PET | Evaluation of MR Based Respiratory Motion Correction Technique i…
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작성자 : 서울대 핵의학과 작성일2017-02-02 조회3,022회관련링크
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Yong Ho Do, Hong Jae Lee, Jin Eui Kim
Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea
[Purpose] Respiratory motion during PET/MR acquisition may result in image blurring and error in measurement for volume and quantification of lesion. The aim of this study was to evaluate changes of quantitative accuracy, tumor volume and image quality by applying MR based respiratory motion correction technique (MBRMCT) using integrated PET/MR scanner.
[Materials & Method] Data of 8 patients (aged 60.1 ± 9.1 y) underwent 18F-FDG liver PET/MR (Biograph mMR 3.0T, Siemens) study were collected. PET listmode data for 7 minutes was
simultaneously acquired with maximum average gate (MAG), minimum time gate (MTG) and none gate (NG) T1 weighted MR images. Gated PET reconstruction was performed using mu-maps generated from MAG and MTG by setting 35% of efficiency window. Maximum SUV (SUVmax), peak SUV (SUVpeak), tumor volume and full width at half maximum (FWHM) in the z-axis direction of MAG, MTG and NG PET images were evaluated.
[Results] Compared to NG, mean SUVmax and SUVpeak were increased in MAG 13.62%(p=0.002),
7.42%(p=0.002), MTG 14.50%(p=0.001), 7.97%(p=0.001) and mean tumor volume and FWHM were decreased in MAG 13.47%(p=0.004), 17.48%(p=0.056), MTG 13.98%(p=0.003), 17.66%(p=0.05) respectively. Mean SUVmax and SUVpeak of MTG were increased by 0.77%(p=0.28), 0.51%(p=0.398) and mean tumor volume and FWHM were decreased by 0.58%(p=0.523), 0.23%(p=0.487) compared to MAG. There was no statistically significant difference between MTG and MAG which increase total scan time for 7 and 1.5 minutes.
[Conclusion] SUV, accuracy of tumor volume and image quality were improved in both of MAG and MTG by applying MBRMCT without installing additional hardware in liver PET/MR study. More accurate information can be provided with the increase of 1.5 minutes scan time if applying MBRMCT to various abdominal PET/MR studies affected by respiratory motion.
[Key Words] Respiratory motion correction, PET/MR, SUV, Liver cancer