Which of the following statements about the biodistribution of Tc sestamibi is true?

• A. It is concentrated in the bones.
• B. It shows significant uptake in the heart and salivary glands.
• C. It is not taken up by abdominal organs.
• D. It has minimal uptake in the brain.

Answer: (B)

The statement that Tc sestamibi shows significant uptake in the heart and salivary glands is accurate, reflecting the behavior of this radiopharmaceutical in the body. Tc sestamibi is primarily used in myocardial perfusion imaging, where it is utilized to assess blood flow to the heart muscle. The high uptake in cardiac tissues allows for detailed imaging of myocardial viability and perfusion, making it a valuable tool in cardiology.

In addition to the heart, Tc sestamibi also accumulates in the salivary glands, which is important for certain diagnostic applications, such as evaluating parathyroid adenomas or for assessing gland function. This characteristic reinforces its utility as a diagnostic agent, distinguishing it from other radiopharmaceuticals that may not show similar patterns.

Other statements regarding the biodistribution of Tc sestamibi do not hold true. For instance, while it may exhibit some uptake in bones, it is not a primary site of concentration; hence, the assertion that it is concentrated in the bones is misleading. The biodistribution also extends to various abdominal organs, contradicting the claim that it is not taken up by such organs. Additionally, while minimal uptake in the brain may be observed, it is not significant enough to warrant the conclusion