Degradation of myocardial perfusion SPECT images caused by contaminants in thallous (201Tl) chloride

Purpose Thallous (201Tl) chloride is a single-photon emission computed tomography (SPECT) tracer mainly used for assessing perfusion and viability of myocardial tissue. 201Tl emits X-rays around 72 keV and gammas at 167 keV, and has a half-life of 73 h. Regulations allow an intrinsic contamination up to 3–5%, which is mainly caused by 200Tl (368...