GI Radiology > Pancreas > Inflammatory > Pancreatitis

Pancreatitis

Chronic Pancreatitis:

Chronic pancreatitis presents with different diagnostic and therapeutic challenges compared to acute pancreatitis; the role of imaging may be interventional as well as diagnostic. Chronic pancreatitis is characterized by parenchymal atrophy, ductal calcifications, and ductal dilatations and strictures. The etiologies of pancreatitis were listed in the previous table.

Chronic pancreatitis may present with upper abdominal pain, signs of obstructive jaundice or duodenal obstruction, or exocrine/endocrine dysfunction of the pancreas itself (malabsorption, hyperglycemia). Diagnosis of chronic pancreatitis is usually based on clinical symptoms, detection of endocrine/exocrine insufficiency, and morphological finding on imaging.

Plain Film:

 Although the pancreas is not directly visualized on plain films, multifocal or chunky pancreatic calcifications may be present on plain films.

Ultrasonography:
Ultrasound is often used in the initial assessment; the sensitivity varies between 48-96% (depending on the degree of morphological changes). US can demonstrate the echogenicity of the parenchyma, dilation of the pancreatic or common bile duct, calcifications, and pseudocysts.

Computed Tomography (CT):
CT is most commonly used modality to evaluate chronic pancreatitis. CT may reveal parenchymal atrophy, inflammatory changes, calcifications, pseudocysts, bile or pancreatic duct dilation, or gallstones. Spiral CT with IV contrast is optimal, and can usually discriminate chronic pancreatitis from pancreatic carcinoma. Chronic pancreatitis enhances similar to the normal pancreas during the bolus phase of IV contrast enhancement.

CT Signs of Chronic Pancreatitis

Fluid collections (pseudocyst)

Duct dilatation and strictures

Granular pancreatic calcifications

Pseudocyst with pancreatic calcification
Other CT Signs:
-Atrophic or enlarged pancreas with loss of normal internal structure
-Stranding in peripancreatic fat
-Pancreatic stones

Endoscopic Retrograde Cholangiopancreatography (ERCP):
ERCP is considered the most sensitive imaging modality for diagnosing chronic pancreatitis. However, there may be few imaging findings in patients with less advanced disease. ERCP may also be difficult in patients with severe strictures or obstructing stones/calcifications. Furthermore, a normal ERCP does not rule-out pancreatitis, since ERCP may miss microlithiasis. Duct abnormalities such as irregular contours, strictures, dilatation, and opacified pseudocysts are all indicative of chronic pancreatitis, and are listed in the following table.
ERCP Signs of Chronic Pancreatitis

-Irregular duct contours
-Alternating areas of stricture & dilatation
-Intraductal calcifications
-Double duct sign: non-specific sign of ductal obstruction

Several classifications systems have been developed for the evaluation of chronic pancreatitis. The table below demonstrates one such system.
Grade Schematic
(Pott G, Schrameyer B., ERCP Atlas. Phila.: B. C. Decker, Inc., 1989, p 82.)		 ERCP
NL
I
II
III
IV
-filled pseudocyst

Bile duct changes secondary to chronic pancreatitis may be demonstrated on ERCP. The following table summarizes bile duct findings on ERCP in chronic pancreatitis.

Bile Duct Changes in Chronic Pancreatitis on ERCP

>Concentric
--Periductal fibrosis
--Edema (from acute pancreatitis)

>Narrowing of distal CBD
--Smooth, gently tapered, relatively long

Magnetic Resonance Cholangiopancreatography (MRCP):

 MRCP can depict dilation and stenosis of the main duct, and side branch dilation as well. Stones within the duct are well visualized as intraductal filling defects on MRCP. MRCP provides a better estimate of the extent of stenosis compared to ERCP, since ERCP's contrast mildly dilates the ducts, while MRCP reflects the physiological state of the duct.

Interventional radiology:

 Interventional and surgical treatments should be considered in cases with persistent jaundice, duodenal obstruction, pseudocyst formation, and pain.