Which imaging study utilizes sulfur colloid to visualize the gastrointestinal tract?

The imaging study that utilizes sulfur colloid to visualize the gastrointestinal tract is the hepatobiliary scan. This scan is specifically designed to assess the function of the liver, gallbladder, and bile ducts. Sulfur colloid is a radiopharmaceutical that is taken up by the reticuloendothelial system, particularly in the liver and spleen, making it ideal for evaluating liver function and identifying conditions such as cholestasis or gallbladder dysfunction.

In a hepatobiliary scan, sulfur colloid is injected intravenously, and its distribution and activity are monitored using a gamma camera. The resulting images provide valuable information regarding the anatomy and function of the liver and biliary system, including gallbladder ejection fraction and visualization of bile duct obstructions or abnormalities.

While the GI Bleed scan is also involved in gastrointestinal diagnosis, it typically uses different radiopharmaceuticals such as technetium-99m-labeled red blood cells or other agents to identify bleeding sites in the gastrointestinal tract. The thyroid scan focuses on assessing thyroid gland function and anatomy, usually utilizing iodine isotopes. The MUGA scan is a cardiac imaging study that evaluates heart function using technetium-labeled red blood cells, thus not relevant in this context.