Magnetic resonance imaging of involved brain in HCL before and after chemoimmunotherapy. (A) Axial gradient-echo (GRE) sequence demonstrates innumerable microhemorrhages scattered throughout the supratentorial and infratentorial brain involving both cerebral and cerebellar hemispheres as well as the brainstem (arrows). (B) Axial fluid-attenuated inversion recovery (FLAIR) and (C) sagittal T1 sequences demonstrate multiple small acute hemorrhages at the gray-white junction in the supratentorial and infratentorial brain (these were hyperdense on unenhanced computed tomography scan; not shown) (arrowheads). (D) Axial GRE sequence after chemoimmunotherapy shows multiple microhemorrhages scattered throughout supratentorial and infratentorial brain, consistent with old blood. (E) Axial FLAIR and (F) axial T1 sequences show complete resolution of lesions after chemoimmunotherapy.