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Although the current literature is limited, available data suggest that (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging improves the evaluation of patients with recurrent pancreatic carcinoma and cholangiocarcinoma. There is evidence that PET/CT is particularly useful in the setting of elevated tumor markers and negative or equivocal CT findings. This article reviews the nature of these carcinomas in the post-therapy setting and describes the strengths and limitations of PET/CT when used for monitoring recurrence. [ABSTRACT FROM AUTHOR]

Peripancreatic lymphatic networks are frequently involved in pancreatobiliary carcinoma, affecting the prognosis. However, little attention has been paid to CT imaging of normal and pathological conditions of peripancreatic lymphatic networks. We evaluated multi-detector row CT (MDCT) images of peripancreatic lymphatic networks invaded by pancreatic carcinoma and compared them with those of normal peripancreatic lymphatic networks using imaging reconstruction every 1 mm with a multiplanar reformation technique. Apart from the region around the pancreatic body and tail, normal peripancreatic lymphatic networks were detected as "linear structures" on MDCT. However, peripancreatic lymphatic invasion by pancreatic carcinoma was frequently identified as "reticular," "tubular," or "soft tissue mass" appearances in the peripancreatic fat tissues. Peripancreatic lymphatic invasion by pancreatic carcinoma was more frequently detected around the common hepatic artery, celiac artery, superior mesenteric artery, and left para-aortic area. Depending on the tumor location, positive peripancreatic lymphatic invasion was most frequent at the area around the common hepatic artery in the head region and at the area around the celiac artery in the body and tail regions. Knowledge of CT imaging of normal and pathological peripancreatic lymphatic networks is essential for determining the accurate staging of pancreatic carcinoma. [ABSTRACT FROM AUTHOR]

Objective: To demonstrate the contrast-enhancement behavior of pancreatic carcinoma on dynamic contrast-enhanced CT (DCE-CT), and the relationship between the degree of contrast-enhancement and the vascularity (vessel density) and amount of fibrous stroma (fibrosis within the tumor) on pathological specimen. Methods: The contrast-enhancement values were measured by producing the subtracting images for obtaining largest region of interests to reduce measurement errors and variability. Vascularity was determined by immunostaining of the tissue sections with factor 8 and the fibrous stroma was determined by picrosirius staining. Correlation of the findings of DCE-CT with pathological findings was performed in 21 patients with pancreatic carcinoma. Results: All but one patient exhibited a gradually increasing enhancement, but there was considerably wide range in contrast-enhancement values of tumors. Examination of the overall relationship between vascularity and fibrous stroma with contrast-enhancement behavior showed that tumor with more fibrosis and higher vascularity had a higher contrast effect through all phases of dynamic study. Tumors having liver metastases tended to be less fibrotic than tumors without liver metastases. Conclusion: The contrast-enhancement behavior of pancreatic carcinoma may be helpful in estimating vascularity and the extent of tumor fibrosis and possibility of liver metastases. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the imaging findings of hepatic metastases from pancreatic cancers, especially wedge-shaped enhancement and its etiology. Dynamic CT and MR images were performed in 87 patients with liver metastases from pancreatic carcinomas, and CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) in 51 patients. Liver metastases were multiple in 84 patients (97%) and solitary in only three (3%). In 44 of 87 patients (51%), all liver metastases showed ring-like enhancement compatible with metastatic adenocarcinomas on dynamic CT and/or dynamic MR imaging. In 37 patients, more than one metastatic lesion showed wedge-shaped contrast enhancement on dynamic CT, dynamic MRI and CTHA, and wedge-shaped perfusion defect on CTAP adjacent to metastatic tumors. Six patients showed multiple wedge-shaped enhancements, which were initially diagnosed as multiple arterioportal shunts (AP shunts). However, metastatic tumors appeared within the area of wedge-shaped enhancement and increased in size on follow-up CT and/or MR images. After all, 43 of 87 patients (49%) had AP shunt like contrast enhancement adjacent to liver metastases. Liver metastases from pancreatic carcinomas frequently show transient wedge-shaped enhancement, and should not be misdiagnosed as nontumorous arterioportal shunts. [ABSTRACT FROM AUTHOR]

Background: We assessed the potential usefulness of contrast-enhanced power Doppler ultrasonography (US) for differentiating pancreatic carcinoma from chronic focal pancreatitis. Methods: Twenty-six consecutive patients with ductal carcinoma (n=16) and chronic focal pancreatitis (n=10) underwent power Doppler US examinations before and after intravenous injection of an air-based contrast agent (Levovist, Schering, Berlin, Germany). Final diagnosis was obtained by surgery in all patients. The following parameters before and after intravenous administration of contrast agent were evaluated for each lesion: number, morphology and course of the vessels within the lesion and time to maximum detectable enhancement. Number of the lesion vessels and time to maximum enhancement for each lesion were compared by with Student t test. Results: After injection of contrast agent, nine of 16 (56.2%) carcinomas showed a larger total number of vessels (p<0.005) and faster enhancement (p<0.0001) compared with chronic focal pancreatitis. Irregular vessels with a serpiginous course that penetrated the tumor was predominant in carcinoma (eight of 16 cases), whereas focal pancreatitis presented mostly as avascular masses (five of 10 cases). Conclusion: Contrast-enhanced power Doppler US provides useful findings for differentiating pancreatic carcinoma from chronic focal pancreatitis. [ABSTRACT FROM AUTHOR]

The aim of this study was to demonstrate the feasibility of body diffusion-weighted (DW) MR imaging in the evaluation of a pancreatic carcinoma. In nine normal volunteers and in eight patients with pancreatic carcinoma, DW images were obtained on the axial plane scanning with a multisection spin-echo-type single-shot echo planar sequence with a body coil. Moreover, we measured the apparent diffusion coefficient (ADC) value in a circular region of interest (ROI) within the normal pancreas, pancreatic carcinoma, and tumor-associated chronic pancreatitis. On the DW images, all eight carcinomas were clearly shown as high signal intensity relative to the surrounding tissue. The ADC value (×10−3 mm2/s) in the carcinoma was 1.44 ± 0.20, which was significantly lower compared to that of normal pancreas (1.90 ± 0.06) and tumor-associated chronic pancreatitis (2.31 ± 0.18). Diffusion-weighted (DW) images can be helpful in detecting the pancreatic carcinoma and accessing the extent of the tumor. [ABSTRACT FROM AUTHOR]

We report a case of tumor-associated focal chronic pancreatitis of the uncinate process of the pancreas. The chronic pancreatitis was secondary to stenosis of the main pancreatic duct from invasion by a common bile duct carcinoma. A feature distinguishing the chronic pancreatitis from pancreatic carcinoma was the localized dilatation of pancreatic duct branches evident in the focal lesion of the uncinate process. Correspondence to: T. Gabata --> [ABSTRACT FROM AUTHOR]