What is the keV photopeak of Tc-99m sestamibi?

The keV photopeak of Tc-99m sestamibi is actually 140.5 keV. This is significant because the energy level of the photopeak corresponds to the gamma radiation emitted during the decay of Tc-99m, which is critical in nuclear medicine for imaging procedures.

Tc-99m is commonly used in various imaging techniques, such as myocardial perfusion scans, due to its favorable properties, including its suitable half-life and the energy of the emitted photons. Knowing the exact photopeak energy is essential for optimizing the detection settings on imaging equipment, ensuring accurate image acquisition and minimizing background noise, thus improving diagnostic quality.

The distinctions among the given choices illustrate the importance of precision in radiopharmaceutical practices. The other values, while close, do not accurately represent the emission energy of Tc-99m sestamibi, which could lead to misinterpretations in a clinical setting if employed for calibration or quality control in imaging studies.