| With advances in science and medical technology, | | | | regional glucose uptake. Use of this tracer results in the |
| doctors now have more tools at their disposal for | | | | most common type of PET scan but there are other |
| detecting and diagnosing cancer of various types than | | | | tracer molecules that can be used in PET to show the |
| ever before. While many have heard of MRIs, CAT | | | | tissue concentration of many other types of molecules |
| scans, and x-rays, the PET Scan is a very useful tool | | | | or cells of interest. |
| that actually shows more detail than the other | | | | Like many imaging techniques, PET imaging is used as |
| diagnostic tools. | | | | both a medical and research tool. The diagnostic tool is |
| Positron emission tomography, or PET, is a form of | | | | used heavily in clinical oncology where it is used for |
| nuclear medicine imaging. The technique produces a | | | | medical imaging of tumors and for searching for |
| three-dimensional, or 3D, image or picture of the | | | | metastases, or new spots of spreading cancer. This |
| functional processes in the body. The PET system | | | | type of imaging is also used for clinical diagnosis of a |
| detects pairs of gamma rays that are emitted | | | | variety of certain diffuse brain diseases. As an |
| indirectly by a positron-emitting radionuclide, or tracer, | | | | example, PET imaging is used for diffuse brain |
| which is introduced into the body just before the test. | | | | diseases like those that cause various types of |
| The images developed by the test, including images of | | | | dementia. The imaging system is also important for |
| tracer concentration, are then reconstructed by | | | | mapping normal human brain and heart function. |
| computer analysis in a three-dimensional view. In the | | | | As a research tool, PET is used in pre-clinical studies |
| latest scanners, the reconstruction is frequently | | | | that utilize animals. The scan allows for repeated |
| produced with the assistance of a CT X-ray scan that | | | | investigations into the same subjects. While it may |
| is performed on the patient during the same test as | | | | seem intrusive, this repeated testing is extremely |
| the PET scan in the same machine even. | | | | valuable in cancer research as it results in a vast |
| There are a variety of biologically active molecules | | | | increase in the statistical quality of the data as it allows |
| that can be chosen for a PET scan. FDG is one of | | | | a subject to act as the control for that subject as well. |
| these molecules. When this molecule, which is an | | | | PET imaging also reduces the number of animals |
| analogue of glucose, is chosen, the concentration of | | | | needed for a study substantially. |
| tracer shows tissue metabolic activity in terms of | | | | |