- PURPOSE: After properly staged renal injury many children will undergo radiological reevaluation with computerized tomography, the modality frequently favored for its widespread availability and anatomical detail. The ALARA (as low as reasonably achievable) concept attempts to balance the potential future risk of radiation induced malignancy with the added information obtained by the study. At our institution ultrasound has been increasingly adopted as the followup imaging technique of choice. We sought to evaluate this practice in pediatric blunt renal trauma management. MATERIALS AND METHODS: We retrospectively analyzed the trauma database of a pediatric referral center for patients treated between 1997 and 2007. A total of 73 children with blunt renal trauma were identified. Associated injuries, mechanism of trauma, type of management, imaging studies, complications and delayed/missed injuries were evaluated. RESULTS: Mean patient age was 10.5 years and the male-to-female ratio was 3:2. In all patients the mechanism was blunt trauma. Average grade of injury at hospitalization was 2.4, with high grade injury observed in 32% of patients. Repeat computerized tomography was obtained in 11 patients (9 for nonurological injuries). Three nephrectomies were done in the setting of hemodynamic instability and 1 pseudoaneurysm was embolized. Four enlarging symptomatic urinomas were suspected by ultrasound. No clinically important injuries or complications due to delayed diagnosis were detected in patients followed with ultrasound. CONCLUSIONS: Our experience suggests that after initial computerized tomography for accurate staging of pediatric blunt renal trauma monitoring can be performed with ultrasound in most patients (excluding those with hemodynamic instability or deemed to require computerized tomography for associated injuries). Selective reevaluation with computerized tomography can be reserved for those with serial or ambiguous abnormalities detected on ultrasound, thus decreasing exposure to radiation.