Which ingredients in a sulfur colloid kit are combined and heated?

The correct choice involves the mixture of pertechnetate, thiosulfate, and acid. This combination is crucial for preparing the sulfur colloid used in nuclear medicine.

When combining pertechnetate with thiosulfate and acid, the thiosulfate reacts with the pertechnetate under controlled heating conditions to produce a colloidal suspension of technetium-99m. The sulfur colloid is important for imaging the liver and spleen because it localizes in the reticuloendothelial system, allowing for effective visualization during scans.

In contrast, the other choices do not relate to the preparation of a sulfur colloid kit. Thallium-201 with saline is used for cardiac imaging, Tc99m-MDP and ethanol is not a standard combination for a sulfur colloid, and Tc132m sulfur with potassium chloride does not reflect the substances needed for the colloid preparation. Thus, only the first option is relevant and correct in the context of sulfur colloid kit preparation.