Genitourinary Imaging

Key points

• • Ultrasound is often the first test for the urinary tract, showing the size of the kidneys, blockage (hydronephrosis) and stones, without radiation.
• • A plain X-ray of the kidneys, ureters and bladder shows many urinary stones, which are often visible because they contain calcium.
• • CT is the most sensitive test for urinary stones and for staging tumours of the kidney and bladder.
• • Contrast studies, such as an intravenous urogram, outline the drainage system as the dye is excreted by the kidneys.
• • In pregnancy and in children, ultrasound and MRI are preferred to avoid the radiation of X-rays and CT.