Head to toe: expand your diagnosis on routine imaging to include endometriosis

Endometriosis is a common condition primarily impacting women of childbearing age. Despite increasing awareness that endometriosis can be diagnosed non-invasively with the correct imaging techniques, there exists a significant delay in diagnosis, to the tune of 5-10 years. This gap can be narrowed by understanding that this is a disease that lends itself to pattern recognition, and learning to recognize the characteristic patterns on any imaging study will allow earlier diagnosis and prevent long-term complications that can occur with progressive, untreated endometriosis. The disease is often multifocal and thus can present with a wide array of nonspecific symptoms. When clinical findings do not suggest endometriosis, patients often undergo non-targeted imaging, such as chest, abdominal, or pelvic computed tomography (CT); Magnetic Resonance imaging (MRI) studies optimized for neurologic or musculoskeletal indications; or ultrasound (US) exams performed for palpable masses or nonspecific abdominal pain. Familiarity with endometriosis's characteristic patterns across organ systems and how it can masquerade as other diseases helps radiologists broaden their differential to include endometriosis, even on studies not originally aimed at its detection. This review article will describe those imaging findings of endometriosis affecting various organ systems that mimic other pathologies and will enable the reader to pause and question whether endometriosis should be included in the differential.