Cerebral microbleed assessment on MRI in a memory clinic: Reliability, prevalence, and implications for anti‐amyloid therapy

Abstract INTRODUCTION Cerebral microbleeds (CMBs) represent an important magnetic resonance imaging (MRI) marker of cerebral small vessel pathology in memory‐clinic populations, where vascular and neurodegenerative pathologies frequently overlap. METHODS This cross‐sectional study included 747 patients from a Swedish memory clinic who underwent 3T MRI with susceptibility‐weighted imaging. Two readers assessed CMBs using standardized criteria. Inter‐ and intra‐observer agreement were evaluated before and after protocol refinement. CMB prevalence and burden were analyzed across diagnostic groups and by cerebrospinal fluid amyloid status. RESULTS CMBs were present in 28.6% of patients and frequently observed in subjects with mild cognitive impairment or dementia. Inter‐observer agreement improved from κ = 0.71 to κ = 0.82 after protocol refinement. Among amyloid‐positive patients with cognitive impairment, 11.2% exceeded proposed CMB thresholds for anti‐amyloid therapy eligibility. DISCUSSION Standardized CMB assessment improves reliability in memory‐clinic populations. Given its growing impact on treatment eligibility and safety, consistent evaluation is essential for patient management.