It is of immense importance to perform fluoroscopy during voiding phase of VCUG (Voiding Cystourethrogram) procedures in order to rule out vesicourethral reflux. It is difficult to know exactly when a child will start voiding, so the child is intermittently imaged by fluoroscopy. Fluoroscopy involves radiation, and this we try to diminish as much as possible. We suggest application of small urinary sensor in the perineum of the patient, that will signal the beginning of urination, and only then fluoroscopy will begin. This urinary sensor should cut down substantially radiation dose to the patient.