Not sure what study you are looking at...
- Brain and Heart, sharp - PET
- Brain and Heart, not as sharp - whole body HMPAO
- Heart, no Brain - Thallium, MIBI, I-123 MIBG
- No Heart or Brain - if marrow, gut, lacrimal glands then Gallium
- No Heart or Brain, not Gallium - with liver, spleen and kidneys (hottests) then Octrotide
- Spleen, liver and marrow - WBC
- No Heart or Brain - crappy images think I-131 or MIBG