PET | The Comparison of SUV (Standard Uptake Value) according to the cha…
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작성자 : 서울대 핵의학과 작성일2017-02-02 조회3,219회관련링크
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PET center in Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea1
JungJin Lim, MT;JaeIl Kim, MT; HongJae Lee, MT; HyeonJoo Kim, MT1,
Background and Purpose : The introduction of Fusion PET has brought a higher diagnostic value compared to conventional PET. In particular, it not only allows accurate determination of location through CT images but also accurate compensation of attenuation, which greatly improves image quality. This paper examines the differences of SUV in attenuation corrected image according to the tube voltage. Subjects and Methods : For patient examination, six sick patients were selected and
18F-FDG was intravenously injected. After one hour, under the same conditions, the
tube voltage of CT was changed to 90, 120, and 140 kVp. Then the CT and PET images were obtained. CT images with changed tube voltages were applied to the 3D-RAMRA algorithm to produce attenuation corrected images. ROI was set for each attenuation corrected image and the maximum SUV values were measured and compared.
Results : Based on the attenuation corrected images with the tube voltage of CT set to 120 kVp which is used now, at each ROI for liver the SUV showed the difference of +2.08% at 90 kVp, and -1.01% at 140 kVp.
The SUV showed the difference of +1.42% at 90 kVp, and +0.37% at 140kVp in the lung.
At each ROI for bone the SUV showed the difference of +0.60% at 90 kVp, and
-0.04% at 140kVp. In the last, the SUV showed the difference of +1.63% at 90 kVp, and -0.32% at 140 kVp in the lesion.
Conclusion : The higher the energy of radiation that penetrates a subject, the lower gets the attenuation coefficient of the subject and the lower the attenuation correction value than the actually measured value. Furthermore, the higher the density of subject for the same penetrated radiation, the higher gets the attenuation coefficient of the subject and the higher the attenuation correction value than the actually measured value. This pattern was found in the results of this paper as well. However the changes in the result values were insignificant because the difference of changing energy was too small.
key word : Fusion PET, CTAC, attenuation corrected image, SUV