Intrahepatic Portosystemic Venous Shunt Presenting as a Cystic Mass in a Patient without Liver Cirrhosis: A Case Report

Intrahepatic portosystemic shunt is a rare disease that requires an accurate diagnosis because the lesion may be associated with hepatic encephalopathy and an invasive and expansive examination might be unnecessarily conducted. A cystic mass on an ultrasound examination in a patient without liver cirrhosis was diagnosed as an intrahepatic portosystemic venous shunt by using color Doppler imaging and computed tomography. We report here on the radiologic features of a congenital intrahepatic portosystemic venous shunt in a noncirrhotic liver.

Saccular Aneurysm of Intraheparic Portal Vein Mimicking Hypervascular Hepatic Mass: A Case Report

A portal vein aneurysm is divided into two groups; an extrahepatic portal vein aneurysm and an intrahepatic portal vein aneurysm. The morphology of an aneurysm can be divided into types such as fusiform, bilobulated and saccular. A saccular aneurysm that arises from the intrahepatic portal branch is extremely rare. We report here a case of a saccular aneurysm of the intrahepatic portal branch mimicking an intrahepatic hypervascular mass, as seen on a dynamic CT scan, with the radiological findings.

Usefulness of High-Frequency Compound Spatial Sonography in the Assessment of Hepatitis B Virus Related Chronic Liver Disease

PURPOSE: To evaluate the liver parenchyma according to the echo patterns of CSS (compound spatial sonography), and to correlate them with the extent of hepatic fibrosis and the serum aminotransferase level. MATERIALS AND METHODS: The CSS images were classified into the following three echo patterns: type I, a normallooking echo; type II, hyperechoic or hypoechoic nodules scattered in a normal-looking echo; type III, a severely heterogeneous echogenic or hypoechoic honeycomb-like echo. The CSS findings were correlated with the histopathology findings in 63 patients with HBV. The serum aminotransferase levels and the occurrence of acute exacerbation in 168 patients with HBV, with and without a progressed parenchymal echo pattern, and who were followed up more than 1-year period, were compared. The interobserver agreement between the two radiologists for assessing the parenchymal echo pattern was scored. RESULTS: The correlation between the CSS pattern and hepatic fibrosis was statistically significant (correlation coefficient = 0.58, p < 0.05). The baseline serum aminotransferase level was not significantly different between the patients with and without a progressed parenchymal echo pattern. However, the rate of acute exacerbation was higher in patients with a progressed parenchymal echo pattern (p < 0.05). The interobserver agreement was good (k statistic = 0.63, 0.78). CONCLUSION: The liver parenchymal pattern based on the 5-12 MHz CSS is a useful and objective tool for diagnosing and monitoring HBV related chronic liver disease.

Focal Sparing of the Fatty Liver Caused by a Nontumorous Arterioportal Shunt

We present two cases of focal fatty sparing caused by a nontumorous arterioportal shunt. Two patients underwent ultrasonography (US) as a part of routine medical screening, which revealed a hypoechoic lesion in the diffuse fatty liver. Each lesion appeared to be an arterioportal shunt on triphasic mutidetector computed tomography (CT) and was seen as being slightly hyperdense on noncontrast CT. No tumors were delineated around or within the arterioportal shunt. Both lesions remained unchanged on six-month follow-up US.

Intrahepatic Cholangiocarcinoma with Sarcomatous Change: Case Report

Cholangiocarcinomas have several histologic types, but intrahepatic cholangiocarcinoma with sarcomatous change is rare. A 71-year-old man was admitted to our hospital because of fever which had lasted two months. Ultrasonography (US) of the upper abdomen demonstrated a huge hepatic mass with central solid and peripheral cystic portions, and computed tomography (CT) revealed a heterogeneous hepatic mass with a central area in which enhancedment was delayed. Magnetic resonance imaging (MRI) disclosed a huge mass of predominantly low signal intensity at T1WI, and peripheral portions of high signal intensity and a central portion of intermediate signal intensity at T2WI. The pathologic diagnosis was cholangiocarcinoma with sarcomatous change.

Focal Hepatic Lesions: Contrast-Enhancement Patterns at Pulse-Inversion Harmonic US using a Microbubble Contrast Agent

OBJECTIVE: To analyze the contrast-enhancement patterns obtained at pulseinversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. MATERIALS AND METHODS: We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HCC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. RESULTS: Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral nodular enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. CONCLUSION: Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

Hypereosinophilic Syndrome with Hepatic Involvement in a Young Child

Hypereosinophilic syndrome, whose etiology is unknown, involves the infiltration of various organs by a large number of eosinophils. The sites of involvement are the heart, skin, lung, liver, nervous system, and gastrointestinal tract. The disorder occurs mostly in middle-aged men and is characterized by striking peripheral eosinophilia. There have been few reports of hypereosinophilic syndrome in patients younger than 15 years and the disease also shows a predilection for males. We report a case of hypereosinophilic syndrome with hepatic involvement in a 17-month-old girl, and correlate the imaging features with the pathologic findings.

The Detectability of Hepatic Metastases in Candidates of Radiofrequency Ablation: Comparison for Helical CT Scanning and Late-Phase Pulse-Inversion Harmonic Imaging

PURPOSE: To compare dual-phase helical CT and pulse inversion harmonic US using microbubble contrast agents in the detection of hepatic metastases prior to radiofrequency (RF) ablation. MATERIALS AND METHODS: Twenty-one patients in whom hepatic metastases from colorectal cancer had been diagnosed by dual-phase CT scanning and who were considered to be candidates for RF ablation underwent pulse-inversion barmonic US examination. Images were obtained 5 minutes after the bolus injection of microbubble contrast agent SH U 508 A (4.0 g, 300 mg/mL). The number of metastatic tumors revealed by CT and US was determined, and the findings were statistically analysed. The influence of the results of US examination on treatment planning was also evaluated. RESULTS: In 21 patients, 48 metastatic lesions were detected by helical CT, and 56 lesions by US. These eight additional lesions revealed by US occurred in six patients (29%), and their diameter was 3-13 (mean, 7.2) mm. In three of these patients, RF ablation could not be performed, while in the other three, the additional lesions were ablated. CONCLUSION: Pulse-inversion harmonic US imaging using microbubble contrast agents may depict small hepatic metastatic tumors that were not apparent at CT. US-therefore appears to be useful in the planning of treatment prior to the RF ablation of hepatic metastases.

Nodular Regenerative Hyperplasia of the Liver in an Infant: Case Report

Nodular regenerative hyperplasia (NRH) of the liver is an uncommon disease entity, especially in the pediatricage group. A few cases have been reported in the radiologic literature, but follow-up imaging studies are rare. We describe a case of NRH, diagnosed by ultrasound-guided needle biopsy, in a seven-month-old infant with cri-du-chat syndrome. Initial ultrasound revealed several small hypoechogenic nodules in the liver, but CT and MR failed to demonstrate their presence. Two follow-up sonographic examinations were performed 7 and 20 months later, revealing increases in the size and number of the nodules.

Peribiliary Cysts with Intrahepatic Bile Duct Obstruction: A Case Report

Peribiliary cysts involve cystic dilatation and necroinflammatory change in the peribiliary glandular tissue of the larger biliary tree in association with portal hypertension or severe hepatobiliary disease. They are usually asymptomatic and found incidentally. However, rare cases causing symptoms or the mass effect of bile duct compression require differential diagnosis. They may be benign or malignant lesions resulting from narrowing of the bile duct and involving dilatation of the proximal intrahepatic bile duct. We recently encountered a case of peribiliary cysts associated with intrahepatic duct dilatation, and confirmed by surgery, and present the imaging and pathologic findings. Sonography and CT revealed the presence of multiple cystic lesions along the hepatic hilum, and the larger left portal tract and left intrahepatic ducts were dilated. Histopathologic examination indicated that the cysts were compressing the central bile duct.

Peripheral Cholangiocarcinoma: Radiologic Significance of Hypoechoic Halo Sign on Sonography

PURPOSE: To determine the prevalence and characteristics of the hypoechoic halo sign in peripheral cholangiocarcinoma. MATERIALS AND METHODS: Seventeen sonograms of 17 patients with peripheral cholangiocarcinoma histologically proven by either percutaneous needle biopsy (n=16) or surgical biopsy (n=1) were retrospectively reviewed. The size, margin, homogeneity and internal echogenicity of the masses as well as their peritumoral ductal dilatation and intratumoral calcification were ascertained, and the presence of a hypoechoic halo, and if present, its thickness and type, were also determined. We arbitrarily defined a 'thin' and 'thick' halo respectively, as one with a thickness less than of less than 3 mm, and 3 mm or more, and classified halos as 'intratumoral', 'extratumoral', or 'mixed'. RESULTS: Tumor diameter ranged from 4 to 13.5 (mean, 7.3) cm, and the margin was well-defined in 15 cases (smooth: n=2; lobulated: n=13) and irregular in two. Echogenicity was slightly heterogeneous in 11 cases, severely heterogeneous in three, and homogeneous in three, while the central portion was hyperechoic in eight cases, isoechoic in seven, and hypoechoic in only two. A hypoechoic halo was detected in 10 of 15 tumors(67%) with isoechoic centers. In evaluating the halo, two cases in which the mass was hypoechoic were excluded. All ten hypoechoic halos were at least 3 (range, 4-13; mean, 8.3) mm thick; in two cases the presence of a halo was equivocal, and in three there was no halo. Eight of ten halos were the mixed type, two were intratumoral, and none were extratumoral. Peritumoral ductal dilatation was seen in four cases (24%), but no internal calcification was observed. CONCLUSION: US showed that the margins of peripheral cholangiocarcinomas were mostly well-defined and smooth (12%) or lobulated (76%), and that masses were mainly heterogeneous (64%). A hypoechoic halo, which in all cases was thick and in 80% of cases was mixed, was noted in 67% of tumors with a hyper (47%) or isoechoic (41%) center. A halo of this kind may be useful in isoechoic mass detection and also in the differentiation of hyperechoic peripheral cholangiocarcinoma from hepatic hemangioma, the most common hyperechoic benign tumor.

Usefulness of High-Resolution Sonography for Assessement of Hepatocellular Carcinoma in the Transgenic Mice Expressing Hepatitis B Virus X-protein: A Preliminary Study

PURPOSE: To determine the value of high resolution ultrasonography (US) for the detection of hepatocellular carcinoma in the HBx transgenic mice. MATERIALS AND METHODS: Forty-two HBx transgenic mice aged 8-20 (mean, 14) months underwent high-resolution ultrasound using a 10 -12 MHz linear transducer. US findings indicating the presence or absence, number, size and echogenicity of each hepatic tumor were analyzed, and inaddition, color or power Doppler US was used to analyse tumoral vascularity. In each animal, sacrificed less than five hours after US examination, sonographic and pathologic findings were correlated. RESULT: On gross pathologic examination, 20 hepatocellular carcinomas measuring 1.5 -15 (mean, 4.7) mm in diameter were found in 16 mice; US revealed that 17 of the tumors were homogeneous hypoechoic nodules. With regard to tumor detection, sensitivity was 85%, specificity 96%, positive predictive value 0.944, negative predictive value 0.897, and overall accuracy 90%. Doppler US revealed that in three nodules, intratumoral vessels were present. Inthe other 26 mice, gross examination showed that no mass was present; microscopically, however, four nodules measuring 0.3 -1.2 mm were found in four of these animals. Tumoral vascularity detected by color Doppler US corresponded to the intratumoral vessel within the nodules. One peritoneal nodule, confirmed as a metastatic tumor, was found at the greater omentum. CONCLUSION: In HBx transgenic mice, high-resolution US is valuable for the detection of hepatocellular carcinoma.

Ultrasonographic Classification of Atypical Hepatic Hemangiomas

Cavernous hemangioma is the most common benign hepatic tumor. Typically, the most common features revealed by ultrasound(US) include its small size(4cm or less in diameter), uniform hyperechogenicity, welldefined margins, position in the subcapsular region of the right lobe of the liver, and some posterior echo enhancement. In addition, follow-up scanning may reveal changes in size, though this is rare. The US findings of hepatic hemangiomas may vary, however, especially when lesions are large and/or multiple. For that reason, differential diagnosis between this condition and hepatocellular carcinomas, metastatic lesions, lymphomas and other tumors is difficult. An understanding of the various sonographic findings of hepatic hemangioma can facilitate the early detection of the condition.

Post-operative Imaging of Living Related Liver Transplantation in Pediatric Patients

PURPOSE: The purpose of this study was to evaluate the findings and significance of postoperative imaging after living related liver transplantation (LRLT) in pediatric patients. MATERIALS AND METHODS: We retrospectively reviewed all imaging findings, including those of post-LRLT ultra-sonography (US) and computed tomography (CT), in 20 children who had undergone LRLT at our institute. RESULTS: Postoperative findings on US and CT were perihepatic or subcapsular fluid collection (60%), periportal edema (35%), anastomotic narrowing of the IVC (10%), biliary stricture (5%), and focal hepatic infarction (5%). Liver biopsy was performed in nine patients in whom rejection was clinically suspected, and pathologic examination revealed acute rejection in five. US and CT revealed perihepatic fluid collection in one of these, periportal edema and fluid collection in two, and normal findings in two. CONCLUSION: An understanding of the various postoperative findings after LRLT is helpful for accurate diagnosis and appropriate decisions regarding the preservation of normal graft function.

Post-operative Imaging of Living Related Liver Transplantation in Pediatric Patients

PURPOSE: The purpose of this study was to evaluate the findings and significance of postoperative imaging after living related liver transplantation (LRLT) in pediatric patients. MATERIALS AND METHODS: We retrospectively reviewed all imaging findings, including those of post-LRLT ultra-sonography (US) and computed tomography (CT), in 20 children who had undergone LRLT at our institute. RESULTS: Postoperative findings on US and CT were perihepatic or subcapsular fluid collection (60%), periportal edema (35%), anastomotic narrowing of the IVC (10%), biliary stricture (5%), and focal hepatic infarction (5%). Liver biopsy was performed in nine patients in whom rejection was clinically suspected, and pathologic examination revealed acute rejection in five. US and CT revealed perihepatic fluid collection in one of these, periportal edema and fluid collection in two, and normal findings in two. CONCLUSION: An understanding of the various postoperative findings after LRLT is helpful for accurate diagnosis and appropriate decisions regarding the preservation of normal graft function.

Liver Hmangioma: Comparison of Echogenecity and Contrast-enhancement on Dynamic MRI

PURPOSE: To evaluate the differences in sonographic appearance and hemodynamics between hypoechoic andhyperechoic hemangioma. MATERIAL AND METHOD: We retrospectively reviewed the sonographic appearance and MRIfindings of 23 hypoechoic hepatic hemangiomas in 16 consecutive patients. Nine were men and seven were women, witha mean age of 50 years(range, 40-72). We analyzed the sonographic appearance such as size, shape, border,echogenecity, posterior acoustic enhancement and the presence of fatty liver, and MRI findings such as signalintensity, enhancement pattern. For comparison, we also reviewed the sonographic appearance and MRI findings of 23hyperechoic hemangiomas in 16 randomly selected patients. RESULTS: There were no differences in size, shape,incidence of posterior acoustic enhancement, MR signal intensity or enhancement pattern between hypoechoic andhyperechoic hemangiomas(p>0.05, Chi-square). However, fatty infiltration of the liver and echogenic rim of themasses were more commonly seen in hypoechoic hemangiomas(9:1, 5:0, respectively, p<0.05). CONCLUSIONS: There wereno differences in MR enhomcement pattern or incidence of posterior acoustic enhancement between hypoechoichyperechoic hemangioma. The vascularity of a mass therefore seems to contribute little to its echogenecity.

Ultrasonographic and CT Findings of Hepatosplenic Tuberculosis

PURPOSE: To evaluate the ultrasonographic and CT findings of hepatosplenic tuberculosis MATERIALS AND METHODS: We retrospectively reviewed the ultrasonographic and CT findings of confirmed hepatosplenic tuberculosis in 12patients. Six were men and six were women ; their average age was 41, and most were in their twenties. Lesions ofthe liver and spleen, as well as associated findings such as abdominal tuberculosis and other organ involvement oftuberculosis were analyzed. RESULTS: There were three cases of hepatic tuberculosis, seven of splenictuberculosis, and two of hepatosplenic involvement of tuberculosis. On the basis of the ultrasonographic and CTfindings, hepatosplenic tuberculosis was classified as one of two patterns : miliary or micronodular, ormacronodular. The micronodular type was more common (9/12 cases) being characterized by innumerable micronodules,and with easy coalescence in the liver and spleen in five of the nine cases. The macronodular type of low densitymass was noted in the other three patients. Splenomegaly was noted in 12 cases and hepatomegaly in ten. Pulmonarytuberculosis-including the miliary type(n=5)-was noted in eight patients. Associated abdominal tuberculosis suchas lymphadenopathy with central low density and peripheral rim enhancement (n=6), tuberculous peritonitis(n=3),highly attenuated ascites(n=6), adrenal tuberculosis(n=1), renal tuberculosis(n=1), ovarian abscess(n=1), psoasabscess(n=1), and systemic tuberculosis such as central nervous system tuberculoma(n=2), cervicallymphadenopathy(n=4) and tuberculous spondylitis(n=1) were noted. CONCLUSION: Ultrasonography and CT werevaluable in the detection and diagnosis of hepatosplenic tuberculosis

Sclerosing Hepatocellular Carcinoma: Case Report

Sclerosing hepatocellular carcinoma is a rare primary hepatocellular neoplasm which is not associated with hepatitis type B and liver cirrhosis. It is characterized by intense fibrosis in which the tubular neoplastic structures are embedded. The authors report a case of sclerosing hepatocellular carcinoma which mimics hemangioma or hypervascular metastatic tumor and on sprial CT shows early enhancement of the cellular component and delayed enhancement of the fibrotic component.

Hypereosinophilic Syndrome with Hepatic Involvement: US, CT and MRI Findings

PURPOSE: To evaluate the findings of US, CT and MRI in the hepatic involvement of hypereosinophilic syndrome. MATERIALS AND METHODS: We reviewed imaging findings of hypereosinophilic syndrome with hepatic involvement innine patients. Imaging studies were US(n=9), conventional CT(CCT, n=6), dynamic incremental CT(DICT, n=3), and MRIwith conventional spin-echo sequence(MRI-CSE, n=3). For DICT, we obtained images of the early arterial phase(n=1),portal venous phase(n=3) and the late venous phase(n=3). T1WI were obtained with 600-700 msec/13-17 msec(TR/TE) and T2WI were obtained with 1850-2300 msec/80-90 msec(n=3). Gadolinium enhanced T1WI were also obtained(n=2). RESULTS: US showed multiple hypoechoic or isoechoic nodules(7/9) and appeared normal(2/9). CCT showed multiplehypodense nodules(5/6) and appeared normal(1/6). DICT showed patchy, multiple hypodense nodules and showed hepaticnodules during the portal venous phase only(3/3). MRI-CSE showed one to several focal high-signal nodules on T2WIand subtle low-signal nodules on T1WI(2/3), and showed several subtle high-signal lesions on Gd-enhanced T1WI(1/2)and appeared normal on T1, T2WI(1/3). CONCLUSION: Hepatic involvement of hypereosinophilic syndrome showed varied imaging findings on US, CT and MRI.