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July 19, 2010

QC on gamma camera

This is one of my daily main job. Do qc on gamma camera. There are two gamma cameras in our department placed in two different room.  Each room is monitor by one physicist. It took about 30mins to complete one cycle of qc. Mesin gamma camera ni digunakan dlm nuclear medical imaging (a.k.a nuclear medicine) to view and analyze imej tubuh badan manusia.

gamma camera (under my monitoring)
 

 lab technologist is doing a scanning process

Gamma camera principle
 
A gamma camera consists of one or more flat crystal planes (or detectors) optically coupled to an array of photomultiplier tubes, the assembly is known as a "head", mounted on a gantry. The gantry is connected to a computer system that both controls the operation of the camera as well as acquisition and storage of acquired images. The system accumulates events, or counts, of gamma photons that are absorbed by the crystal in the camera.

The crystal scintillates in response to incident gamma radiation. When a gamma photon leaves the patient (who has been injected with a radioactive pharmaceutical), it knocks an electron loose from an iodine atom in the crystal, and a faint flash of light is produced when the dislocated electron again finds a minimal energy state. The initial phenomenon of the excited electron is similar to the photoelectric effect and (particularly with gamma rays) the Compton effect. After the flash of light is produced, it is detected. Photomultiplier tubes (PMTs) behind the crystal detect the fluorescent flashes (events) and a computer sums the counts. The computer reconstructs and displays a two dimensional image of the relative spatial count density on a monitor. This reconstructed image reflects the distribution and relative concentration of radioactive tracer elements present in the organs and tissues imaged.
 
~~ Ringkas je ni. Kalo xphm tu buat2 phm jela. Tp rasanya principle ni basic je kot, fizik spm pun ade sentuh sket2 kan..
 
Source: Wikipedia

1 comment:

L i 3 z @ said...

lorr..nnt balik nak rilexkan otak. pk benda yg menarik sket. xmola pk keje.