Pancreatic changes in primary sclerosing cholangitis: evaluation with MR imaging

MRI of cholangiocarcinoma

Cholangiocarcinomas are the second most common primary hepatobiliary tumors after hepatocellular carcinomas. They can be categorized either based on their location (intrahepatic/perihilar/extrahepatic distal) or their growth characteristics (mass-forming/periductal-infiltrating/intraductal) because they exhibit varied presentations and outcomes based on their location and or pattern of growth. The increased risk of cholangiocarcinoma in PSC necessitates close surveillance of these patients by means of imaging and laboratory measures; and because currently surgical resection is the only effective treatment for cholangiocarcinoma, the need for accurate pre-operative staging and assessment of resectability has emphasized the role of high quality imaging in management. Today magnetic resonance imaging (MRI) is the modality of choice for detection, pre-operative staging and surveillance of cholangiocarcinoma.

Pancreatic duct changes are not associated with early signs of chronic pancreatitis at magnetic resonance imaging (MRI) in patients with primary sclerosing cholangitis

OBJECTIVE

The association between chronic pancreatitis (CP) and primary sclerosing cholangitis (PSC) has been reported previously. The aims of the present study were to evaluate the presence of early pancreatic abnormalities and duct changes, using MRCP/MRI in PSC and to evaluate possible risk factors for these changes and their clinical importance.

MATERIALS AND METHODS

One hundred and three patients with PSC were identified among all MRI liver/pancreas referrals in 2001-2005. MRCP was used to grade pancreatic duct changes in three groups: grade 0 (normal), grade 1 (mild) and grade 2 (severe). For detection of early MRI signs of CP, the pancreas-spleen signal intensity ratio (SIR), the arterial and early venous phase ratio (A/PV ratio) and the age-related size of the pancreas were evaluated.

RESULTS

Pancreatic duct changes were found in 24% of the PSC patients. The pancreatic duct changes were associated with extrahepatic biliary involvement and long duration of PSC but not associated with pancreas-spleen SIR, A/PV ratio, pancreas size, previous post-ERCP or acute pancreatitis. Severe pancreatic duct changes were significantly associated to abdominal pain. Clinically significant CP was seen in one PSC patient (1%).

CONCLUSIONS

Pancreatic duct changes are associated with extrahepatic bile duct strictures and not with the early MRI signs of CP. Therefore, pancreatic duct changes seem to be part of the spectrum of PSC and should not be defined as CP. Pancreatic duct changes are of limited clinical importance but may contribute to abdominal pain in PSC.

Cholangiocarcinoma: current and novel imaging techniques

The radiologic manifestations of cholangiocarcinomas are extremely diverse, since these tumors vary greatly in location, growth pattern, and histologic type. Familiarity with the imaging manifestations of cholangiocarcinomas is important for accurate detection and characterization of these tumors and assessment of resectability. Advances in imaging techniques have led to the availability of an array of modalities that, used independently or in combination, can aid in the accurate diagnosis and evaluation of cholangiocarcinomas in preparation for advanced surgical procedures and treatment planning. Response to novel targeted therapies can also be assessed with newer imaging tools. Hence, knowledge of current and emerging imaging applications is essential for correct diagnosis and appropriate management of these tumors.

The patient with unexplained elevated serum liver enzymes

The pattern of elevated serum liver enzymes in symptomatic or asymptomatic patients allows for an initial classification of liver diseases into cholestatic or hepatocellular diseases. A female patient with extrahepatic cholestasis due to segmental bile duct strictures and a localized mass lesion within the pancreas is presented. Although many diagnostic procedures were performed in this case the diagnosis was not obtained before surgical laparotomy was initiated with bioptic sampling from bile ducts, lymph nodes and pancreatic tissue. Microscopic examination of the specimen revealed extensive biliary and pancreatic scarring together with periductal infiltrates composed of lymphocytes and plasma cells consistent with sclerosing cholangitis in systemic autoimmune pancreatitis. The patient completely recovered upon treatment with prednisone and azathioprine. The difficult approach to the final diagnosis is discussed in light of established and modern diagnostic tools.

Magnetic resonance imaging in the detection of pancreatitis and pancreatic neoplasms

This article presents current magnetic resonance imaging techniques for the diagnosis of acute and chronic pancreatitis and pancreatic neoplasms. It emphasises the need for a comprehensive protocol combining imaging sequences of the pancreatic parenchyma with magnetic resonance angiography and secretin-enhanced magnetic resonance cholangiopancreatography in order to evaluate the full range of pancreatic inflammatory and neoplastic conditions. Imaging characteristics that may indicate a specific diagnosis are discussed.

Lymphoplasmacytic chronic cholecystitis and biliary tract disease in patients with lymphoplasmacytic sclerosing pancreatitis

Lymphoplasmacytic sclerosing pancreatitis (LPSP) represents a distinctive form of chronic pancreatitis characterized by diffuse fibroinflammatory infiltrates that can involve both the pancreatic ducts and acinar parenchyma. Several cases of inflammatory infiltrates within the gallbladder have been reported in association with LPSP, but the spectrum of gallbladder pathology in patients with LPSP has not been systematically reviewed. Many patients with LPSP have distal CBD fibrosis, strictures, and inflammation, features that overlap somewhat with primary sclerosing cholangitis (PSC). In PSC, a pattern of gallbladder pathology termed "diffuse acalculous lymphoplasmacytic chronic cholecystitis" has been previously described as showing a triad of diffuse, mucosal-based, plasma cell-rich inflammatory infiltrates. We studied 20 gallbladders from patients with LPSP and compared them with 20 gallbladders in PSC, 20 gallbladders with chronic cholelithiasis, and 10 gallbladders from patients with benign (non-LPSP) pancreatic disease. The following features were evaluated: degree and composition of mucosal inflammation and deep (mural) inflammation, lymphoid nodules, metaplasia, dysplasia/neoplasia, fibrosis, muscular hypertrophy, Rokitansky-Aschoff sinuses, and cholesterolosis. The majority (60%) of gallbladders in LPSP contained moderate or marked inflammatory infiltrates and lymphoid nodules, frequencies similar to PSC but significantly higher than in chronic cholelithiasis and benign non-LPSP pancreatic disease. LPSP gallbladders received the highest scores for deep inflammation of all groups, and 35% of LPSP gallbladders showed transmural chronic cholecystitis. Overall, "diffuse lymphoplasmacytic chronic cholecystitis" was present in 50% of PSC cases and 25% of LPSP cases, but in only 5% of chronic cholelithiasis and none of non-LPSP benign pancreatic disease. Mucosal inflammation in LPSP gallbladders correlated significantly with the presence of inflammation in the extrapancreatic portion of the CBD. These findings suggest that inflammatory pathology of the gallbladder is frequently associated with LPSP and that it is part of the spectrum of biliary tract disease in these patients, rather than a simple reflection of the pancreatitis itself.

Do patients with primary sclerosing cholangitis have a greater frequency of pancreatic abnormalities at MRI than patients with other liver diseases?

PURPOSE

It has been proposed that there is an increased frequency of pancreatic abnormalities in patients with primary sclerosing cholangitis (PSC). Our purpose is to compare the frequency of pancreatic abnormalities detected at MRI in patients with PSC and to compare these findings with those found in a matched cohort with other liver diseases.

METHOD

We identified 29 patients who had either a histologic or an endoscopic retrograde cholangiopancreatography diagnosis of PSC and 29 age- and gender-matched patients with liver disease without PSC who underwent MRI at 1.5 T. The protocol included breath-hold T1-weighted gradient echo, echo train, fast spin echo, T2-weighted images and dynamic gadolinium-enhanced MRI. Two blinded readers retrospectively evaluated the MR images for abnormalities of pancreatic size and morphology, T1 and T2 signal intensity, duct size and irregularities, arterial-phase contrast enhancement, focal pancreatic masses, cystic lesions, peripancreatic fluid/edema, ascites, and capsular-like rim surrounding the pancreas.

RESULTS

The prevalence of pancreatic and peripancreatic abnormalities was 10 of 29 (35%) in PSC patients and 14 of 29 (48%) in control patients. MR findings included ascites (9 PSC, 12 controls), peripancreatic edema (7 PSC, 11 controls), atrophy (4 PSC, 3 control), increased T2 signal (3 PSC, 4 controls), cystic lesions (2 PSC, 3 controls), abnormal T1 signal (1 PSC, 2 controls), and dilated pancreatic ducts (3 PSC, 2 controls). Quantitative parameters were not significantly different between PSC patients and the control subjects with pancreatic findings.

CONCLUSION

There is no significant difference in pancreatic abnormalities detected on MRI between patients with PSC and those with other liver diseases.

MR imaging of pancreatic diseases

This article presents current MR imaging techniques for the pancreas, and review a spectrum of MR imaging features of various pancreatic diseases. These include: 1) congenital anomalies such as anomalous union of pancreatobiliary ducts, divisum, and annular pancreas, 2) inflammatory diseases, including acute or chronic pancreatitis with complications, groove pancreatitis, and autoimmune pancreatitis, tumor-forming pancreatitis, 3) pancreatic neoplasms, including adenocarcinoma, islet cell tumors, and cystic neoplasms (microcystic adenoma, mucinous cystic neoplasms, and intraductal mucin-producing pancreatic tumor). Particular attention is paid to technical advances in MR imaging of the pancreas such as fat-suppression, MR pancreatography (single- or multi-slice HASTE), and thin-section 3D multiphasic contrast-enhanced dynamic sequences. Imaging characteristics that may lead to a specific diagnosis or narrow the differential diagnosis are also discussed.