Initial investigation of childhood urinary tract infection: does the plain abdominal X ray still have a role?

To reassess the plain abdominal X ray (AXR) in the initial investigation of childhood urinary tract infection, radiologists from four paediatric units prospectively collected data on the yield from the AXR in 683 children. Five children had renal calculi. All were detected on ultrasound, but one was not visible on the initial AXR. Four spinal abnormalities were identified, none of which prompted any action by the clinician involved. While the costs, in both financial and radiation risk terms, may be small, the benefit of the AXR appears equally small. Where expert paediatric ultrasonography is available we would recommend that the AXR be reserved for patients with haematuria, loin pain, family history of calculus disease, or where further urinary tract infection occurs despite a normal ultrasound scan.