Positron-Emission Tomography
How does it work?
For PET scan, a radioactive substance is attached, or tagged, to a natural body compound, most commonly glucose, and injected into the body. The image results from emission of positrons-positively charge particles-from the tissues. PET scans operate on the principle that cancerous cells use small glucose that normal ones do, those attracting a larger amount of the radioactive substance. As a result, diseased tissues emit a greater number of positrons which register as a variation in color or degree of lightness on the final image.
Whereas CT scans and MRI scans review the shape and structure of organs and tissue PET scans shows how they are functioning thus revealing chances at an earlier stage. PET scans can be performed in combination with CT scan, the superimposed image enhancing the details. PET scans may give false result, however, if patient have eaten within a certain time prior to the scan of if there blood sugar levels, perhaps because of diabetes are out side the acceptable range. Also, because of the radioactivity is very short-lived, timing is important.
Risks:
For PET scan, a radioactive substance is attached, or tagged, to a natural body compound, most commonly glucose, and injected into the body. The image results from emission of positrons-positively charge particles-from the tissues. PET scans operate on the principle that cancerous cells use small glucose that normal ones do, those attracting a larger amount of the radioactive substance. As a result, diseased tissues emit a greater number of positrons which register as a variation in color or degree of lightness on the final image.
Whereas CT scans and MRI scans review the shape and structure of organs and tissue PET scans shows how they are functioning thus revealing chances at an earlier stage. PET scans can be performed in combination with CT scan, the superimposed image enhancing the details. PET scans may give false result, however, if patient have eaten within a certain time prior to the scan of if there blood sugar levels, perhaps because of diabetes are out side the acceptable range. Also, because of the radioactivity is very short-lived, timing is important.
Risks:
Because the amount of radioactive substance which is very low and it radioactivity short-lived, radio exposure is low. Still, it can pose the risk to a developing fetus. Hence, women who may be pregnant to inform their doctor and imaging staff. And women of child bearing age may be asked to give a blood or urine sample to test for pregnancy. If a PET scan is used in conjunction with a CT scan, then the risk associated with CT scans should also be taken into account.
Benefits:
Benefits:
because PET scans show not just the shape of organ and tissue but also how well they are working, this scans can uncover problems before changing in tissue structure can be seen with CT or MRI.
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