Skull Base–related Lesions at Routine Head CT from the Emergency Department: Pearls, Pitfalls, and Lessons Learned

Authors: Hernan R. Bello, Joseph A. Graves , Saurabh Rohatgi, Mona Vakil, Jennifer McCarty, Rudy L. Van Hemert, Stephen Geppert, Ryan B. Peterson


Routine non–contrast material–enhanced head CT is one of the most frequently ordered studies in the emergency department. Skull base–related pathologic entities, often depicted on the first or last images of a routine head CT study, can be easily overlooked in the emergency setting if not incorporated in the interpreting radiologist’s search pattern, as the findings can be incompletely imaged. Delayed diagnosis, misdiagnosis, or lack of recognition of skull base pathologic entities can negatively impact patient care. This article reviews and illustrates the essential skull base anatomy and common blind spots that are important to radiologists who interpret nonenhanced head CT images in the acute setting. The imaging characteristics of important “do not miss” lesions are emphasized and categorized by their cause and location within the skull base, and the potential differential diagnoses are discussed. An interpretation checklist to improve diagnostic accuracy is provided.

©RSNA, 2019

SA-CME LEARNING OBJECTIVES
After completing this journal-based SA-CME activity, participants will be able to:

Discuss the complex anatomy of the skull base.

Characterize easily missed skull base lesions on nonenhanced head CT images in the acute setting.

Identify clinical or imaging red flags that may necessitate further workup.