FDG and blood flow

FDG and Blood Flow : 

FDG and Blood Flow Presented by: Sama A. Alhamdan Level 5

What is FDG?? : 

What is FDG?? Fluorodeoxyglucose; it is a glucose analog, used in positron emission tomography (PET), fluorine-18 in the FDG is positron-emitting radioactive isotope, it is taken up by high-glucose-using organs and used for the assessment of glucose metabolism in the heart, brain and also used for tumors imaging.

History : 

History The FDG compound was first administered to two human volunteers by Abass Alavi; an Iranian nuclear medicine professor, in 1976. Brain images obtained with an ordinary (non-PET) nuclear scanner demonstrated the concentration of FDG in that organ.

How a blood flow scan done?? : 

How a blood flow scan done?? A dose of FDG in solution (5 to 10 millicurie) is injected rapidly into a saline drip running into a vein, patient was fasting for at least 6 hours, and has low blood sugar (patients with blood glucose levels over 180 mg/dL ”diabetics”, must be re-scheduled). Patient wait an hour for the sugar to distribute and taken up into organs uses glucose, physical activity must be kept to a minimum to minimize uptake of the radioactive sugar in muscles. Then, patient is placed in PET scanner for a series of one or more scans, that may take from 20 minutes to an hour.

The Concept: : 

The Concept: PET-FDG scans offer metabolic imaging, it detects differences in the metabolism of tissues. The most metabolically active tissues have the greatest needs for sugar from the bloodstream, when the sugar is labelled, the scans detect these areas. metabolic activity can be increased with inflammation, infection, and normal body activities (organs like heart, brain, and bowel have normal uptake), PET scans tend to pick up cancer, because cancer cells have greater metabolic activity and divide faster than normal tissue.

What is ACD?? : 

What is ACD?? PET scanners use annihilation coincidence detection (ACD) instead of collimation to obtain projections of the activity distribution in the subject. Positron interacts with an electron by annihilation, the electron-positron pair is converted into two photons emitted in opposite directions. Both annihilation photons interact with detectors within the scanner. If the interactions occurring at nearly the same time, it called Annihilation Coincidence Detection.

Brine scan: : 

Brine scan: brain cells need glucose to operate. Thus, the radioactive glucose(FDG) injected travels to the brain, where it collects in greater concentration in the most active (has high metabolic rate) areas. The PET scanner detects the location and concentration of the radioactive glucose by detecting the gamma rays when it emits positrons during radioactive decay.

Heart scan: : 

Heart scan: intravenous injection of 10.0 millicuries of FDG is injected, 45 minutes later imaging of the myocardium showed uptake of the FDG radiotracer. FDG moved into cells in proportion to plasma glucose.

Cancer Screening: : 

Cancer Screening: Cancer screening including FDG-PET showed reasonable accuracy and could detect a wide variety of cancers at early stages.

Slide 12: 

PET image shows increased FDG uptake in the right breast (black arrow) and axila (white arrow). In Brest Cancer:

References: : 

References: [1]http://en.wikipedia.org/wiki/FDG [2]http://www.csulb.edu/~cwallis/482/petscan/pet_lab.html [3]http://www.nmr.mgh.harvard.edu/martinos/research/technologiesPET.php [4]http://circ.ahajournals.org/cgi/content/full/91/9/2299 [5]http://www.mghradrounds.org/index.php?src=gendocs&link=2006_april [6]http://onctalk.com/2007/01/09/pet-scanning-intro/ [7]http://www.kjronline.org/abstract/view_articletext.asp?year=2007&page=429

Thank you.. : 

Thank you..