Pancreatic parenchymal and intraductal calcification virtually diagnostic of chronic pancreatitis
Pancreatic atrophy (often more apparent in body/tail)
Fibroinflammatory “mass” related to chronic pancreatitis may be very difficult to differentiate from malignancy
– Most common in head and may demonstrate variable enhancement due to presence/absence of fibrosis
• MR: More sensitive for early changes compared to CT
Loss of normal high T1WI signal of parenchyma
↓ parenchymal enhancement on T1WI C+ arterial phase
Dilated (> 3 mm), irregular pancreatic duct with strictures and dilated side branches (“chain of lakes” appearance)
Stones within pancreatic duct appear as signal voids
Secretin MRCP may identify earliest signs of CP
– Loss of normal duct distension (due to ↓ duct compliance) after secretin administration
– Secretin may improve visualization of side branches
– ↓ secretion of fluid into duodenum suggests pancreatic exocrine dysfunction
PATHOLOGY
• Most commonly caused by alcohol abuse (∼ 75% of cases)
• Other causes include idiopathic, hereditary pancreatitis, autoimmune pancreatitis, and systemic diseases
• Gallstones, hyperlipidemia, trauma, and drugs often cause acute/recurrent pancreatitis, but rarely chronic pancreatitis
CLINICAL ISSUES
• Endocrine and exocrine deficiencies due to progressive destruction of gland may lead to steatorrhea and diabetes
• Most patients treated with pain management, lifestyle modification (cessation of alcohol and smoking, frequent small meals), and pancreatic enzyme replacement
• Surgery an option in patients who fail medical therapy
(Left) Ultrasound image demonstrates multiple large, coarse calcifications in the pancreatic head, some of which demonstrate posterior acoustic shadowing, compatible with chronic pancreatitis.
(Right) Coronal MRCP demonstrates a dilated main pancreatic duct with dilated side branch ducts , as well as a distal pancreatic duct stricture . Chronic pancreatitis is a scirrhous process that commonly causes stricture or occlusion of the ducts.
(Left) Coronal MRCP MIP reconstruction demonstrates characteristic changes of “big duct” chronic pancreatitis, including a dilated main pancreatic duct with dilatation of multiple side branches, stricture in the downstream duct, and a large pseudocyst near the pancreatic tail.
(Right) Axial CECT demonstrates extensive parenchymal calcifications throughout the pancreas in a patient with known chronic pancreatitis. The multiple cysts scattered throughout the pancreas in this case represent small pseudocysts.
TERMINOLOGY
Definitions
• Progressive, irreversible inflammatory damage to pancreas resulting in parenchymal fibrosis, morphologic changes, and loss of endocrine/exocrine function
IMAGING
General Features
• Best diagnostic clue
Atrophic pancreatic parenchyma with a dilated, beaded main pancreatic duct (MPD) and intraductal calculi
• Size
Pancreas usually atrophic
• Morphology
Pancreatic calcification
– Almost diagnostic of chronic pancreatitis
– ∼ 90% of calcific pancreatitides are caused by alcoholism
Other 10% = mostly hereditary pancreatitis
– Present in 40-60% of patients with alcoholic pancreatitis
• Other features
75% of cases in USA are due to alcoholism
Developing countries: Malnutrition and alcoholism
CT Findings
• Earliest stages may not produce visible changes, but morphologic abnormalities more apparent in later stages
Dilated, beaded, irregular pancreatic duct with strictures
Pancreatic parenchymal and intraductal calcification virtually diagnostic of chronic pancreatitis (CP)
– ∼ 90% of calcific pancreatitis caused by alcoholism (remaining 10% mostly hereditary pancreatitis)
Pancreatic atrophy (often more apparent in body/tail)
Intra- and peripancreatic pseudocysts
• Splenic vein often thrombosed with resultant varices and splenomegaly
• Fibroinflammatory “mass” related to chronic pancreatitis may be very difficult to differentiate from malignancy
Most common in pancreatic head and may demonstrate variable enhancement
– Hypoenhancing mass usually due to fibrosis, whereas isodense mass implies lack of fibrosis
MR Findings
• Normal MR appearance of pancreas
Parenchyma diffusely high signal on T1WI (≥ liver)
Parenchyma variable in signal on T2WI
Pancreas enhances avidly and homogeneously on T1W C+ images (hyperintense to liver on arterial phase and isointense on delayed phase)
Normal pancreatic duct measures < 3 mm and side branches are not normally visualized
• More sensitive for early changes of chronic pancreatitis compared to CT (although less sensitive for calcifications)
Loss of normal high T1WI signal of parenchyma (due to fibrosis replacing parenchymal proteinaceous fluid)
Diminished parenchymal enhancement on T1W C+ images on arterial phase with increased delayed enhancement due to fibrosis
↓ parenchymal enhancement and T1WI signal can also be seen in older patients with age-related fibrosis
• Changes in pancreatic duct (usually later finding) nicely demonstrated on T2WI or MRCP
Dilated (> 3 mm), irregular pancreatic duct with strictures and dilated side branches (“chain of lakes” appearance)
Visualization of side branches, which are not normally visible, may be subtle sign
Stones within pancreatic duct appear as signal voids
Cambridge criteria for ERCP may be applied to MRCP
• Pancreatic atrophy and pseudocysts in later stages
• Secretin MRCP can help visualize earliest findings of chronic pancreatitis and evaluate pancreatic exocrine dysfunction
Loss of normal duct distension (due to ↓ duct compliance) after secretin administration in CP
– Normal duct dilates ≥ 1 mm compared to baseline (< 1 mm distension suggests CP)
Secretin may improve visualization of side branches (finding that suggests CP)
↓ secretion of fluid into duodenum suggests pancreatic exocrine dysfunction, suggesting CP
– Grade I: Fluid seen in duodenal bulb (most suggestive of pancreatic exocrine dysfunction)
– Grade II: Fluid seen in 2nd portion of duodenum
– Grade III: Fluid reaches 3rd portion of duodenum
• MR, like CT, cannot reliably distinguish fibroinflammatory mass (due to CP) from malignancy
Radiographic Findings
• Radiography
Abdominal radiographs: May demonstrate small, irregular, or coarse calcifications (local or diffuse) in expected location of pancreas in upper abdomen
Upper GI series: May reveal changes in 2nd part of duodenum
– Thickened, irregular mucosal folds, luminal narrowing, and varying degrees of atony with dilatation of proximal duodenum ± stomach
– Enlarged major duodenal papilla
• ERCP
Considered gold standard test for chronic pancreatitis
Dilated, irregular, and beaded main pancreatic duct with sites of stricture and dilated side branches
Intraductal calculi appear as filling defects within MPD
Intrapancreatic portion of CBD may be narrowed, but demonstrates smooth, tapered narrowing (not abrupt narrowing as with malignancy)
– May produce double duct sign due to stricture of distal CBD and MPD (similar to malignancy)
Buy Membership for Radiology Category to continue reading. Learn more here
Fibroinflammatory “mass” related to chronic pancreatitis may be very difficult to differentiate from malignancy
in the pancreatic head, some of which demonstrate posterior acoustic shadowing, compatible with chronic pancreatitis.
, as well as a distal pancreatic duct stricture 
. Chronic pancreatitis is a scirrhous process that commonly causes stricture or occlusion of the ducts.
in the downstream duct, and a large pseudocyst 
near the pancreatic tail.
scattered throughout the pancreas in this case represent small pseudocysts.
Loss of normal high T1WI signal of parenchyma (due to fibrosis replacing parenchymal proteinaceous fluid)
Dilated, irregular, and beaded main pancreatic duct with sites of stricture and dilated side branches
Intrapancreatic portion of CBD may be narrowed, but demonstrates smooth, tapered narrowing (not abrupt narrowing as with malignancy)
