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Bruce, I've had a couple of PET scans. The idea is simple but hard to believe. You get an injection. The injection contains a substance [ligand] which has an affinity for what part of the anatomy is to be studied. Flouradopa is the favorite for most. I used a cocaine analog. The ligand has atoms in it to which positive charges [positrons] have been added. If you remember any of your physics or chemistry, you know the things in orbit around the nucleus are negatively charged.... Remember the antimatter bombs in Startrek? When a positron and an electron(-) meet, there is an explosion. Gamma ray particles are sent out.., sent out with equal and opposite direction and force. The PET scan uses usually sodium receivers to detect the gamma rays. There are gamma rays everywhere, but having two at the same time with exactly equal force and exactly opposite direction does not happen often by chance. These "rarities" are recorded by a computer attached to the scanner. These are "hits," and the direction is recorded. These non-random gamma ray particles are used to map the area of interest. This shows the activity [locations] of the ligand in the organ of interest, head in my case and probably your head too. This "map" produces what is essentially a picture of metabolism in the brain. It does not hurt, you do not light up, and you cannot rent yourself out as a streetlight or energy source to your local power company. The ligand has a very short half-life so the "stuff" must be created and used very quickly. Have fun. There are not many PET scanners in the world. Will Johnnston A.P.D.A. DelMarVA Chapter Pres. 4049 Oakland School Road Salisbury MD 21804 USA 410-543-0110 ---------- From: Bruce Anderson <[log in to unmask]> To: [log in to unmask] Subject: Pet Scan Date: Friday, April 23, 1999 2:04 PM A neurologist last week recommended I get a Pet scan and wrote me a prescription for one. He then ducked ou t before I had a chance to ask him about it. Can anyone tell me what it is, what it's suppose to diagnose and what it's like? It must be pretty rare because he said I would have to go to Columbia Univ., Hosp, in NYC for it and I live in western NJ. Thanks -maybe I wandered into a veterinary neurologist's office by mistake.........