Imaging presentations of foreign bodies that make for a challenging diagnosis: pictorial essay

Foreign bodies (FBs) can pose a diagnostic dilemma because a wide range of objects, comprising items incidentally detected or deliberately retained in the body, can be discovered on imaging investigations. Single or multiple FBs may be retained at different sites including the gastrointestinal tract, the genitourinary system, the respiratory tract, and the soft tissues, all of which warrant medical attention. More importantly, ensuing, serious complications related to harmful positioning of these objects can significantly hamper normal function of any involved organ system. Because various FBs may be detected throughout the body, it is important that radiologists are also familiar with a myriad of life-threatening complications associated with retained items, including impaction, obstruction, perforation, hemorrhage, embolization, chemical dissolution, poisoning, and sepsis. Imaging plays a key role in the detection, localization, and characterization of FBs. Radiologists need to describe in exhaustive detail suspected items with regard to the anatomical location, type, shape, and composition of the object under investigation. Clinicians can then predict whether the foreign object(s) will pass through the body uneventfully or need to be addressed in a surgical procedure.