Robert L. Lebowitz, M.D. Children' s Hospital, Harvard Medical School Boston, Massachusetts

Five-year-old girl with fever, left sided back pain and positive urine culture (enterococcus). Ultrasonography of the kidneys showed a left mass-like lesion (figure 1) with increased echogenicity and poor vascular flow on Doppler interrogation of the kidney (figure 2). A CT scan showed multiple focal areas of poor enhancement. The findings were typical for acute pyelonephritis (figure 3). She was treated with intravenous antibiotic, her condition improved and she became afebrile. A follow-up ultrasound exam showed that the kidney had returned to normal (figure 4). A voiding cystourethrogram showed left sided vesicoureteral reflux (figure 5).