Ureteropelvic junction disruption secondary to blunt trauma: Excretory phase imaging (delayed films) should help prevent a missed diagnosis

Purpose: Ureteropelvic junction disruption is a rare condition which is often diagnosed after some delay, The aim of this study is to examine the current status of this entity and to determine if improvements could be made in the diagnosis. Materials and Methods: We evaluated 5 consecutive adult cases of ureteropelvic junction disruption secondary to blunt trauma and compared the findings to those reported in literature. Results: The diagnosis was delayed by at least 24 hours in 4 of the 5 cases (80%). Compared to the literature, in which most delays in diagnosis were the result of genitourinary tract imaging being omitted, most of our delays (3 cases) were a result of the initial contrast enhanced spiral (helical) computerized tomography (CT) failing to provide the diagnosis. This failure occurred because of either absence of contrast extravasation (2 cases) or only subtle extravasation (1 case), which was not recognized by the radiologist, The delay in diagnosis resulted in added morbidity in all circumstances. Conclusions: Ureteropelvic junction disruption continues to be diagnosed late in a large proportion of cases. Absence of gross contrast extravasation on nephrogram phase scanning using spiral CT may not exclude a major injury of the ureteropelvic junction. Addition of delayed CT of the kidney 5 to 8 minutes or longer after contrast material injection (during the excretory phase) may increase the probability of extravasation being demonstrated and, thus, reduce the possibility of missing a ureteropelvic junction disruption.