Gamma Camera is mainly a functional imaging modality that provides detailed functional information on organs such as kidneys, thyroid, liver, heart, brain, skeletal system, gastrointestinal system, etc. In many clinical conditions, the abnormality starts to appear with the changes in the function of the organ or body, and slowly it reflects in structure. Since Gamma scans see the function, they can diagnose diseases early. It is also called SPECT (Single-photon emission computed tomography) when used for 3-dimensional imaging. Various radiopharmaceuticals labelled with Technitium-99m (99mTc), Iodine-131 (131I), Thallium-201 (201Tl), Gallium-67 (67Ga), Lutetium-177 (177Lu), Samarium-153 (153Sm) are used in gamma cameras for diagnostic and therapeutic imaging purposes depending upon the need of the patient.