137Cs 점선원을 이용한 감쇠 보정기법들의 평가 (Assessment of Attenuation Correction Techniques with a 137Cs Point Source) |
Author |
봉정균2.김희중1,2.손혜경2.권윤영2.박해정1,2.윤미진1,2.이종두2.정해조2, |
Jung-Kyun Bong, Ph.D.2, Hee-Joung Kim, Ph.D.1,2, Hye-Kyoung Son, M.Sc.2, Yun-Young Park, B.Sc.2, Hae-Joung Park, Ph.D.1,2, Mijin Yun, M.D.1,2, Jong-Doo Lee, M.D. & Ph.D.1,2, Hae-Jo Jung, Ph.D.2 |
Affiliation |
연세대학교 핵의학과1, 진단방사선과 방사선의과학 연구소2 Division of Nuclear Medicine1, Department of Radiology, Yonsei University College of Medicine, Research Institute, of Radiological Science2, Yonsei University, Seoul, Korea |
Abstract |
Purpose: The objective of this study was to assess attenuation correction algorithms with the 137Cs point source for the brain positron emission tomography (PET) imaging process.
Materials & Methods: Four different types of
phantoms were used in this study for testing various types of the attenuation correction techniques. Transmission data of a 137Cs point source were acquired after infusing the emission source into phantoms and then the emission data were subsequently acquired in 3D acquisition mode. Scatter corrections were performed with a background tail-fitting algorithm. Emission data were then reconstructed using iterative reconstruction method with
a measured (MAC), elliptical (ELAC), segmented (SAC) and remapping (RAC) attenuation correction, respectively.
Reconstructed images were then both qualitatively and quantitatively assessed. In addition, reconstructed images of
a normal subject were assessed by nuclear medicine physicians. Subtracted images were also compared.
Results:
ELAC, SAC, and RAC provided a uniform phantom image with less noise for a cylindrical phantom. In contrast, a
decrease in intensity at the central portion of the attenuation map was noticed at the result of the MAC.
Reconstructed images of Jaszack and Hoffan phantoms presented better quality with RAC and SAC. The
attenuation of a skull on images of the normal subject was clearly noticed and the attenuation correction without
considering the attenuation of the skull resulted in artificial defects on images of the brain.
Conclusion: the
complicated and improved attenuation correction methods were needed to obtain the better accuracy of the
quantitative brain PET images.(Korean J Nucl Med 39(1):57-68, 2005) |
Keyword |
Positron emission tomography; Attenuation correction; 137Cs point source |
Full text Article |
3901057.pdf
|
|
|