When TIME is kidney: an imaging-based diagnostic algorithm for iatrogenic ureteral injuries

Iatrogenic ureteral injuries are uncommon but potentially severe complications of abdominal, pelvic, and endourological procedures. Because many injuries are not recognized intraoperatively and may initially produce nonspecific clinical or laboratory findings, imaging frequently provides the first indication of ureteral damage. Computed tomography urography is the principal cross-sectional technique in clinically stable adults, while retrograde and antegrade pyelography provide direct luminal assessment when urinary excretion is absent, CT findings remain indeterminate, or treatment is planned. Imaging should establish ureteral continuity, identify urinary extravasation, assess drainage, localize the lesion, and detect associated collections and infection. We propose the TIME framework-Transection, Isolated obstruction, Mixed injury, and Extravasation-only-as a practical imaging-based description of the principal patterns of iatrogenic ureteral injury. The framework is applied hierarchically. Demonstrated complete loss of native ureteral continuity defines TIME-T. TIME-I denotes obstruction without demonstrated leakage; TIME-M denotes concomitant leakage with upstream collecting-system dilatation and at least partially preserved continuity; and TIME-E denotes leakage without upstream collecting-system dilatation and with preserved or partially preserved continuity. This pictorial review describes the multimodality imaging findings of iatrogenic ureteral injury, introduces the TIME framework, highlights common diagnostic pitfalls, and presents a time-sensitive algorithm intended to support structured radiological assessment and multidisciplinary communication.