Related Experiment Video
Updated: Apr 17, 2026
MRI and PET in Mouse Models of Myocardial Infarction
Published on: December 19, 2013
Accelerated acquisition of tagged MRI for cardiac motion correction in simultaneous PET-MR: phantom and patient
Chuan Huang1, Yoann Petibon2, Jinsong Ouyang3
1Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114; Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115; and Departments of Radiology, Psychiatry, Stony Brook Medicine, Stony Brook, New York 11794.
Purpose:
Degradation of image quality caused by cardiac and respiratory motions hampers the diagnostic quality of cardiac PET. It has been shown that improved diagnostic accuracy of myocardial defect can be achieved by tagged MR (tMR) based PET motion correction using simultaneous PET-MR. However, one major hurdle for the adoption of tMR-based PET motion correction in the PET-MR routine is the long acquisition time needed for the collection of fully sampled tMR data. In this work, the authors propose an accelerated tMR acquisition strategy using parallel imaging and/or compressed sensing and assess the impact on the tMR-based motion corrected PET using phantom and patient data.
Methods:
Fully sampled tMR data were acquired simultaneously with PET list-mode data on two simultaneous PET-MR scanners for a cardiac phantom and a patient. Parallel imaging and compressed sensing were retrospectively performed by GRAPPA and kt-FOCUSS algorithms with various acceleration factors. Motion fields were estimated using nonrigid B-spline image registration from both the accelerated and fully sampled tMR images. The motion fields were incorporated into a motion corrected ordered subset expectation maximization reconstruction algorithm with motion-dependent attenuation correction.
Results:
Although tMR acceleration introduced image artifacts into the tMR images for both phantom and patient data, motion corrected PET images yielded similar image quality as those obtained using the fully sampled tMR images for low to moderate acceleration factors (<4). Quantitative analysis of myocardial defect contrast over ten independent noise realizations showed similar results. It was further observed that although the image quality of the motion corrected PET images deteriorates for high acceleration factors, the images were still superior to the images reconstructed without motion correction.
Conclusions:
Accelerated tMR images obtained with more than 4 times acceleration can still provide relatively accurate motion fields and yield tMR-based motion corrected PET images with similar image quality as those reconstructed using fully sampled tMR data. The reduction of tMR acquisition time makes it more compatible with routine clinical cardiac PET-MR studies.
Insights
Accelerated tagged MR (tMR) acquisition significantly reduces scan times for cardiac PET-MR motion correction. This method maintains diagnostic image quality, making cardiac PET-MR more feasible for routine clinical use.
Area of Science:
- Medical Imaging
- Nuclear Medicine
- Cardiovascular Imaging
Background:
- Cardiac and respiratory motion degrade PET image quality, impacting diagnostic accuracy.
- Tagged MR (tMR)-based PET motion correction improves myocardial defect detection but requires long acquisition times.
Purpose of the Study:
- To develop and evaluate an accelerated tMR acquisition strategy for PET motion correction.
- To assess the impact of accelerated tMR on motion-corrected PET image quality using phantom and patient data.
Main Methods:
- Retrospective acceleration of tMR data using parallel imaging (GRAPPA) and compressed sensing (kt-FOCUSS).
- Motion field estimation via nonrigid B-spline registration on accelerated and fully sampled tMR images.
- Incorporation of motion fields into motion-corrected ordered subset expectation maximization (OSEM) reconstruction with motion-dependent attenuation correction.
Main Results:
- Accelerated tMR introduced artifacts but yielded comparable PET image quality to fully sampled tMR at acceleration factors <4.
- Quantitative analysis showed similar myocardial defect contrast.
- Even at high acceleration factors, motion-corrected PET images were superior to uncorrected images.
Conclusions:
- Accelerated tMR (4x acceleration) provides accurate motion fields for PET motion correction.
- This acceleration reduces tMR acquisition time, enhancing compatibility with routine clinical cardiac PET-MR.
- The method preserves diagnostic image quality for clinical applications.
