ANSWERS

1. What is the purpose of contrast radiography?
   To allow better visualisation of structures or organs, either by altering the radio-opacity of the structure of interest or that of the surrounding tissues.
2. List the 3 main types of positive contrast agent and state their most common use.
   • Barium sulphate - investigation of the alimentary canal.
   • Water soluble iodine containing preparations - investigation of the urogenital system.
   • Low osmolar non-ionic media - myelography.
3. What is meant by double contrast radiography?
   An investigation of a hollow organ using both a positive contrast medium (used to coat the inner lining) and a negative agent (gas or air, to distend that organ).
4. Why are heavy sedation or general anaesthesia contraindicated in the case of a "barium swallow"?
   Due to the risk of regurgitation and aspiration.
5. Prior to a gastrogram, the patient may be given glucagon. Why?
   In order to delay gastric emptying.
6. List 6 conditions that may indicate the need for a barium series.
   • Abdominal dilation.
   • Chronic vomiting.
   • Haematemesis.
   • Malabsorption.
   • Palpation of an abdominal mass.
   • Weight loss.
7. Name 2 contrast agents commonly used in myelography.
   • Iohexol.
   • Iopamidol.
8. State the site for lumbar puncture.
   L4-5 or L6-7.
9. What is angiocardiography?
   A technique used to demonstrate heart disease. The heart chambers are opacified by a bolus injection of water soluble iodine containing contrast medium.
10. List 2 conditions in which portal venography may aid a diagnosis.
    • Cirrhosis of the liver.
    • Congenital portosystemic shunts.
11. What is the name of the contrast medium used in bronchography?
    Propyliodine.
12. What term describes contrast radiography of a joint space?
    Arthrography.