Recently, finger-like projections (FLP) and subarachnoid haemorrhage extension (SAHE) of lobar intracerebral haemorrhage (LH) on acute CT together with ApoE4 genotype have been used in a prediction model for histopathologically proven cerebral amyloid angiopathy (CAA). Our aim was to analyse FLP and SAHE on acute/early subacute magnetic resonance imaging (MRI) and to assess the association with probable CAA diagnosis according to modified Boston criteria.Methods: We retrospectively studied MRI scans (and CT if available) performed <7 days in a cohort of consecutive acute LH patients >55 years.Results: Forty-six patients (24 men and 22 women; mean age 73; 28 probable and 18 possible CAA patients) were analysed. Mean symptom onset-MRI delay was 1.3 days (including 26 patients with MRI <24 h). Both probable and possible CAA groups were comparable regarding age, sex, time MRI and CT performance, MRI field strength, and LH volume. On MRI, both FLP and SAHE were observed more frequently in probable than in possible CAA (FLP 43 vs. 6%, p = 0.0073; SAHE 79 vs. 44%, p = 0.027), and associated with larger LH volumes (FLP, p = 0.011; SAHE, p = 0.047). FLP was associated with earlier performed MRI (mean 0.3 vs. 1.75 days, p = 0.025). In the subgroup of 35 patients with available CT (performed a mean of 2.2 days before or after MRI), FLP presence on CT was observed more frequently in probable than in possible CAA (57 vs. 7%, p = 0.0039). Concordance of MRI and CT for FLP presence/absence was 89%.Conclusions: In acute LH patients, FLP and SAHE on acute/early subacute phase MRI are associated with probable CAA diagnosis. Larger LH volumes are associated with FLP and SAHE on MRI, and early performed MRI with FLP.