Diagnostic value and influencing factors of 11C-PIB in mild cognitive impairment and Alzheimer′s disease / 中华核医学与分子影像杂志

ABSTRACT

Objective:To investigate the diagnostic value of 11C-Pittsburgh compound B (PIB) in patients with mild cognitive impairment (MCI) and Alzheimer′s disease (AD) and explore the factors that may affect the binding of 11C-PIB. Methods:From January 2017 to December 2019, the 11C-PIB uptake of 6 patients with normal cognitive (NC; 3 males, 3 females, age: (64.5±12.3) years), 11 patients with MCI (4 males, 7 females, age: (64.5±9.8) years) and 21 patients with AD (7 males, 14 females, age: (68.1±9.1) years) from Daping Hospital, Army Medical University were retrospectively analyzed. Regional 11C-PIB binding was assessed by using standardized uptake value ratio (SUVR) and visual reading of 11C-PIB scan. Clinical data, including age, gender, education level, cognitive impairment, neuropsychological scale score, vascular risk factors (VRF), apolipoprotein E (ApoE) gene, were collected and differences among groups were analyzed by using one-way analysis of variance, least significant difference t test or Fisher exact test. Factors that affected the 11C-PIB binding were analyzed by multiple linear regression. Results:SUVR of cerebral lobe among NC, MCI and AD groups were significantly different (range of mean SUVR: 1.16-1.26, 1.19-1.35 and 1.40-1.61; F values: 5.331-9.279, all P<0.05). For positive PIB patients, SUVR of posterior cingulate and precuneus were increased in MCI group compared with NC group (1.20±0.15 vs 1.50±0.12, 1.18±0.15 vs 1.59±0.13; F values: 6.389 and 10.668, t values: -2.33 and -3.10, both P<0.05), and there were no significant differences in all lobes between MCI and AD group ( t values: from -1.29 to -0.51, all P>0.05). Visual analysis showed that the positive rates of PIB in frontal lobe (85.7%(18/21)), posterior cingulate (85.7%(18/21)), precuneus (81.0%(17/21)), temporal lobe (81.0%(17/21)) and occipital lobe (47.6%(10/21)) in AD were higher than those in MCI (4/11, 4/11, 4/11, 3/11 and 1/11, respectively; all P<0.05). Multiple linear regression showed that the degree of cognitive impairment were independent risk factors for SUVR of all lobes ( b values: 0.377-0.536, all P<0.05). The ApoE ε4 gene was independent risk factor for SUVR of precuneus ( b=0.290, P<0.05). Conclusion:11C-PIB is helpful for clinical diagnosis of MCI and AD patients and the degree of cognitive impairment and ApoE ε4 gene may be independent risk factors for increasing 11C-PIB binding.