Emergent and Nonemergent Nonbowel Torsion: Spectrum of Imaging and Clinical Findings
Although bowel torsion is more commonly described in the medical literature, torsion can affect various organs within the chest, abdomen, and pelvis, including the testes, ovaries, gallbladder, spleen, heart, and pulmonary lobes. A structural abnormality such as a mass (a “lead point”) that promotes twisting around a vascular pedicle often predisposes an organ or other anatomic structure to torsion. Radiologists play a central role in detecting torsion, identifying the anatomy involved, and triaging patients for either emergent surgical intervention, which may be critical for organ salvage, or conservative management. Imaging findings that are suggestive or indicative of emergent torsion include an ectopic location and enlargement or edema of part or all of an organ, decreased blood flow at color Doppler ultrasonography, and a twisted vascular pedicle. Blood flow to an organ is quickly compromised by the constriction of vessels within the twisted pedicle, and ischemia may result; a delay in diagnosis and surgical treatment can lead to complications such as infarction, hemorrhagic necrosis, and abscess. By contrast, torsion of mobile fatty structures such as testicular appendages, epiploic appendages, omental fat, and pericardial fat pads, although it may produce pain mimicking that in an emergent condition, requires only conservative management. Imaging features of this nonemergent condition include a fatty mass, which is usually located alongside the colon when torsion involves the omentum or an epiploic appendage, with associated inflammatory stranding and tenderness at palpation. The radiologist should be familiar with these manifestations of nonemergent torsion to prevent unnecessary surgical intervention.