Which of the following isotopes is used in the in vitro method for MUGA tagging?

Technetium-99m is the isotope used in the in vitro method for MUGA tagging due to its favorable physical and chemical properties. It has a half-life of about 6 hours, allowing sufficient time for the radioactivity to be administered and for imaging to be performed without excessive decay. Additionally, Technetium-99m emits gamma rays that are ideal for single-photon emission computed tomography (SPECT) imaging, which is commonly used in cardiac studies, such as the Multiple Gated Acquisition (MUGA) scan.

The in vitro method specifically involves the labeling of red blood cells with Technetium-99m, which allows for the assessment of cardiac function by measuring the blood flow and the heart's pumping capacity. Its widespread availability and the ease of radiolabeling red blood cells make it the preferred choice for this application in nuclear medicine.

The other isotopes listed do not align with the needs of the MUGA scan. Rubidium-82 is typically used for PET imaging of the heart, while Carbon-11 is primarily used in research settings for PET imaging. Strontium-89, on the other hand, is mainly used for pain relief in metastatic bone disease and does not serve a purpose in