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 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.
Applications for PET Scanning
PET Scanning is dramatically transforming the way physicians obtain
vital diagnostic information for patients. Seeing these metabolic
changes at their earliest stages gives physicians a crucial advantage in
detecting and treating many diseases. PET is useful for identifying
Alzheimer's Disease, epilepsy and other central nervous system
disorders. Cardiac PET scans can also help determine if patients with
chronic ischemic heart disease may benefit from revascularization
PET's most common and important applications are in oncology, or cancer
care. When it comes to managing cancer, the goal is to use as few tests
as possible to provide the best and most effective treatment for our
patients. PET imaging can often detect tumors before such structural
scans as X-Ray, magnetic resonance imaging (MRI) and computed tomography
(CT) can identify them or when other tests are inconclusive. The
scanner's extreme sensitivity makes it possible to detect cancers at
their earliest stages and pinpoint their exact locations.
PET also provides critical information about whether a tumor is
malignant or not, the extent of the disease, and whether it has spread
to other organs. And it can be used to look for signs of cancer
recurrence and monitor the effectiveness of chemotherapy and other
The benefits of PET include:
Detailed diagnostic information not available from other tests
(like CT and MRI)
Shorter time for definitive diagnosis
Earlier detection of disease with fewer invasive diagnostic
Precise staging of the disease and better monitoring of
More effective tracking of chemotherapy results
Avoidance of unnecessary surgery
Where do I go for my PET scan?
Once found only in research laboratories, PET scans have been available
to patients of Main Line Health Imaging for nearly five years. The unit
is housed at Lankenau Medical Center, but results can be sent via a
secure network connection to Bryn Mawr and Paoli Hospitals so patients
can be evaluated and treated at their home hospitals after completing
Main Line Health Imaging offers a combined PET/CT system at Bryn Mawr
Hospital Outpatient Imaging Services and Paoli Hospital. This
state-of-the-art technology acquires all PET and CT information in one
simple scan streamlining the testing process for patients and
What Happens Next?
An experienced Main Line Health radiologist will analyze your PET scans
and send a report to your referring physician, who will inform you on
your test results. Results cannot be given directly to the patient or
For more information, call 1.866.CALL.MLH.