ARTICLEImaging of Important Causes of Brain Stem Enlargement Beyond the Low-Grade GliomaCox, Mougnyan MD; Hendi, Aditi MD; Hou, Angela MD; Friedman, David MDAuthor Information Dr. Cox is Radiology Resident, Dr. Hendi is Radiology Resident, Dr. Hou is Medicine Resident, and Dr. Friedman is Associate Professor, Department of Radiology, Thomas Jefferson University, 1068 Main Bldg, 132 South 10th St, Philadelphia, PA 19107; E-mail: email@example.com. After participating in this activity, the diagnostic radiologist should be better able to diagnose by imaging the many important causes of brain stem enlargement in addition to the more common low-grade glioma. The authors and all staff in a position to control the content of this CME activity and their spouses/life partners (if any) have disclosed that they have no relationships with, or financial interests in, any commercial organizations pertaining to this educational activity. Lippincott Continuing Medical Education Institute, Inc., is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Lippincott Continuing Medical Education Institute, Inc., designates this enduring material for a maximum of 2 AMA PRA Category 1 Credits™. Physicians should only claim credit commensurate with the extent of their participation in the activity. To earn CME credit, you must read the CME article and complete the quiz and evaluation on the enclosed answer form, answering at least seven of the 10 quiz questions correctly. This continuing medical education activity expires on April 14, 2016. Contemporary Diagnostic Radiology: April 15, 2015 - Volume 38 - Issue 8 - p 1-7 doi: 10.1097/01.CDR.0000463202.02733.e3 Buy Take the CME Test Metrics Abstract The brain stem is a critical part of the central nervous system (CNS); it houses the cranial nerve nuclei and cardiopulmonary centers, and serves as a conduit for descending tracts into the spinal cord. The brain stem is located in the posterior fossa, and anatomically is composed of the midbrain (most rostral part of the brain stem), pons, and medulla. Gliomas are the most common cause of brain stem enlargement. However, a variety of other pathologic processes such as infection, metastasis, inflammation or demyelination, hemorrhagic lesions, posterior reversible encephalopathy syndrome, and hypertrophic olivary degeneration also may involve the brain stem, and occasionally cause diagnostic dilemmas. In some instances, combining the clinical presentation with the radiologic findings may even obviate the need for biopsy of this critical region of the central nervous system. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.