Differential diagnosis of T2 hyperintense brainstem lesions: Part 2. Diffuse lesions.

Diffuse brainstem lesions are poorly defined, often large abnormalities and include tumors (gliomas and lymphomas) vasculitis (Behçet's disease), traumatic brainstem injury, degenerative disorders (Wallerian degeneration), infections, processes secondary to systemic conditions (central pontine myelinolysis, hypertensive or hepatic encephalopathy), and ischemic pathology (leukoaraiosis). Magnetic resonance imaging is the most appropriate imaging modality to use in evaluating lesions of this type, but often findings are nonspecific. Therefore, radiologists need to bear in mind such additional information as patient age and clinical features in making a differential diagnosis.