Application of OTSU-based self-attenuation correction PET reconstruction technology in 18F-AV45 imaging / 中华核医学与分子影像杂志

ABSTRACT

Objective:To explore the application of OTSU-based self-attenuation correction PET (sacPET) reconstruction technology in 18F-florbetapir (AV45) imaging. Methods:From November 2018 to December 2019, 7 confirmed Alzheimer′s disease (AD) patients (4 males, 3 females, age (69.6±4.5)years) and 3 healthy controls (HC; 1 male, 2 females, age (68.0±4.6) years) were recruited prospectively for 18F-AV45 PET imaging in the First Affiliated Hospital of Sun Yat-Sen University. Original data collected by PET acquisition was processed with sacPET reconstruction and then compared with standard PET images by visual analysis and semi-quantitative analysis. Fisher exact test, Kappa test and Pearson correlation analysis were used to analyze data. Results:In HC group and AD group, the radioactive distribution showed by sacPET images and that by standard PET images were similar, and the contrast of gray-white matter in sacPET images was weaker than that in standard PET images. Moreover, the positive uptake area of the cortex in the AD group was smaller than that in standard PET images. Visual analysis showed 19 positive regions in sacPET images and 22 in standard PET images, with no statistical difference of positive rates of the sub-regions in the cortex between the two PET images (all P>0.05), and the overall consistency of 88.00% (44/50; Kappa=0.75 (95% CI 0.57-0.94), P<0.05). Semi-quantitative analysis showed that the standardized uptake value ratio (SUVR) of frontal lobe and cingulate gyrus measured by sacPET was lower than that measured by standard PET (0.93±0.06 vs 0.96±0.06 and 0.99±0.04 vs 1.01±0.04; t values 5.30 and 5.10, both P<0.01), while SUVR of parietal lobe, temporal lobe and occipital lobe measured by sacPET was higher than that measured by standard PET (0.78±0.08 vs 0.68±0.07, 0.97±0.07 vs 0.91±0.08 and 0.94±0.11 vs 0.71±0.12; t values 6.27, 7.36 and 16.90, all P<0.01). The overall SUVR of sacPET images was significantly correlated with the standard PET images ( r=0.75, P<0.001). Conclusion:For 18F-AV45 imaging, sacPET reconstruction technology can obtain reliable and effective PET images without CT data, but its accuracy and precision still need to be improved.