Imaging features of intracerebral hemorrhage with cerebral amyloid angiopathy: Systematic review and meta-analysis

Background We sought to summarize Computed Tomography (CT)/Magnetic Resonance Imaging (MRI) features of intracerebral hemorrhage (ICH) associated with cerebral amyloid angiopathy (CAA) in published observational radio-pathological studies. Methods In November 2016, two authors searched OVID Medline (1946-), Embase (1974-) and relevant bibliographies for studies of imaging features of lobar or cerebellar ICH with pathologically proven CAA ("CAA-associated ICH"). Two authors assessed studies' diagnostic test accuracy methodology and independently extracted data. Results We identified 22 studies (21 cases series and one cross-sectional study with controls) of CT features in 297 adults, two cross-sectional studies of MRI features in 81 adults and one study which reported both CT and MRI features in 22 adults. Methods of CAA assessment varied, and rating of imaging features was not masked to pathology. The most frequently reported CT features of CAA-associated ICH in 21 case series were: subarachnoid extension (pooled proportion 82%, 95% CI 69-93%, I-2 = 51%, 12 studies) and an irregular ICH border (64%, 95% CI 32-91%, I-2 = 85%, five studies). CAA-associated ICH was more likely to be multiple on CT than non-CAA ICH in one cross-sectional study (CAA-associated ICH 7/41 vs. non-CAA ICH 0/42;chi(2) = 7.8, p = 0.005). Superficial siderosis on MRI was present in 52% of CAA-associated ICH (95% CI 39-65%, I-2 = 35%, 3 studies). Conclusions Subarachnoid extension and an irregular ICH border are common imaging features of CAAassociated ICH, but methodologically rigorous diagnostic test accuracy studies are required to determine the sensitivity and specificity of these features.