Nuclear & US scans. Intravenous pyelogram gives much better anatomic detail than either us or nuclear scan, now mostly replaced by ct & ultrasound. Mag3 nuclear scan best to quantitate obstruction & relative function. Dmsa nuclear scan best to demonstrate kidney scars & areas of diminished or absent function. Ultrasound scan uses no radiation, good for screening for hydronephrosis, kidney cysts, tumors & stones.