radio-imaging effectiveness :: essays research papers

Radiation can be apply in both diagnosis and therapeutic manners. The radiation emitted from radio receiverisotopes can demolish tissue and in the therapeutic use the destruction of cancerous and otherwise dangerous tissues. And with diagnosis the gamma particle pass through the dust tissues with minimal damage to a gamma camera.To evaluate the effectiveness of PET, SPECT, magnetic resonance imaging and X-rays, we first need some basic knowledge on how all(prenominal) of them work.PET stands for positron emission tomography and works by an tool collecting radiation emitted from a radioisotope injected the patient physical structure. The strengths of emission are record by a gamma camera, which has a serial of scintillation crystals, for each one connected to a photomultiplier tube. The crystals convert the gamma rays, emitted from the patient, to photons of light, and the photomultiplier tubes convert and amplify the photons to galvanic signals. These electrical signals ar e then processed by a computer to generate images. The table is then moved, and the process is repeated, resulting in a series of skip slice images of the body over the region of interest (e.g. brain, breast, liver). These thin slice images can be assembled into a three dimensional office of the patients bodyNowadays, PET scanning devices are most often utilize in conjunction with CT scanners, so that a more high-fidelity image can be observed by the doctor for easier diagnosis of diseases or disorders.SPECT (Single Photon Emission Computed Tomography) works in a way a good deal the same to PET. But the radioactive substances used in SPECT (Xenon-133, Technetium-99, Iodine-123) have time-consuming decay times than those used in PET, and emit single preferably of double gamma raysMRI has a more complex ruler for its function it works by creating a magnetic field so strong that the hydrogen protons in the body are forced into alignment with the magnetic field. Short bursts o f radio waves are sent from the scanner into your body. The radio waves knock the protons from their position. When the burst of radio waves stops, the protons go can into position. They realign back to being in parallel with the magnetic field. As the protons realign, in a process known as relaxation, they emit tiny radio signals. A receiving device in the scanner detects these signals. The type of tissue can be interpreted from the strength of the signal emitted.Most of the hydrogen atoms in the body are in water molecules.