A 72-year-old man underwent Persantine 201Tl myocardial SPECT imaging that showed a transient area of extracardiac radiotracer accumulation inferior to the inferior wall of the left cardiac ventricle, and a persistent, rounded, cold area in the liver. CT of the abdomen confirmed a cystic lesion in the liver corresponding to the cold area, and the transient extracardiac tracer accumulation area corresponded to a large aneurysm of the distal descending thoracic aorta. An extracardiac abnormal area of 201Tl localization, 'hot' or 'cold', should be included for scan interpretation to depict thoracic and/or upper abdominal lesions(s).