Emphysematous pyelitis: findings in five patients.

Emphysematous pyelitis (EP) is a benign entity. To our knowledge, it has not been reported frequently in the radiology literature. Previous articles have not focused on EP but rather have included other gas-forming entities (eg, emphysematous pyelonephritis [EPN]). The authors describe imaging findings in EP and distinguish them from findings in EPN in five cases. Computed tomography is the current method for demonstrating isolated gas production inside the urinary collecting system. The prognosis is excellent, with rapid complete recovery after medical treatment.