Surrounding Liver Parenchyma Research Articles

Superparamagnetic iron oxide–enhanced magnetic resonance images of hepatocellular carcinoma: Correlation with histological grading

Superparamagnetic iron oxide (SPIO)–enhanced magnetic resonance (MR) imaging has been used for the detection of hepatic tumors. However, little is known about this technique in relation to hepatocellular carcinoma (HCC). The aim of this study was to investigate whether SPIO–enhanced MR imaging can be useful in assessing histological grades of HCC. The authors studied histologically proven tumors including 31 HCCs and 6 dysplastic nodules. The ratio of the Kupffer-cell count in the tumorous tissue relative to that in the nontumorous tissue (Kupffer-cell–count ratio) decreased as HCCs became less well differentiated. The ratio of the intensity of the tumorous lesion to that of the nontumorous area on SPIO–enhanced MR images (SPIO intensity ratio) correlated inversely with Kupffer-cell–count ratio in HCCs and dysplastic nodules (r = −.826, P < .001) and increased as the degree of differentiation of HCCs decreased, indicating that the uptake of SPIO in HCCs decreased as the degree of differentiation of HCCs declined. All of the dysplastic nodules and some well-differentiated HCCs showed hypointense or isointense enhancement, relative to the surrounding liver parenchyma, indicating greater or similar uptake of SPIO in the tumor when compared with nontumorous areas. These results suggest that SPIO–enhanced MR imaging reflects Kupffer-cell numbers in HCCs and dysplastic nodules, and is useful for estimation of histological grading in HCCs, although uncertainties persist in differentiating dysplastic nodules from well-differentiated HCCs. (Hepatology 2000;32:205-212.)

Prognostic value of estrogen receptor concentrations in hepatocellular carcinoma and the surrounding liver parenchyma

The role of estrogen receptor (ER) in hepatocellular carcinoma (HCC) and the surrounding liver is not fully clarified. This study included 79 patients who had undergone curative hepatic resection between 1983 and 1991. ER concentrations were measured by a binding assay method for 79 HCCs and 49 surrounding liver tissues. The ER status in tumor and liver was retrospectively analyzed in terms of clinicopathological factors and intrahepatic recurrence (IHR) of the tumor. ERs were found in 24 (30%) of 79 HCC samples and in 26 (53%) of 49 liver samples, averaging 1.77±4.07 (range 0–25.6) and 2.51±3.57 (range 0–18.6) fmol/mgp, respectively. There were three types of changes in the tumor ER contents as compared to the surrounding liver. The tumor ER contents were unchanged in 39% (19/49) where ER was undetectable in both tumor and the surrounding liver. A decrease in the tumor ER contents was found in 45% (22/49), while the remaining 16% (8/49) had an increase in the tumor ER concentrations. There were no significant differences in the clinicopathological data between ER-positive and ERnegative HCCs. Although the patients in the last group had the poorest IHR-free survival rate, the multivariate analysis with Cox proportional hazard model could not identify ERs in HCC and the surrounding liver to be independent prognostic factors for IHR-free survival. The tumor ER contents can decrease, increase or remain unchanged. However, the majority of HCCs lack ERs. Estrogens may not be involved in tumor development in cases in which the liver has already lost ER. ERs in HCC or liver may not be a useful prognostic indicator after curative hepatic resection.

Intraarterial infusion chemotherapy with lipiodol-CDDP suspension for hepatocellular carcinoma.

To quantitatively evaluate the usefulness of lipiodol-CDDP suspension (LCS) chemotherapy in hepatocellular carcinoma (HCC). CDDP (cis-diamminedichloroplatinum) powder was prepared by removing the water and NaCl from aqueous CDDP. Two quantities of prepared CDDP powder, 10 mg and 20 mg, were mixed with 1 ml each of iopamidol 300 mgI/ml (IP300) and lipiodol (LPD) using a high pressure pumping method, thus producing LCS. Thirty-two patients with HCC, who had good renal function [creatinine clearance (Ccr) 50 ml/min or more], received additional intraarterial infusion chemotherapy with LCS or LCS alone. The most frequently observed CDDP powder sizes were 5.95-10.90 microm (average: 11.59 microm). The LCS obtained demonstrated a suspension of 2-12 microm (average 3.69 microm) immediately after mixing, and no significant changes were observed in LCS particle sizes 3 hr after mixing. Moreover, the sustained release with LCS was observed for up to 3 hr. Meanwhile, the peripheral free platinum concentration between intraarterial infusion chemotherapy with LCS and intraarterial infusion with the aqueous solution of CDDP, with respect to variance residence time (VRT), showed a significant difference, with a p value of 0.0382. The survival rate was 89.84% at 1 year, 73.78% at 2 years, and 68.51% at 3 years. Furthermore, the platinum concentration in the tumor was 25-95 times the concentration in the surrounding liver parenchyma. Good clinical results can be expected by applying LCS to HCC.

Microvessel density of hepatocellular carcinoma: its relationship with prognosis.

To elucidate the relationship between angiogenesis and prognosis after curative resection of hepatocellular carcinoma (HCC). An immunohistochemical study using anti-CD34 monoclonal antibody was carried out on surgical specimens from 78 HCC patients who had undergone curative resection; microvessel density (MVD) was counted and the overall survival and disease-free survival were analyzed retrospectively. Blood vessels in the tumor were strongly stained by anti-CD34 antibody, but not those in the surrounding liver parenchyma. There were three types of tumor vessels: capillary-like (n = 59), sinusoid-like (n = 16) and mixed-type (n = 3). The median MVD count was 100 per field. The HCC were designated as hypovascular (n = 36) with an MVD count below 100, and hypervascular (n = 42) with an MVD count of 100 or more per field. The 5-year survival and disease-free survival rates were 49.7% and 42.8% respectively, and statistical analysis showed that the MVD level was not correlated with tumor size, capsule status, Edmondson's grade, alpha-fetoprotein level, associated cirrhosis, gamma-glutamyltransferase, and serum HBsAg status. The sinusoid-like tumor vessels appeared more frequently in the more differentiated tumors (P<0.05). No statistical difference in overall and disease-free survival between different MVD levels and microvessel types was found. Tumor size was the only predicting factor in the entire series. In patients with small HCC (< or =5 cm, n = 40), 5-year survival and disease-free survival rates were 58.9% and 52.7% respectively, higher than the values in large HCC (39.8% and 32.0% respectively, P<0.05). The MVD level was an independent predicting factor of disease-free survival, 5-year disease-free survival in the hypovascular group (74.6%) being better than that in the hypervascular group (34.7%, P<0.05). The MVD level was not related to tumor size, capsule statuo, Edmondson's grade, alpha-fetoprotein level, associated cirrhosis, gamma-glutamyltransferase and serum HBsAg status. In the entire series, tumor size was the only factor influencing survival after curative resection. However, in patients with small HCC, the MVD level was an independent factor of disease-free survival. The pathological and clinical implications of different types of tumor vessels in HCC remain to be studied.

Hepatic hemangioma: contrast-enhancement pattern during the arterial and portal venous phases of spiral CT.

The objective of the present study was to evaluate contrast-enhancement patterns of hepatic hemangioma according to size during hepatic arterial (30-s delay) and portal venous (65-s delay) phases of spiral computed tomography (CT). During a 10-month-period, 73 patients with 118 hemangiomas underwent two-phase spiral CT examination. The enhancement patterns of tumors were divided into four types based on the attenuation of surrounding liver parenchyma: peripherally nodular high, uniform high, iso, and low. The diameter of the tumors were <10 mm (n = 39), 11-20 mm (n = 33), and >21 mm (n = 46). Overall, the most common enhancement patterns of hemangioma were peripherally nodular high (66/118, 55. 9%) during the arterial and portal venous phases. The second most common contrast-enhancement patterns of hemangioma were uniform high (15/118, 12.7%) during the arterial and portal venous phases. In tumors smaller than 20 mm, 11 (9.3%) had low-low attenuation and two (1.7%) had iso-low attenuation during the arterial and portal venous phases, respectively. In conclusion, at two-phase spiral CT, the most common contrast-enhancement patterns of hemangioma are peripherally nodular high and/or uniform high during the arterial and portal venous phases. However, hemangiomas smaller than 2 cm may have atypical enhancing patterns including low and iso-attenuation.

Relationships between echo level and histologic characteristics in small hepatocellular carcinomas

The relationships between ultrasound echo level and histologic characteristics of hepatocellular carcinomas (HCCs) of 2 cm or less in diameter were studied. The apparent echo level and frequency-dependent attenuation from the abdominal wall to the tumor and surrounding liver parenchyma were quantitated on B-mode images using diagnostic ultrasound equipment. The inherent echo level corrected by the frequency-dependent attenuation was used in this study. Histologic specimens were collected by sonographically guided small-gauge core-needle biopsy. Increase in deposition of fat and changes in cellular density and in connective tissue density were evaluated histologically. From the quantitative comparison of echo levels and histologic characteristics, it was evident that the deposition of fat caused an increase in echo levels. A reduction in connective tissue density resulted in a decrease in echo levels in hypoechoic HCCs, which had no or little fat deposition. The estimation of echo level in small HCCs may be useful in predicting the tumors' histologic characteristics.

Relationships between echo level and histologic characteristics in small hepatocellular carcinomas

Purpose The relationships between ultrasound echo level and histologic characteristics of hepatocellular carcinomas (HCCs) of 2 cm or less in diameter were studied. Methods The apparent echo level and frequency-dependent attenuation from the abdominal wall to the tumor and surrounding liver parenchyma were quantitated on B-mode images using diagnostic ultrasound equipment. The inherent echo level corrected by the frequency-dependent attenuation was used in this study. Histologic specimens were collected by sonographically guided small-gauge core-needle biopsy. Increase in deposition of fat and changes in cellular density and in connective tissue density were evaluated histologically. Results From the quantitative comparison of echo levels and histologic characteristics, it was evident that the deposition of fat caused an increase in echo levels. A reduction in connective tissue density resulted in a decrease in echo levels in hypoechoic HCCs, which had no or little fat deposition. Conclusions The estimation of echo level in small HCCs may be useful in predicting the tumors' histologic characteristics. © 1998 John Wiley & Sons, Inc. J Clin Ultrasound 26:295–301, 1998.

Expression of hepatitis B virus X protein in HBV-infected human livers and hepatocellular carcinomas.

Transactivation of cellular genes and functional inactivation of p53 by the hepatitis B virus (HBV) X gene-encoded protein (HBx) are proposed as alternative mechanisms for induction of hepatocellular carcinomas (HCCs) in chronic HBV infection. Using an immunohistochemical approach, we studied the expression of HBx in 39 explanted livers with HBV-associated disease. Because the data reported previously have been inconsistent, possibly due to the application of different antibodies, we compared results with 5 polyclonal and 6 monoclonal anti-HBx antibodies from five laboratories. Ten of the 11 antibodies reacted with recombinant HBx by Western blotting, but only 1 polyclonal and 2 monoclonal antibodies reacted specifically with HBx in tissue, and were thus suitable for immunohistochemistry. Three other polyclonal antibodies reacted with tissue components in addition to HBx. One polyclonal and 4 monoclonal antibodies did not recognize the HBx in the tissue. HBx was demonstrated in 16 of 30 (53.3%) cirrhotic livers and 10 of 18 (58.8%) HCCs by all specific antibodies. The expression of HBx, among three HBV antigens examined, was found to be preferentially maintained in HCC and the surrounding liver parenchyma, including focal or nodular preneoplastic lesions. However, the immunoreactivity was always limited to the cytoplasm of a small number of parenchymal and neoplastic cells. The role of X gene expression in HBV-associated human hepatocarcinogenesis remains to be established.

Quantitative ultrasonic analysis of liver metastases

The performance of five features of ultrasonic tissue characterization (UTC) of metastases in vivo in liver was investigated. We acquired serial radiofrequency data sets of 12 patients with metastases in the liver from adenocarcinoma of the colon. Parenchyma and metastases UTC features were estimated in semiautomatically segmented regions. Over 200 metastases were measured in patients and 43 dummy metastases in healthy volunteers. Two attenuation features could be estimated in only 15% of the metastases, and these were not different from those in parenchyma. The texture features signal-to-noise ratio (SNR) could not discriminate real from dummy metastases. Average backscatter intensity, b0, is an established discriminative echographic image feature. However, the metastases that were hypoechoic relative to surrounding parenchyma appeared to be isoechoic relative to normal liver parenchyma. They were visible because of an increased b0 in the surrounding liver parenchyma. Finally, we found an increased backscatter coefficient slope vs. frequency in hypoechoic metastases that may predict a deterioration of lesion contrast at higher transducer frequencies. We conclude that the backscatter coefficient slope can improve detection of metastases, and that b0 measured relative to normal liver parenchyma should be used to correctly correlate metastasis echography with histology.

Urinary excretion of the collagen cross-link pyridinoline increases during liver fibrogenesis

Background/Aims: Pyridinoline, a specific cross-link of mature collagen, increases in liver during fibrogenesis and its hepatic level is related to the degree of reversibility of the fibrotic process. Since pyridinoline is excreted in urine, we have investigated the relationship between its urinary level and liver fibrogenesis in a model of mild and reversible liver fibrosis, murine schistosomiasis. Methods: Pyridinoline was measured by HPLC in urine and in liver of Schistosoma mansoni-infected mice during the acute and the chronic phases of the infection. Collagen deposition was measured colorimetrically. Both the isolated granulomas and the surrounding liver parenchyma were analyzed. Results: In infected mice, pyridinoline increased mainly in the isolated granulomas, corresponding to the fibrotic lesions, and slightly in the surrounding parenchyma. The urinary excretion of pyridinoline increased during liver fibrogenesis and was correlated to the duration of infection ( r=0.81) and to the collagen content of granulomas ( r=0.81). The treatment of infected mice by praziquantel, an antiparasitic drug, did not lead to significant changes in liver collagen cross-linking by pyridinoline either in granulomas or in parenchyma. The major effect of the drug was targeted at the collagen content of parenchyma, which decreased by 50%, 18 weeks after treatment. The urinary level of pyridinoline of treated mice was negatively correlated to the length of the treatment follow-up ( r=−0.76). Conclusions: The measurement of the urinary excretion of pyridinoline could be helpful to monitor the remodeling of liver extracellular matrix occurring in fibrogenesis and the effect of chemotherapy.

Biphasic contrast-enhanced multisection dynamic MR imaging of the liver: potential pitfalls.

Biphasic contrast material-enhanced dynamic magnetic resonance (MR) imaging is an important technique for evaluating liver disease. However, several potential diagnostic pitfalls may be encountered, including lobar, segmental, subsegmental, and subcapsular hyperperfusion abnormalities; early-enhancing pseudolesions, particularly in the medial segment of the left hepatic lobe; heterogeneous hyperperfusion abnormalities throughout the liver; and hypointense pseudolesions due to vascular artifacts, unenhanced hepatic vessels, partial volume artifacts, magnetic susceptibility artifacts, and regenerative nodules in cirrhosis. These abnormalities sometimes have appearances similar to those of true lesions or tumor spread to the surrounding liver parenchyma on arterial-dominant phase dynamic MR images. In most cases, however, no corresponding abnormalities are seen with other pulse sequences or on delayed-phase MR images. In addition, hyperperfusion abnormalities due to readily recognizable causes are often found in characteristic locations and thus can be differentiated from true tumors. An understanding of the causes of these potential pitfalls and how to avoid them will help radiologists understand and correctly interpret images.

Cholangiocarcinoma: delayed CT contrast enhancement patterns.

To determine the usefulness of delayed post-equilibrium-phase contrast material-enhanced images in evaluation of intrahepatic cholangiocarcinoma. Review of surgical, pathologic, and radiologic records revealed 47 patients with proved cholangiocarcinoma with delayed (6-36 minutes) post-equilibrium-phase contrast-enhanced computed tomographic (CT) scans. Unenhanced, dynamic contrast-enhanced, and delayed images were retrospectively reviewed, and enhancement patterns for cholangiocarcinoma lesions were recorded. Degree of delayed enhancement was compared with that of surrounding liver parenchyma. Patterns of delayed enhancement were characterized as homogeneous or heterogeneous. Enhancement characteristics were correlated with histologic findings. Thirty-five (74%) of 47 patients had tumors with mild or marked hyperattenuating delayed contrast enhancement, of which 18 had tumors with homogeneous hyperattenuating enhancement. In three patients, the only evidence of tumor was on the delayed images. In one patient, the tumor was not definable at any imaging phase. Tumors with delayed enhancement tended to be fibrous; however, degree of contrast material retention did not always correlate with the fibrous content of tumors at histopathologic analysis. Delayed tumoral contrast enhancement is a typical feature of intrahepatic cholangiocarcinoma and may aid in the detection and characterization of such lesions at CT.

High-resolution dynamic MR imaging of hepatocellular carcinoma with a phased-array body coil.

High spatial resolution dynamic magnetic resonance (MR) imaging performed with a phased-array body coil is a useful tool for evaluating hepatocellular carcinoma. The examination consists of fast spin-echo T1- and T2-weighted images obtained in a single breath hold; multisection, dynamic, fast gradient-echo images obtained in a single breath hold; and contrast material-enhanced images obtained in the arterial-dominant and delayed phases. Hepatocellular carcinoma, with its predominantly arterial blood supply, usually appears hyperintense on arterial-dominant phase images and isointense or hypointense relative to liver parenchyma on delayed-phase images. Hepatocellular carcinomas, especially those larger than 1.5 cm, contain a fibrous capsule or an inner septum, which allows them to be differentiated from other tumors. These characteristics are particularly important in the diagnosis of hypovascular hepatocellular carcinomas, which do not have an arterial blood supply and thus do not enhance. Extracapsular invasion, a relatively common finding in advanced cases, is seen as a nodular enhancing area that projects into the surrounding liver parenchyma adjacent to the main tumor on arterial-dominant phase images and as an iso- or hypointense area on delayed-phase images. Portal vein invasion appears as an obstruction of the vein, and portal vein tumor thrombi appear as intermediate-signal-intensity masses. The technique can also be helpful in the follow-up of treatment.

Changes in contrast enhancement of hepatocellular carcinoma and liver: effect of temporary occlusion of a hepatic vein evaluated with spiral CT.

To assess the hemodynamics of the liver and of hepatocellular carcinomas (HCCs) with hepatic vein occlusion. Selected hepatic veins were temporarily occluded with a balloon catheter in 21 patients with 28 nontreated nodular HCCs. Computed tomographic (CT) arteriography was performed without and with temporary occlusion of a hepatic vein that drained the blood from segmental liver parenchyma containing tumor by using a unified spiral CT and angiography system. The degree of enhancement and change in appearance of the HCC in each condition were compared. All HCCs were well-enhanced, almost round masses at CT arteriography. At CT arteriography with hepatic vein occlusion, however, HCCs were changed as follows: (a) the absolute attenuation of the HCC was decreased in 27 (96%) of 28 tumors compared with that at CT arteriography without hepatic vein occlusion, while attenuation of the surrounding liver parenchyma was increased; (b) the size of the highly enhanced area in HCC became smaller in 17 (61%) tumors (of these, two disappeared); and (c) the shape was changed in 12 (43%) tumors. Hepatic vein occlusion resulted in reciprocal hemodynamic changes in the liver parenchyma relative to HCCs: Enhancement of the liver increases and that of HCCs decreases.

Xanthogranulomatous cholecystitis: a radiological study of 12 cases and a review of the literature.

Twelve cases of xanthogranulomatous cholecystitis (XGC) are presented, and their radiologic appearance is described. Four men and eight women, aged 31-82 years old, with XGC were reviewed. Abdominal ultrasound (US) was performed in all patients. Computed tomography (CT) was performed in five patients, barium enema examination in two, and percutaneously CT-guided fine-needle aspirative biopsy of the gallbladder in one. Barium enema examination showed an indentation of the hepatic flexure. Cholelithiasis was present in all patients, and sludge was present in six. The gallbladder wall was thickened in all patients, irregular in nine, and could not be properly differentiated from surrounding liver parenchyma or from other adjacent structures in most patients. A curvilinear halo, hypoechoic on US and with low attenuation on CT, within the gallbladder wall was found in three patients and pericholecystic fluid in two others. On CT, the pericholecystic fat had streaky soft tissue densities in three cases. Percutaneously CT-guided fine-needle aspirative biopsy of the gallbladder was nondiagnostic. The diagnosis of gallbladder carcinoma was considered preoperatively in three patients. Despite the characteristic histologic appearance of XCG, radiologic findings are nonspecific, varying from signs observed in other forms of cholecystitis to the appearance of a gallbladder neoplasm.

Iodized-oil retention within hepatic hemangioma: characteristics on iodized-oil CT.

The purpose of this study was to describe the characteristic computed tomographic (CT) appearance of iodized-oil retention in hepatic hemangioma and to evaluate the duration of the retention of iodized oil on follow-up CT. Seventeen hepatic hemangiomas of 14 patients were studied with CT performed 1-3 weeks after injection of 2-9 ml of iodized oil (iodized-oil CT) for the characterization of focal hepatic lesions, which needed differential diagnosis with hepatocellular carcinoma in 10 patients, for therapy in two patients, and for chemoembolization therapy of accompanying hepatocellular carcinomas in two. Twelve patients had 1-7 follow-up CT scans within an interval of 1-38 months. In all cases, iodized-oil CT showed iodized-oil retention within the tumor, regardless of tumor size, shape, location, and amount of injected iodized oil. The distribution was incomplete and predominantly peripheral in all cases. Central retention was also seen in seven cases, in which a relatively large amount of iodized oil was injected, but retention of iodized oil in the tumor was incomplete even in two cases in which a large amount of iodized oil was injected to relieve symptoms and in three cases in which prominent uptake of surrounding liver parenchyma was seen. Patterns of retention were predominantly spotty in five, predominantly nodular in four, and mixed in eight patients. Retention materials slowly washed out but persisted for at least 3 months and up to 38 months (mean = 18.1 months), and complete washout was not seen in any cases at follow-up CT. In all cases of hepatic hemangiomas, iodized oil was retained, and retention persisted over several months. Distribution and patterns of retention were characteristically peripheral, spotty, and nodular at iodized-oil CT. Knowledge of the iodized-oil CT appearance of hepatic hemangioma would be helpful to interpret follow-up CT studies of patients who have undergone iodized-oil chemoembolization procedures.

PET studies with C-11 ethanol in intratumoral therapy of hepatocellular carcinomas

Positron emission tomography (PET) is a noninvasive functional method for the study of solid tumor perfusion, metabolism and interaction with different therapeutic agents. The aim of the study was the investigation of the metabolism of hepatocellular carcinomas (HCC) and the kinetics during a treatment with intratumoral ethanol by PET. The ongoing study includes seven patients with child. A cirrhosis and HCC (UICC stage III-IVA; tumor size 3-6 cm). Dynamic PET studies (60 min) with 18F-fluordeoxyglucose (FDG) were performed prior to therapy to assess tumor viability. The evaluation of the FDG data demonstrated a liver-equivalent uptake in six of the tumors (well and moderately differentiated HCC), which were poorly delineated against the normal liver parenchyma. One moderately differentiated HCC showed an increased FDG metabolism, indicating no correlation between histology and metabolism. A dose of 37-80 MBq 11C-ethanol was applied together with a nonlabelled therapeutic dose of the drug via a puncture needle positioned under sonography. Five out of seven tumors demonstrated a high 11C uptake shortly after the end of the ethanol injection followed by constant 11C-ethanol concentration during the whole study period of 45 min. The PET data demonstrated no significant elimination of the 11C-ethanol from the tumor and no accumulation in the surrounding liver tissue. One case showed a decrease of the intra-tumoral 11C-ethanol concentration due to a punkture of a tumor vein, and in another case the surrounding liver parenchyma demonstrated significant 11C uptake in the early phase following paratumoral injection of the drug. In conclusion, PET is a useful tool for the study of the mechanism and the kinetics of percutaneous intratumoral ethanol injection of HCC.

MR imaging enhancement with superparamagnetic iron oxide in chronic liver disease: influence of liver dysfunction and parenchymal pathology.

To analyze the influence of liver dysfunction and parenchymal pathology on the accumulation of superparamagnetic iron oxide (SPIO). We evaluated MR images of 13 patients having small hepatic neoplasms before and after administration of SPIO (10 micronol/kg). Biopsy and laboratory data confirmed the presence of severe cirrhosis in two patients, mild cirrhosis in four, chronic hepatitis in five, and normal livers in two. Degrees of liver dysfunction or liver parenchymal pathology were correlated with reductions in signal intensity of the liver and spleen after administration of SPIO. Signal intensity reduction was evaluated using a 1.5 Tesla MR unit. Response to SPIO of the liver and spleen did not correlate with liver parenchymal pathology, although reductions in signal intensity of the liver were somewhat small in severely cirrhotic livers. There were slight correlations between signal intensity alterations of the liver and laboratory data such as the indocyanine green retention rate (correlation coefficient 0. 47), albumin (0.36), total bilirubin (0.36), and serum glutamic oxaloacetic transaminase (GOT) (0.46). Signal intensity reduction of spleen did not correlate with liver function tests except for serum GOT. In patients with cirrhosis, heterogeneous structures were detected in the nontumorous portions of the liver. However, these did not prevent the diagnosis of small hepatomas. The uptake of SPIO showed some correlation with liver function but not with chronic liver parenchymal pathology. SPIO provided sufficient contrast between tumor and surrounding liver parenchyma among patients with chronic liver disease.

Characterization of focal hepatic tumors value of two-phase scanning with spiral computed tomography

Spiral computed tomography (CT) allows imaging of the liver during the peak contrast material levels due to the capability of fast data acquisition. The objective of this study was to evaluate the usefulness of two-phase spiral CT in the differential diagnosis of focal hepatic tumors. One hundred two patients who had hepatic tumors (211 nodules; 149 hepatocellular carcinomas [HCCs], 36 metastases, and 26 hemangiomas) underwent two-phase spiral CT with 10-mm collimation at 10 mm/second table speed and 120 mL of contrast material injected at the rate of 3 mL/second. Computed tomography images of the hepatic arterial phase and late (equilibrium) phase were obtained at 35-second and 180-second delays, respectively. The enhancement patterns of tumors were divided into six types and were compared with the attenuation of surrounding liver parenchyma: totally high, peripherally high, centrally high, mixed, iso, and low. The common enhancement patterns of HCC in two-phase spiral CT were totally high in the arterial phase and low (n = 63, 42%) or iso (n = 28, 19%) in the late phase. Metastasis showed peripherally nonnodular high attenuation (n = 9, 25%) or low attenuation (n = 9, 25%) in the arterial phase and low attenuation in the late phase, followed by totally high attenuation in the arterial phase and iso in the late phase (n = 6, 17%). Hemangiomas showed totally or peripherally nodular enhancement in the arterial and late phases (n = 23, 89%). In distinguishing hemangiomas from malignant tumors, totally high or peripherally nodular high attenuation in the late phase was the most useful contrast enhancement pattern (96% of hemangioma vs. 0% of malignant tumors). In distinguishing HCCs from metastases, a combination of contrast enhancement pattern of totally high attenuation in the arterial phase and low in the late phase was the most useful contrast enhancement pattern (42% of HCCs vs. 0% of metastases). The predictability of differentiation between hemangiomas and malignant tumors and between HCCs and metastases was 99% and 90% with spiral CT, respectively. Two-phase spiral CT is useful in the differential diagnosis of focal hepatic tumors with evaluation of contrast enhancement patterns.

Hepatic pseudolesion in the left lobe around the falciform ligament at helical CT.

To determine the prevalence and possible cause of pseudolesions in the left hepatic lobe around the falciform ligament at hepatic helical computed tomography (CT). Portal venous-dominant CT scans of 472 consecutive patients were reviewed. CT of the left hepatic lobe was performed after injection of contrast material into the portal vein in 73 patients, the hepatic artery in 32, and the internal thoracic artery in four. The scans were compared with those obtained at helical CT, and the findings were analyzed. Pseudolesions were seen on 64 (14%) of 472 helical CT scans and correlated well (accuracy, 96%) with portal perfusion defects. They were not more enhanced than the surrounding liver parenchyma at CT arteriography with hepatic artery injection but were enhanced in two patients at CT arteriography with internal thoracic artery injection. Pseudolesions are caused by portal perfusion defects and may receive an aberrant blood supply.