What is PET/CT Scan?
The PET/CT combines the strengths of two well-established imaging services in one imaging session. A PET/CT scan is noninvasive, painless and takes about 30 minutes.
PET, or positron emission tomography, monitors the biochemical functioning of cells by detecting how they process certain compounds, such as glucose (sugar). Cancer cells metabolize glucose at a much higher level than normal tissues. By detecting increased glucose use with a high degree of sensitivity, PET identifies cancerous cells - even at an early stage when other medical imaging services may miss them. However, PET cannot pinpoint the exact size and location of tumors to a precision necessary for optimal diagnosis and treatment planning.
That's where CT, or computed tomography, comes in. CT yields a detailed picture of the body's anatomical structures by taking cross-sectional images or X-ray slices of the body. While CT does an excellent job of depicting structures and anatomy, it may miss small or early stage tumors.
Currently, physicians can overlay the results of PET and CT scans performed separately to identify and locate tumors, but a patient may not be positioned identically for both scans and the two images may be difficult to line up exactly, degrading the accuracy of the diagnostic information. However, the combined PET/CT machine allows physicians to rapidly perform both scans in one session without having to move the patient. This means physicians can precisely overlay the metabolic data of the PET scan and the detailed anatomic data of the CT scan to pinpoint the location and state of tumors.