Is the preliminary film necessary prior to the micturating cystourethrogram in children?

The aim of the study was to determine the value of the preliminary film in children undergoing a micturating cystourethrogram (MCU). The coded computer reports of 806 children undergoing MCUs in a 12-month period were retrospectively reviewed for abnormalities of the lumbar spine, hips, or for calcifications. Vesicoureteric reflux was present in 185 patients (23%). Four patients had renal calculi (0.5%), and in all cases the abnormality was evident on preceding imaging of the upper urinary tract. Spinal anomalies (other than known meningomyelocele) were present in four patients. The clinically obvious abnormalities present in these were a sacral teratoma, a sacral lipoma, scoliosis with tracheo-oesophageal fistula, and a cutaneous angioma with a sacral pit. No patients (other than those with known meningomyelocele) had dislocated hips diagnosed. If the preliminary film had not been performed in 806 patients, neither spinal anomaly, renal calculus, nor congenital dislocated hip would have been missed. The low incidence of plain film anomalies indicates that in our population a plain film is not justified routinely.