Radiographic review of anatomy and pathology of the masticator space: what the emergency radiologist needs to know

The differential diagnosis of a masticator space (MS) lesion is broad, owing in part to the multiple structures contained within such a small region. It is also because the MS is adjacent to many of the other deep spaces within the head and neck, which can act as gateways for disease spread. Therefore, emergency radiologists must be familiar with anatomy of the MS, as well as adjacent spaces in order to provide an accurate diagnosis to the referring clinician. This article illustrates the anatomy and common pathologies within the MS using a case-based multimodality approach. Common masticator space pathologies can be categorized into inflammatory/infectious, neoplastic, and vasoformative lesions. Important imaging features of MS lesions and patterns of disease spread will be discussed, with the aim of making this complex deep space more approachable in the emergent setting.