Different Types of Testing
Anatomic tests are tests that examine the shape of the pancreas. This type of testing can identify masses, scarring, cysts, stones, swelling and other pathological processes that change the contours of the gland or duct system. They can also provide valuable information about complications occurring in organs and structures that are near the pancreas.
Major structural tests include
- CT scan
- MRI / MRCP
- Ultrasound / endoscopic ultrasound
ERCP is an acronym for endoscopic retrograde cholangiopancreatography. This powerful tool, which combines the use of endoscopy and radiology, plays a central role in the diagnosis as well as the treatment of many disorders of the pancreas, bile ducts, gall bladder, and liver. In skillful hands, ERCP can provide the best possible images to detect abnormalities of the pancreatic duct and bile duct, and also has the potential–during the same procedure–to deliver the necessary treatment for many disorders of the pancreas and biliary systems.
Disorders that can be diagnosed and treated by ERCP include, but are not limited to: acute and chronic pancreatitis, benign and malignant tumors of the pancreas, bile ducts, gall bladder, and liver; bile duct and pancreatic stones and gall bladder sludge; strictures (blockages) of the bile duct and pancreas; obstructive jaundice; pancreatic pseudocysts and biliary cysts; pancreatic and bile duct disruptions (duct leaks); and sphincter of Oddi dysfunction (sometimes referred to as SOD or biliary dyskinesia, a disorder of the outlet of the bile duct or pancreas duct which may cause abdominal pain and other pancreas and bile duct symptoms). Thus, ERCP provides minimally-invasive treatment options, largely on an outpatient basis, for conditions that would otherwise require major surgery.
The Computed Tomography (CT) Scan uses X-rays to calculate the presence of structures in the body based on their density.
The CT scan image to the left is from a patient with chronic pancreatitis. the arrow is pointing to the head of the pancreas, which if filed with stones (which appear white). The scan also shows the liver on the left side, the two kidneys under the pancreas, the spine between the kidneys, and the spleen on the right. This scan was done with intravenous contrast so that the blood vessels appear light in color, but not as light as stones.
MRI / MRCP
The magnetic resonance imaging (MRI) is a medical test that uses radio waves to detect structures based on their chemical nature. The MRI can be tuned to visualize liquid, allowing the duct system of the pancreas and liver to be seen. The information obtained in the latter way is similar to an ERCP, and is called a magnetic resonance cholangiopancreatography (MRCP). Even better images and some information on pancreatic function can be obtained by giving the patient the hormone secretin just before the test to stimulate the pancreatic duct to secrete fluid from the duct cells. The advantages of MRI and MRCP are that they do not expose the patient to radiation.
Ultrasound / EUS
Ultrasound (or transabdominal ultrasound) uses sound waves to produce an echo image of the organs of the body. The advantage is that it is relatively inexpensive and safe, but has the disadvantage of not being able to see very deep in the body, and the sound waves are blocked by bone and are not transmitted through air or gas. The primary use of transabdominal ultrasound is in identifying gallstones, and looking at the pancreas in children since the distance from the skin to the pancreas is smaller in younger psople.
Many of the limitations seen in adults have been overcome by placing the ultrasound probe on the end of a special endoscope, resulting in endoscopic ultrasound (EUS). EUS has become a very powerful tool because the physician can position the probe very close to the structure in question, use doppler to identify blood vessels, and use special biopsy needles to gain samples from small masses or cysts that cannot be seen with traditional endoscopes.