What type of imaging can be performed to detect infections using Tc-99m?

• A. CT scans
• B. X-rays
• C. Bone scans
• D. MRI scans

Answer: (C)

The detection of infections using Tc-99m is effectively accomplished through bone scans. Tc-99m is a radiopharmaceutical widely used in nuclear medicine because it emits gamma rays that can be detected by a gamma camera, allowing for imaging of various physiological processes. When it comes to detecting infections, particularly osteomyelitis (an infection of the bone), Tc-99m-labeled compounds can be used to visualize areas of increased bone metabolism or blood flow, which are indicative of infection. The radiotracer localizes in areas with high inflammatory activity, making it suitable for identifying infections in bone structures.

In comparison, other imaging modalities such as CT scans, X-rays, and MRI scans do not utilize Tc-99m and are primarily visualizing anatomical structures or assessing morphology rather than functional aspects like infection. CT scans provide detailed cross-sectional images; X-rays show bone integrity and are typically used for fracture detection; and MRI scans excel at soft tissue imaging, but they do not provide the same functional metabolic information that Tc-99m bone scans do regarding infectious processes in the skeleton. Hence, the use of Tc-99m-labeled radiopharmaceuticals for bone scans is specifically targeted for detecting infections among the options provided.