Radiology Practice Test

Which imaging method is commonly used to identify gallstones?

1. MRI

2. X-ray

3. Ultrasound

4. CT Scan

The correct answer is: Ultrasound

Ultrasound is the imaging method most commonly used to identify gallstones due to its high sensitivity and specificity for this condition. It utilizes sound waves to produce images of the gallbladder and surrounding structures, allowing for the visualization of gallstones, which appear as echogenic foci (bright spots) within the gallbladder. The procedure is non-invasive, does not involve ionizing radiation, and can be performed at the bedside, making it a preferred initial imaging modality in many clinical settings. Other imaging techniques, while useful for certain circumstances, are less effective at identifying gallstones. For example, MRI is excellent for soft tissue evaluation and can visualize certain biliary tree disorders, but it is not the first choice for gallstones due to cost and patient convenience. X-rays can show gallstones, but many types of gallstones, particularly cholesterol stones, are not radiopaque and may not be visible. CT scans can also detect gallstones, but they are typically used in more complex cases or when complications such as pancreatitis are suspected, making ultrasound the first-line investigation for suspected gallstones.