Imaging Findings in Parasitic and Vector-borne Infections of the Head, Neck, and Spine.

While many parasitic and vector-borne infections have traditionally been considered to have geographically limited distribution, factors including climate change, the immigration and world travel of individuals, and the importing and exporting of goods continue to shift ecosystems and expand the geographic distributions of parasites and insect vectors and the infections they transmit. Because they may be unexpected, cases emerging in regions of nonendemicity can result in a medical mystery, and because appropriate management relies on an accurate diagnosis, identification of these diseases is vital. Radiologists should be aware of these infections and their potential sequelae to help limit the delays in diagnoses and potentially lifesaving treatment that can occur if the diagnosis is not promptly suggested and investigated. Although some imaging findings are nonspecific, a knowledgeable radiologist can play a crucial role in correlating imaging features or patterns of features with laboratory findings and available clinical information to reveal the diagnosis and/or develop a differential diagnosis. The authors describe a variety of parasitic and vector-borne infections that affect humans, with a specific focus on those that manifest in the head, neck, and spine. A brief introduction to these infections is provided and includes relevant epidemiologic factors, clinical presentations, and potential complications, with the sequelae associated with head, neck, and nervous system infections more thoroughly described. Case examples are included to demonstrate the imaging features associated with acute and chronic and common and uncommon sequelae of these infections across multiple imaging modalities. ©RSNA, 2026 Supplemental material is available for this article.