Often, instead of Thallium, they use Technetum-99 (Tc99) for the scan. This element is usually the product of bombarding molybdenum-99 with neutrons using a cyclotron.
Also, Tc99 can be used for brain, bone and other medical scans. I remember undegoing a nuclear cell survival study using an isotope of chromium. This was in conjunction with a centrifuge study for human physiology.
Absostuninglutely!!!