E2133. Reviewing Nuclear Shuntogram: A Simplified Approach to Avoid the Headaches
  1. Megan Mercer; Medical University of South Carolina
  2. Jonathan Revels; New York University
  3. Lisa Blacklock; University of New Mexico
  4. Shana Elman; University of New Mexico
  5. Manuela Matesan; University of Washington
  6. David Lewis; University of Washington
  7. Saeed Elojeimy; Medical University of South Carolina
Cerebrospinal fluid (CSF) shunting is commonly performed to treat communicating and noncommunication hydrocephalus by alleviating excess fluid via a catheter-based system consisting of a proximal catheter, a valve/reservoir, and a distal catheter. Unfortunately, complications do arise including obstruction, valve malfunction, over-shunting, and catheter discontinuity. It is important to diagnose and treat complications expediently to prevent symptom recurrence. Diagnostic evaluation of a shunt includes a radiographic shunt series, a CT of the head, and a radionuclide CSF shuntogram.

Educational Goals / Teaching Points
Within this exhibit, we first explore the indications for and protocol of radionuclide CSF shuntogram. Then, we review how to inject a CSF shunt appropriately, radiotracer options, and how to recognize inadequate injection. We then delve into radionuclide CSF shuntogram interpretation with examples of both normal and abnormal study findings including proximal shunt obstruction, distal shunt obstruction, gravity-dependent drainage, catheter discontinuity, and over-shunting. Troubleshooting and pathology mimics are discussed. Comparison with other studies such as head CT and radiographic shunt series is also explained. We describe how to report pertinent findings that can be useful to the clinical team.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This exhibit includes an overview of radionuclide CSF shuntogram; ACR appropriateness criteria; radiotracer options, shunt access, CSF pressure, and protocol optimization; complications and malfunctions of CSF shunts; necessary prior imaging such as head CT and radiographic shunt series; troubleshooting study complications and pathologic mimics.

CSF shunting is critical to the treatment of hydrocephalus, but shunts do not always work perfectly. It is important to diagnose and troubleshoot shunts to identify compromise and restore function. A radionuclide CSF shuntogram can assist in shunt evaluation. It is essential for the radiologist to be familiar with protocoling and interpreting these studies in the appropriate clinical setting.