TY - JOUR
T1 - Non-rigid Motion-compensated 3D Whole-heart T2 mapping in a hybrid 3T PET-MR system
AU - Schneider, Alina
AU - Munoz Escobar, Camila
AU - Hua, Alina
AU - Ellis, Sam
AU - Jeljeli, Sami
AU - Kunze, Karl
AU - Neji, Radhouene
AU - Reader, Andrew
AU - Reyes-Torres, Eliana
AU - Ismail, Tevfik
AU - Botnar, Rene
AU - Prieto Vasquez, Claudia
N1 - Funding Information:
This work was supported by EPSRC (EP/L015226/1, EP/P032311/1, EP/P007619/1, and EP/P001009/1). This research was supported by the National Institute for Health Research (NIHR) Cardiovascular Health Technology Cooperative (HTC) and the Biomedical Research Centre based at Guy's and St. Thomas' NHS Foundation Trust and King's College London. This research was funded in part, by the Wellcome Trust NS/A000049/1. For Open Access, the author has applied a CC BY public copyright license to any Author Accepted Manuscript version arising from this submission.
Publisher Copyright:
© 2024 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.
PY - 2024/5
Y1 - 2024/5
N2 - PURPOSE: Simultaneous PET-MRI improves inflammatory cardiac disease diagnosis. However, challenges persist in respiratory motion and mis-registration between free-breathing 3D PET and 2D breath-held MR images. We propose a free-breathing non-rigid motion-compensated 3D T
2 -mapping sequence enabling whole-heart myocardial tissue characterization in a hybrid 3T PET-MR system and provides non-rigid respiratory motion fields to correct also simultaneously acquired PET data.
METHODS: Free-breathing 3D whole-heart T
2 -mapping was implemented on a hybrid 3T PET-MRI system. Three datasets were acquired with different T
2 -preparation modules (0, 28, 55 ms) using 3-fold undersampled variable-density Cartesian trajectory. Respiratory motion was estimated via virtual 3D image navigators, enabling multi-contrast non-rigid motion-corrected MR reconstruction. T
2 -maps were computed using dictionary-matching. Approach was tested in phantom, 8 healthy subjects, 14 MR only and 2 PET-MR patients with suspected cardiac disease and compared with spin echo reference (phantom) and clinical 2D T
2 -mapping (in-vivo).
RESULTS: Phantom results show a high correlation (R
2 = 0.996) between proposed approach and gold standard 2D T
2 mapping. In-vivo 3D T
2 -mapping average values in healthy subjects (39.0 ± 1.4 ms) and patients (healthy tissue) (39.1 ± 1.4 ms) agree with conventional 2D T
2 -mapping (healthy = 38.6 ± 1.2 ms, patients = 40.3 ± 1.7 ms). Bland-Altman analysis reveals bias of 1.8 ms and 95% limits of agreement (LOA) of -2.4-6 ms for healthy subjects, and bias of 1.3 ms and 95% LOA of -1.9 to 4.6 ms for patients.
CONCLUSION: Validated efficient 3D whole-heart T
2 -mapping at hybrid 3T PET-MRI provides myocardial inflammation characterization and non-rigid respiratory motion fields for simultaneous PET data correction. Comparable T
2 values were achieved with both 3D and 2D methods. Improved image quality was observed in the PET images after MR-based motion correction.
AB - PURPOSE: Simultaneous PET-MRI improves inflammatory cardiac disease diagnosis. However, challenges persist in respiratory motion and mis-registration between free-breathing 3D PET and 2D breath-held MR images. We propose a free-breathing non-rigid motion-compensated 3D T
2 -mapping sequence enabling whole-heart myocardial tissue characterization in a hybrid 3T PET-MR system and provides non-rigid respiratory motion fields to correct also simultaneously acquired PET data.
METHODS: Free-breathing 3D whole-heart T
2 -mapping was implemented on a hybrid 3T PET-MRI system. Three datasets were acquired with different T
2 -preparation modules (0, 28, 55 ms) using 3-fold undersampled variable-density Cartesian trajectory. Respiratory motion was estimated via virtual 3D image navigators, enabling multi-contrast non-rigid motion-corrected MR reconstruction. T
2 -maps were computed using dictionary-matching. Approach was tested in phantom, 8 healthy subjects, 14 MR only and 2 PET-MR patients with suspected cardiac disease and compared with spin echo reference (phantom) and clinical 2D T
2 -mapping (in-vivo).
RESULTS: Phantom results show a high correlation (R
2 = 0.996) between proposed approach and gold standard 2D T
2 mapping. In-vivo 3D T
2 -mapping average values in healthy subjects (39.0 ± 1.4 ms) and patients (healthy tissue) (39.1 ± 1.4 ms) agree with conventional 2D T
2 -mapping (healthy = 38.6 ± 1.2 ms, patients = 40.3 ± 1.7 ms). Bland-Altman analysis reveals bias of 1.8 ms and 95% limits of agreement (LOA) of -2.4-6 ms for healthy subjects, and bias of 1.3 ms and 95% LOA of -1.9 to 4.6 ms for patients.
CONCLUSION: Validated efficient 3D whole-heart T
2 -mapping at hybrid 3T PET-MRI provides myocardial inflammation characterization and non-rigid respiratory motion fields for simultaneous PET data correction. Comparable T
2 values were achieved with both 3D and 2D methods. Improved image quality was observed in the PET images after MR-based motion correction.
UR - https://onlinelibrary.wiley.com/doi/full/10.1002/mrm.29973
UR - http://www.scopus.com/inward/record.url?scp=85181530322&partnerID=8YFLogxK
U2 - 10.1002/mrm.29973
DO - 10.1002/mrm.29973
M3 - Article
C2 - 38181169
SN - 0740-3194
VL - 91
SP - 1951
EP - 1964
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
IS - 5
ER -