Which isotope is most commonly used for thyroid imaging?

The most commonly used isotope for thyroid imaging is Iodine-131 (I-131). This isotope has specific properties that make it ideal for assessing thyroid function and structure. I-131 is a radioactive iodine that is readily taken up by the thyroid gland, which specializes in absorbing iodine to produce thyroid hormones.

When used in imaging, I-131 emits both beta and gamma radiation, allowing for both therapeutic and diagnostic applications. In the context of thyroid imaging, the gamma emissions are detected using nuclear medicine imaging equipment, providing valuable information about the metabolic activity of the thyroid tissue. This makes I-131 particularly useful in diagnosing conditions such as hyperthyroidism, thyroid nodules, or malignancies.

In contrast, while Iodine-125 (I-125) can also be used for thyroid procedures, it is not the first choice for imaging due to its more limited uptake and imaging characteristics compared to I-131. Gallium-67 (Ga-67) and Indium-111 (In-111) are used in other imaging contexts, such as tumor detection and infection imaging, but they do not have the same affinity for the thyroid gland and are not suitable for thyroid-specific imaging. Thus, I-131's unique properties make it