Value of visual analysis and SUVR during 18F-AV45 PET/CT imaging in the diagnosis of mild cognitive impairment and Alzheimer′s disease

Abstract

Objective To evaluate the value of visual analysis and standardized uptake value ratio (SUVR) during 18F-florbetapir (AV45) PET/CT brain imaging in diagnosis of β-amyloid (Aβ) deposition in patients with mild cognitive impairment (MCI) and Alzheimer′s disease (AD), and to explore the clinical ancillary value of the two indexes. Methods From December 2018 to July 2019, a total of 47 subjects, including 5 (3 males, 2 females, age (58±13) years) normal controls (NC), 8 (2 males, 6 females, age (66±10) years) patients with AD and 34 (16 males, 18 females, age (70±7) years) patients with MCI were enrolled. All subjects underwent 18F-AV45 PET/CT scan. All images were evaluated by visual analysis and SUVR were calculated. The diagnostic efficiencies of visual analysis and SUVR were compared by McNemar test and Kappa test. One-way analysis of variance and Welch test were used to compare data differences. The best threshold value of SUVR was obtained by receiver operating characteristic (ROC) curve analysis. Results The positive rate of Aβ deposition for all subjects was 46.81%(22/47) by SUVR analysis, and 38.30%(18/47) by visual analysis. There was no significant difference between the two methods (χ2=33.15, P>0.05), and the consistency was good (Kappa=0.83). Considering the clinical diagnosis as thegold standard, the Aβ deposition obtained by visual analysis and SUVR analysis can effectively distinguish AD from NC, and the sensitivities were 7/8 vs 8/8, respectively, both specificities were 5/5(χ2=9.48, P>0.05), with good consistency (Kappa=0.84). SUVR quantitative analysis could distinguish AD from NC, AD from MCI (F values: 3.99-8.79, all P 0.05). ROC curve analysis showed that the best threshold value of precuneus′ SUVR was 1.08 for the differential diagnosis of AD and NC; for the differential diagnosis of AD and MCI, the best threshold value of lateral temporal′s SUVR was 1.06. Conclusion Visual analysis was consistent with SUVR′s qualitative determination during 18F-AV45 PET/CT imaging for brain Aβ deposition, while SUVR quantitative analysis could assist in the differential diagnosis of AD and NC, AD and MCI. Key words: Alzheimer Disease; Cognition disorders; Amyloidogenic proteins; Positron-emission tomography; Tomography, X-ray computed