Ansa Pancreatica-Type Anatomic Variation of the Pancreatic Duct in Patients with Recurrent Acute Pancreatitis and Chronic Localized Pancreatitis

Ansa pancreatic is a rare variation of pancreas duct. Ansa pancreatica is characterized by focal accessory duct atrophy and an additional curved duct linking main and accessory ducts replacing atrophied duct. Ansa pancreatica is considered as a predisposing factor of recurrent pancreatitis. Pancreatitis can be localized in pancreas head and uncinate process, because pancreas head and uncinate process might be drained through the additional hooked duct of ansa pancreatica. We reports three cases of localized chronic or recurrent pancreatitis cases with underlying ansa pancreatica type anatomic variation.

Sclerosing Cholangitis: Clinicopathologic Features, Imaging Spectrum, and Systemic Approach to Differential Diagnosis

Sclerosing cholangitis is a spectrum of chronic progressive cholestatic liver disease characterized by inflammation, fibrosis, and stricture of the bile ducts, which can be classified as primary and secondary sclerosing cholangitis. Primary sclerosing cholangitis is a chronic progressive liver disease of unknown cause. On the other hand, secondary sclerosing cholangitis has identifiable causes that include immunoglobulin G4-related sclerosing disease, recurrent pyogenic cholangitis, ischemic cholangitis, acquired immunodeficiency syndrome-related cholangitis, and eosinophilic cholangitis. In this review, we suggest a systemic approach to the differential diagnosis of sclerosing cholangitis based on the clinical and laboratory findings, as well as the typical imaging features on computed tomography and magnetic resonance (MR) imaging with MR cholangiography. Familiarity with various etiologies of sclerosing cholangitis and awareness of their typical clinical and imaging findings are essential for an accurate diagnosis and appropriate management.

What we need to know when performing and interpreting US elastography

According to the increasing need for accurate staging of hepatic fibrosis, the ultrasound (US) elastography techniques have evolved significantly over the past two decades. Currently, US elastography is increasingly used in clinical practice. Previously published studies have demonstrated the excellent diagnostic performance of US elastography for the detection and staging of liver fibrosis. Although US elastography may seem easy to perform and interpret, there are many technical and clinical factors which can affect the results of US elastography. Therefore, clinicians who are involved with US elastography should be aware of these factors. The purpose of this article is to present a brief overview of US techniques with the relevant technology, the clinical indications, diagnostic performance, and technical and biological factors which should be considered in order to avoid misinterpretation of US elastography results.

Immunoglobulin G4-Related Kidney Disease: A Comprehensive Pictorial Review of the Imaging Spectrum, Mimickers, and Clinicopathological Characteristics

Immunoglobulin G4 (IgG4)-related kidney disease (IgG4-KD) has recently been demonstrated to be an important part of IgG4-related sclerosing disease (IgG4-SD). However, since IgG4-KD is still relatively unfamiliar to radiologists and physicians as compared to IgG4-SD involving other organs, it could, therefore, be easily missed. In this article, we present a comprehensive pictorial review of IgG4-KD with regards to the imaging spectrum, mimickers, and clinicopathologic characteristics, based on our clinical experience with 48 patients during the past 13 years, as well as a literature review. Awareness of the broad imaging spectrum of IgG4-KD and differential diagnosis from its mimickers will thus facilitate its early diagnosis and treatment.

Recent advances in the imaging of hepatocellular carcinoma

The role of imaging is crucial for the surveillance, diagnosis, staging and treatment monitoring of hepatocellular carcinoma (HCC). Over the past few years, considerable technical advances were made in imaging of HCCs. New imaging technology, however, has introduced new challenges in our clinical practice. In this article, the current status of clinical imaging techniques for HCC is addressed. The diagnostic performance of imaging techniques in the context of recent clinical guidelines is also presented.

Solid Pancreatic Tumors with Unilocular Cyst-Like Appearance on CT: Differentiation from Unilocular Cystic Tumors Using CT

OBJECTIVE: To describe the computed tomography (CT) features of neuroendocrine tumors (NETs) and solid pseudopapillary tumors (SPTs) with unilocular cyst-like appearance, and to compare them with those of unilocular cystic tumors of the pancreas. MATERIALS AND METHODS: This retrospective study was approved by our Institutional Review Board, and informed consent was waived. We included 112 pancreatic tumors with unilocular cyst-like appearance on CT (16 solid tumors [nine NETs and seven SPTs] and 96 cystic tumors [45 serous cystadenomas, 30 mucinous cystic neoplasms, and 21 branch-duct intraductal papillary mucinous neoplasms]). Two radiologists reviewed the CT images in consensus to determine tumor location, long diameter, morphological features, wall thicknesses, ratio of wall thickness to tumor size, wall enhancement patterns, intratumoral contents, and accompanying findings. Fisher's exact test was used to analyze the results. RESULTS: All 16 solid tumors had perceptible walls (mean thickness, 2.7 mm; mean ratio of wall thickness to tumor size, 7.7%) with variable enhancement. Four NETs and seven SPTs had hemorrhage, calcifications, and/or mural nodules. Six CT findings were specific for solid tumors with unilocular cyst-like appearance: a thick (> 2 mm) wall, uneven thickness of the wall, high ratio of wall thickness to tumor size, hyper- or hypo-attenuation of the wall in the arterial and portal phase, and heterogeneous internal contents. When three or more of the above criteria were used, 100% specificity and 87.5-92% accuracy were obtained for solid tumors with unilocular cyst-like appearance. CONCLUSION: A combination of CT features was useful for distinguishing solid tumors with unilocular cyst-like appearance from unilocular cystic tumors of the pancreas.

Primary Malt Lymphoma of the Common Bile Duct

Primary mucosa-associated lymphoid tissue (MALT) lymphoma arising in the common bile duct (CBD) is extremely rare. In our case of MALT lymphoma, CT and MRI showed long, segmental, irregular wall thickening of the CBD and minimal dilatation of the upstream bile duct. A preoperative diagnosis of cholangiocarcinoma was made, but histologic evaluation confirmed MALT lymphoma of the CBD. We herein present a rare case of MALT lymphoma of the CBD with CT and MRI findings.

Imaging Findings in a Case of Mixed Acinar-Endocrine Carcinoma of the Pancreas

Mixed acinar-endocrine carcinoma (MAEC) of the pancreas is extremely uncommon. We report here a rare case of MAEC of the pancreas presenting as watery diarrhea. This is the first report in the English-language literature that describes the imaging findings of MAEC of the pancreas, including computed tomography (CT), magnetic resonance (MR) imaging, and MR cholangiopancreatography features.

A Case of Primary Paraganglioma that Arose in the Pancreas: the Color Doppler Ultrasonography and Dynamic CT Features

Paragangliomas rarely originate from the pancreas and they are characterized on imaging studies as well-marginated, hypervascular masses with cystic areas. We herein report on a case report of pancreatic paraganglioma in a 57-year-old woman, which was confirmed on pathology. Color Doppler ultrasonography and dynamic CT demonstrated a well-demarcated, extremely hypervascular mass with prominent intratumoral vessels and early contrast filling of the draining veins from the mass. Endoscopic retrograde cholangiopancreatography showed that the main pancreatic duct was displaced and mildly dilated.

Solitary Fibrous Tumor of the Pancreas: Imaging Findings

We report here a case of a pathologically proven solitary fibrous tumor of the pancreas. A 54-year-old man was referred to our hospital for further evaluation of a pancreatic mass that was found incidentally. CT, MR imaging, and endoscopic ultrasonography showed a well-defined, enhancing mass with cystic portions of the pancreas body. MR cholangiopancreatography showed no pancreatic duct dilatation. A solitary fibrous tumor of the pancreas is a very rare lesion.

Pancreatic Metastases from a Hemangiopericytoma of the Leg: A Case Report

Hemangiopericytoma of the pancreas has rarely been described, and its radiological findings have never been described in the radiological literature. We report a case of a metastatic hemangiopericytoma involving the pancreas in a 48-year-old woman. CT, MR, and angiography showed three, well-demarcated, heterogeneously enhancing masses with necrosis and hemorrhage in the pancreas.

Hepatic Hemangiomas with Peritumoral Sparing of Fatty Infiltration in Hepatic Steatosis: Findings on Contrast-enhanced MR Imaging and on Sonography

PURPOSE: We wanted to determine the frequency of peritumoral sparing of fatty infiltration (PTSF) around hepatic hemangioma in hepatic steatosis and to evaluate the finding of these tumors on dynamic contrast-enhanced MR imaging and on sonography. MATERIALS AND METHODS: This study included 76 hemangiomas in 67 patients suffering with hepatic steatosis. A diagnosis of hemangioma was based on the histologic findings, hemangioma SPECT or a compatible enhancement pattern on the dynamic contrast-enhanced MR study. For chemical shifting, PTSF was defined when there wasn't any decrease in signal intensity of the liver parenchyma on the opposed-phase images as compared with the in-phase images, and this intensity appeared as a hyperintense area around the tumor. We evaluated the frequency of PTSF and we analyzed if the presence of PTSF was related to the tumor size, the rapidity of enhancement or an associated arterioportal shunt. Among those, sonographic images were available in 55 hemangiomas. We also evaluated the sonographic appearances of hemangiomas with PTSF. RESULTS: Of the 76 hemangiomas, PTSF was noted on the MR chemical-shift images in 57 hemangiomas (75%). There was no significant relationship between tumor size and the presence of PTSF (p=.578). However, this finding was more frequently found in high-flow hemangiomas than in the slow-flow ones (p=.0038) and it was also related to the presence of associated arterioportal shunt (p=.0158). Sonographically, hemangiomas with PTSF were commonly surrounded by a peritumoral low-echoic area (28/41, 68%); these tumors more frequently showed a thin high-echoic rim on sonography than did the tumors without this finding (p=.0055). CONCLUSION: PTSF is commonly seen in hemangiomas in hepatic steatosis patients. Hepatic hemangiomas with PTSF tend to show rapid enhancement on dynamic MR imaging and this is accompanied by arterioportal shunt. They tend to be seen as an iso- or low-echoic mass with a thin high-echoic rim on sonography, and the mass is commonly surrounded by a peritumoral low-echoic area.

Imaging Findings of Abdominal Extraosseous Plasma Cell Neoplasm

PURPOSE: To evaluate the imaging findings of abdominal extraosseous plasma cell neoplasm. MATERIALS AND METHODS: From April 2000 to January 2005, eight patients (four men, four women; mean age, 50.6 years) with pathologically proved, extraosseous plasma cell neoplasm involving the abdominal organs were included in this study. The diagnoses were based on consensus agreement between two radiologists who retrospectively reviewed CT, ultrasonography, and enteroclysis findings. We evaluated the findings by focusing on the location, size, margin, and enhancement pattern of the lesion, and lymphadenopathy on each image. RESULTS: There were multiple myeloma in four patients and extramedullary plasmacytoma in the remaining four. Involved abdominal organs were the liver (n = 4), spleen (n = 4), lymph node (n = 3), stomach (n = 1), small bowel (n = 1), and colon (n = 1). The hepatic involvement of plasma cell neoplasm presented as a homogeneous, well-defined, solitary mass (n = 1), multiple nodules (n = 1), and hepatomegaly (n = 2). Its involvement of the spleen and lymph node appeared as splenomegaly and lymphadenopathy, respectively. Its involvement of the gastrointestinal tract including the stomach, small bowel, and colon, presented as a homogeneous, diffuse wall thickening or mass in the gastrointestinal tract. CONCLUSION: Abdominal extraosseous plasma cell neoplasm involves occasionally the liver, spleen, and lymph node, and rarely the gastrointestinal tract. When we encounter a well-defined, homogeneous lesion of the abdominal organs in patients diagnosed or suspected as having plasma cell neoplasm, we should consider its involvement of the abdominal organs.

Bile Duct Hamartomas: US, CT and MR Findings in Eight Patients, Focusing on the US Findings

PURPOSE: To describe the US, CT and MR findings in eight patients with bile duct hamartomas. MATERIALS AND METHODS: Bile duct hamartomas were diagnosed in eight patients (5 men and 3 women; age range, 41-69 years; mean age, 56 years) by liver biopsy. The US, CT and MR findings were retrospectively reviewed. RESULTS: Ultrasonographically, the bile duct hamartomas presented diffuse inhomogeneous and coarse echo texture with focal lesions, including bright spotty echoes or small hyperechoic nodules (n=7), hypoechoic nodules (n=7) and comet-tail echo (n=3) in seven patients. 16 of the 39 definable hypoechoic nodules that ranged in size from 5 mm to 16mm showed posterior enhancement. CT revealed innumerable hypodense nodules measuring 2-5 mm (n=3), 2-13 mm (n=1), 2-15 mm (n=2) and 2-18 mm (n=1) in seven patients. They were usually irregular in shape and showed no enhancement, but became more apparent after the administration of intravenous contrast medium. The innumerable hypodense nodules on enhanced CT scans were uniformly (n=5) or nonuniformly (n=2) distributed throughout the liver. In four patients, MR images showed multiple small cyst-like lesions 2-13 mm in diameter. These small cystlike lesions were much more apparent on T2-weighted images or MR cholangiography. The diagnosis was made by either core-needle or wedge biopsy. In one patient, a small single lesion on the liver surface was not visible on the imaging studies. Pathologic examination revealed multiple bile duct hamartomas of varying size or microhamartomas. CONCLUSION: Although the bile duct hamartomas on CT and MR presented as numerous intrahepatic, small cyst-like lesions, they on US showed variable findings consisting of inhomogeneous and coarse echo texture with focal lesions, including bright spotty echoes or small hyperechoic nodules, hypoechoic nodules, and comet-tail echoes.

Hepatic Tuberculosis: Unusual CT and Sonographic Findings

A case of infiltrative type of hepatic tuberculosis is presented. Ultrasonography revealed a very ill-margined, heterogenously low echoic lesion in the right hepatic lobe. CT scans demonstrated a very ill-defined, geographic, hypodense lesion with minimal contrast enhancement mimicking cholangiohepatitis or infiltrative tumor in the right hepatic lobe.

Differential Diagnosis of Benign and Malignant Intraductal Papillary Mucinous Tumors of the Pancreas: MR Cholangiopancreatography and MR Angiography

OBJECTIVE: To compare the usefulness of magnetic resonance cholangiopancreatography (MRCP) and MR angiography (MRA) in differentiating malignant from benign intraductal papillary mucinous tumors of the pancreas (IPMTs), and to determine the findings which suggest malignancy. MATERIALS AND METHODS: During a 6-year period, 46 patients with IPMT underwent MRCP. Morphologically, tumor type was classified as main duct, branch duct, or combined. The diameter of the main pancreatic duct (MPD), the extent of the dilated MPD, and the location and size of the cystic lesion, septum, and communicating channel were assessed. For all types of IPMTs, enhanced mural nodules and portal vein narrowing were evaluated at MRA. RESULTS: Combined-type IPMTs were more frequently malignant (78%) than benign (42%) (p < 0.05). Compared with benign lesions, malignant lesions were larger, and the caliber of the communicating channel was also larger (p < 0.05). Their dilated MPD was more extensive and of greater diameter (p < 0.05), and the presence of mural nodules was more frequent (p < 0.001). CONCLUSION: Combined MRCP and MRA might be useful for the differential diagnosis of malignant and benign IPMTs of the pancreas.

Anatomic Variation in Intrahepatic Bile Ducts: an Analysis of Intraoperative Cholangiograms in 300 Consecutive Donors for Living Donor Liver Transplantation

OBJECTIVE: To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation. MATERIALS AND METHODS: The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct. RESULTS: The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3). CONCLUSION: The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%).

Extracorporeal Shock Wave Lithotripsy on Pancreatic Duct Stones in Patients with Chronic Pancreatitis: Evaluation of Therapeutic Results with CT

PURPOSE: To demonstrate by CT scanning the effect of extracorporeal shock wave lithotripsy (ESWL) on pancreatic duct stones in patients with chronic pancreatitis. MATERIALS AND METHODS: Pancreatic duct stones in 11 patients with chronic pancreatitis were subject to ESWL using an electrohydraulic lithotripter. Endoscopic stone removal using a basket had failed in ten patients, and in one, endoscopy was impossible due to a previous Whipple's operation. CT scans obtained before and after ESWL were evaluated by two radiologists: the longest and shortest diameters of the target stone were measured, and according to the degree of fragmentation, determined by comparing the area of the stone before and after ESWL, a grade (1-5) was assigned. In each case, the pre- and post- treatment diameter of the main pancreatic duct, measured at the pancreatic body, was also compared. RESULTS: Disintegration of the target stone was achieved in all patients: grade 1 (over 75% of the area remained, compared with that of the initial stone) was assigned in two patients; grade 2 (51-75% of the original area) in one; grade 3 (26-50%) in four; grade 4 (under 25%) in two; and grade 5 (complete clearance of the target stone) in two. The mean area decreased from 175 mm2 to 69 mm2 after ESWL (p<0.05); a decrease of more than 50% was observed in eight patients (73%). The mean diameter of the main pancreatic duct decreased from 7.36 to 4.81 mm (p<0.05). No severe adverse effects or complications were noted, and all patients showed clinical improvement. Follow-up studies indicated that pancreatic duct stones recurred in three patients. CONCLUSION: ESWL can cause the fragmentation of pancreatic duct stones without significant complications, and should be considered where endoscopic stone removal has failed. CT is a suitable non-invasive and accurate tool for evaluating the therapeutic results of ESWL.

CT Findings of Small Bowel Metastases From Primary Lung Cancer

PURPOSE: To evaluate the CT findings of small bowel metastases from primary lung cancer. MATERIALS AND METHODS: Of the 1468 patients with primary lung cancer between 1990 and 2000, 13 patients who had metastasis to the small intestine were collected. Of these 13 patients, nine who underwent CT scan were included for analysis. The pathologic diagnoses of primary lung cancer in these nine patients were squamous cell carcinoma in six, adenocarcinoma in two, and large cell carcinoma in one. CT scans were analyzed with regard to the site and patterns (intraluminal mass/bowel wall thickening/bowel implants) of metastatic masses, and the presence or absence of complication such as intussusception, obstruction, or perforation of the small bowel. The medical records of the patients were also reviewed retrospectively for evaluation of presenting abdominal symptom and time interval of metastases from initial diagnosis of lung cancer. RESULTS: Metastatic lesions were distributed throughout the small intestine: the duodenum in five, the jejunum in four, the ileum in six, and both jejunum and ileum in one patient. The size of metastatic masses of small bowel ranged from 1.3 cm to 5.0 cm (mean size, 2.6 cm) On CT, the small bowel was involved with intraluminal masses (mean size, 3.4 cm) in eight patients, diffuse wall thickening (mean thickness, 1.6 cm) in five, and bowel implants (mean size, 2.2 cm) in two. Complications occurred in seven patients, including intussusceptions without obstruction in two patients and with obstruction in two, obstruction without intussusceptions in two, and bowel perforation in one. Of 9 patients, 6 had at least one symptom referable to the small bowel including abdominal pain in 4, anemia in 3, vomiting in 1, and jaundice in 1. Lung cancer and small bowel lesions were detected simultaneously in four patients and the time interval of metastases from initial diagnosis of lung cancer ranged from 10 days to 30 months (median interval, 54 days) in 5 patients. CONCLUSION: CT helps in defining the extent and pattern of small bowel metastases as well as in demonstrating their complication.

Biliary Ascariasis: MR Cholangiography Findings in Two Cases

We describe the imaging features of two cases of biliary ascariasis. Ultrasonography and CT showed no specific abnormal findings, but MR cholangiography clearly demonstrated an intraductal linear filling defect that led to the correct diagnosis. MR cholangiography is thus a useful technique for the diagnosis of biliary ascariasis.