Positron Emission Tomography (PET) is a valuable tool to visualize cancer cells. It usually takes about 6~7 minutes to acquire enough PET data for one bed position, so the patient respiratory motion is inevitable. Motion blur deteriorates image quality so that miss detection of malignant tumors and incorrect quantification may occur.
There have been many research on motion correction of PET to improve image quality. Motions were estimated from PET images with low spatial resolution or CT images with high radiation dose. Recently developed simultaneous PET-MR allows us to acquire PET and MR images at the same time. We estimated motion from high-quality MR images with no radiation dose and applied estimated motion to motion correction in PET. The figures show that compared to no motion correction (top left) and conventional gating method (top right), our proposed motion correction based on the estimated motion from MR images (bottom left) significantly improved the contrast and reduced the noise (bottom right).
- Y Petibon, J Ouyang, X Zhu, C Huang, T G Reese, S Y Chun, Q Li, G El Fakhri, “Cardiac motion compensation and resolution modeling in simultaneous PET-MR: a cardiac lesion detection study,” Physics in Medicine and Biology, 58(7): 2085-2102, Mar. 2013.
- S Y Chun, T Reese, J Ouyang, B Guerin, C Catana, X Zhu, N Alpert, G El Fakhri, “MRI-based nonrigid motion correction in simultaneous PET/MRI,” Journal of Nuclear Medicine, 53(8):1284-1291, Aug. 2012. (Cover Article)
- B Guerin, S Cho, S Y Chun, X Zhu, N M Alpert, G El Fakhri, T Reese, C Catana, “Nonrigid PET motion compensation in the lower abdomen using simultaneous tagged-MRI and PET imaging,” Medical Physics, 38(6):3025-3038, June 2011.