Positron Emission Tomography/Computed Tomography (PET/CT) Scan
What is positron emission tomography (PET)?
Positron emission tomography (PET) is an imaging technology that takes advantage of body metabolism and cell function in body tissues to show where diseases are hiding—particularly cancers. PET is unlike any other imaging technique because it doesn’t simply record structures; it records metabolic activity. The unique ability of the PET scanner to see chemical and physiological changes of disease at the cellular level—and much faster than with other imaging tools—allows for earlier detection and more accurate diagnosis of diseases. PET can also be used to determine appropriate treatments for disease and efficiently track the body's response to those treatments.
In a PET scan, a small amount of a short-lived radioactive tracer is injected into the patient via a sugar solution. This material discharges positively-charged particles, or positrons, which when absorbed by cells can be traced to reveal the locations of high metabolic activity. A camera picks up the tracer's signals, and a computer converts them into precise, three-dimensional pictures of these cells.
PET scanning gives physicians the ability to actually see the chemical changes that are occurring inside a cell. Whereas other conventional imaging techniques show only body anatomy and structure, PET images reveal the chemical functioning of an organ or tissue-crucial information that helps doctors determine the best courses of treatment.
For even more insight and understanding, these PET images can be combined with images obtained from computerized tomography (CT) scans, which show great anatomical detail, giving physicians the most complete picture possible of a disease—a study of both form and function.
The PET scan is completely painless and safe, using the same amount of radiation as a routine X-ray. A typical PET scan takes approximately 30–45 minutes, but expect to be at the facility for up to two hours. Main Line Health Imaging was one of the first in the Philadelphia region to offer this cutting-edge technology.
Hybrid technology enhances diagnosis and treatment
Combining the power of positron emission tomography with computerized tomography, the PET/CT scanner is setting a new standard of imaging excellence at Main Line Health Imaging. At Main Line Health, we produce both functional and anatomical images of exceptional quality in one simple procedure. Designed for maximum imaging flexibility, ease of use and patient comfort, the PET/CT captures highly detailed views of the body in seconds, allowing a wide range of assessments, such as tracking blood flow in detail through the heart and assessing tumor activity.
With applications for oncology, cardiology and neurology, the hybrid unit offers radiologists unparalleled capabilities for diagnosing disease, monitoring disease activity and planning treatment.
- By studying metabolic activity, PET yields vital information in cancer cases. It assesses tumor activity and depth, finds residual cancer cells, and monitors for recurrent disease. PET's information is so precise, for example, that it can identify if a spot on a lung is cancerous or not.
- CT scans take thin cross-sectional images of the body, akin to slices of bread, which physicians can rotate, examine, and correlate on a computer screen. When combined with the functional information of PET alone, a PET/CT scan provides precise information on the location of the abnormal metabolic activity that is associated with tumors on PET scans. This allows more accurate diagnosis and treatment.
While each imaging test alone is effective to detect numerous conditions, the ability of the PET/CT to fuse the tests provides significantly more information on disease location and metabolism.
PET/CT Scan preparation
Your physician may have ordered a PET/CT scan for you. PET/CT scans are performed to help your doctor appropriately plan treatment for your medical condition.
- You are required to have NOTHING to eat or drink EXCEPT water four hours prior to your scheduled appointment time.
- Non-diabetics can take all medications with water as long as they can be tolerated on an empty stomach. Diabetics: Oral diabetics may NOT take their diabetes medications within four hours of their scheduled arrive time. Insulin diabetics may NOT take their insulin within six hours of their scheduled arrival time. Insulin pump patients must call for instructions (484.337.2200).
- Drink three glasses of water the day of the exam.
- For dinner the night before the exam, please eat a high-protein, low-carbohydrate meal (e.g., fish, steak, chicken, vegetables, etc.). Avoid pastas, potatoes, breads, etc. On exam day, if time allows, while still adhering to the four-hour fasting requirement above, a SMALL high-protein, low-carbohydrate meal is allowed (e.g., eggs, bacon, sausage). Avoid cereal, bagels, breads, sugar, etc. If you are unsure of the fasting and/or meal requirements, please call 484.337.2200 to confirm.
- Refrain from ALL exercise 24 hours prior to exam.
- If your CAT scan, MRI or previous PET/CT scan was not performed at one of the Main Line Health facilities, please bring in a disc with your scans on them the day of your study. (If you are unsure, please call 484.337.2200.)
- You can expect to be at the PET/CT center about two hours. The actual scan itself can range from 10–20 minutes.
- Please wear comfortable clothing with no zippers, snaps or buttons.
The PET/CT scan procedure
- To begin your procedure, a small amount of radioactive glucose is injected into a vein in your arm. The tracer is not a medication or a dye so you will not feel any differently from the injection or have any reaction. After the injection, you will wait approximately one hour while the injected material is distributed throughout your body.
- There are no side effects from the injected tracer.
- Scan time will be 10-20 minutes.
Please make an effort to arrive at least 30 minutes prior to your appointment.
Registration will take place at the same location as your appointment: Main Line Health Newtown Square, 3855 West Chester Pike, Newtown Square, PA 19073. (Parking is free and abundant.)
Please bring a copy of your physician’s order script and insurance card to your exam. Results from your PET/CT scan will be available to your physician within 48 hours of the exam.
The PET/CT isotope is specially ordered for you and your particular study 24 hours before your exam. It cannot be reused! Therefore, should you need to cancel your appointment, it is important that you call us at least 24 hours in advance. If, for any reason, you are unable to keep your appointment, please notify us as soon as possible by calling 484.337.2200.