E2281. Myriad of Brain and Meningeal Contrast Enhancement on CT and MRI: A Pictorial Review
  1. Mamta Gupta; Allegheny Helth Network
  2. Charanjeet Singh; Allegheny Helth Network
Intravenous contrast agents play a very important role for study of CNS pathology, for better assessment of the size, morphology and localization of many diseases. In this exhibit, we discuss the different patterns of enhancement in Computed tomography (CT) and magnetic resonance imaging (MRI) of brain and meninges, and explain the pathophysiology that lies in each kind of enhancement.

Educational Goals / Teaching Points
To understand the mechanisms of contrast-enhancement on CT and MRI in the central nervous system (CNS). To provide an approach to intracranial pathology on the basis of their pattern, and discuss the potential pitfalls we must take into account when studying an enhancing intracranial lesion.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Mechanisms of contrast enhancement: Pathophysiology of contrast-enhancement: Physiological/normal enhancing structures: Types of enhancement (Case/quiz based examples of following but not limited to, with brief description, interpretation, imaging appearance, differential diagnosis and pitfalls of each case will be described and teaching points/pearls will be made/highlighted): Extraaxial enhancement- Pachymeningeal or Dura-Arachnoid Enhancement, Leptomeningeal or Pia-Arachnoid Enhancement. Intraaxial enhancement – Ring like lesions: ‘MAGIC DR’. M: Metastasis, A: Abscesses, G: Glioblastoma, I: Infarct (subacute), C: Contusion, D: Demyelinating diseases, R: Radiation necrosis / resolving hematoma. Open ring, Homogenous ring, Irregular ring, Gyral, Nodular cortical and subcortical, Nodular deep and periventricular, Cyst-with-nodule, Periventricular, Some nonenhancing lesions.

It is very important for the radiologist to understand the pathophysiology that lies on the different contrast-enhancing patterns in the brain and meninges in MRI, and to recognize those situations on which enhancement is not a reliable feature to asses in intracranial pathology, as occurs in those brain tumors that are treated with antiangiogenics.