Chronic pancreatitis is a prolonged inflammatory process of the pancreas that results in scarring and damage to the pancreas. This results in reduced function of the pancreas. In this country, we see this most commonly with alcohol abuse. Other causes can include cystic fibrosis, autoimmune causes when the immune system attacks the pancreas, obstructive lesions from a tumor or stone and from repeated episodes of acute pancreatitis.
Clinically, patients can present with diabetes because the pancreas can’t produce insulin as well. Malabsorption or poor use of the nutrients you use because the pancreas helps with this function. Patients can also have chronic pain and acute episodes of pancreatitis superimposed on more chronic process.
There are specific changes we sometimes see on CT scan of the abdomen and other imaging studies. Most often, I see multiple small calcifications in the pancreas on CT scattered throughout the pancreas. It helps when there is a history that suggests chronic pancreatitis. Other causes of pancreatic calcifications include malnutrition which is rare in this country. Cystic fibrosis can cause chronic pancreatitis and small scattered calcifications. I also see small scattered calcifications in older patients for no apparent reason. Some tumors will calcify but these are associated with a cyst or mass and are more localized. Blood vessels around the pancreas can also calcify and cause this appearance.
Another feature seen on CT is dilation of the pancreatic duct. The pancreatic duct is normally not seen or barely seen on CT. When the duct is seen well and dilated, I start thinking of chronic pancreatitis particularly if the history is appropriate. Side branch dilation of the pancreatic duct is better seen on MRI as is main pancreatic duct beading and irregularity.
Sometimes pseudocysts or chronic collections related to prior episodes of pancreatitis are seen. Later, you may see small shrunken pancreatic tissue or in some cases, enlargement from inflammation. Chronic pancreatitis also leads to mass like abnormalities which can be confused for cancer. Some secondary findings such as liver cirrhosis related to alcohol abuse may be seen.
Chronic pancreatitis can lead to chronic pain, diabetes and problems with absorption of nutrients. There is an increased risk of pancreatic cancer. These patients are frequently imaged because of symptoms. The appearance on CT is often characteristic with calcifications, dilated pancreatic duct, and areas of scarring. MRI is best for evaluating chronic pancreatitis, particularly abnormalities of the duct.