Trends in Imaging Use During the Emergency Department Evaluation of Flank Pain

Purpose: Patients with acute flank pain or kidney pain are most commonly evaluated in the emergency department with computerized tomography. Currently our understanding of radiographic practice patterns in emergency imaging for flank pain is limited. We characterized the use of conventional radiography (x-ray), ultrasound and computerized tomography in the emergency department evaluation of patients with acute flank pain. Materials and Methods: We performed a retrospective, cross-sectional analysis of emergency department visits using data on 2000 to 2008 from the National Hospital Ambulatory Medical Care Survey. Specific visits for a complaint of flank or kidney pain were further analyzed. Results: During the study period there was a significant increase in computerized tomography use (p <0.0001) and a significant decrease in x-ray use (p = 0.035) while ultrasound use remained stable (p = 0.803). During that period the proportion of patients with flank pain who were diagnosed with a kidney stone remained stable at approximately 20% (p = 0.135). Conclusions: Between 2000 and 2008 there was a significant increase in computerized tomography use for the emergency evaluation of patients with flank pain.