This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nuclear medicine, Subject name: Radiology
Which is used for calculation of ejection fraction? 
Select and explain. 
A. MUGA, B. SPECT using thallium 201, C. PET myocardial perfusion imaging, D. Sestamibi scan with pharmacological stress
A: MUGA
Answer: A: MUGA 
Explanation: Nuclear Imaging of hea: MUGA scan (Multi-gated acquisition scan): Tc 99m labeled RBC is used Evaluate ventricular function / ejection fraction- Cardiac ventriculography (but most accurate investigation for ventricular function is -MRI) Tc99m labeled RBC is very sensitive investigation for detecting minimal lower GIT bleeding (as low as 0.1 ml per minute) PET scanning in hea: - N-13 ammonia PET = very sensitive for myocardial perfusion -18 FDG-PET = Myocardial bility If N-13 ammonia PET (-) & 18 FDG PET (-) - Suggestive of scar tissue If N-13 ammonia PET (-) & 18 FDG PET (+) - Hibernating myocardium Note: C-11 methionine PET is better than 18 FDG PET - for brain tumors