Whats the difference between a Pet Scan and a CT Scan ?

PET (positive emission tomography) with regards to technology is far more advance than CT(computed tomography) coz in pet scan it is an imaging technique that produces images of actual organ functioning(thru computer you can see a composite picture of the brain at work). While CT scan it's like an advance x-ray machine. Using multiple narrow x-ray beam to scan the e.g head in successice layer and an images are displayed on an oscilloscope or T.V. monitor. Before the procedure in pet scan you need to inhale a radioactive gas or injected.While CT scan -injection of a water-soluble iodinated contrast.

The first one scans a pet, and the second scans a city.

it's not a pet scan, it's a CAT scan and it is the same thing as a CT scan.

The two above answers are wrong, Pet Scan usually is used to diagnose cancer its a relatively new technology, It can scan your whole body for cancer. CT scans are used to scan different parts of body that they think, can have a problem, like lung cancer. It gives a more detailed image than an X-Ray.

PET scan is used to assess function, CT scan is just a 3D x-Ray.

Hi there!! Got this from the internet... Hope this helps... God bless!!!!


What is PET?

Positron Emission Tomography (PET) is a powerful imaging technique that holds great promise in the diagnosis and treatment of many diseases, particularly cancer. A non-invasive test, PET scans accurately image the cellular function of the human body. In a single PET scan your physician can examine your entire body. PET scanning provides a more complete picture, making it easier for your doctor to diagnose problems, determine the extent of disease, prescribe treatment, and track progress.

What is PET/CT?

PET (Positron Emission Tomography) and CT (Computed Tomography) scans are both standard imaging tools that physicians use to pinpoint disease states in the body. A PET scan demonstrates the biological function of the body before anatomical changes take place, while the CT scan provides information about the body's anatomy such as size, shape and location. By combining these two scanning technologies, a PET/CT scan enables physicians to more accurately diagnose and identify cancer, heart disease and brain disorders.

CT Scans put me to sleep and PET scans don't.

Seriously... a CT scan takes pictures in "slices". You are rolled through this tube-like thing and it takes cut-aways of whatever they are scanning, sort of like those children's books where you peel away the different see-through layers to get inside the boat or car, whatever.
A PET Scan doesn't do slices. It's not in a tube but more of a rectangle, and the x-ray part of it gets very close up to your skin. You are often laying down in the same spot for awhile, while it takes multiple pictures.
Both are quite claustrophobic, and both might allow you to listen to music via headphones while doing the scan. Also, you might need contrast, which is injected to give a different type of picture.
Hope that helps a little bit.

A Pet Scan is a step above a CT scan. My mother just wet through both procedures. They found a lump in her neck and did a CT scan. Because the CT scan was inconclusive, they had her go through a Pet scan which showed the lump better. I know this isn't much help but it's better than a Pet scan being a scan of your pet, etc, etc,etc.

Computed tomography (CT), originally known as computed axial tomography (CAT or CAT scan) and body section roentgenography, is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation. The word "tomography" is derived from the Greek tomos (slice) and graphia (describing). CT produces a volume of data which can be manipulated, through a process known as windowing, in order to demonstrate various structures based on their ability to block the x-ray beam. Although historically (see below) the images generated were in the axial or transverse plane (orthogonal to the long axis of the body), modern scanners allow this volume of data to be reformatted in various planes or even as volumetric (3D) representations of structures.

A PET SCAN
A short-lived radioactive tracer isotope which decays by emitting a positron, chemically incorporated into a metabolically active molecule, is injected into the living subject (usually into blood circulation). There is a waiting period while the metabolically active molecule (usually a sugar) becomes concentrated in tissues of interest, then the subject is placed in the imaging scanner. The short-lived isotope decays, emitting a positron. After travelling up to a few millimeters the positron annihilates with an electron, producing a pair of annihilation photons (similar to gamma rays) moving in opposite directions. These are detected when they reach a scintillator material in the scanning device, creating a burst of light which is detected by photomultiplier tubes. The technique depends on simultaneous or coincident detection of the pair of photons: photons which do not arrive in pairs (i.e., within a few nanoseconds) are ignored.
The most significant fraction of electron-positron decays result in two 511keV photons being emitted at almost 180 degrees to each other, hence it is possible to localise their source along a straight line of coincidence. In practice the line of coincidence has a finite width as the emitted photons are not exactly 180 degrees apart. Using statistics collected from tens-of-thousands of coincidence events, a map of their origin in the body can be plotted. The resulting map shows the tissues in which the molecular probe has become concentrated, and can be interpreted by nuclear medicine physician or radiologist in the context of the patient's diagnosis and treatment plan. PET scans are increasingly read alongside CT scans or MRI scans, the combination giving both anatomic and metabolic information (what the structure is, and what it is doing). PET is used heavily in clinical oncology (medical imaging of tumors and the search for metastases) and in human brain and heart research.

More importantly, consider why you're getting a scan, and think about how your lifestyle is contributing to the symptoms. (ie) bad eating habits soda, chips, candy bars, etc causing diabetes.

Ask your Doc how you can help correct your symptoms naturally. Or better yet, how you can compliment his recomendations with diet or exercise.