Cortical superficial siderosis and β-amyloid-PET positivity are not regionally associated in patients with cerebral amyloid angiopathy

Ziel/Aim To evaluate whether β-amyloid-(Aβ)-PET positivity and cortical superficial siderosis (cSS) in patients with cerebral amyloid angiopathy (CAA) are regionally colocalized. Methodik/Methods Ten patients with probable or possible CAA (73.3±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 fibrillary Aβ. In all cortical regions of the Hammers atlas, cSS positivity (MRI: ITK-SNAP segmentation) and Aβ-PET positivity (PET:≥mean value+2 standard deviations of 14 healthy controls) were defined. Regional agreement of cSS- and Aβ-PET positivity was evaluated. Aβ-PET quantification was compared between cSS-positive and corresponding contralateral cSS-negative atlas regions. Furthermore, Aβ-PET quantification of cSS-positive regions was evaluated in voxels close to cSS and in direct cSS voxels. Ergebnisse/Results cSS- and Aβ-PET positivity did not indicate similarity of their regional patterns, despite a minor association between the frequency of Aβ-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 Aβ-PET positivity. When analyzing all composite brain regions, Aβ-PET values in regions close to cSS were significantly higher than in regions directly affected with cSS (p<0.0001). However, Aβ-PET values in regions close to cSS were not different when compared to corresponding contralateral cSS-negative regions (p=0.603). Schlussfolgerungen/Conclusions cSS and Aβ-PET positivity have no regional association in patients with CAA. Thus, specific evaluation of Aβ-PET in cSS-positive regions is probably not useful for visual reading of Aβ PETs in patients with CAA. Publication History Article published online: 14 April 2022 © 2022. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany