Pancreas Imaging: Options for Imaging
Guest: Dr. Joseph Romagnuolo – Gastroenterology-Hepatology
Host: Dr. Linda Austin – Psychiatry
Dr. Linda Austin: I am Dr. Linda Austin. I am interviewing Dr. Joe Romagnuolo who is Associate Professor of Medicine at the Digestive Disease Center here at the Medical University of South Carolina. Dr. Romagnuolo, let’s talk about how one goes about imaging or taking pictures, diagnostic studies, of the pancreas. That is an area of real expertise for you. What are some of the techniques available today?
Dr. Joe Romagnuolo: The most basic test that we use is a plain abdominal ultrasound through the abdomen. Even plain x-rays can sometimes find things like calcifications that you can see in chronic pancreatitis and that is a very simple test to get.
Dr. Linda Austin: So, that is just really calcium deposits, right?
Dr. Joe Romagnuolo: That is right.
Dr. Linda Austin: What do those calcium deposits indicate?
Dr. Joe Romagnuolo: Those calcium deposits usually indicate that there has been scarring or fibrosis and that it has been there for a considerable period of time or that there are actual calcified stones in the pancreatic duct and if they are big enough, they will show up on abdominal x-ray.
Generally, though, abdominal ultrasound, because the pancreas is so deep in the abdomen, it really is behind the stomach and lies right on top of the spine, from the outside is usually not a great imaging test for the pancreas, but it is a place to start. Generally, if the pancreas is thought to be the potential cause for a patient’s symptoms, then a CT scan of the abdomen, preferably with some intravenous contrast or dye, is a better test.
Dr. Linda Austin: Now, from the patient’s point of view, what is involved in that test?
Dr. Joe Romagnuolo: The CT scan, or CAT scan, involves lying on a table where you do through a scanning doughnut that will x-ray to give virtual cuts of the inside of the body and, specifically, the pancreas. When one requests a CT scan of the abdomen and the pancreas is the organ of interest, then generally it should be done with what is called a pancreatic protocol where they will inject dye at the right time and they will do fine cuts through the pancreas.
Dr. Linda Austin: In other words, show slices of it. Is that right?
Dr. Joe Romagnuolo: That is right. So, if you had a general CT scan of the abdomen without dye, for example, or without a pancreatic protocol, the slices through the pancreas could be quite far apart and the timing of the dye might not be appropriate for picking up a pancreatic problem. So, sometimes, even though you have had a CT scan of the abdomen, a CT scan with the proper pancreatic protocol might need to actually be repeated, if the pancreas is what you wanted to image.
Dr. Linda Austin: It sounds as if, from the patient’s point of view, it is a fairly simple procedure to go through. Is that correct?
Dr. Joe Romagnuolo: It is.
Dr. Linda Austin: What is the range of disorders? What are some of the diagnoses that you, as a gastroenterologist, can detect with those images?
Dr. Joe Romagnuolo: In broad terms, you can have benign things wrong with the pancreas or something malignant going on in the pancreas and that can be either a tumor or a cyst. Most cysts that are in the pancreas that are not due to inflammation, that are not due to pancreatitis or what we call a pseudo cyst, are actually cystic tumors and, so, they need a further work-up. In terms of the benign conditions, pancreatitis is generally what we are looking for. So, we are looking for signs of inflammation or scarring from previous inflammation or ongoing inflammation.
Dr. Linda Austin: Can you always tell with this study? Is it that detailed?
Dr. Joe Romagnuolo: No. So, a CT scan can miss disease in the pancreas. It can even miss cancer, unfortunately, especially when it is under 2 cm, or about an inch, in size. MRI can be more sensitive at picking up, especially, a duct abnormality. There is a special kind of MRI called an MRCP (Magnetic Resonance Cholangiopancreatography) that you can do that outlines the bile duct and the pancreas duct with very high resolution and can pick up duct abnormalities very well. The best test to pick up pancreatic tumor or early chronic pancreatitis or fibrosis, or scarring in the pancreas, is an endoscopic ultrasound.
Dr. Linda Austin: Why would one not start with an MRI, then, if it is more sensitive than a CT scan?
Dr. Joe Romagnuolo: The CT scan, I think, in terms of picking up tumors is, if it is done with a pancreatic protocol and done with fine slices, probably comparable to the MRI for picking up a pancreatic tumor. In terms of getting duct detail like you would want to get if chronic pancreatitis was suspected, the MRCP is a better test for that. The ducts show up much better with MRCP than they do with a CT scan.
Dr. Linda Austin: I see.
Dr. Joe Romagnuolo: In terms of a good quality CT scan aimed at the pancreas and an MRI of the pancreas, the MRI is only marginally better and it is a little bit more expensive.
Dr. Linda Austin: I see. What other techniques are available to explore the pancreas?
Dr. Joe Romagnuolo: Endoscopic ultrasound is one of the newest techniques to look at the pancreas. In terms of detecting chronic pancreatitis, meaning, scarring in the pancreas, endoscopic ultrasound (EUS) is the best test for picking up early disease. It provides very high resolution and high detail images of the pancreas.
Because the pancreas is within millimeters of the stomach wall and the intestine wall, when we go down with a scope, which has an ultrasound probe on the tip, and we press it right up against the back of the stomach or the intestine, we can see the pancreas in high resolution and pick up those scars even if they are only 1 or 2 mm in size. In terms of picking up pancreas cancer, because we can pick up things that are 1 to 5 mm in size, we can definitely pick up tumors that are well under the detection threshold for CT scan and MRI. So, we can pick up tumors in the very early stage that are resectable, or removable, with surgery that might not even be visible with a CT scan or MRI.
Dr. Linda Austin: Dr. Romagnuolo, thank you so much for talking with us today.
Dr. Joe Romagnuolo: Thank you.
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