Hypertensive arteriopathy (HA) and cerebral amyloid angiopathy (CAA) are the two most common forms of cerebral small vessel disease. On MRI, chronic small vessel disease-related abnormalities include white matter hyperintensities, dilated perivascular spaces (DPVS), lacunar infarction, and hemorrhagic features (e.g. cerebral microbleeds, CMB). In the cerebellum, deep CMB involving the dentate nucleus (DN) is associated with HA, whereas the presence of superficial cerebellar CMB are associated with CAA. DPVS are observed in both diseases, predominant in the subcortical white matter (especially in the centrum semiovale) in CAA whereas HA-related DPVS are predominant deep in the brain inside or nearby the basal ganglia.

To the best of our knowledge, DN-DPVS have never been studies systematically in small vessel disease. The researchers want to study DN-DPVS on T2-weighted 3T MRI in patients with HA or CAA and to compare both groups.

Inclusion Criteria:

• Patient registered in the CHU de Nîmes (France) stroke database with lobar intracerebral hemorrhage [ICH], subarachnoid hemorrhage or cortical superficial siderosis for CAA or basal ganglion ICH for HA
• Patient managed at the CHU de Nîmes (France) between 01/1/2015 and 31/12/2024
• Patient with T2-weighted MRI performed with a 3T magnet

Exclusion Criteria:

• Refusal to participate

Patients with lobar intracerebral hemorrhage [ICH], subarachnoid hemorrhage or cortical superficial siderosis for CAA or basal ganglion ICH for HA