Neurosarcoidosis: Radiologic Features in Five Patients

This paper describes the radiological features in five biopsy-confirmed cases of neurosarcoidosis. The imaging appearance of neurosarcoidosis is highly variable, making the diagnosis difficult on the basis of intracranial images alone. However, if there is evidence of spread along the pia mater, and meningeal mass formation with a lower intensity in the central area and higher intensity in the peripheral area on T2-weighted and FLAIR images, neurosarcoidosis can be considered.

Lymphoepithelial cyst of the pancreas: case report with special reference to imaging--pathologic correlation

We report a case of resected lymphoepithelial cyst of the pancreas with special reference to the imaging-pathologic correlation. Visualization of a multilocular cystic nature with internal heterogeneous hyperechogenicity on ultrasound, hyperdensity on precontrast computed tomography, and granular hypointensity on T2-weighted image due to abundant internal keratin substances were considered to be keys to the differential diagnosis from other cystic lesions of the pancreas.

Intraluminal duodenal diverticulum: MR findings

We report a case of intraluminal duodenal diverticulum with special reference to its magnetic resonance imaging findings. An intraluminal duodenal fluid collection surrounded by a hypointense rim on T2-weighted or magnetic resonance cholangiopancreatographic images, the shape of which is changed by peristalsis, is considered to be almost diagnostic for intraluminal duodenal diverticulum.

MRI findings of primary biliary cirrhosis: correlation with Scheuer histologic staging

Magnetic resonance imaging (MRI) findings of primary biliary cirrhosis (PBC; currently regarded as a vanishing bile duct syndrome) are not established. In this report, we describe our preliminary analysis of the relation between MRI findings and histopathologic staging of PBC and review clinical, morphologic, and MRI findings of PBC especially focusing on the staging of PBC.

Solid serous cystadenoma of the pancreas: MR imaging with pathologic correlation

We report a case of solid type serous cystadenoma of the pancreas. Computed tomographic and magnetic resonance (MR) images showed a hypervascular solid tumor that was difficult to differentiate from endocrine tumor of the pancreas. However, the tumor showed marked hyperintensity similar to that of hepatic cyst on MR cholangiopancreatography, indicating not a solid but rather a cystic nature. MR cholangiopancreatography (heavily T2-weighted image) is quite useful for clearly differentiating solid from cystic tumors.

Focal sparing of fatty liver in segment II associated with aberrant left gastric vein

We present a patient with aberrant left gastric vein (LGV) that directly enters the posterior edge of segment II in the liver. The corresponding area was focally spared of fatty liver. We consider that this aberrant LGV contributed to the cause of focal sparing. This is the first report of the use of helical CT and Doppler ultrasound to depict the aberrant LGV that directly enters the liver.

Tumor-associated focal chronic pancreatitis from invasion of the pancreatic duct by common bile duct carcinoma: radiologic-pathologic correlation

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.

Cystic duct remnant carcinoma with widespread invasion along the extrahepatic bile duct wall: dynamic CT findings

We report a case of remnant cystic duct carcinoma with widespread invasion along the common bile duct wall. Thin-slice dynamic computed tomography showed circumferential wall thickening of the extrahepatic bile duct (from the common hepatic duct to the intrapancreatic common bile duct) and the remnant cystic duct. Pathologically, the extrahepatic bile duct wall was thickened due to submucosal tumor infiltration by cystic duct papillary adenocarcinoma.

Accumulation of iodized oil within the nonneoplastic liver adjacent to hepatocellular carcinoma via the drainage routes of the tumor after transcatheter arterial embolization

PURPOSE

After transcatheter arterial embolization (TAE) with iodized oil (Lipiodol), a relatively dense accumulation of Lipiodol is often seen in the nontumorous liver adjacent to a hypervascular hepatocellular carcinoma (HCC) nodule. We compared this phenomenon with the findings obtained with single-level dynamic CT during hepatic arteriography (SLDCTHA) and presumed its possible mechanism.

METHODS

Fifty-six patients with HCC underwent hepatic angiography including SLDCTHA followed by segmental or subsegmental TAE with a mixture of an anticancer drug and Lipiodol. We compared the drainage area of the HCC depicted on SLDCTHA with the Lipiodol accumulation in the nontumorous liver adjacent to the HCC on CT after TAE (LpCT).

RESULTS

In 26 of the 56 patients, a definite corona enhancement around the HCC, suggesting the drainage of blood from the tumor into the surrounding liver parenchyma, was seen on the late phase of SLDCTHA. In 17 of these 26 patients (65.4%), LpCT showed a more intense accumulation of Lipiodol in the nontumorous liver adjacent to the HCC that corresponded to the drainage area revealed on SLDCTHA.

CONCLUSION

The drainage of blood from the HCC was considered to be a possible mechanism of the accumulation of Lipiodol in the nontumorous liver adjacent to the HCC.

Peritumoral spared area in fatty liver: correlation between opposed-phase gradient-echo MR imaging and CT arteriography

BACKGROUND

The purpose of the present study was to evaluate the magnetic resonance findings of a spared area of fatty liver caused by hepatic tumors and clarify the etiology of this phenomenon by computed tomographic (CT) arteriography.

METHODS

Six patients with hepatic tumors (metastases from colon cancer, n = 3; breast cancer, n = 2; hepatocellular carcinoma, n = 1) were examined. In-phase (IP) and opposed-phase (OP) T1-weighted spoiled gradient-echo images were obtained. CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) were also performed. Pathologic confirmation was obtained in three patients with metastases from colon cancer.

RESULTS

In all six patients, peritumoral ringlike or wedge-shaped hyperintense areas in relation to the tumor and the surrounding steatotic liver parenchyma were clearly visualized on OP images alone. This area appeared as a perfusion defect on CTAP and ringlike or wedge-shaped enhancement on CTHA. Pathologically, the peritumoral hyperintense areas on OP images were compatible with the spared area of fatty liver.

CONCLUSION

A peritumoral spared area can be demonstrated with OP images. The etiology of the phenomenon is correlated with decreased portal flow and increased arterial flow in the peritumoral hepatic parenchyma.

Pseudolesion in segment IV of the liver adjacent to the falciform ligament caused by drainage of the paraumbilical vein: demonstration by power Doppler ultrasound

A case of a pseudolesion in segment IV of the liver, adjacent to the falciform ligament, was observed on conventional CT and CT during arterial portography. The pseudolesion was caused by drainage of the paraumbilical vein. Power Doppler ultrasound was helpful in recognizing this pseudolesion by depicting that the paraumbilical vein was connected to vessels in this area. Although the direction of flow could not be determined, power Doppler ultrasound is a useful method for confirming non-invasively the aetiology of pseudolesions in this area.

Dynamic CT of hepatic abscesses: significance of transient segmental enhancement

OBJECTIVE

The purpose of this study was to evaluate dynamic CT findings of hepatic abscesses, especially segmental hepatic enhancement, and to clarify the cause.

MATERIALS AND METHODS

Twenty-four abscesses in eight patients were examined by early (30 sec) and late phase (90 sec) dynamic CT. Patients underwent abscess drainage (n = 1), hepatic resection (n = 2), or antibiotic therapy (n = 5). CT during arterial portography and CT during hepatic arteriography were performed in one patient. We retrospectively observed the frequency and changes of segmental hepatic enhancement on dynamic CT and determined its cause using radiologic and pathologic correlation.

RESULTS

Sixteen abscesses (67%) showed transient segmental hepatic enhancement and three abscesses showed only segmental hepatic enhancement in the early phase. Four abscesses in one patient who underwent CT during arterial portography and CT during hepatic arteriography showed a segmental perfusion defect on CT during arterial portography and segmental enhancement on CT during hepatic arteriography. On follow-up dynamic CT performed 10-17 days after the initial CT, segmental hepatic enhancement surrounding hepatic abscesses decreased or disappeared in all abscesses. Pathologic examination of two patients showed marked inflammatory cell infiltration with stenosis of portal venules within the portal tracts surrounding hepatic abscesses without definite inflammation in the liver parenchyma.

CONCLUSION

Segmental hepatic enhancement on dynamic CT is frequently associated with hepatic abscesses and may be caused by decreased portal flow resulting from inflammation of the portal tracts.

CT arteriographic confirmation of focal hepatic fatty infiltration adjacent to the falciform ligament associated with drainage of inferior vein of Sappey: a case report

We experienced a case of focal fatty infiltration in the anteromedial edge of the medial segment of the liver adjacent to the falciform ligament associated with advanced esophageal cancer. By using CT during selective right internal thoracic arteriography, we confirmed that the inferior vein of Sappey drained into the area of focal fatty infiltration. This is the first case to directly establish the relationship between drainage of the inferior vein of Sappey and occurrence of focal fatty infiltration of the liver.

MR imaging of focal splenic extramedullary hematopoiesis in polycythemia vera: case report

We report a case with focal mass-like lesion of the spleen in polycythemia vera. Magnetic resonance imaging of the lesion showed homogeneous hyperintensity on T2-weighted images, with progressive enhancement on dynamic magnetic resonance images after bolus injection of gadolinium. The magnetic resonance features of focal splenic extramedullary hematopoiesis have not been previously reported.

Intrahepatic biliary calculi: correlation of unusual MR findings with pathologic findings

We report a case of intrahepatic biliary calculi. A localized dilated intrahepatic duct of the left lateral segment of the liver was filled with material that showed marked hyperintensity on T1- and T2-weighted magnetic resonance (MR) images. These MR findings are unusual for intrahepatic stones. Pathologically, the stones were muddy bilirubin calculi, the chemical and physical characteristics of which are surmised to have been the cause of the unusual MR findings.

Enlargement of hilar periportal space: a sign of early cirrhosis at MR imaging

The purpose of this study was to determine whether the finding of an enlarged hilar periportal space is a sign for early cirrhosis at magnetic resonance (MR) imaging. Forty-one pathologically proved cirrhotic patients in the early stage of disease who did not show conventional imaging findings of cirrhosis (early cirrhosis group) and 47 patients without history of chronic liver diseases (control group) were included in this study. MR images were qualitatively and quantitatively evaluated for the presence of enlargement of the periportal space. Enlargement of the periportal space was seen in 98% of patients in the early cirrhosis group, while this finding was seen in 11% of patients in the control group (P < 0.0001). The mean value of the hilar periportal fat thickness was significantly greater (P < 0.0001) in the early cirrhosis group (15.5 +/- 6.2 mm) than in the control group (5.3 +/- 3.1 mm). The sensitivity, specificity, accuracy, and positive predictive value of this finding for the MR diagnosis of cirrhosis with a cutoff value of 10 mm were 93%, 92%, 92%, and 91%, respectively. Enlargement of the hilar periportal space is a helpful sign at MR imaging in the discrimination between normal and early cirrhotic livers.

Free MRA of the abdomen: postprocessing dynamic gadolinium-enhanced 3D axial MR images

Dynamic contrast-enhanced whole-abdomen axial images were obtained by using a fat-suppressed, three-dimensional, breath-hold enhanced fast spoiled gradient-echo technique, configured for optimal evaluation for detection and characterization of liver lesions. We then evaluated the feasibility of using these images to reconstruct "free" abdominal magnetic resonance angiography, without additional cost or acquisition time, in 32 randomly chosen patients. The aorta, celiac trunk, superior mesenteric, hepatic, splenic, and renal arteries were clearly depicted.

Hepatocellular carcinoma: association with increased iron deposition in the cirrhotic liver at MR imaging

PURPOSE

To determine whether the frequency of hepatocellular carcinoma (HCC) in patients with cirrhosis is affected by hepatic iron deposition as detected with magnetic resonance (MR) imaging.

MATERIALS AND METHODS

In a retrospective search of MR imaging and histopathology records, 196 patients with histopathologically proved cirrhosis and with (n = 80) or without (n = 116) HCC who underwent T2-weighted conventional or fast spin-echo and gradient-echo (GRE) (echo time > or = 6.0 msec) imaging were identified. MR images were qualitatively and quantitatively evaluated for diffuse hepatic iron deposition and siderotic regenerative nodules to assess their correlation with the presence of HCC.

RESULTS

Hepatic parenchymal iron deposition was seen in 79 (40%) patients, and iron deposition in regenerative nodules was seen in 71 (36%) at MR imaging. The mean signal intensity ratio of GRE images in patients with hepatic iron deposition was significantly lower than that in patients without it (P < .001). The frequency of HCC in patients with iron deposition in regenerative nodules (52% [37 of 71 patients]) was significantly higher (P = .015) than that in patients without iron in regenerative nodules (34% [43 of 125 patients]).

CONCLUSION

The occurrence of HCC may be associated causally with iron deposition in regenerative nodules in patients with cirrhosis. MR imaging can enable detection of iron deposition in regenerative nodules as a possible risk factor for the development of HCC.

Expanded gallbladder fossa: simple MR imaging sign of cirrhosis

PURPOSE

To determine the frequency on magnetic resonance (MR) images of a widened pericholecystic space, which the authors call the expanded gallbladder fossa sign, and to assess the sensitivity and specificity of this sign for cirrhosis.

MATERIALS AND METHODS

Three-hundred thirteen patients who underwent MR imaging were included in this study, including 190 with pathologically proved cirrhosis (cirrhosis patients) and 123 without history of chronic liver diseases (control subjects). MR images were qualitatively evaluated by three independent observers for the presence of the expanded gallbladder fossa sign. This sign was considered present if there was enlargement of the pericholecystic space (i.e., gallbladder fossa) and the space was bounded laterally by the edge of the right hepatic lobe and medially by the edge of the left lateral segment, in conjunction with nonvisualization of the left medial segment.

RESULTS

The expanded gallbladder fossa sign was seen in 129 cirrhosis patients and in three control subjects (P < .001). The sensitivity, specificity, accuracy, and positive predictive value of this sign for the MR diagnosis of cirrhosis were 68%, 98%, 80%, and 98%, respectively.

CONCLUSION

The expanded gallbladder fossa sign on MR images is a frequently present, specific indicator of cirrhosis. This sign can be used as a simple and highly specific sign of cirrhosis, if present, despite the overall sensitivity of 68%.

Correlation between the blood supply and grade of malignancy of hepatocellular nodules associated with liver cirrhosis: evaluation by CT during intraarterial injection of contrast medium

OBJECTIVE

The purpose of this study is to evaluate the correlation between the intranodular blood supply revealed by CT during intraarterial injection of contrast medium, mainly using helical CT, and the grade of malignancy of hepatocellular nodules associated with liver cirrhosis as classified by the International Working Party of the World Congress of Gastroenterology.

SUBJECTS AND METHODS

We studied 201 histologically proven nodules (101 resected and 100 biopsied nodules), including 47 low-grade dysplastic nodules (low-DNs), 56 high-grade dysplastic nodules (high-DNs), 24 well-differentiated hepatocellular carcinomas (wd-HCCs), and 74 moderately or poorly differentiated HCCs (mp-HCCs), in 139 cirrhotic patients. Findings on CT during arterial portography (n = 201) and CT during hepatic arteriography (n = 74) were reviewed and compared with the histologic diagnosis.

RESULTS

CT findings were classified into four types relative to the surrounding liver: type A (isodense), type B (slightly hypodense), type C (partially hypodense), and type D (markedly hypodense) on CT during arterial portography and type I (isodense), type II (hypodense), type III (partially hyperdense), and type IV (hyperdense) on CT during hepatic arteriography. On CT during arterial portography, the distributions of each type were low-DN (n = 47 [A, n = 36; B, n = 8; C, n = 3]), high-DN (n = 56 [A, n = 18; B, n = 20; C, n = 10; D, n = 8]), wd-HCC (n = 24; [B, n = 4; C, n = 13; D, n = 7]), and mp-HCC (n = 74 [D, n = 74]). On CT during hepatic arteriography, the distributions were low-DN (n = 26 [I, n = 18; II, n = 7; III, n = 1]), high-DN (n = 19 [I, n = 6; II, n = 7; III, n = 4; IV, n = 2]), wd-HCC (n = 15 [I, n = 1; III, n = 8; IV, n = 6]), and mp-HCC (n = 14 [IV, n = 14]). We found a statistically significant correlation between the four types and the grade of malignancy of these nodules.

CONCLUSION

Findings on CT during arterial portography and CT during hepatic arteriography correlated positively with histologic grading when overlap in appearance between dysplastic nodules and HCCs occurred. The concept revealed in this study can apply to diagnoses made on the basis of Doppler sonography, dynamic CT, and MR imaging.

Pseudolesion in segments II and III of the liver on CT during arterial portography caused by aberrant right gastric venous drainage

We report three cases of pseudolesions caused by aberrant right gastric venous drainage (AGVD) in segment II/III of the liver as demonstrated on CT during arterial portography (CTAP). On CTAP, the lesions were seen as wedge-shaped perfusion defects, and on hepatic arteriography, AGVD directed to the area with the perfusion defect was visible in all three cases. When a perfusion defect is detected at the edge of segments II/III at CTAP, a pseudolesion caused by AGVD should be suspected.

Giant hyperplasia of the caudate lobe of the cirrhotic liver: correlation with an anomaly of the caudate portal branch

Different imaging appearances of giant hyperplastic change of the caudate lobe of the liver are presented in a patient with liver cirrhosis. The mass like caudate lobe was isoechoic on ultrasound, hypodense on postcontrast computed tomography (CT), hyperintense on T1-weighted magnetic resonance, images and isointense on T2-weighted images. These imaging findings are similar to those of dysplastic nodule in cirrhotic liver. The caudate lobe received normal portal flow on CT during arterial portography, but superior mesenteric arteriography showed precocious or early division of the caudate portal branch. We suspect that caudate hyperplastic change may be correlated to anomalous caudate portal vein branch.

Pseudolesion in segment IV of the liver on MRI: prevalence and morphology in 250 cirrhotic livers compared with 250 normal livers

PURPOSE

The goal of our study was to assess the prevalence of pseudolesion in segment IV of the liver on MRI in patients with and without liver cirrhosis.

METHOD

Patients were divided into three groups: 10 patients with angiographically confirmed aberrant gastric venous drainage and liver cirrhosis (Group 1), 250 consecutively selected patients with liver cirrhosis (Group 2), and 250 with normal liver (Group 3). The signal intensity of pseudolesion in segment IV on T1- and T2-weighted MRI in the 510 patients was analyzed.

RESULTS

In Group 1, five pseudolesions were visible and hyperintense on T1-weighted images. On T2-weighted images, four were visible and hypointense. In Group 2, 11 were seen (4.4%). All were hyperintense on T1-weighted images. Five were hypointense on T2-weighted images. In Group 3, one pseudolesion was seen (0.4%).

CONCLUSION

The prevalence of pseudolesion in segment IV on MRI is higher in liver cirrhosis than in normal liver. The lesion is hyperintense on T1-weighted images when visible.

Pancreatic cancer associated with granulocyte-colony stimulating factor production confirmed by immunohistochemistry

We report an 83-year-old man with pancreatic body cancer of 4.5 cm in diameter. Peripheral leukocyte count was 15,700/microl and the serum concentration of granulocyte-colony stimulating factor (G-CSF) was 123 pg/ml (normal, 6.0-21.9 pg/ml) on admission. Furthermore, not only K-ras codon 12 (GGT --> GAT) but also p53 at codon 247 (CGG --> CCG) mutations were identified in the pancreatic juice aspirated endoscopically. We performed chemotherapy with two courses of 5-fluorouracil, pirarubicin hydrochloride, and mitomycin-C, resulting in no beneficial effect. After the second course the patient developed interstitial pneumonia, probably caused by anticancer drugs, and died 4 months after the tumor was detected. In the autopsy tissue, the tumor macroscopically occupied the pancreas body and was 7 x 6 x 5 cm in size. Histopathologic diagnosis of the tumor was poorly differentiated adenosquamous carcinoma. Immunohistochemical staining of the autopsy tissue showed that pancreatic cancer cells were positive for G-CSF. This is the first case report of G-CSF-positive pancreatic cancer confirmed by immunohistochemistry.

[Usefulness of T2-weighted images using single shot fast spin echo (SSFSE) pulse sequence for the evaluation of pancreatobiliary diseases: comparison with MRCP using SSFSE]

Single shot fast spin echo (SSFSE) pulse sequence provides us with a thick single-slice MR cholangiopancreatography (MRCP) as well as thin multi-slice MRCP, and T2-weighted images are also obtained with SSFSE sequences. In comparison with conventional spin-echo and fast spin-echo sequences, T2-weighted image using SSFSE sequence has the advantages of the abscence of motion artifacts and the extremely short acquisition times. MRCP using SSFSE sequence is useful in the conspicuity of bile duct, pancreatic duct, and cystic lesions. However, T2 weighted image using SSFSE is superior to MRCP not only for the differentiation between solid and cystic lesions but also for the visualization of contour of different organs and lesions.

Differentiation of hypervascular hepatic pseudolesions from hepatocellular carcinoma: value of single-level dynamic CT during hepatic arteriography

PURPOSE

The purpose of our study was to assess the efficacy of single-level dynamic CT during hepatic arteriography (D-CTA) in the differentiation between hypervascular hepatocellular carcinoma (HCC) and hypervascular pseudolesion.

METHOD

D-CTA was performed in nine cases with HCC and nine cases with pseudolesion. Findings on D-CTA were retrospectively analyzed.

RESULTS

The transition of the stain of pseudolesion on D-CTA was divided into three phases: (1) inflow of the contrast material into the portal vein within the lesion, (2) lesion staining, and (3) fading out of the stain; that of HCC was divided into four phases: (1) inflow of CM into tumor, (2) tumor staining, (3) inflow of CM into the adjacent liver, and (4) coronal stain of adjacent liver. The coronal stain was seen in all HCCs but not in any pseudolesions.

CONCLUSION

The present study suggest that D-CTA is a helpful option in the differentiation between HCC and pseudolesion.

Delayed MR imaging of the liver: correlation of delayed enhancement of hepatic tumors and pathologic appearance

BACKGROUND

The value of delayed magnetic resonance (MR) imaging (6 min) and ultradelayed MR imaging (1-4 h) for differentiating of hepatic tumors was studied.

METHODS

Postcontrast delayed and ultradelayed MR images were obtained after administration of 0.1 mmol/kg of Gd-DTPA in 30 patients with various malignant hepatic tumors.

RESULTS

Delayed enhancement in the center of the tumors was seen in 13 patients on the delayed MR images and in 22 patients on the ultradelayed MR images. On the ultradelayed images, peripheral hypointense rim was seen in 12 patients and central focal hypointense area was seen in eight patients. Pathologically, the portion showing delayed enhancement corresponded to abundant fibrous stroma, the hypointense rim to rich proliferation of tumor cells, and the central hypointense areas to coagulative necrosis.

CONCLUSION

Ultradelayed MR imaging can characterize different tissue components within various hepatic tumors.

CTAP in budd-chiari syndrome: evaluation of intrahepatic portal flow

BACKGROUND

To assess the intrahepatic portal flow in patients with Budd-Chiari syndrome (BCS) by computed tomography (CT) during arterial portography (CTAP).

METHODS

Five patients with BCS [with (n = 3) and without (n = 2) inferior vena cava (IVC) obstruction] underwent both CTAP and postcontrast CT following CTAP. CTAP and postcontrast CT after angioplasty were also performed in one patient. Findings on CTAP and postcontrast CT were analyzed retrospectively.

RESULTS

Patients with IVC obstruction and a patent large hepatic vein showed homogeneous hepatic enhancement on CTAP. Patients without IVC obstruction and with no patent large hepatic veins showed heterogeneous hepatic enhancement, which consisted of patchy enhancement and more definite enhancement in the central part of the liver. On postcontrast CT, the patchy enhancement was enlarged compared with that on CTAP in these patients. The heterogeneous hepatic enhancement became homogeneous in the patient who underwent angioplasty.

CONCLUSION

We suggest that the more marked the blood congestion, the more heterogeneous the hepatic enhancement becomes on CTAP. Heterogeneous hepatic enhancement on CTAP is seen in such cases without any patent hepatic veins.

Obstructive jaundice caused by lymphangitis carcinomatosa of bile duct wall from gastric carcinoma

We report a case of advanced gastric carcinoma presenting with obstructive jaundice. Computed tomography showed marked lymphadenopathy in the hepatoduodenal ligament and concentric bile duct wall thickening. Histologically, extrahepatic bile duct wall was thickened due to submucosal lymphangitic spread of gastric carcinoma (lymphangitis carcinomatosa). Lymphangitis carcinomatosa may be considered when extrahepatic bile duct wall thickening is seen in patients with obstructive jaundice.

Biliary cystadenoma with mesenchymal stroma of the liver: correlation between unusual MR appearance and pathologic findings

We reported a case of the biliary cystadenoma of the liver. The cystic mass had lobulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid.

Hypervascular hepatocellular carcinoma: evaluation of hemodynamics with dynamic CT during hepatic arteriography

PURPOSE

To assess the hemodynamics and the main drainage vessel of hypervascular hepatocellular carcinoma.

MATERIALS AND METHODS

Single-level dynamic computed tomography during hepatic arteriography (CTHA) was performed in 32 patients with hepatocellular carcinoma. Carcinoma was confirmed with histologic (n = 9) or clinical (n = 23) examination results. Single-level CTHA findings were retrospectively analyzed. Histologic specimens from 40 livers with hepatocellular carcinoma were also examined, with special attention to vessels along the rim of the lesion.

RESULTS

Contrast material enhancement on single-level CTHA images occurred in four phases: (a) inflow of the contrast material into tumor, (b) tumor enhancement, (c) inflow of the contrast material into adjacent liver, and (d) corona enhancement of adjacent liver. Corona enhancement was seen in all lesions. A bright branching structure in the corona enhancement area, suggestive of a portal venule, was visible at the start of adjacent liver staining in 21 lesions. Continuity between a tumor sinusoid and a tiny vessel in the inner layer of the pseudocapsule was histologically confirmed in 10 of 40 specimens. Continuity between a tiny vessel in the inner layer and a portal vein in the outer layer of the pseudocapsule was confirmed with findings on serial sections from one liver.

CONCLUSION

The main drainage of hepatocellular carcinoma lesions may be a protal venule.

Transjugular intrahepatic portosystemic shunt: histologic and immunohistochemical study of autopsy cases

PURPOSE

To assess the histologic findings associated with stenosed and occluded transjugular intrahepatic portosystemic shunt (TIPS) tracts.

METHODS

Four TIPS tracts within three autopsy livers were histologically studied for vascular components by routine staining and immunohistochemical staining. TIPS had been performed for bleeding from esophageal varices in patients with cirrhosis of the liver.

RESULTS

Two TIPS, examined on days 4 and 53, showed occlusion by fibrin thrombus. In the former, no endothelial cells were detected, but coagulative necrosis of hepatocytes was found in the surrounding liver. In the latter, bile pigments were seen on the luminal surface. In the two other TIPS without tract occlusion, examined on days 49 and 293, a layer of endothelial cells, proliferation of smooth muscle cells, and deposition of an extracellular matrix such as collagen were confirmed. In the tract examined on day 293, there was protrusion of hepatocytes into the lumen through the stent wires.

CONCLUSION

Short- and midterm TIPS occlusions were caused by thrombus forming after necrosis of hepatocytes and bile leakage, respectively. Long-term TIPS stenosis was associated with a combination of pseudointimal hyperplasia and ingrowth of hepatocytes.

Posterior aspect of hepatic segment IV: patterns of portal venule branching at helical CT during arterial portography

PURPOSE

To determine the anatomy of the portal venous system in the posterior aspect of segment IV of the liver by using helical computed tomography (CT) during arterial portography (CTAP).

MATERIALS AND METHODS

One hundred consecutive patients underwent CTAP. Helical CT during hepatic arteriography was performed in 20 patients. In seven patients with hepatocellular carcinoma in the posterior aspect of segment IV, the feeding arteries were also analyzed.

RESULTS

A venule from the intrahepatic portal vein to segment IV was seen in all patients. Other findings included a tiny venule from the distal part of the main left portal vein (n = 36), from the proximal left main portal vein (n = 20), and from the right portal vein (n = 18). Aberrant right gastric venous drainage and/or parabiliary venous drainage directly into the posterior aspect was present in 14 patients. In two patients, a tiny accompanying artery was seen on images from CT during hepatic arteriography. In seven patients with hepatocellular carcinoma, the main feeding artery branched from the right (n = 2) or left (n = 5) hepatic artery.

CONCLUSION

CTAP adequately demonstrates the tiny portal venous and arterial branches from the main right or left portal vein that distribute to the posterior aspect of segment IV. Knowledge of this vascular anatomy is clinically important.

Segmental hyperintensity on T1-weighted MRI of the liver: indication of segmental cholestasis

The purpose of this study was to determine the relationship between segmental hyperintensity of the liver on T1-weighted images and segmental cholestasis in patients with obstructive jaundice. T1-weighted and T2-weighted MR images were obtained of 73 patients with obstructive jaundice caused by various diseases. Fat-suppressed T1-weighted images were also obtained of 10 patients. Eleven patients with segmental intrahepatic bile duct dilatation (cholestasis) showed segmental hyperintensity on T1-weighted images and/or fat-suppressed T1-weighted images and no signal intensity difference on T2-weighted images. Sixty-two patients with widespread intrahepatic bile duct dilatation showed no intensity difference on T1-weighted and T2-weighted images (P < .01). Segmental hyperintensity on T1-weighted images was correlated with intrahepatic cholestasis.

Aberrant gastric venous drainage into the medial segment: demonstration by color Doppler sonography

BACKGROUND

Aberrant gastric venous drainage (AGVD) into the posterior edge of the medial segment of the liver (segment IV) is the main cause of pseudolesion on computed tomography (CT) during arterial portography. We estimated the prevalence of AGVD into the medial segment of the liver with color and power Doppler ultrasound (US).

METHODS

Screening gray-scale and color Doppler and power Doppler US were performed in 100 consecutive patients. AGVD was defined as a venous structure that ascended parallel to the main portal vein and drained independently into segment IV.

RESULTS

AGVDs were observed in eight of 100 patients (8%) with color and power Doppler US. Power Doppler US depicted these veins more clearly than did color Doppler US. Gray-scale US did not show any AGVDs. Two of eight patients with AGVDs detected by color Doppler US underwent celiac arteriography and CT during arterial portography (CTAP). In these two patients, celiac arteriography directly demonstrated AGVDs draining into segment IV, which revealed nontumorous perfusion defects (pseudolesions) on CTAP.

CONCLUSION

Color and power Doppler US are useful imaging methods for demonstrating AGVDs.

Aberrant gastric venous drainage in a focal spared area of segment IV in fatty liver: demonstration with color Doppler sonography

PURPOSE

To clarify the correlation between aberrant gastric venous drainage and a focal spared area at the posterior edge of segment IV in fatty liver by using color Doppler ultrasound (US).

MATERIALS AND METHODS

Seventeen patients with fatty liver were examined with gray-scale, color Doppler, and power Doppler US. In one patient with a focal spared area, arteriography and computed tomography (CT) were performed during injection of contrast medium into the right gastric artery.

RESULTS

Focal spared areas of fatty liver at segment IV were shown in five of 17 patients. In all five patients with a focal spared area, aberrant gastric venous drainage was observed with color Doppler US. Power Doppler US depicted aberrant gastric venous drainage more clearly than color Doppler US. On the other hand, no definite aberrant gastric venous drainage was seen in the 12 patients who had no focal spared area. In one patient who underwent selective arteriography of the right gastric artery and CT arteriography, aberrant gastric venous drainage into segment IV was directly demonstrated.

CONCLUSION

Focal spared areas at segment IV in fatty liver correlate strongly with aberrant gastric venous drainage. Noninvasive imaging methods such as color and power Doppler US are useful for depicting these aberrant drainage veins.

Gallbladder varices: demonstration of direct communication to intrahepatic portal veins by color doppler sonography and CT during arterial portography

Gallbladder varices were correctly diagnosed by color Doppler sonography and computed tomography during arterial portography (CTAP) in two patients with portal vein thrombosis. One patient with multiple hepatocellular carcinomas showed extrahepatic and intrahepatic portal vein occlusion by a tumor thrombus. The other patient, with liver cirrhosis, had a portal vein thrombosis. Color Doppler sonography clearly showed the portal vein occlusion, cavernous transformation of collateral veins, and gallbladder varices that drained into the intrahepatic portal venous branches. The intrahepatic portal venous branch, connecting to the gallbladder varices, exhibited reverse flow from the periphery to the hilum of the liver. CTAP also demonstrated gallbladder varices communicating directly with the intrahepatic portal vein branches in both patients. Gallbladder varices developed as a venous collateral because of extrahepatic portal vein occlusion. Color Doppler sonography and CTAP are useful for detecting these varices and planning biliary surgery in patients with portal vein thrombosis.

Transjugular intrahepatic portosystemic shunt after previous recanalization of a chronically thrombosed portal vein via a transmesenteric approach

We report a cirrhotic patient with complete occlusion of the portal vein with marked cavernous transformation due to chronic thrombosis in whom a transjugular intrahepatic portosystemic shunt (TIPS) was successfully created after direct minilaparotomy mesenteric vein catheterization, lysis and aspiration of the thrombus, and stenting in the portal vein. The methods used, we believe, provide a new technique for performing TIPS in chronically thrombosed portal veins in which previously no effective surgical therapeutic options were available.

Imaging findings of mucinous type of cholangiocellular carcinoma

OBJECTIVE

To demonstrate the imaging findings seen in two cases of mucinous type of cholangiocellular carcinoma of the liver.

MATERIALS AND METHODS

The CT and MR findings of two patients with pathologically proven mucinous type of cholangiocellular carcinoma were analyzed.

RESULTS

One of them showed calcification, both cases had no enhancing on the arterial dominant phase of dynamic CT, but showed enhancement in the periphery and internal septations on the equilibrium phase. The internal signal intensity was homogenous, and extremely hypo- and hyperintense on T1- and T2-weighted images, respectively.

CONCLUSION

Imaging findings were unique reflecting the characteristic pathological features that cancer cell nests are suspended in a large mucinous lake, and the specific diagnosis was considered to be possible by the integrated imaging diagnosis.

Peribiliary cysts in cirrhotic liver: observation on computed tomography

BACKGROUND

To analyze the frequency and number of suspected peribiliary cysts in cirrhotic liver on computed tomography (CT).

METHODS

Three hundred forty-six cases with clinically diagnosed liver cirrhosis (LC) and 307 cases with clinically diagnosed non-LC were subjected to the study. The frequency and number of suspected peribiliary cysts on CT were compared between the two groups. The existence of peribiliary cysts was suggested when a cyst was observed around the second- to fourth-order branches of the intrahepatic portal vein.

RESULTS

Peribiliary cysts were suggested on CT in 31 of 346 cirrhotic livers (9.0%) and 10 of 307 noncirrhotic livers (3.3%). This difference in the frequency of peribiliary cysts was statistically significant (chi2, p < 0.01). Multiple peribiliary cysts were seen in 71% of cirrhotic patients with peribiliary cyst. The size of peribiliary cysts was smaller than 1.5 cm in diameter.

CONCLUSION

Peribiliary cyst is radiologically observed more frequently in cirrhotic liver than in noncirrhotic liver and is occasionally multiple.

Aberrant gastric venous drainage in cirrhotic livers: imaging findings in focal areas of liver parenchyma

PURPOSE

To analyze imaging finding in focal areas of liver parenchyma with aberrant gastric venous drainage (AGVD) in cirrhotic livers.

MATERIALS AND METHODS

Eighteen patients with AGVD confirmed with computed tomography (CT) during arterial portography and arteriography underwent ultrasound (US) (n = 18), CT (n = 18), magnetic resonance (MR) imaging (n = 12), dynamic CT (n = 14), and dynamic MR imaging (n = 8). Imaging and histologic (n = 2) findings were analyzed.

RESULTS

The focal area with AGVD was hypoechoic on US scans (n = 7), hypoattenuating on CT scans (n = 4), hyperintense on T1-weighted MR images (n = 6), and hypointense on T2-weighted MR images (n = 5). Early enhancement was seen with dynamic CT (n = 8) and with dynamic MR imaging (n = 6), without definite staining on arterial phase of arteriography. Histologic findings revealed hyperplastic changes of liver.

CONCLUSION

The imaging findings, except for early enhancement, were very similar to those of adenomatous hyperplasia or well-differentiated hepatocellular carcinoma. The early enhancement was considered due to early venous return compared with that of the surrounding liver.

Successful embolization of a large superior gluteal artery pseudoaneurysm emerging during anticoagulant therapy

Gross hemorrhage is the most serious complication of anticoagulant therapy. We report the discovery and treatment of a large pseudoaneurysm of the superior gluteal artery in one patient who had been receiving oral anticoagulant therapy. We diagnosed the pseudoaneurysm by contrast-enhanced computed tomography, and embolized the artery with stainless steel coils. The exact cause of the pseudoaneurysm remains unclear, however, minor trauma appears most likely.

Peribiliary cysts in liver cirrhosis: US, CT, and MR findings

OBJECTIVE

We report the imaging features of hepatic peribiliary cysts (PC) and the course of their development on CT.

MATERIALS AND METHODS

Both CT and US findings were correlated with histopathologic findings in two patients with PC at autopsy. Five patients with cysts around the portal vein on CT but without histologic correlation were also included in this study. In six patients the course of PC development was observed.

RESULTS

In the two autopsy cases cystic dilatation of the peribiliary glands was confirmed. The cases showed continuous small cysts along the portal veins reflecting the periportal collar seen on CT and the abnormal MR signal intensity of the periportal area. Ultrasound (US) showed round or tubular anechoic lesions around the large portal tracts mimicking dilatation of the bile ducts. Clustered cysts and echogenic dots or bands around PC were also seen. In three of six cases the PCs gradually enlarged and increased in number.

CONCLUSION

In patients with liver cirrhosis PCs can be demonstrated by CT, US, and MRI in the vicinity of the hepatic hilum. Peribiliary cysts enlarge gradually and must be differentiated from dilatation of bile ducts or edema of portal tracts.

Focal sparing of segment IV in fatty livers shown by sonography and CT: correlation with aberrant gastric venous drainage

OBJECTIVE

One of the most common sites of focal sparing in fatty livers (focal spared area) shown by sonography or CT is the posterior edge of segment IV. The differentiation of such a focal spared area from tumor has been a diagnostic challenge. The purpose of this study was to determine if a correlation exists between the focal spared area at the posterior edge of segment IV in fatty liver and the decrease of portal perfusion from the main portal vein due to aberrant gastric venous drainage directed into segment IV.

SUBJECTS AND METHODS

Seventeen patients with fatty liver diagnosed on the basis of sonographic and CT findings who had hepatic arteriography and/or CT during arterial portography (CTAP) were included in the study. Seven patients had a focal spared area more than 2 cm in the longest diameter at the posterior edge of segment IV, and 10 patients did not have a focal spared area. The frequency of aberrant gastric venous drainage shown by arteriography (17 patients) and/or by CTAP (15 patients) was compared in the two groups of patients.

RESULTS

Hepatic arteriography showed aberrant gastric venous drainage in all patients who had a spared area, and CTAP showed a portal perfusion defect at the posterior edge of segment IV in all five patients with a focal spared area who underwent CTAP. On the other hand, no definite aberrant gastric venous drainage and portal perfusion defect were seen in any patient without a spared area. The difference in the frequency of aberrant gastric venous drainage between the two groups of patients was statistically significant (chi-square test, p < .0001).

CONCLUSION

Our results show that a strong correlation exists between the focal spared area at the posterior edge of segment IV in fatty liver and aberrant gastric venous drainage directed to segment IV. Focally decreased blood flow from the main portal vein associated with aberrant gastric venous drainage is a likely cause of the focal spared area. This fact is important for the differential diagnosis of hepatic tumors.