Which procedure uses radioactive chemicals and a scanner to image the motion of the heart wall?

• A. MUGA scan
• B. Myelography
• C. Nasogastric intubation
• D. Ophthalmoscopy

Answer: (A)

This item tests understanding of imaging methods that assess how the heart walls move using radioactive material and a scanner. A MUGA scan, or radionuclide ventriculography, injects a small amount of radioactive tracer into the bloodstream and uses a gamma camera to image the heart while ECG gating captures many phases of the cardiac cycle. This approach provides functional information about wall motion and allows calculation of the left ventricular ejection fraction, making it ideal for imaging heart-wall motion. The other options are not about evaluating cardiac wall motion with radioactive tracers: myelography visualizes the spinal canal with contrast on X-ray; nasogastric intubation involves placing a tube into the stomach; ophthalmoscopy examines the interior of the eye.