label: Superficial CNS hemosiderin deposition
label_lc: superficial cns hemosiderin deposition
description: An anomaly that can be ascertained by iron-specific magnetic resonance imaging (MRI) sequences such as gradient-echo (GRE) and susceptibility-weighted imaging (SWI). Superficial siderosis of the central nervous system is a chronic condition due to persistent or repeated long-term bleeding into the subarachnoid space, leading to subpial hemosiderin deposition. Hemosiderin deposition on MRI is seen as a T2 hypointensity and preferentially outlines the cerebellum and brainstem surface.