Imaging findings of primary hepatic angiosarcoma on gadoxetate disodium-enhanced liver MRI: comparison with hepatic haemangiomas of similar size.

AIM: To describe imaging characteristics of primary hepatic angiosarcoma on gadoxetate disodium-enhanced dynamic magnetic resonance imaging (MRI) and to determine features that differentiate angiosarcomas from similar-sized haemangiomas. MATERIALS AND METHODS: The study included 15 patients with hepatic angiosarcomas and 35 patients with size-matched hepatic haemangiomas who underwent gadoxetate disodium-enhanced liver MRI. The number, size, growth pattern, signal intensity (SI) characteristics, and SI changes on dynamic scans were evaluated and compared between the two entities. RESULTS: Overall, hepatic angiosarcomas significantly more often showed lesion multiplicity (86.7%), capsular retraction (40%), prominent intratumoural vessels (66.7%), vascular invasion (20%), heterogeneous SI on T2-weighted (100%) and hepatobiliary phase images (80%), and intralesional haemorrhage (60%, all p<0.05). On dynamic scans, angiosarcomas demonstrated enhancing foci of irregular or rim-like nodular/linear or bizarre (86.7%) shapes, with centrifugal or bizarre patterns of progressive enhancement (53.3%). Enhancement of angiosarcomas was less than that of the blood pool on visual grading, but the enhancement curves followed that of the aorta. Regardless of size, angiosarcomas showed heterogeneous T2 SI, intratumoural haemorrhage, and heterogeneity during the hepatobiliary phase, whereas these findings were more common in haemangiomas >6 cm in diameter. CONCLUSION: Gadoxetate disodium-enhanced dynamic liver MRI is capable of depicting vascular hallmarks of hepatic angiosarcomas. Heterogeneous SI on T2-weighted and hepatobiliary phase images, multiplicity, and an enhancement curve following that of the aorta are also distinctive features that differentiate angiosarcomas from haemangiomas.

Radiofrequency ablation as an alternative to hepatic resection for single small hepatocellular carcinomas.

BACKGROUND: This study aimed to investigate whether radiofrequency ablation (RFA) is an alternative to surgical resection for hepatocellular carcinoma (HCC) within the context of current guidelines. METHODS: This retrospective study included patients with normal portal pressure and serum bilirubin level who initially underwent liver resection or RFA for a single HCC of maximum size 3 cm. Between-group differences in cumulative rates of survival and recurrence specific for HCC were analysed in the entire cohort and in a propensity score-matched cohort. RESULTS: A total of 604 patients were enrolled, 273 in the liver resection group and 331 in the RFA group. The 5- and 10-year HCC-specific survival rates for the resection and RFA groups were 87·6 versus 82·1 per cent and 59·0 versus 61·2 per cent respectively (P = 0·214), whereas overall 5- and 10-year recurrence-free survival rates for the corresponding groups were 60·6 versus 39·4 per cent and 37·5 versus 25·1 per cent respectively (P < 0·001). In the propensity score-matched cohort (152 pairs), there were no differences in HCC-specific survival (hazard ratio (HR) 1·03 for RFA versus resection; P = 0·899), whereas recurrence-free survival again differed between the treatment groups (HR 1·75; P < 0·001). RFA was independently associated with poorer outcomes in terms of treatment-site recurrence-free survival (adjusted HR 1·66; P = 0·026), but not non-treatment-site recurrence-free survival (adjusted HR 1·15; P = 0·354). CONCLUSION: Although RFA carries a higher risk of treatment-site recurrence than hepatic resection, it provides comparable overall survival in patients with a single small HCC without portal hypertension or a raised bilirubin level.

Percutaneous radiofrequency ablation using internally cooled wet electrodes for treatment of colorectal liver metastases.

AIM: To evaluate the efficacy and safety of internally cooled wet (ICW) electrodes, which provide interstitial infusion of saline and intra-electrode cooling simultaneously, in the percutaneous radiofrequency ablation (RFA) of liver metastases from colorectal cancer. MATERIALS AND METHODS: From February 2008 to October 2010, 27 patients with 35 hepatic metastatic lesions (mean size 1.99cm; range 0.7-3.8cm) underwent RFA using ICW electrodes. Of these 35 tumours, 32 had diameters ≤3cm, and three had diameters of 3-4cm. Moreover, 18 tumours were non-subcapsular and 17 were subcapsular. RESULTS: No patients (0%) had major complications after RFA. During follow-up (median 27 months; range 4.5-36 months), 14 of the 35 treated lesions (40%) showed local tumour progression. The local tumour progression-free survival rates at 1 and 3 years were 73 and 56%, respectively. The local tumour progression-free survival period was significantly longer in patients with tumours ≤2cm than >2cm (p<0.001), but did not differ significantly between patients with non-subcapsular and subcapsular tumours (p=0.454). The overall 1 and 3 year survival rates after RFA were 100 and 77%, respectively. CONCLUSIONS: Percutaneous RFA using ICW electrodes is safe and technically feasible for the treatment of liver metastases from colorectal cancer. It provides effective local tumour control with low complication rates and reduced number of needle placements.

Increase of modified retrograde to antegrade flow ratio on doppler ultrasounds of the hepatic vein indicating tricuspid regurgitation during follow-up of liver transplantation: correlation with echocardiographic results.

The purpose of this study was to explore the best parameter of hepatic vein (HV) Doppler ultrasounds (DUS) that correlated with echocardiographic findings of and particularly the optimal cutoff value for tricuspid regurgitation (TR) following liver transplantation (LT). Thirty-six patients underwent echocardiography and DUS after LT from January 2006 to July 2007. Echocardiographic records were searched for TR grade and peak velocity of TR flow. The HV DUS parameters included peak velocity of retrograde flow (R), peak velocity of antegrade flow (A), the difference between R and A (R-A), the ratio of R to A (R/A ratio), and a modified R/A ratio, namely, the product of the R/A ratio and the R/A duration ratio. Correlation tests and receiver-operator characteristic analyses explored their interrelations and to obtained cutoff values to diagnose moderate and severe TR. TR grade best correlated with the modified R/A ratio (rho = 0.585), followed by the R/A ratio (rho = 0.503) and R (rho = 0.455). The modified R/A ratio was the most accurate parameter for the diagnosis of moderate and severe TR (Az = 0.825 and 0.895, respectively); its cutoff value was > or =0.11 for moderate TR (sensitivity and specificity both 77.78%) and 0.13 for severe TR (sensitivity, 100%; specificity, 81.2%). The modified R/A ratio best correlated with echocardiographic results of TR, although the strength of correlation was only moderate. Additionally, the modified R/A ratio was an accurate DUS parameter to diagnose moderate and severe TR among patients following LT.

Gastric schwannomas: radiological features with endoscopic and pathological correlation.

AIM: To describe the radiological, endoscopic, and pathological findings of gastric schwannomas in 16 patients. MATERIALS AND METHODS: The radiological, endoscopic, and pathological findings of 16 surgically proven cases of gastric schwannoma were retrospectively reviewed. All patients underwent computed tomography (CT) and four patients were evaluated with upper gastrointestinal series. Two radiologists reviewed the CT and upper gastrointestinal series images by consensus with regard to tumour size, contour, margin, and growth pattern, the presence or absence of ulcer, cystic change, and the CT enhancement pattern. Endoscopy was performed in eight of these 16 patients. Six patients underwent endoscopic ultrasonography. Pathological specimens were obtained from and reviewed in all 16 patients. Immunohistochemistry was performed for c-kit, CD34, smooth muscle actin, and S-100 protein. RESULTS: On radiographic examination, gastric schwannomas appeared as submucosal tumours with the CT features of well-demarcated, homogeneous, and uncommonly ulcerated masses. Endoscopy with endoscopic ultrasonography demonstrated homogeneous, submucosal masses contiguous with the muscularis propria in all six examined cases. On pathological examination, gastric schwannomas appeared as well-circumscribed and homogeneous tumours in the muscularis propria and consisted microscopically of interlacing bundles of spindle cells. Strong positivity for S-100 protein was demonstrated in all 16 cases on immunohistochemistry. CONCLUSION: Gastric schwannomas appear as submucosal tumours of the stomach and have well-demarcated and homogeneous features on CT, endoscopic ultrasonography, and gross pathology. Immunohistochemistry consistently reveals positivity for S-100 protein in the tumours.

Secretin-stimulated MRCP.

Secretin-stimulated magnetic resonance cholangiopancreatography not only facilitate the depiction of anatomic variations or morphologic changes of the pancreatic duct in the normal and diseased pancreas but also help assessing functional abnormalities of the exocrine pancreas. In this article, we illustrate findings of normal pancreas and various pancreatic diseases on magnetic resonance cholangiopancreatography after secretin stimulation.

Autoimmune pancreatitis: radiologic findings in 20 patients.

BACKGROUND: Autoimmune pancreatitis is a new clinical entity that is characterized by peculiar histopathologic and laboratory findings and by a dramatic clinical response to corticosteroid therapy. We evaluated the radiologic findings of autoimmune pancreatitis. METHODS: Computed tomographic, magnetic resonance imaging, endoscopic retrograde cholangiopancreatographic, and ultrasonographic findings of 20 patients with autoimmune pancreatitis in our hospital between November 2000 and December 2003 were retrospectively reviewed regarding changes and ancillary findings in the pancreatic parenchyma, the main pancreatic duct, peripancreatic vessels, and distal common bile duct. In addition, follow-up images were reviewed for changes in any abnormality seen on the initial examinations. RESULTS: Pancreatic parenchymal enlargement was invariably seen that was diffuse (n = 19) or focal (n = 1), with homogeneous contrast enhancement on computed tomography (n = 20) and magnetic resonance imaging (n = 15). Capsule-like rim enhancement was seen in six patients. There was focal (n = 18) or diffuse (n = 2) narrowing of the main pancreatic duct and it was usually multifocal (n = 17) in the former. Narrowing of the peripancreatic veins was seen in 14 patients. There was tapered (n = 15) or abrupt (n = 3) narrowing of the distal common bile duct in 18 patients, with contrast enhancement of the narrowed segment in eight. Invariably, changes in the pancreatic parenchyma, main pancreatic duct, peripancreatic vessels, and common bile duct were normalized on follow-up studies after steroid therapy. CONCLUSION: In this series, common radiologic findings of autoimmune pancreatitis were (a) diffuse pancreas enlargement, (b) multifocal narrowing of the main pancreatic duct, (c) narrowing of peripancreatic veins, and (d) tapered narrowing of the distal common bile duct with frequent contrast enhancement. These findings were usually reversible with steroid therapy.

Abdominal cavernous Iymphangiomas: CT findings.

Two adult patients with histopathologically proved cavernous lymphangiomas and one adult patient with lymphangiomas of strongly presumed cavernous type by cytologic and computed tomographic findings are reported. On computed tomograms, multiple, aggregated, small, and tiny cysts without a solid portion, along the lymphatic channels are characteristic computed tomographic findings for cavernous lymphangiomas.

Intragastric metastasis in a patient with gastric cancer: unusual CT manifestation.

We describe computed tomographic findings of intragastric metastasis in a patient with gastric cancer. On computed tomography, the intragastric metastatic lesion appeared as an exophytically growing cystic masss with minimal thickening of the adjacent gastric wall, thus mimicking an exophytically growing submucosal tumor or adenocarcinoma.

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.

Radicicol suppresses transformation and restores tropomyosin-2 expression in both ras- and MEK-transformed cells without inhibiting the Raf/MEK/ERK signaling cascade.

The antibiotic radicicol suppresses transformation in a variety of transformed cells. The antineoplastic effects of the drug have been attributed to the degradation of Raf and the inactivation of the Ras/Raf/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling cascade. Here we demonstrate that radicicol induces cell spreading, suppresses anchorage-independent cell growth, and increases the expression of the high-molecular weight tropomyosin isoform TM-2 in cells stably expressing a constitutively active form of MEK-1 as well as in ras-transformed cells. Furthermore, the reverting effects of the drug are achieved at concentrations below those required to deplete Raf from the cell or to inhibit the phosphorylation of ERK or its substrates Elk and pp90(RSK). In contrast, low concentrations of radicicol significantly inhibited activator protein (AP-1) and serum response factor (SRF)-mediated transcription. The lack of correlation between the effects of radicicol on cell phenotype and on the signaling activities of the Raf/MEK/ERK pathway indicate that Raf depletion or disruption of proximal signaling events in the mitogen-activated protein kinase pathway are not the predominant mechanisms by which the drug suppresses the transformed phenotype. Our observation that low concentrations of radicicol block transcriptional activities mediated by AP-1 and SRF suggests that interference with signaling upstream of these transcription factors may contribute to the reverting effects of the drug.

CT differentiation of mesenteric ischemia due to vasculitis and thromboembolic disease.

PURPOSE: The purpose of this work was to differentiate CT findings of acute mesenteric ischemia due to vasculitis (MV) or thromboembolism (MTE). METHOD: CT scans of 69 patients with mesenteric ischemia caused by MV (n = 37) or MTE (n = 32) were analyzed. After dividing the patients into groups with and without MV, we compared them with regard to gastrointestinal tract involvement patterns, mesenteric changes, and presence or absence of vascular thrombosis, atherosclerosis, other organ changes, and ascites. RESULTS: Duodenum was involved only in the MV group (30%). The MV group had preferential involvement of the small intestine (89%) to large intestine (51%), whereas the MTE group showed even distribution. Multisegmental bowel involvement was more common in the MV group (86%) than in the MTE group (44%), especially in both jejunum and ileum and both small and large intestine. The MV group showed prominent involvement of the superior mesenteric vessel territory, although the MTE group showed even distribution. Splenomegaly and hydronephrosis were more frequently seen in the MV group and vascular thrombosis and atherosclerosis in the MTE group. CONCLUSION: Although considerable overlap was noted, CT is useful in differentiating MV from MTE.

Hepatic MR imaging: comparison of 2D and 3D gradient echo techniques.

BACKGROUND: To compare fat-suppressed three-dimensional gradient echo (3D-GRE) and two-dimensional gradient echo (2D-GRE) techniques for hepatic magnetic resonance imaging. METHODS: For 107 patients with suspected focal hepatic lesions, unenhanced 2D-GRE multislice in-phase and opposed-phase images and 3D-GRE images were obtained. Two radiologists independently and in random order reviewed the images. Quantitative analysis compared contrast-to-noise ratio (C/N) of liver masses and of the liver to spleen and signal-to-noise ratio (S/N) of the liver. Subjective grading of lesion conspicuity, confidence for lesion detection, artifacts, and overall image quality were also evaluated. RESULTS: Conspicuity and confidence for focal lesions was statistically significantly higher on 3D-GRE than on 2D-GRE images. Liver-to-spleen C/N was higher on 3D-GRE images than on in-phase and opposed-phase 2D-GRE images (p < 0.01). Liver S/N was higher on in-phase 2D-GRE images than on 3D-GRE and opposed-phase 2D-GRE images (p < 0.001). Lesion-to-liver C/N was higher on 3D-GRE images than on 2D-GRE images for nonsolid lesions (p < 0.05), but there was no significant difference for solid lesions. Motion and pulsation artifacts were significantly fewer on 3D-GRE images, but graininess and shading were significantly higher. Overall image quality was not significantly different for the three sequences. CONCLUSION: Fat-suppressed 3D-GRE sequences can afford comparable or better image quality than 2D-GRE images and may have the potential to detect more focal hepatic lesions.

Stimulation of tumor growth by human soluble intercellular adhesion molecule-1.

Because serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) are elevated in cancer and sICAM-1 is angiogenic, we tested the ability of sICAM-1 to promote tumor growth. Our preliminary experiments showed that exogenous sICAM-1 significantly stimulated the growth of human tumors in vivo. Human fibrosarcoma transfectants, which express ICAM-1, produce ICAM-1 on the cell surface and release sICAM-1 into the medium without any apparent effect on cell growth in vitro. We found that conditioned medium from sense ICAM-1 transfectants compared with mock or antisense ICAM-1 transfectants stimulates endothelial cell migration in vitro and neovascularization in the chick chorioallantoic membrane assay. Tumor cells transfected with sense constructs form faster growing tumors than mock- and antisense-transfected cells in both chick embryos and nude mice models. Serum levels of human sICAM-1 from nude mice bearing sense ICAM-1 transfectants correlate positively with tumor weight. Sense ICAM-1 transfectants are more proliferative and induce more blood vessel formation than mock and antisense transfectants in nude mice. Because expression of ICAM-1 does not affect tumor cell growth in vitro, the angiogenic activity of sICAM-1 produced by sense ICAM-1 transfectants may be involved in the stimulation of tumor growth. Therefore, sICAM-1 may perform dual functions that are essential for tumor growth: angiogenesis and escape from immune surveillance.

Hepatic iron deposition on MR imaging in patients with chronic liver disease: correlation with serial serum ferritin concentration.

BACKGROUND: To evaluate the relationship between magnetic resonance (MR) imaging grading of iron deposition and serial serum ferritin concentration in patients with chronic viral liver diseases. METHODS: In 80 patients with viral hepatitis and cirrhosis, MR images including T2*-weighted gradient echo images (echo time > or = 6.5 ms) were reviewed. The grades of parenchymal iron deposition and iron-containing nodules in the liver and spleen and the liver-to-muscle and spleen-to-muscle signal intensity ratios were compared with the most recent, the mean, the lowest, and the highest values from all available serum ferritin levels. RESULTS: The serum ferritin concentration was significantly correlated with the grades of iron deposition in liver and spleen and with the grades of iron-containing nodules seen on MR images (p < 0.05). Liver-to-muscle signal intensity ratio was weakly correlated with the ferritin concentrations. Among categories of ferritin concentration, correlation with MR grades was highest for mean ferritin concentration (r = 0.487, p < 0.001). CONCLUSION: MR imaging grades of hepatic iron and siderotic nodules correlate with serum ferritin, especially with the mean levels.

Diagnostic pitfalls in the cholangiographic diagnosis of choledochoceles: cholangiographic quality and its effect on visualization.

BACKGROUND: We wanted to establish reasonable cholangiographic diagnostic criteria by determining the sensitivity of cholangiography in detecting choledochoceles and those factors that could compromise visualization of choledochoceles. METHODS: Over 4 years, 21 patients (seven male, 14 female; mean age = 67 years) were confirmed as having choledochoceles on endoscopic retrograde cholangiopancreatography (ERCP). Cholangiographic diagnosis was made by following three criteria: a radiolucent halo around the distal common bile duct (CBD), bulbous dilatation of the distal CBD, and the presence of sequential morphologic changes on serial cholangiography. Any two or more combinations of these three criteria were considered enough to diagnose a choledochocele on cholangiography. We compared cholangiographic imaging findings with the ERCP results. RESULTS: Of 21 patients with choledochoceles, nine (43%) were correctly diagnosed on cholangiography. A radiolucent halo was present in six (28%) patients; four of these cases showed optimal duodenal filling, one showed faint duodenal filling, and one showed poor duodenal filling. The shapes of the distal CBD were bulbous, conelike, and blunt. Morphologic changes such as collapsing and bulging of the choledochocele could be seen in 12 (57%) patients on serial cholangiography. Waists were seen in 11 (52%), pseudowebs in four (19%), and wrinkling of the distal CBD in seven (33%). CONCLUSION: Cholangiography should be obtained with optimal timing and adequate conditions to diagnose choledochocele correctly.

CT of patients with right-sided colon cancer and distal ileal thickening.

OBJECTIVE: The purpose of this study was to analyze the incidence and primary causes of distal ileal wall thickening in 131 patients with right-sided colon cancer. SUBJECTS AND METHODS: During a 2-year period, 131 patients underwent surgical resection for right-sided colon cancer. Of these patients, we analyzed 13 who had distal ileal wall thickening on CT before surgery and also had the cause determined at pathology. CT findings were analyzed with regard to the morphologic features of colonic tumors, bowel wall involvement patterns of the distal ileum, and changes in the pericolic space. RESULTS: Distal ileal wall thickening occurred in 13 (10%) of the 131 patients who had right-sided colon cancer. Three patients had polypoid colon cancer, whereas the other 10 had infiltrative colon cancer. The mean thickness of the involved colonic segments was 1.6 cm (range, 1.0-2.2 cm) with a mean length of 5.2 cm (range, 2.5-10.0 cm). Pericolic infiltration was mild in six patients and moderate in four patients. The mean length and thickness of the affected ileal segments were 3.2 cm (range, 1.5-6.0 cm) and 1.1 cm (range, 0.7-2.0 cm), respectively. On histopathologic examination, neoplastic processes involved the distal ileum in nine (69%) of the 13 patients. This involvement was caused by either direct tumor invasion in seven patients or lymphatic spread in two. In four patients (31%), nonneoplastic processes with edema and congestion involved the distal ileum. CONCLUSION: The distal ileum may be abnormally thickened in about 10% of patients with right-sided colon cancer; this thickening results from tumor extension (69%) or a nontumorous process (31%).

Radiologic features of vasculitis involving the gastrointestinal tract.

Vasculitides can cause local or diffuse pathologic changes in the gastrointestinal tract, resulting in nonspecific paralytic ileus, mesenteric ischemia, submucosal edema and hemorrhage, or bowel perforation or stricture. The extent and clinical course of disease depend on the size and location of the affected vessel and the histologic characteristics of the lesion. Vasculitis may primarily involve large vessels (eg, giant cell arteritis, Takayasu arteritis), medium-sized vessels (eg, polyarteritis nodosa, Kawasaki disease, primary granulomatous central nervous system vasculitis), or small vessels (eg, Wegener granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, Henoch-Schönlein syndrome, systemic lupus erythematosus, rheumatoid vasculitis, Behçet syndrome). Radiologic findings in various types of vasculitis often overlap considerably and therefore have limited value in making a specific diagnosis. Nevertheless, the possibility of vasculitis should be considered whenever mesenteric ischemic changes occur in young patients, are noted at unusual sites (eg, stomach, duodenum, rectum), have a tendency to concomitantly involve the small and large intestine, and are associated with genitourinary involvement. Knowledge of systemic clinical manifestations in affected patients may suggest and even help establish the specific diagnosis.

Radiologic findings of abdominal polyarteritis nodosa.

OBJECTIVE: The purpose of this study was to evaluate the radiographic and imaging findings of seven patients with polyarteritis nodosa involving the abdomen. CONCLUSION: Vasculitis should be considered when multiple abdominal organs have abnormal radiologic findings; however, angiography is necessary to specifically diagnose polyarteritis nodosa.

Radiological features of leiomyomatous tumors of the colon and rectum.

PURPOSE: The purpose of this study was to evaluate the radiological features of 12 pathologically proven cases of colorectal leiomyomatous tumors. METHOD: A retrospective analysis of radiologic findings was performed in 12 patients with pathologically proven colorectal leiomyomatous tumors (2 leiomyomas and 10 leiomyosarcomas). Available radiologic studies included abdominal CT scans in 11 patients, double contrast barium studies in 4, and pelvic MRI in 1. On imaging, we evaluated the size, tumor margin (smooth or lobulated), morphologic appearance, growth patterns (endocolic, exocolic, or combined), contrast enhancement patterns, presence or absence of calcification within the tumors, and metastasis. RESULTS: The involved tumor sites were the colon in 2 patients and the rectum in 10. The mean tumor size was 7.9 cm (range 2-15 cm): It was 3.5 cm in leiomyomas and 8.8 cm in leiomyosarcomas. On imaging studies, the tumor margin was smooth in three patients and lobulated in nine, with endocolic growth in one, exocolic in four, and combined in the remaining seven. Eight of the 12 tumors showed varying degrees of internal necrosis with heterogeneous contrast enhancement. Dystrophic calcification was noted in five patients. Metastasis was seen in the liver in three patients at the time of initial diagnosis, and lymphadenopathy was noted in two patients (paraaortic space in one and perirectal space in two). CONCLUSION: Although rare, the diagnosis of leiomyomatous tumor may be suggested especially when the tumor occurring in the colorectum shows exocolic growth or calcification with varying degree of internal necrosis.