Radiology of sigmoid volvulus.

Sigmoid volvulus is often a surgical emergency. The diagnosis is usually reached on the basis of both clinical and radiologic assessment. A review of the radiologic findings in 20 patients diagnosed as having sigmoid volvulus is presented. Typical radiographic features are illustrated. Reasons for their absence in certain cases are discussed. [Key words: Volvulus, sigmoid; Diagnostic problems; Sigmoid, volvulus].