E1170. Demystifying CNS Intravascular Lymphoma (IVL): Five Key Imaging Features For Prompt Diagnosis
  1. Masis Isikbay; University of California, San Francisco
  2. Soonmee Cha; University of California, San Francisco
Central nervous system intravascular lymphoma (CNS IVL) is a condition that can affect the cerebral vasculature by causing occlusion of both arteries and veins throughout the anterior and/or posterior circulation. Given this pathophysiology the clinical presentation of this condition is varied, including symptoms ranging from cognitive impairment to paralysis. Similarly, there is a wide array of imaging findings that may also be seen in the setting of CNS IVL. This variability can make it a difficult diagnosis to consider, which is unfortunate given the importance of expedient identification for clinical management. The purpose of this work is to provide an organized framework for identifying key imaging features that help reliably make the prompt diagnosis of CNS IVL.

Educational Goals / Teaching Points
1. CNS IVL has a nonspecific clinical presentation. 2. Imaging features of CNS IVL can be variable and nonspecific however there are five key imaging features that aid in a prompt diagnosis. 3. Definitive tissue diagnosis can be expedited based on imaging features.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Standard MR imaging (including diffusion/susceptibility sequences) is necessary for the diagnosis of CNS IVL and there are five key imaging features for this condition which include: 1. Multifocal pattern of acute intra-parenchymal hemorrhage in non-vascular territories (Image 1). 2. Atypical pattern of white matter lesions distinct from chronic microvascular ischemia on T2/FLAIR MR imaging (Image 2). 3. Minimal to no contrast enhancement with white matter lesions (Image 2). 4. Scattered acute infarcts on diffusion not always corresponding to white matter lesions (Image 3). 5. Various patterns, size, and distribution of scattered microhemorrhages on susceptibility sequences (Image 3).

The key imaging features described here help keep CNS IVL on the differential. Other diagnosis to consider are: stroke, primary angiitis of CNS, and atypical infection. Definitive tissue diagnosis relies on prompt imaging diagnosis and radiologists to raise the suspicion CNS IVL.