Oncology PET-CT Scan – The benefits of PET and CT scans, working together

Jun 20, 2013 -  What is a PET-CT scan? Is it two scans – or one?
A PET (Positron emission tomography) is a highly sensitive radiology-imaging scan, which is used to diagnose abnormalities at the molecular level. A CT (computed tomography) scan provides a detailed image of the body's internal anatomy to better pinpoint the location of disease. The GE Discovery ST PET-CT uses both of these well-established imaging tools during a single exam to more accurately map out location(s) and areas of disease.

Why are PET-CT scans beneficial to the doctor?
The combined PET-CT scan provides physicians with more sensitivity, speed, resolution, and diagnostic confidence when diagnosing and treating their patients. The PET scan, administered with a glucose-based IV solution, makes ‘bright spots’ to show where an area of disease might be in a specific area or organ. The CT scan outlines the organs and other more dense material, making a detailed map, so the Radiologist can isolate the location with much higher accuracy than using just the PET scan alone. This image helps the radiologist determine if disease is present, the location and extent of disease, and track how rapidly it is spreading.

Why are PET-CT scans beneficial to you?
The combined PET-CT test is better for the patient because it saves time and is more accurate in pinpointing areas of disease for earlier detection of cancers. Early detection is proven to be key for successful outcomes and less disruption in your life.

How do I prepare for a PET-CT scan?
Based on the type of PET-CT scan, you will receive specific instructions on when to last eat, drink or take a medication. You may also be asked to refrain from exercising or lifting heavy objects the day before and the day of the scan. At the time of the test, you will need to remove any metal objects including jewelry, eyeglasses, dentures and hairpins, as they may affect the CT images. You may be allowed to wear your own clothing or a hospital gown during the exam.

What should I expect during the scan?
First, a nurse or PET-CT technologist will insert an intravenous (IV) line into a vein in your arm or hand and administer a substance consisting of a radiotracer and other ingredients that mimic those normally used in the body including water, sugars, proteins, and oxygen. You will then relax in a reclining chair in a quiet room for 45-60 minutes. At the time of the exam you will be asked to recline on the PET-CT examination table. You will then be positioned for the best view of the area to be scanned and asked to remain motionless during the remainder of the exam.

The PET-CT machine will automatically move you into the bore (opening of the scanner) and the imaging will begin. You will need to remain still during imaging. You will be able to speak to the radiology technician, and they will check in with you regularly to make sure you are OK and to update you on the time remaining. The CT scan will be done first, followed by the PET scan. On occasion, a second CT scan with intravenous contrast will follow the PET scan.

The actual CT scan takes less than two minutes. The PET scan takes 20-30 minutes. The PET scan images are then fused with the CT images.

When the initial scan is complete, you may be asked to wait until the technologist checks the images in case additional ones are needed. Occasionally, more images are taken for clarification or better visualization of certain areas. The need for additional images does not necessarily mean there was a problem with the exam or that something abnormal was found, and should not be a cause of concern.

How are the results of the PET-CT scan given?
After your exam, a radiologist will interpret the images and forward a report to your referring physician who will, in turn, report the findings to you.

Request ECHN for all your imaging needs. PET-CT scans are performed at the ECHN Manchester Memorial Hospital location with convenient appointment times, including Saturdays.

American College of Radiology

American Board of Radiology

(Developed jointly by Radiological Society of North America and the American College of Radiology) http://www.radiologyinfo.org


Find A Doctor  

Health Information  


Proper Body Mechanics Proper Body Mechanics 4/14/2014
Fred Bailey, Director of ECHN Rehabiltation Services Fred Bailey, Director of ECHN ... 9/22/2011

See Video Library