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.

Peliosis Hepatis with Hemorrhagic Necrosis and Rupture: a Case Report with Emphasis on the Multi-Detector CT Findings

We report here on an uncommon case of peliosis hepatis with hemorrhagic necrosis that was complicated by massive intrahepatic bleeding and rupture, and treated by emergent right lobectomy. We demonstrate the imaging findings, with emphasis on the triphasic, contrast-enhanced multidetector CT findings, as well as reporting the clinical outcome in a case of peliosis hepatis with fatal hemorrhage.

Hypervascular Hyperplastic Nodules Appearing in Chronic Alcoholic Liver Disease: Benign Intrahepatic Nodules Mimicking Hepatocellular Carcinoma

PURPOSE: Hypervascular hyperplastic nodules in those patients with chronic alcoholic liver disease and who are hepatitis B and C negative have recently been reported on. The purpose of this study was to correlate the radiologic and pathologic findings with the clinical significance of these hypervascular hyperplastic nodules in chronic alcoholic liver disease. MATERIALS AND METHODS: The study included eight hypervascular nodules of seven patients with chronic alcoholic liver disease, and these patients had abused alcohol for more than 20 years. Eight hypervascular nodules were seen on the arterial phase of dynamic CT scans, but the possibility of HCC was excluded pathologically (n=4) or clinically. The radiologic and pathologic findings, and the changes of these nodules on follow up CT scans were retrospectively analyzed. RESULTS: All nodules showed good enhancement on the arterial phase. The tissue equilibrium phase of the dynamic CT scans showed isodensity in seven patients and low density in one patient. Ultrasound scans revealed hypoechoic findings for three nodules, isoechoic findings for two nodules, hyperechoic findings for one nodule, and two nodules were not detected. Angiograms (n=6) showed late incremental tumor staining, and all the nodules were well seen on the sinusoidal phase. CT during hepatic angiography (n=4) showed well stained tumor. CT during arterial portography (n=4) showed no defect in three nodules and nodular defect in one nodule. The MR images (n=3) showed low signal intensity in two nodules and iso-signal intensity in one nodule on T2WI. Five of six cases for which follow up CT scans were performed showed decrease in size and one was disappeared. CONCLUSION: Radiologically, it is often difficult to differentiate the hypervascular hyperplastic nodules seen in the chronic alcoholic liver disease from hepatocellular carcinoma, and histological confirmation is needed for excluded hepatocellular carcinoma. However, late tumor staining during the sinusoidal phase without any blood supply by feeding vessels or any arterioportal shunt on the angiogram, isodensity during the tissue equilibrium phase of dynamic CT and low signal intensity on T2WI may suggest the presence of hypervascular hyperplastic nodule.

Depiction of Viable Tumor in Hepatocellular Carcinoma Treated with Transarterial Chemoembolization: Multiphasic Helical CT with Review of the Previous Serial CT Images

OBJECTIVE: The purpose of our study was to assess whether a review of multiphasic helical CT combined with the previous serial CT images could be helpful to depict a viable tumor in hepatocellular carcinoma treated with transarterial chemoembolization. MATERIALS AND METHODS: Twenty-four consecutive patients with 35 hepatocellular carcinomas underwent transarterial chemoembolization followed by hepatic resection. First, three radiologists independently analyzed the last CT images taken before resection for the presence of viable tumor. A second analysis was then performed using the last CT combined with the previous serial CT images. The CT analyses were then compared with the pathologic results. The added value of the review of the previous serial CT images was evaluated by performing a receiver operating characteristic analysis. The sensitivity, specificity and diagnostic accuracy for the depiction of viable tumor were also assessed, and the characteristics of the false-negative lesions were pathologically evaluated. RESULTS: The mean diagnostic accuracies (Az values) for the depiction of viable tumor with using the last CT alone and with the review of the previous serial CT images for all observers were 0.885 and 0.901, respectively, which were not significantly difference (p> 0.05). However, the additional review of the previous serial CT images allowed the observers to render a correct diagnosis for three lesions that had been incorrectly diagnosed with the review of last CT alone. The sensitivity, specificity and diagnostic accuracy of the last CT along with the review of the previous serial CT images were 78%, 97% and 84%, respectively. All of the 16 false-negative lesions diagnosed by each observer showed 90% or greater necrosis on the pathologic examination. CONCLUSION: For the depiction of viable tumor in hepatocellular carcinoma treated with transarterial chemoembolization, although the difference in the diagnostic accuracies was not statistically significant, a review of the multiphasic helical CT combined with the previous serial CT images could help reach a correct diagnosis for those lesions incorrectly diagnosed with the review of the last CT alone.

Analysis of the Hepatic Segments on the Isotropic Multi-planar Reformatted CT Images

PURPOSE: We wanted to evaluate the diverse distribution and relation of the hepatic segments, as divided by the portal venous territories, on the isotropic multi-planar reformatted (MPR) CT images and we wanted to find their correlation to the intrahepatic venous structures. MATERIALS AND METHODS: Fifty adult patients who underwent portal phase CT images and who had the normal liver contours at CT were included in our study. The portal phase images were obtained with a slice collimation and reconstruction interval of 1.25 mm, and they were reformatted in the coronal and sagittal planes with a slab thickness of 3 mm. For analysis of these MPR images, various terms were newly defined according to the portal venous territories (e.g., three vertical planes [right, middle and left] and one transverse plane and their plane angles, the transverse and longitudinal angles). Also, the dominant segments of the right lobe were newly divided into the S7- and S8-dominant types by comparing the transverse angles. The imaging analysis was then conducted for the following: (1) the diversity of the three vertical planes and the one transverse plane and their plane angles, (2) the proportion of the dominant segments of the right lobe and their relation with the plane angles, and (3) the correlation between the dominant segments and the intrahepatic venous structures. RESULTS: The number of the S7- and the S8-dominant types was 21 and 29, respectively. The vertical and transverse planes were undulating and diverse according to the dominant segments as follows: the plane angles of the right vertical and middle vertical planes were more vertical in the S7-dominant type than in the S8-dominant type (p < 0.001). The right transverse plane angle was more horizontal in the S8-dominant type (p < 0.05). The left transverse plane angle seemed to be rather vertical than horizontal. For the intrahepatic venous structures, despite of our limited data, the anomalous intrahepatic venous structures might have some correlation with the dominant segments. CONCLUSION: According to our results, we suggest that the isotropic MPR images could successfully depict the vertical and transverse planes of the real hepatic segments, as divided by the portal venous territories, which were diverse according to their dominant types.

Hepatic Perfusion Disorders: A Pictorial Review of CT and MR Imaging

The liver has a unique dual blood supply through the portal vein and the hepatic artery. There are several communications between these two vessels under various conditions such as in hepatic tumors, trauma and liver cirrhosis, vascular compromise, among others. When vascular compromise occurs, this dual blood supply system can cause changes in the volume of blood flow in individual vessels or even in the direction of blood flow. With rapid image acquisition and increased resolution available in multislice CT and MR imaging, hepatic perfusion disorders are now more frequently encountered than in the past. Familiarity with imaging findings of these perfusion disorders will be helpful in characterizing focal hepatic lesions and will also help to avoid false positive diagnoses.

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.

Atypical Hepatic Hemangiomas with Multiple Calcifications Mimicking Hepatic Metastases: Case Report

Although hepatic hemangioma is the most common benign tumor of the liver, it is rarely associated with calcifications. We report on the case of an asymptomatic 58-year-old man in whom multiple hepatic masses containing calcifications were discovered incidentally at ultrasonography. The radiologic features mimicked those of multiple hepatic metastases.

Multi-Slice Spiral CT of Living-Related Liver Transplantation in Children: Pictorial Essay

In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three-dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection.

Hepatic CT Enhancement: Comparison between Dimeric and Monomeric Nonionic Contrast Agents in Rabbits

PURPOSE: To determine the hepatic and vascular enhancement profiles with nonionic dimeric, iodixanol, contrast agent in the rabbit and to compare them with nonionic monomeric, ioversol, contrast agent. MATERIALS AND METHODS: Seven rabbits initially underwent hepatic dynamic CT scan with either iodixanol or ioversol, followed by repeated CT scan with other unused contrast agent with one week interval between scans. Pre and post contrast attenuation values of hepatic parenchyma, aorta and portal vein were measured sequentially. The mean enhancement of the hepatic parenchyma, aorta and portal vein were compared between two agents. The mean peak enhancement and peak enhancement time of the liver, aorta, and portal vein were also compared. RESULTS: The attenuation values of ioversol showed a greater mean hepatic enhancement than iodixanol from 18 seconds to 39 seconds after injection (from late arterial phase to early portal venous phase) with a statistical significance (p<0.05). The mean peak enhancement of hepatic parenchyma, aorta and portal vein was also greater using ioversol than iodixanol, but the mean peak enhancement times of ioversol and iodixanol were nearly identical. CONCLUSION: Ioversol may have the greater effects than iodixanol on hepatic tumor conspicuity, especially from late arterial phase to early portal veneous phase.

Detection of Small Hypervascular Hepatocellular Carcinomas in Cirrhotic Patients: Comparison of Superparamagnetic Iron Oxide-Enhanced MR Imaging with Dual-Phase Spiral CT

OBJECTIVE: To compare the performance of superparamagnetic iron oxide (SPIO) -enhanced magnetic resonance (MR) imaging at 1.5T and dual-phase spiral computed tomography (CT) for the depiction of small hypervascular hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Forty-three patients with 70 small nodular HCCs (5-20 mm; mean, 13.7 mm) were examined. Diagnosis was based on the results of surgical biopsy in 22 patients and by the combined assessment of MR imaging, lipiodol CT, alpha feto-protein levels, and angiographic findings in 21. MR imaging consisted of respiratory-triggered turbo spin-echo T2-weighted imaging, T1-weighted fast low-angle shot, and T2* -weighted fast imaging with steady-state precession imaging before and after SPIO enhancement. CT imaging was performed with 5-mm collimation and 1: 1.4 pitch, and began 30 and 65 secs after the injection of 150 mL of contrast medium at a rate of 3 mL/sec. Two blinded observers reviewed all images independently on a segment-by-segment basis. Diagnostic accuracy was evaluated using receiver operating characteristics (ROC) analysis. RESULT: The mean areas (Az) under the ROC curves were 0.85 for SPIOenhanced MR imaging and 0.79 for dual-phase spiral CT (p .05). CONCLUSION: SPIO-enhanced MR imaging is more sensitive than dual-phase spiral CT for the depiction of small hypervascular hepatocellular carcinomas.

Focal Nodular Hyperplasia with Retraction of Liver Capsule: A Case Report

Focal nodular hyperplasia (FNH) is characterized by the presence a central scar with radiating fibrous septa. Our case had a capsular retraction, which was the result of an extension of the central scar to the surface. In addition, a hypointense scar on the T2-weighted image and a minimal enhancing central scar on the enhanced T1-weighted image, which was due to dense, sclerotic collagenous tissue, were observed. We report the first case of FNH with a capsular retraction.

Multidetector-row CT Angiography of Hepatic Artery: Comparison with Conventional Angiography

PURPOSE: To determine the usefulness of three-dimensional CT angiography using multidetector-row CT (MDCT) for delineating the arterial anatomy of the liver. MATERIALS AND METHODS: Hepatic arterial three-dimensional CT angiography was performed using MDCT (Lightspeed Qx/I; GE Medical Systems, Milwaukee, Wis., U.S.A.) in 45 patients with HCC undergoing conventional angiography for transcatheter hepatic arterial chemoembolization. The scanning parameters during the early arterial phase were 2.5 mm slice thickness, 7.5 mm rotation of table speed, and a pitch of 3. Images were obtained by one radiologist using maximum intensity projection from axial CT images obtained during the early arterial phase. Two radiologists blinded to the findings of conventional angiography independently evaluated the hepatic arterial anatomy and the quality of the images obtained. RESULTS: Compared with conventional angiography, reader A correctly evaluated the hepatic arterial anatomy depicted at three-dimensional CT angiography. Reader B's evaluation was correct in 40 of 45 patients. Interobserver agreement was good (kappa value, 0.73), and both readers assessed the quality of three-dimensional CT angiography as excellent. CONCLUSION: Three-dimensional CT angiography using MDCT was accurate for delineating the arterial anatomy of the liver, and interobserver agreement was good. The modality may provide, prior to conventional angiography, valuable information regarding a patient's hepatic arterial anatomy.

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.

Focal Eosinophilic Necrosis of the Liver in Patients with Underlying Gastric or Colorectal Cancer: CT Differentiation from Metastasis

OBJECTIVE: To determine the helical CT findings which help differentiate between focal eosinophilic necrosis (FEN) of the liver and metastasis in patients with underlying gastric or colorectal cancer. MATERIALS AND METHDOS: In 21 patients with underlying gastric and colorectal cancer examined during a recent 18-month period, the presence of FEN (n=90) was proven at CT. The diagnosis was verified by biopsy in eight patients and by the transient nature of the findings related to peripheral eosinophilia (>10%) in the remainder. For comparison, 20 consecutive patients with pathologically proven hepatic metastasis from gastric or colorectal cancer (n=158) were selected. Single-phase helical CT images (7-mm collimation, pitch 1:1) were independently analyzed in a random order by two blinded readers. The parameters evaluated included the margin (depicted border, fuzzy), shape (spherical, non-spherical), attenuation (subtle hypoattenuation, hypoattenuation), and the presence or absence of rim enhancement. RESULTS: FEN far more frequently showed a fuzzy margin (81%, 84%), subtle hypoattenuation (89%, 91%), and a non-spherical shape (84% for both readers) than metastasis, for which the respective findings were 6%, 22%; 20%, 39%; and 15%, 23%. Rim enhancement was seldom found in FEN (0%, 2%), but was recognized by both readers in 40% of metastases. For all parameters, the results were statistically significant (p < .01), and showed that both readers correctly differentiated FEN from metastasis in 78% of the patients (32/41). Interobserver agreement was, in addition, excellent (K= 0.66). CONCLUSION: When focal hepatic lesions with a fuzzy margin, non-spherical shape and subtle hypoattenuation without rim enhancement are found, the possibility of FEN should be considered even in patients with underlying gastrointestinal malignancy.

CT Numbers of Liver and Spleen in Normal Children

PURPOSE: To determine the mean liver CT numbers, and differences between liver and spleen, and liver and back muscle CT numbers in normal children, and to correlate the findings with sex and age. MATERIALS AND METHODS: One hundred and five normal children aged 2-14 years underwent pre-contrast CT scanning. Mean CT numbers of the liver, spleen, and back muscles were calculated, as well as the differences in CT numbers between the liver and spleen (liver-spleen CT numbers), and between the liver and back muscles (liver-back muscles CT numbers). The results were correlated with age and sex. RESULTS: For all children, mean liver, spleen, and back muscle, and liver-spleen and liver-back muscle CT numbers were 70.22+/-6.51 HU, 53.28+/-3.0 HU, 58.31+/-3.57 HU, 17.13+/-6.57 HU, and 11.88+/-5.94 HU, respectively. Mean liver CT numbers and the difference between liver and spleen CT numbers were high in children aged less than seven, bet mean spleen and back CT numbers, and the difference between liver and back muscle CT numbers were not different by age. By sex, all the CT numbers did not vary according to age. The sex of a subject did not affect the CT number. CONCLUSION: The children's mean liver CT number was 70.22+/-6.51 HU and the difference between liver and spleen CT numbers was 17.13+/-6.57 HU. Younger children had higher liver CT and liver-spleen CT numbers than older children. No CT numbers varied according to sex.

Detection of Hepatocelluar Carcinoma on Triple-Phase Images of Liver Using Multi-Detector Row Helical CT

PURPOSE: To determine whether triple-phase multi-detector-row helical CT images of the liver improves the detection rate of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty-one patients with 103 HCCs underwent triple-phase multi-detector-row helical CT imaging of the entire liver after contrast administration. Early and late arterial phase images were obtained serially during a single breath-hold, and portal venous-phase images were then obtained. Each image set was independently assessed for the presence of HCC by two radiologists unaware of the possible presence of tumors, and for each phase the detection rate was determined. For each arterial-phase image, lesion conspicuity (attenuation of a tumor compared with that of its parenchyma) was calculated. RESULTS: For reader 1, the detection rates for the early arterial, late arterial, and portal venous phase were 81%, 77%, and 55%, respectively, and for reader 2 were 83%, 81%, and 68%, respectively (p>0.05). When triplephase imaging findings were combined, the detection rate was significantly higher than when only those of the early or late arterial, and portal venous, phase were used (p0.05). CONCLUSION: Triple-phase imaging of the liver, involving the early arterial, late arterial, and portal venous phase, and using multi-detector-row helical CT, increases the detection rate of HCC.

Hepatic Arterioportal Shunts: Dynamic CT and MR Features

With the increased temporal resolution available in dynamic computed tomography (CT) and magnetic resonance imaging (MRI), hepatic arterioportal shunts are now more frequently encountered than in the past. The condition occurs in various hepatic diseases in which portal or hepatic venous flow is compromised. The underlying mechanism and the degree of shunt affect its appearance at dynamic imaging. The dynamic CT and MRI findings have been summarized as early enhancement of peripheral portal veins, and wedge-shaped transient parenchymal enhancement during the hepatic arterial phase. Recognition of arterioportal shunt can suggest the presence of a previously unsuspected disorder and avoids false-positive diagnosis or overestimation of a hepatic disease. Familiarity with the pathophysiology of arterioportal shunt also allows investigation of the hepatic hemodynamic changes occurring in various hepatic diseases.