4D-CT와 결합한 호흡게이트 PET을 이용한 PET영상의 호흡 인공산물 분석 (Analysis of Respiratory Motion Artifacts in PET Imaging Using Respiratory Gated PET Combined with 4D-CT) |
Author |
조병철1·박성호1·박희철1·배훈식1·황희성2·신희순3, |
Byung Chul Cho, Ph.D.1, Sung Ho Park, Ph.D.1, Hee Chul Park, M.D.1, Hoonsik Bae, M.D.1, Hee Sung Hwang, M.D.2, Hee-Soon Shin, M.S.3 |
Affiliation |
한림대학교 의과대학 방사선종양학교실1, 진단방사선과교실2, GE Healthcare, Korea3 Department of Radiation Oncology1, Division of Nuclear Medicine, Department of Radiology2, Hallym University College of Medicine, Chunchon, Korea1,2, GE Healthcare, Korea3 |
Abstract |
Purpose: Reduction of respiratory motion artifacts in PET images was studied using respiratory-gated PET (RGPET)
with moving phantom. Especially a method of generating simulated helical CT images from 4D-CT datasets was
developed and applied to a respiratory specific RGPET images for more accurate attenuation correction. Materials
and Methods: Using a motion phantom with periodicity of 6 seconds and linear motion amplitude of 26 mm,
PET/CT (Discovery ST; GEMS) scans with and without respiratory gating were obtained for one syringe and two
vials with each volume of 3, 10, and 30 ml respectively. RPM (Real-Time Position Management, Varian) was used
for tracking motion during PET/CT scanning. Ten datasets of RGPET and 4D-CT corresponding to every 10% phase
intervals were acquired. From the positions, sizes, and uptake values of each subject on the resultant phase
specific PET and CT datasets, the correlations between motion artifacts in PET and CT images and the size of
motion relative to the size of subject were analyzed. Results: The center positions of three vials in RGPET and
4D-CT agree well with the actual position within the estimated error. However, volumes of subjects in non-gated
PET images increase proportional to relative motion size and were overestimated as much as 250% when the
motion amplitude was increased two times larger than the size of the subject. On the contrary, the
corresponding maximal uptake value was reduced to about 50%. Conclusion: RGPET is demonstrated to remove
respiratory motion artifacts in PET imaging, and moreover, more precise image fusion and more accurate
attenuation correction is possible by combining with 4D-CT.(Korean J Nucl Med 39(3):174-181, 2005) |
Keyword |
Respiratory motion artifacts, F-18 FDG, PET, Respiratory gated PET, 4D-CT |
Full text Article |
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