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Multidetector-row computed tomography (MDCT) and magnetic resonance (MR) imaging are currently the most frequently performed imaging modalities for the study of pancreatic disease. In cases of suspected autoimmune pancreatitis (AIP), a dynamic quadriphasic (precontrast, contrast-enhanced pancreatic, venous and late phases) study is recommended in both techniques. In the diffuse form of autoimmune pancreatitis (DAIP), the pancreatic parenchyma shows diffuse enlargement and appears, during the MDCT and MR contrast-enhanced pancreatic phase, diffusely hypodense and hypointense, respectively, compared to the spleen because of lymphoplasmacytic infiltration and pancreatic fibrosis. During the venous phase of MDCT and MR imaging, the parenchyma appears hyperdense and hyperintense, respectively, in comparison to the pancreatic phase. In the delayed phase of both imaging modalities, it shows retention of contrast media. A 'capsule-like rim' may be recognised as a peripancreatic MDCT hyperdense and MR hypointense halo in the T2-weighted images, compared to the parenchyma. DAIP must be differentiated from non-necrotizing acute pancreatitis (NNAP) and lymphoma since both diseases show diffuse enlargement of the pancreatic parenchyma. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT has an important role. In the focal form of autoimmune pancreatitis (FAIP), the parenchyma shows segmental enlargement involving the head, the body-tail or the tail, with the same contrast pattern as the diffuse form on both modalities. FAIP needs to be differentiated from pancreatic adenocarcinoma to avoid unnecessary surgical procedures, since both diseases have similar clinical and imaging presentation. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT and MR imaging both have an important role. MR cholangiopancreatography helps in the differential diagnosis. Furthermore, MDCT and MR imaging can identify the extrapancreatic manifestations of AIP, most commonly biliary, renal and retroperitoneal. Finally, in all cases of uncertain diagnosis, MDCT and/or MR follow-up after short-term treatment (2-3 weeks) with high-dose steroids can identify a significant reduction in size of the pancreatic parenchyma and, in FAIP, normalisation of the calibre of the upstream main pancreatic duct. [ABSTRACT FROM AUTHOR]

Objective: To describe MR imaging features of non-hyperfunctioning neuroendocrine pancreatic tumours by comparing them to histopathology and to determine the accuracy of MR imaging in predicting biological behaviour. Materials and Methods: After institutional review board approval, we retrospectively reviewed 45 patients with pathologically proven NF-NET of the pancreas and ≥1 preoperative MR/MRCP examinations. Of the NF-NETS, 29/45 (64.4 %) were G1 and 16/45 (35.5 %) were G2. Image analysis included the lesion maximum diameter, vascular encasement, extrapancreatic spread, signal intensity on T1- and T2-weighted, contrast enhancement features, and presence of metastases. Tumour vessel density was calculated on the histological specimen using a grid. Results: The median maximum diameter of NF-NETs was 20 mm (range 5-200 mm). Eighty per cent of the NF-NETs were hypointense on T1-weighted images, 82.2 % were hyperintense on T2-weighted images, and 75.6 % were hypervascular. Overall MRI accuracy showed a mean AUC of 0.86 compared to pathology. Lesions with a maximum diameter of 30 mm irregular margins, absence of a cleavage plane with the main pancreatic duct, vascular encasement, extrapancreatic spread and abdominal metastases were significantly associated with malignant NF-NETs. No correlation was found between the tumour vessel density and contrast-enhanced MR imaging pattern. Conclusions: Hyperintensity on T2-weighted images and iso-/hypervascularity occurred in 27/45 (60.0 %) of NF-NETs. MRI identifies malignant NF-NETs with a sensitivity of 93.3 % and a specificity of 76.9 % (AUC = 0.85). Key Points: • Non-hyperfunctioning neuroendocrine pancreatic tumours (NF-NET) pose a difficult diagnostic challenge. • On T2-weighted MRI, 82.2 % of neuroendocrine tumours appeared hyperintense. • MR imaging showed 0.94 sensitivity and 0.77 specificity in predicting biological behaviour. • The hyper-/isointensity during dynamic MRI did not correlate with vessel density at pathology. [ABSTRACT FROM AUTHOR]

OBJECTIVES:Autoimmune pancreatitis (AIP) is a particular type of chronic pancreatitis that can be classified into diffuse and focal forms. The aim of this study was to analyze clinical and instrumental features of patients suffering from the diffuse and focal forms of AIP.METHODS:AIP patients diagnosed between 1995–2008 were studied.RESULTS:A total of 87 AIP patients (54 male and 33 female patients, mean age 43.4±15.3 years) were studied. Focal-type AIP was diagnosed in 63% and diffuse-type in 37%. Association with autoimmune diseases was observed in 53% of cases, the most common being ulcerative colitis (30%). Serum levels of IgG4 exceeded the upper normal limits (135 mg/dl) in 66% of focal AIP and in 27% of diffuse AIP (P=0.006). All patients responded to steroids. At recurrence non-steroid immunosuppressive drugs were successfully used in six patients. Recurrences were observed in 25% of cases, and were more frequent in focal AIP (33%) than in diffuse AIP (12%) (P=0.043), in smokers than in non-smokers (41% vs. 15%; P=0.011), and in patients with pathological serum levels of IgG4 compared to those with normal serum levels (50% vs. 12%; P=0.009). In all, 23% of the patients underwent pancreatic resections. Among patients with focal AIP, recurrences were observed in 30% of operated and in 34% of not operated patients.CONCLUSIONS:Focal-type and diffuse-type AIP differ as regards clinical symptoms and signs. Recurrences occur more frequently in focal AIP than in diffuse AIP. The use of non-steroid immunosuppressants may be a therapeutic option in relapsing AIP. [ABSTRACT FROM AUTHOR]

Spontaneous rupture of a pancreatic pseudocyst into the portal vein is described. This has been previously reported in only five cases. Diagnosis was made by computed tomography (CT) and was confirmed by CT-guided transhepatic portography. [ABSTRACT FROM AUTHOR]

Seven cases of duodenal duplication in the adult are reported. The ultrasound and computed tomographic findings are analyzed. The relationship between duodenal duplication and pancreatitis is discussed. [ABSTRACT FROM AUTHOR]