The Sol Goldman Pancreatic Cancer Research Center

Radiology


Radiographic imaging is in many ways the mainstay of managing patients with pancreatic cancer. A number of technologies can be used to visualize pancreatic masses, but we would like to emphasize the four most common- computerized axial tomography (CAT) scanning, endoscopic ultrasound (EUS), positron emission tomography (PET), and magnetic resonance imagining (MRI).

CT Scan (computerized axial tomography)
CT scans are generated using a special machine (of course called a CAT scanner!) that rapidly directs multiple X-ray beams at multiple different angles and levels to the abdomen. Contrast dye, given to the patient orally and/or into the blood stream (intravenously), can help make the organs visible by appearing white on the X-ray films. A computer processes the X-ray information and produces the CT images, usually as cross-sectional slices of the abdomen. Exquisitely detailed three-dimensional images can now also be produced using advanced image processing methods. CT scans can now be performed in 20-30 seconds using newer machines.

CT scanning will visualize the vast majority of pancreatic cancers, and it provides important information to guide treatment. For example, the relationship of the cancer in the pancreas to important blood vessels adjacent to the pancreas can be seen, a feature used by surgeons to determine if the tumor can be safely removed surgically. The liver and other organs are also visualized, helping to determine if the cancer has spread ("metastasized") beyond the pancreas.

The level of radiation received during a CT scan is modest. Apart from the minute risk (much less than 1% of patients) of an allergic reaction to the contrast dye, a CT scan is without major complication. It is always advisable to inform your doctor of any allergies you have.

CT scans are often the first test doctors order when they suspect a pancreatic cancer, because it is considered one of the most useful imaging techniques.

ctscan This CT shows a cross-sectional "slice" of the abdomen. To understand the anatomy in this image, visualize the patient lying on their back. You are standing at the foot of the bed looking from their feet towards the patient's head.

Major anatomical structures are labelled. A tumor is visible in the head of the pancreas. The arrow indicates the superior mesenteric artery.


Magnetic resonance imaging
Magnetic resonance imaging (MRI) is often used to image the pancreas because it doesn’t use X-rays (ionizing radiation). Instead, a series of powerful magnets and specialized detectors are used to create an accurate image of the pancreas and surrounding structures. The detail seen (resolution) of MRI isn't as good as it is with EUS and CT scanning, but MRI can provide detailed images of the pancreatic duct system (a procedure sometimes referred to as "MRCP").

Positron Emission Tomography
Radioactively labeled sugars (18F-fluorodeoxyglucose [FDG]) are given to the patient and the radioactive tracer is concentrated in areas of the body that actively metabolize (use) sugar. Since many cancers actively metabolize sugar, positron emission tomography (PET) scanning is an excellent technology to evaluate the activity of a tumor.

For example, if a patient has been treated for pancreatic cancer and CT scanning reveals that a lesion remains where the cancer was, PET scanning can be used to determine if the remaining lesion is a scar or if it is actively growing tumor. The scar would be negative on PET scan, while active tumors are often PET positive ("PET avid"). PET scanning is sometimes combined with CT scanning, a test called PET/CT.