I believe they use an isotope of tecknesium (sp?). When atoms of this isotope decay they produce a positron, which finds an electron and they annilate each other. An electron and a positron both contain 511 MeV of rest mass energy, so they will produce two gamma rays of 511 MeV that are directed almost exactly directly away from each other. Sodium Iodide scintillating material surrounds the patient, and then multiple phototubes look at the sodium iodide. The configuration is such that the gamma is absorbed by the sodium iodide, which produces a flash of light, and the phototubes record the light and send the pulse to some pulse analysis hardware and computer. The pulse analysis determines exactly where in the sodium iodide the flash occured, and with two flashes on opposite sides, the computer figures out a straight line between the two, where the original source of the positron will be on this line. When another one occurs, if it occurs at the same spot, a second line will be computed that will intersect the first line, and that will be the spot that the activity is coming from. By analyzing tens of thousands of lines, the computer can come up with a pretty good 3 d view of where all the activity is.
It is not the positron that causes damage to material, after all the loss of an electron is rather non consequential. It is the 511 MeV gamma rays, which is an extremely hard x-ray, like cosmic rays. that can cause damage if absorbed before they get out of the body. Marshall "Jonathan B. Britten" wrote: > I admit that I do not understand the properties of positrons, though > of course I understand they are not x-rays. As to whether or not > they have detrimental health effects, I am not sure. The article I > read cited in particular x-rays and CAT scans; Japan has ordered an > astounding number of CAT machines from the USA, and may have the most > machines of any country per capita. > > On Saturday, Aug 28, 2004, at 00:02 Asia/Tokyo, Ronald Wilson wrote: > > > Pet is not electromagnetic x rays > > > > > > ----- Original Message ----- > > From: "Jonathan B. Britten" <jbrit...@cc.nakamura-u.ac.jp> > > To: <silver-list@eskimo.com> > > Sent: Thursday, August 26, 2004 10:45 PM > > Subject: Re: CS>X-Ray > > > > > >> In Japan, health researchers recently announced that at least three > >> percent of all cancers are directly due to excessive use of x-rays and > >> other invasive electromagnetic diagnostic tests such as CAT and PET > >> scans. Yes, that is three out 100 patients with cancer got that way > >> from their own doctors. > >> > >> The only good thing you can say is that at least the facts finally > >> came > >> out. > >> > >> I was not surprised by the report. I was once quite ill with > >> mycoplasmic pneumonia in this country, and the various doctors gave > >> me > >> at least a dozen x-rays -- in the first case, identical x-rays taken > >> by > >> two different facilities within 24 hours -- before I was well enough > >> to get away from them. I was too ill to protest for a while there. > >> > >> Every year teachers are supposed to take an x-ray as a condition of > >> employment. Every year I do not, and if pushed to the wall will do > >> battle. I can not be sure about the utility of mammograms, but I > >> believe that non-invasive methods, such as Omura's BDORT, are likely > >> to be proven superior in the long run. > >> > >> > >> > >> > >> > >> > >> JBB > >> > >> > >> > >> > >> On Friday, Aug 27, 2004, at 12:56 Asia/Tokyo, sol wrote: > >> > >>> My mother, a salty tongued old devil, never had a mammogram until she > >>> was in her 70's..... she refused to ever have another saying, "if > >>> there was nothing wrong with them before, there damn sure is > >>> afterward". Forget the radiation, she believed all the crushing could > >>> not be good. > >>> sol > >>> > >>> Jim Holmes wrote: Message > >>>> I avoid radiology unless it is absoloutly necessary. Some folks > >>>> think that Breast CA is in-part caused by the "checkup" mammograms. > >>>> JOH > >>>> > >>>> -----Original Message----- > >>>> From: Faye Killian [mailto:fkill...@bayou.com] > >>>> Sent: Thursday, August 26, 2004 5:29 PM > >>>> To: silver-list@eskimo.com > >>>> Subject: CS>X-Ray > >>>> > >>>> I know this has probably been discussed here before but I need > >>>> to > >>>> know. Does taking silver affect you in any way while having an > >>>> x-ray? I have a mammogram coming up and was just concerned about > >>>> it. Have been taking cs for over a year now. > >>>> Faye > >>>> > >>> > >>> -- > >>> "You can complain because roses have thorns or you can rejoice > >>> because thorns have roses." Ziggy > >>> > >>> > >>> > >>> > >>> -- > >>> The Silver List is a moderated forum for discussing Colloidal Silver. > >>> > >>> Instructions for unsubscribing are posted at: http://silverlist.org > >>> > >>> To post, address your message to: silver-list@eskimo.com > >>> Silver List archive: > >>> http://escribe.com/health/thesilverlist/index.html > >>> > >>> Address Off-Topic messages to: silver-off-topic-l...@eskimo.com > >>> OT Archive: http://escribe.com/health/silverofftopiclist/index.html > >>> > >>> List maintainer: Mike Devour <mdev...@eskimo.com> > >>> > >> > >
