ARRT Nuclear Medicine Practice Test 2026 – Complete Prep Guide

The shelf-life of Thallium-201 (Tl-201) is approximately 73 hours. This is an important consideration in nuclear medicine, as it influences both the planning and scheduling of imaging procedures using this radioisotope. Thallium-201, used primarily for myocardial perfusion imaging, has a physical half-life that dictates how long it remains potent and effective for diagnostic imaging.

In practice, a half-life of about 73 hours allows for a sufficient time window to prepare and utilize the isotope for patient imaging. This duration ensures that the radioactivity level is still adequate for the desired diagnostic information while minimizing the patient's exposure to radiation. Understanding the shelf life is crucial in nuclear medicine to ensure the efficiency of radiopharmaceuticals.