Imaging of Acute Conditions of the Perineum.

A wide range of acute conditions can affect the perineum, from self-limited disease to conditions that are potentially life threatening or contribute to substantial patient morbidity if not promptly diagnosed and appropriately treated. Imaging is essential in the clinical management of perineal disease because it allows accurate anatomic localization of the origin and extent of the disease to be determined. Familiarity with complex perineal anatomy, appropriate use of imaging modalities, and the spectrum of imaging findings seen in acute perineal conditions is crucial for radiologists to make a rapid and accurate diagnosis. Various imaging modalities are available to evaluate acute perineal conditions, each with their own advantages and disadvantages. Computed tomography is used most commonly in the acute care setting because of its widespread availability and rapid image acquisition. Ultrasonography could be used to evaluate superficial and palpable abnormalities and is especially helpful for diagnosis of genital injuries. Magnetic resonance (MR) imaging exhibits superior tissue contrast resolution, provides excellent characterization of conditions, and lacks ionizing radiation. Its role is increasing in the acute care setting; however, MR imaging is not always readily available and is currently reserved for use as a problem-solving technique. Retrograde urethrography is the modality of choice for evaluating traumatic urethral injury. RSNA, 2018.