3. Dangers Of Radiation

4. Radiation is usually ionizing meaning it can remove electron from atoms. This makes them radioactive and they give of radiation to make them stable again. This makes it very dangerous because our DNA is also made up of atoms and if they are ionized then it could change the DNA. This can cause Mutation which can be good or bad. Mutation can also cause the cell to divide uncontrollably and this is cancer. This can also cause tissue damage.

5. Radiation is used in Tracers and PET Scanning  Tracers: Radioactive isotopes are used as tracers. They are injected into the Patient or swallowed. Then a detector placed outside the body is used to track it. The readings from the detector are used by the computer to make an image telling us where the strogest radiation is coming from. Iodine-131 is an example of the tracers.  PET scanning: Positron emission tomography is a technique used to show tissue or organ function. They find damaged tissue by finding decreased blood flow. This is used to reveal coronary artery disease and damaged or dead heart muscles caused by heart attacks. It can also record blood flow and activity in the brain and is used to diagnose epilepsy. Cancer cells have a higher metabolism than healthy cells because they are growing. This is used to identify cancer tumour cells. Patient are injected with a substance that is used by the body e.g. glucose containing a positon emitter isotope with a short half life as a tracer e.g. 11C, 13N, 15O, or 18F. The isotopes are made in cyclotron. Positron is an antiparticle so it annihilates and releases high-energy gamma rays. The glucose or whatever containing the radioactive isotope is used more by the cancer cells because they grow. This shows up as a red area in the image made by the computer. This is the location of the tumour cells.

6.  Problems with producing isotopes for PET scanning : Isotopes used in PET scanning have a very short half life so they are made near where they are used because if they are left for long time then they become useless.  Safety precautions: Longer exposure to high concentration of radiation can be a problem because they can cause cancer and tissue damage. So to make sure the patients are safe when they are being treated or diagnosed they are given the lowest possible doses of radiation and the exposure time is made the shortest it can be. Sometimes the patients have to wear lead shielding to protect the areas not being treated. The PET scanners use very little radiation. The intensity of radiation decreases as the distance from the source increases just like light. So the medical personal stand very far away from the source and they remotely control the equipment. They also stand behind lead screen and sometimes wear lead-lined clothing. Their radiation dose is also closely monitored.