Regional Associations of Cortical Superficial Siderosis and β-Amyloid-Positron-Emission-Tomography Positivity in Patients With Cerebral Amyloid Angiopathy

Objective:& nbsp;This is a cross-sectional study to evaluate whether beta-amyloid-(A beta)-PET positivity and cortical superficial siderosis (cSS) in patients with cerebral amyloid angiopathy (CAA) are regionally colocalized.Methods:& nbsp;Ten patients with probable or possible CAA (73.3 & PLUSMN; 10.9 years, 40% women) underwent MRI examination with a gradient-echo-T2*-weighted-imaging sequence to detect cSS and F-18-florbetaben PET examination to detect fibrillar A beta. In all cortical regions of the Hammers Atlas, cSS positivity (MRI: ITK-SNAP segmentation) and A beta-PET positivity (PET: & GE; mean value + 2 standard deviations of 14 healthy controls) were defined. Regional agreement of cSS- and A beta-PET positivity was evaluated. A beta-PET quantification was compared between cSS-positive and corresponding contralateral cSS-negative atlas regions. Furthermore, the A beta-PET quantification of cSS-positive regions was evaluated in voxels close to cSS and in direct cSS voxels.Results:& nbsp;cSS- and A beta-PET positivity did not indicate similarity of their regional patterns, despite a minor association between the frequency of A beta-positive patients and the frequency of cSS-positive patients within individual regions (r(s) = 0.277, p = 0.032). However, this association was driven by temporal regions lacking cSS- and A beta-PET positivity. When analyzing all composite brain regions, A beta-PET values in regions close to cSS were significantly higher than in regions directly affected with cSS (p < 0.0001). However, A beta-PET values in regions close to cSS were not different when compared to corresponding contralateral cSS-negative regions (p = 0.603).Conclusion:& nbsp;In this cross-sectional study, cSS and A beta-PET positivity did not show regional association in patients with CAA and deserve further exploitation in longitudinal designs. In clinical routine, a specific cross-sectional evaluation of A beta-PET in cSS-positive regions is probably not useful for visual reading of A beta-PETs in patients with CAA.

Automated summary

In patients with cerebral amyloid angiopathy (CAA), there is no regional association between cSS and Aβ-PET positivity.