Quantitative VOI-based Analysis of Template-guided Attenuation Correction in 3D Brain PET

A transmission template-guided attenuation correction method was recently proposed and validated in comparison to transmission-based attenuation correction using voxelwise SPM analysis of clinical data. In contrast to brain activation studies, brain PET research studies often involve absolute quantification. As the assessment was carried out by a SPM group analysis alone, validation as to how such quantification can be affected by the two methods needed to be performed to demonstrate how the proposed method performs individually, particularly for diagnostic applications or individual quantification. In this study, we assess the quantitative accuracy of this method using automated volume of interest (VOI)-based analysis by means of the BRASS software for automatic fitting and quantification of functional brain images. There is a very good correlation (R² = 0.91) between the Atlas-guided and measured transmission-guided attenuation correction techniques and the regression line agreed well with the line of identity (slope = 0.96). The mean absolute relative difference between the two methods for all VOIs across the whole population is 2.3% whereas the maximum difference is less than 7%. No proof of statistically significant differences could be verified for all regions. These encouraging results provide further confidence in the adequacy of the proposed approach demonstrating its performance particularly for research studies or diagnostic applications involving quantification.