The combination of the CT scan and the PET scan is still a pretty recent thing. In fact, the proposal to combine the two machines didn’t occur until 1991. And, it wasn’t until 1998 that the first prototype PET/CT scanner became operational.
The concept developed at the University of Geneva when a PET scanner was adapted to be able to fit a different imaging device within the PET scanner. Then, the idea to fit a scanner that would provide more anatomical information (such as a CT scanner) was suggested.
The development of the PET/CT scan took some trials, but now the imaging device is a staple in diagnostic centers across the world. The combination of images the new PET/CT scan provides is known as image fusion, and they can help provide clear images and more concise answers to important diagnostic questions.
But in order to understand how this machine functions, let’s first take a look at how individual CT and PET scans work.
A CT scan is an imaging device with which part of the body is x-rayed from different angles. These images are combined by a computer to produce complete pictures of internal organs. This procedure is often done on an outpatient basis.
A special dye called a contrast material is needed for some CT scans, to help highlight the areas of your body being examined. The contrast material blocks X-rays and appears white on images, which can help emphasize blood vessels, intestines or other structures.
Your doctor may recommend a CT scan to help:
Diagnose muscle and bone disorders, such as bone tumors and fractures
Pinpoint the location of a tumor, infection or blood clot
Guide procedures such as surgery, biopsy and radiation therapy
Detect and monitor diseases and conditions such as cancer, heart disease, lung nodules and liver masses
Monitor the effectiveness of certain treatments, such as cancer treatment
Detect internal injuries and internal bleeding
A pet scan is a nuclear medicine imaging test that reveals how certain tissues and organs are functioning. Before a PET scan, the patient is injected with a harmless radioactive glucose/water solution called a “tracer”. Once the tracer is inside the body, the patient is positioned into the PET scanner.
As the body processes the tracer, positrons begin to collide with electrons, causing gamma rays to be emitted. A PET scanner detects and measures these gamma rays while a computer uses the measurements to create pictures of the various organs at work within the body. In summary, these images give physicians the ability to tell healthy tissue from unhealthy tissue.
The PET scanner itself does not produce any radiation. It merely picks up signals from the tracers already in your body. Your doctor may order a PET scan to inspect the blood flow, oxygen intake, and metabolism of your organs and tissues. PET scans are most commonly used to detect cancer, heart problems, brain disorders and/or problems with the central nervous system.
This advanced nuclear imaging procedure combines positron emission tomography (PET) technology and computed tomography (CT) technology into one machine. A PET/CT scan reveals information about both the structure and function of cells and tissues in the body during a single imaging session.
During a PET/CT scan, the patient is first injected with a glucose solution that contains a very small amount of radioactive material. The substance is absorbed by the particular organs or tissues being examined. While the patient rests on a table and enters the tunnel-shaped scanner, the PET/CT scanner is then able to view the damaged or cancerous cells where the glucose is being taken up. The procedure is painless and varies in length, depending on the part of the body that is being evaluated.
By combining information about the body's anatomy and metabolic function, a PET/CT scan provides a more detailed picture of cancerous tissues than either test does alone. The images are captured in a single scan which provides a high level of accuracy.
If you or anyone you know requires an imaging test, visit Rosetta Radiology. We utilize PET and CT scans together in order to give our patients the most thorough diagnosis. If you would like to make an appointment or ask us questions about PET/CT scans, feel free to give us a call at 212-744-5538.