Nucl Med Mol Imaging.  2007 Feb;41(1):49-53.

Quantitative Comparisons between CT and 68Ge Transmission Attenuation Corrected 18F-FDG PET Images: Measured Attenuation Correction vs. Segmented Attenuation Correction

Affiliations
  • 1Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. btnm.kim@samsung.com

Abstract

PURPOSE: It was reported that CT-based measured attenuation correction (CT-MAC) produced radioactivity concentration values significantly higher than 68Ge-based segmented attenuation correction (Ge-SAC) in PET images. However, it was unknown whether the radioactivity concentration difference resulted from different sources (CT vs. Ge) or types (MAC vs. SAC) of attenuation correction (AC). We evaluated the influences of the source and type of AC on the radioactivity concentration differences between reconstructed PET images in normal subjects and patients. MATERIAL AND METHODS: Five normal subjects and 35 patients with a known or suspected cancer underwent 18F-FDG PET/CT. In each subject, attenuation corrected PET images using OSEM algorithm (28 subsets, 2 iterations) were reconstructed by 4 methods: CT-MAC, CT-SAC, Ge-MAC, and Ge-SAC. The physiological uptake in normal subjects and pathological uptake in patients were quantitatively compared between the PET images according to the source and type of AC.
RESULTS
The SUVs of physiological uptake measured in CT-MAC PET images were significantly higher than other 3 differently corrected PET images. Maximum SUVs of the 145 foci with abnormal FDG uptake in CT-MAC images were significantly highest among 4 differently corrected PET images with a difference of 2.4% to 5.1% (p<0.001). The SUVs of pathological uptake in Ge-MAC images were significantly higher than those in CT-SAC and Ge-MAC PET images (p<0.001).
CONCLUSION
Quantitative radioactivity values were highest in CT-MAC PET images. The adoption of MAC may make a more contribution than the adoption of CT attenuation map to such differences.

Keyword

PET; 18F-FDG; attenuation correction; CT; 68Ge

MeSH Terms

Fluorodeoxyglucose F18*
Humans
Positron-Emission Tomography and Computed Tomography
Radioactivity
Fluorodeoxyglucose F18
Full Text Links
  • NMMI
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2022 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr