||Introduction to Medical Imaging:
There are 3 types of medical Imaging: CT Scanning, MRI Scanning and PET (Molecular Imaging).
CT Scanning uses X-ray beams which penetrate the body and make images of its anatomical structure. CT scanning can give information about structural changes in the body.
MRI (Magnetic Resonance Imaging)
MRI uses very strong magnetic fields to view and map internal structures in the body. MRI provides good contrast between the different soft tissues of the body, which make it especially useful in imaging the brain, muscles, the heart, and many cancers. Unlike CT scans or traditional X-rays, MRI uses no ionizing radiation.
PET (Positron Emission Tomography)
Pet scanning uses a radioisotope that is injected, inhaled or swallowed into the patient. The PET scanner takes images of the radiation emitted when the positrons released by the radioisotope collide with negatively charged electrons in the patient’s body.
Currently, the most common isotope in use is FDG (fluorodeoxyglucose), a radioactive form of glucose, primarily in the diagnosis of cancer. Cancer cells metabolize sugar much more rapidly than normal cells, and the PET scanner detects the increased activity. PET scanning is also used to diagnose neurological and cardiac diseases.
PET imaging was introduced in the 1970’s but became widely available only in the early 1990’s. Since then, it has been the fastest growing area in Medical Imaging. Over the last 20 years, the medical community has seen the benefits of PET (functional) imaging to patients, because the functional changes that PET detects are observable much earlier than the anatomical changes recorded by CT and MRI.
Although FDG has been the mainstay of PET imaging for the last 20 years, many new radioisotopes have been developed to target more than 60 diseases and are about to become commercially available. As soon as the new radioisotopes hit the market, the use of PET Imaging will skyrocket.