Additional tests are often needed prior to deciding on the best treatment plan for you. The most valuable studies used to discover and characterize pancreatic abnormalities include Pancreas Protocol CT scan, MRI with MRCP, Endoscopic Ultrasound (EUS), and ERCP. At times, multiple tests will be used to complement one another to provide the most precise information.
PANCREAS PROTOCOL CT
Pancreas Protocol CT is a noninvasive x-ray study where the organs of the chest, abdomen and pelvis can be visualized through thin slices from top to bottom and front to back. Intravenous (IV) dye is given during the test through a small needle inserted into an arm vein to allow the pancreas, liver and other organs to be viewed in different ways.
Patients lie flat on the table and are surrounded by a large donut-like machine. This machine is very open and airy, so claustrophobia is rarely a problem. The IV dye used in this test is iodine based and it can cause allergic reactions in patients with iodine or shellfish allergies. In this case, a one-day prep with steroids may be used to prevent reactions.
The IV dye can also occasionally affect kidney function, so patients with diabetes or prior kidney disease will be asked to have a blood test (BUN and creatinine) before the procedure to check kidney function.
Advantages of Pancreas Protocol CT include excellent imaging, lower cost relative to MRI or EUS, excellent patient tolerance and convenient availability at all Beaumont hospitals and outpatient x-ray facilities. While the radiation exposure is limited and safe, patients who require many studies for follow-up may benefit from alternative imaging options.
MRI with MRCP
MRI with MRCP also gives excellent imaging of the pancreas, liver and other solid organs with no exposure to radiation. While somewhat more expensive than CT, it holds the advantage of avoiding x-ray exposure for patient's requiring frequent studies. MRI can be more helpful in characterizing some lesions of the liver and provides more detailed pictures of the pancreatic duct than CT.
Like CT, an IV dye is used to improve detail. This dye, gadolinium, does not contain iodine and may be a better choice for iodine allergic patients. Since there is a small risk of kidney injury related to this dye, patients are often asked to undergo a blood test in advance to check kidney function. Patients with metal implants; pacemakers, defibrillators or other metal devices, may not be eligible for this test due to the large magnet used in the MRI machine.
During the MRI with MRCP test, patients lie on a table and are moved inside a fairly narrow tube. This tube sometimes makes claustrophobic patients uncomfortable. In this case, mild sedation can be used or the test can be scheduled on one of the open MRI machines. In an open MRI machine, the tube part of the machine has been cut horizontally so that the patient is not fully enclosed in the machine. Due to the lack of radiation exposure, MRI with MRCP is an excellent option for patients requiring multiple studies over a period of years, such as when following the course of pancreatic cysts.
ENDOSCOPIC ULTRASOUND (EUS)
Endoscopic ultrasound (EUS) is an extremely valuable procedure for the diagnosis of pancreatic cysts or solid tumors. In addition, there is a growing role for use of this test as a screening tool in patients at high risk for pancreatic cancer. A specially trained gastroenterologist performs this test. The patient first receives intravenous sedation to become sleepy and comfortable, and then a flexible tube or endoscope is passed through the mouth. The instrument has an ultrasound probe on its tip that uses harmless sound waves to view the pancreas through the wall of the stomach.
A major advantage of EUS is the ability to collect sample cells or fluid from a pancreatic mass or cyst. These cells are then viewed under the microscope (biopsy) or tested for chemical markers. This information can be an important guide in the decision-making process.
While the test is more invasive than CT or MRI, the additional information gained by needle sampling is valuable in many cases. There is a small risk of bleeding or inflammation of the pancreas (pancreatitis) when the needle aspiration is performed, however the benefit generally outweighs that risk.
ERCP (endoscopic retrograde cholangiopancreatography) is another valuable endoscopic procedure that involves the use of IV sedation and the direct injection of dye into the bile duct or main pancreatic duct. An advantage of ERCP is that these ducts can be directly examined and cells can be sampled and viewed under a microscope (biopsy), if needed. The ERCP procedure allows excellent imaging of the ducts and also gives doctors the opportunity to remove stones or place stents (tubes) to deal with blockages that may be present.
Spyglass is a newer technology that allows a tiny scope or camera to be passed deeply into the duct for more detailed examination or biopsy when needed.