Slide 20 - 24 The following slides show normal uptake of FDG in the body. High uptake will be found in brain and the renal system like kidneys, urethra and bladder. Medium uptake is seen normally in liver, muscles and bones. Normally there should be low or no uptake in lungs and and possibly low or no uptake in bones. The cardiac uptake varies from high to none as well the bowel activity.
RADIOACTIVITY 12 SACE PHYSICS-STAGE 2 SECTION 4 TOPIC 3 PRINCE ALFRED COLLEGE
Neutrinos react very weakly with matter. It took 25 years to detect them and there are millions of neutrinos that pass through the Earth from the sun as if the Earth was not there. This is because they have no real mass or charge.
They can penetrate several centimetres of lead or concrete before being absorbed. 4 cm of lead reduces the intensity of a gamma ray beam by 10%.
They carry no charge and are undeflected by electric and magnetic fields and are therefore only weakly ionising. They cannot attract electrons but can knock them out similar to the photoelectric effect.
The activity of a radioactive sample is directly proportional to the number of remaining atoms of the isotope. After t 1/2 , the activity falls to ½ the initial activity. After 2 t 1/2 , the activity is ¼. It is not till 7 half-lives have elapsed that the activity is 1/128 th of the initial activity.
A Geiger counter is placed near a source of short lifetime radioactive atoms, and the detection count for 30-second intervals is determined. Plot the data on a graph, and use it to find the half-life of the isotope.
World PET Numbers (July 2000) Cameras Per Million Belgium 18 1.78 Germany 80 0.97 Switzerland 7 0.95 Denmark 4 0.75 Sweden 6 0.67 USA 144 0.52 Austria 4 0.52 Finland 2 0.38 Japan 37 0.29 Australia 5 0.26 (0.31) Canada 8 0.26 Netherlands 4 0.24 UK 14 0.23 Italy 12 0.21 Spain 8 0.21 France 8 0.13
Case Study 1: Lymphoma There is a focal region of increased activity in the mid to lower left lung laterally, consistent with intraparenchymal lung involvement at this site and there is a small region of activity at the pleural margin of the mid to lower left lung posterolaterally.
Case Study 5: Head and Neck Cancer Metastatic lymphadenopathy is seen in two mid right cervial nodes, one upper left cervical node, intensely in the subcarinal region, right mid and infrahilar region and retrocarinal region.