This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Radiology
Isotope used in myocardial perfusion scan is - 
Select and explain. 
A. Technetium, B. Thallium, C. Stannous pyrophosphate, D. Gallium
A: Technetium
Answer: A: Technetium 
Explanation: Technitium is used in myocardial perfusion scans