To investigate the correlations between cerebral β-amyloid (Aβ) deposition assessed by ¹⁸F-florbetapir (AV45) PET imaging and clinical cognitive symptoms in patients with subtle cognitive decline (SCD) and mild cognitive impairment (MCI).

Data of twenty-four patients (11 males, 13 females, age: (63.2±7.6) years) diagnosed as SCD (n=15) or MCI (n=9) from December 2018 to March 2019 in Shanghai Jiao Tong University Affiliated Sixth People′s Hospital were collected prospectively. All patients underwent ¹⁸F-AV45 PET imaging, brain MRI T₁ scan and Mini-Mental State Examination (MMSE) within two weeks. ¹⁸F-AV45 PET images were analyzed visually (positive, mild positive, negative). After being pretreated according to the MRI, ¹⁸F-AV45 PET images were analyzed semi-quantitatively by calculating the standardized uptake value ratio (SUVR) of Aβ deposition in 8 regions of interest (ROIs; frontal lobe, lateral parietal lobe, lateral temporal lobe, medial temporal lobe, occipital lobe, basal ganglia, posterior cingulate and precuneus), with cerebellar gray matter as the reference. Partial correlation coefficients between regional SUVRs and MMSE score were calculated.

¹⁸F-AV45 PET imaging showed that 16 patients with positive results and 8 patients with mild positive results. MMSE score of 24 patients was 28.2±2.0, and the SUVR was 0.93-1.87. Correlation analysis revealed that Aβ deposition in frontal cortex (r=-0.432), posterior cingulate lobe (r=-0.434) and precuneus (r=-0.418) was negatively correlated with MMSE score (all P<0.05); and no significant correlations between SUVR and MMSE in other brain regions were found (r values: from -0.412 to -0.110, all P>0.05).

¹⁸F-AV45 PET imaging can noninvasively detect brain Aβ deposition in patients, and can effectively reflect the clinical cognitive status of patients with SCD and MCI to a certain extent.

Cognition disorders; Amyloid; Positron-emission tomography