBER-BBN, Madrid, Spain
| | - Michael Schär
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.,Philips Healthcare, Cleveland, Ohio, USA
| | - Karl H Schuleri
- Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Henry Halperin
- Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Le He
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China
| | - M Muz Zviman
- Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Roy Beinart
- Department of Medicine, Cardiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.,Heart Institute, Sheba Medical Center, Tel Aviv University, Ramat Gan, Israel
| | - Daniel A Herzka
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
41
|
Bamrungchart S, Tantaway EM, Midia EC, Hernandes MA, Srirattanapong S, Dale BM, Semelka RC. Free breathing three-dimensional gradient echo-sequence with radial data sampling (radial 3D-GRE) examination of the pancreas: Comparison with standard 3D-GRE volumetric interpolated breathhold examination (VIBE). J Magn Reson Imaging 2013; 38:1572-7. [PMID: 23417838 DOI: 10.1002/jmri.24064] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 01/10/2013] [Indexed: 02/06/2023] Open
Abstract
PURPOSE To evaluate the diagnostic performance of free breathing three-dimensional gradient echo-sequence with radial data sampling (radial 3D-GRE) in MR imaging of the normal and diseased pancreas, using standard 3D-GRE for comparison in cooperative patients, and to perform a preliminary assessment in noncooperative patients. MATERIALS AND METHODS One hundred and eight consecutive patients underwent 1.5 Tesla MR imaging of the abdomen that included pre- and postcontrast free breathing radial 3D-GRE. The sequences were evaluated by two radiologists retrospectively, independently, and blindly. The results were compared using Wilcoxon-Mann-Whitney test. Kappa statistics were used to measure the extent of agreement between the reviewers. RESULTS The average scores indicated that the overall images quality of radial 3D-GRE was lower than 3D-GRE-VIBE in both pre- and postcontrast study (P = 0.0172 and 0.0001), however it achieved a rating that approximated good. In all patients, radial 3D-GRE had a mild extent of streak artifact, pulsation, susceptibility, and respiratory artifact. Radial 3D-GRE approximated good results for pancreatic edge sharpness and pancreatic ductal clarity, and did not differ significantly between cooperative and noncooperative patients. Respiratory artifact was worse in cooperative than in noncooperative patients (P = 0.02). Demonstration of pancreatic disease was slightly inferior with radial 3D-VIBE, but quality approximated good. CONCLUSION Free breathing radial 3D-GRE may be applicable for pancreatic MR imaging in patients who are unable to suspend respiration.
Collapse
Affiliation(s)
- Saraporn Bamrungchart
- Department of Radiology, University of North Carolina at Chapel Hill, North Carolina, USA; Department of Radiology, Lerdsin hospital, Bangkok, Thailand
| | | | | | | | | | | | | |
Collapse
|
42
|
Wollny G, Kellman P, Santos A, Ledesma-Carbayo MJ. Automatic motion compensation of free breathing acquired myocardial perfusion data by using independent component analysis. Med Image Anal 2012; 16:1015-28. [PMID: 22465078 PMCID: PMC3372575 DOI: 10.1016/j.media.2012.02.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 02/07/2012] [Accepted: 02/12/2012] [Indexed: 11/16/2022]
Abstract
Images acquired during free breathing using first-pass gadolinium-enhanced myocardial perfusion magnetic resonance imaging (MRI) exhibit a quasiperiodic motion pattern that needs to be compensated for if a further automatic analysis of the perfusion is to be executed. In this work, we present a method to compensate this movement by combining independent component analysis (ICA) and image registration: First, we use ICA and a time-frequency analysis to identify the motion and separate it from the intensity change induced by the contrast agent. Then, synthetic reference images are created by recombining all the independent components but the one related to the motion. Therefore, the resulting image series does not exhibit motion and its images have intensities similar to those of their original counterparts. Motion compensation is then achieved by using a multi-pass image registration procedure. We tested our method on 39 image series acquired from 13 patients, covering the basal, mid and apical areas of the left heart ventricle and consisting of 58 perfusion images each. We validated our method by comparing manually tracked intensity profiles of the myocardial sections to automatically generated ones before and after registration of 13 patient data sets (39 distinct slices). We compared linear, non-linear, and combined ICA based registration approaches and previously published motion compensation schemes. Considering run-time and accuracy, a two-step ICA based motion compensation scheme that first optimizes a translation and then for non-linear transformation performed best and achieves registration of the whole series in 32±12s on a recent workstation. The proposed scheme improves the Pearsons correlation coefficient between manually and automatically obtained time-intensity curves from .84±.19 before registration to .96±.06 after registration.
Collapse
Affiliation(s)
- Gert Wollny
- Biomedical Imaging Technologies, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, Avenida Complutense nº 30, 28040 Madrid, Spain
| | - Peter Kellman
- Laboratory of Cardiac Energetics, National Heart, Lung and Blood Institute, National Institutes of Health, DHHS, Bethesda, MD, USA
| | - Andrés Santos
- Biomedical Imaging Technologies, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, Avenida Complutense nº 30, 28040 Madrid, Spain
- CIBER de Bioingeniera, Biomateriales y Nanomedicina (CIBER-BBN), Spain
| | - María J. Ledesma-Carbayo
- Biomedical Imaging Technologies, DIE, ETSI Telecomunicación, Universidad Politécnica de Madrid, Avenida Complutense nº 30, 28040 Madrid, Spain
- CIBER de Bioingeniera, Biomateriales y Nanomedicina (CIBER-BBN), Spain
| |
Collapse
|
43
|
Zhao T, Lu W, Yang D, Mutic S, Noel CE, Parikh PJ, Bradley JD, Low DA. Characterization of free breathing patterns with 5D lung motion model. Med Phys 2009; 36:5183-9. [PMID: 19994528 PMCID: PMC2774350 DOI: 10.1118/1.3246348] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 09/21/2009] [Accepted: 09/22/2009] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To determine the quiet respiration breathing motion model parameters for lung cancer and nonlung cancer patients. METHODS 49 free breathing patient 4DCT image datasets (25 scans, cine mode) were collected with simultaneous quantitative spirometry. A cross-correlation registration technique was employed to track the lung tissue motion between scans. The registration results were applied to a lung motion model: X(-->) = X(-->)0 + alpha(-->)v + beta(-->)f, where X(-->) is the position of a piece of tissue located at reference position X(-->)0 during a reference breathing phase (zero tidal volume v, zero airflow f). alpha(-->) is a parameter that characterizes the motion due to air filling (motion as a function of tidal volume v) and beta(-->) is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation that causes lung motion hysteresis (motion as a function of airflow f). The parameters alpha(-->) and beta(-->) together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The alpha(-->) and beta(-->) distributions were examined for each patient to determine overall general patterns and interpatient pattern variations. RESULTS For 44 patients, the greatest values of /alpha(-->)/ were observed in the inferior and posterior lungs. For the rest of the patients, /alpha(-->)/ reached its maximum in the anterior lung in three patients and the lateral lung in two patients. The hysteresis motion beta(-->) had greater variability, but for the majority of patients, /beta(-->)/ was largest in the lateral lungs. CONCLUSIONS This is the first report of the three-dimensional breathing motion model parameters for a large cohort of patients. The model has the potential for noninvasively predicting lung motion. The majority of patients exhibited similar /alpha(-->)/ maps and the /beta(-->)/ maps showed greater interpatient variability. The motion parameter interpatient variability will inform our need for custom radiation therapy motion models. The utility of this model depends on the parameter stability over time, which is still under investigation.
Collapse
Affiliation(s)
- Tianyu Zhao
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
| | | | | | | | | | | | | | | |
Collapse
|