This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Introduction to Radiology, Subject name: Radiology
Gamma Rays are used in? 
Select and explain. 
A. CT scan, B. DEXA Scan, C. Fluoroscopy, D. PET Scan
D: PET Scan
Answer: D: PET Scan 
Explanation: *PET Scan uses Gamma Rays. *Gamma Rays are used in SCINTIGRAPHY STUDIES(Tc99m radioisotope studies),SPECT(Single Photon Emission Computerised Tomography) studies and PET scan (Positron Emission Tomography), Bone scan (Tc99m-MDP studies) *All other investigations given in the options use X rays.