Tadashi Sekimoto

Characterization of hepatic lesions (≤30 mm) with liver-specific contrast agents: A comparison between ultrasound and magnetic resonance imaging

PURPOSE Imaging-based differentiation of hepatic lesions (≤ 30 mm) between well-differentiated hepatocellular carcinomas (w-HCC) and regenerative nodules (RN) presents difficulties. The aim was to compare the diagnostic abilities to differentiate w-HCC from RN using contrast-enhanced ultrasound and magnetic resonance imaging (MRI) both with liver-specific contrast agents. MATERIALS AND METHODS This prospective study included 67 pathologically proven hepatic lesions (17.5 ± 5.4mm, 54 w-HCCs, 13 RNs) in 56 patients with chronic hepatitis/cirrhosis (male 40, female 16; 29-79y). Hepatic-arterial/liver-specific phase enhancements were assessed quantitatively by ultrasound with perflubutane microbubble agent and MRI with gadolinium-ethoxybenzyl-diethylenetriamine with respect to the histological findings. RESULTS Sensitivity, specificity and accuracy of hepatic-arterial phase hyper-enhancement for w-HCC were 59.3%, 100% and 67.2% by ultrasound and 46.3%, 100% and 56.7% by MRI without significant difference. Meanwhile, those of liver-specific-phase hypo-enhancement for w-HCC were 44.4%, 100% and 55.2% by ultrasound and 87.0% (p<0.0001), 46.2% (p=0.0052) and 79.1% (p=0.0032) by MRI. Diagnostic accuracies for w-HCC by area under the receiver operating characteristic curves were higher in the hepatic-arterial phase in ultrasound (0.8316) than MRI (0.6659, p=0.0101) and similar in the liver-specific phase in ultrasound (0.7225) and MRI (0.7347, p=0.8814). CONCLUSIONS Hypervascularity is a significant feature which distinguishes w-HCC from RN, and ultrasound exerts a beneficial impact better than MRI for such characterization. However, both imaging have comparable abilities in the characterization of non-hypervascular lesions, compensating mutually for the poor sensitivity of ultrasound and the poor specificity of MRI in the liver-specific phase.

Sonographic and clinical features of collateral vessels at the splenic hilum in cirrhosis

AIM To examine the sonographic features of shunt vessels derived from the splenic vein at splenic hilum (SS), and explore the relationship between the SS pattern and clinical presentations. MATERIALS AND METHODS This prospective study in cirrhotic patients consisted of study I (n = 15), which compared the anatomical features of SS at ultrasonography versus angiography, and study II (n = 233), which examined the incidence/haemodynamics of SS and SS-related presentations. RESULTS Study I showed that SS1 (running toward the upper pole of the spleen) corresponded to short gastric veins, and SS2 (running toward the lower pole of the spleen) corresponded to splenorenal/retroperitoneal shunts. In study II, SS were detected in 47.6% of patients (111/233), SS1 in 77.5% (86/111), SS2 in 17.1% (19/111), and SS3 (both SS1 and SS2) in 5.4% (6/111). The incidence of gastric cardia varices was significantly higher in patients with SS2 (6/19) than in those with SS1 (8/86, p = 0.0097), whereas the incidence of gastric fundal varices was significantly higher in patients with SS1 (44/86) than in those with SS2 (1/19, p = 0.00025) or SS3 (0/6, p = 0.015). There was no difference in the incidence of oesophageal varices among the three SS groups. The Child-Pugh score and grade of ascites was significantly worse in patients with SS3 than in those with SS1 (p < 0.0001, p = 0.0009). Hepatic encephalopathy grade was significantly worse in patients with SS2 (p = 0.0047) or SS3 (p < 0.0001) compared to SS1. CONCLUSION The SS pattern facilitates estimation of the possible manifestations, indicating the direction of clinical management of cirrhosis patients. Potential poor liver function is noted in patients with SS3.

Possible widespread presence of hepatitis A virus subgenotype IIIA in Japan: Recent trend of hepatitis A causing acute liver failure.

Aim:  Recently, the number of acute hepatitis A cases has decreased in Japan. However, six patients with acute liver failure caused by hepatitis A virus (HAV) have been admitted to Chiba University Hospital, Japan, in the last 18 months, between 2010 and June 2011. The aim of this study is to characterize the recent HAV genotypes from an urban hospital in Japan and to compare the clinical differences.

Palmitate-induced Regulation of PPARγ via PGC1α: a Mechanism for Lipid Accumulation in the Liver in Nonalcoholic Fatty Liver Disease

The aim was to examine the effect of free fatty acids on the regulation of PPARγ-PGC1α pathway, and the effect of PPARγ/PGC1α in NAFLD. The mRNA and protein expression of PGC1α and phospho/total PPARγ were examined in Huh7 cells after the palmitate/oleate treatment with/without the transfection with siRNA against PGC1a. The palmitate content, mRNA and protein expression of PGC1α and PPARγ in the liver were examined in the control and NAFLD mice. Palmitate (500 μM), but not oleate, increased protein expression of PGC1α and phospho PPARγ (PGC1α, 1.42-fold, P=0.038; phospho PPARγ, 1.56-fold, P=0.022). The palmitate-induced PPARγ mRNA expression was reduced after the transfection (0.46‑fold), and the protein expressions of PGC1α (0.52-fold, P=0.019) and phospho PPARγ (0.43-fold, P=0.011) were suppressed in siRNA-transfected cells. The palmitate (12325.8 ± 1758.9 μg/g vs. 6245.6 ± 1182.7 μg/g, p=0.002), and mRNA expression of PGC1α (11.0 vs. 5.5, p=0.03) and PPARγ (4.3 vs. 2.2, p=0.0001) in the liver were higher in high-triglyceride liver mice (>15.2 mg/g) than in low-triglyceride liver mice (<15.2 mg/g). The protein expressions of both PGC1α and PPARγ were higher in the NAFLD group than in the controls (PGC1α, 1.41-fold, P=0.035; PPARγ, 1.39-fold, P=0.042), and were higher in the high-triglyceride liver group (PGC1α, 1.52-fold, p=0.03; PPARγ, 1.22-fold, p=0.05) than in the low-triglyceride liver group. In conclusion, palmitate appear to up-regulate PPARγ via PGC1α in Huh7 cells, and both PGC1α and PPARγ are up-regulated in the NAFLD mice liver, suggesting an effect on lipid metabolism leading to intrahepatic triglyceride accumulation.

Role of contrast-enhanced ultrasonography with Sonazoid for hepatocellular carcinoma: evidence from a 10-year experience

Hepatocellular carcinoma (HCC) represents primary liver cancer. Because the development of HCC limits the prognosis as well as the quality of life of the patients, its management should be properly conducted based on an accurate diagnosis. The liver is the major target organ of ultrasound (US), which is the simple, non-invasive, and real-time imaging method available worldwide. Microbubble-based contrast agents are safe and reliable and have become popular, which has resulted in the improvement of diagnostic performances of US due to the increased detectability of the peripheral blood flow. Sonazoid (GE Healthcare, Waukesha, WI, USA), a second-generation contrast agent, shows the unique property of accumulation in the liver and spleen. Contrast-enhanced US with Sonazoid is now one of the most frequently used modalities in the practical management of liver tumors, including the detection and characterization of the nodule, evaluation of the effects of non-surgical treatment, intraoperative support, and post-treatment surveillance. This article reviews the 10-year evidence for contrast-enhanced US with Sonazoid in the practical management of HCC.

Influence of splenorenal shunt on long-term outcomes in cirrhosis

Abstract Objective. To examine the clinical effect of splenorenal shunt (SRS) on the long-term outcomes in patients with cirrhosis. Methods. The study consisted of 162 cirrhosis patients (male 85, female 77; 62.6 ± 11.7 years). The clinical findings and prognosis were examined with respect to portal hemodynamics including collateral vessel patterns, with or without the presence of SRS or short gastric vein (SGV). Median observation period was 30 months. Results. The incidence was 18.5% for SRS and 10.5% for SGV. Decompensated cirrhosis was significantly more frequent in patients with SRS (22/30) than those with SGV (5/17, p = 0.0034), and in patients with SRS >5.5 mm (14/15) or >95 ml/min (14/15) (both, median values) than those with SRS <5.5 mm (8/15, p = 0.013) or <95 ml/min (8/15, p = 0.013). Cumulative overall survival rate was 87.4% at 1 year, 73.4% at 3 years, and 59.1% at 5 years. There was no significant difference in the cumulative survival rate according to the development of SRS: 80% at 1 year, 66.6% at 3 years, and 58.3% at 5 years in patients with SRS; 94.1% at 1 year, 87.4% at 3 years, and 72.8% at 5 years in patients with SGV; 88.3% at 1 year, 73.1% at 3 years, and 58% at 5 years in patients without SGV/SRS; 94.1% at 1 year, 87.4% at 3 years, and 72.8% at 5 years in patients with SGV (overall, p = 0.2). Conclusion. In spite of no significant effect on the prognosis in cirrhosis, careful management may be necessary for the patients with SRS because of potential poor liver function demonstrated by the close linkage between the presence of SRS and decompensation.

Heterogeneous staining in the liver parenchyma after the injection of perflubutane microbubble contrast agent.

This study aimed to characterize the features of heterogeneous staining in the liver after injection of perflubutane microbubble agent (Sonazoid(TM), 0.0075 mL/kg). Digitized hepatic contrast sonograms from 906 subjects were reviewed to assess time-related changes in heterogeneous staining and the possible association between this effect and the clinical backgrounds was analyzed. Heterogeneous staining was found in seven subjects (0.77%) on 15-min phase sonograms. The staining initially appeared as hyper-enhanced circular spots in the liver 10 min or later after the agent injection. The number of spots increased gradually with unequally-spaced distribution. Although the staining pattern did not improve during the examination, there were no abnormal findings in vital signs or symptoms on the day and blood test results or sonograms on the following day. Heterogeneous staining is a side effect that impedes ultrasound examination. However, at present, the precise causes and underlying mechanisms of this event are unknown.

Differential Clinical Impact of Ascites in Cirrhosis and Idiopathic Portal Hypertension.

AbstractCirrhosis and idiopathic portal hypertension (IPH) are 2 major diseases showing portal hypertension. However, characteristics and outcomes of IPH with ascites have not yet been determined. The aim of the study was to examine the influence of ascites on the long-term clinical course of IPH.This observational study compared the long-term clinical findings including portal hemodynamics demonstrated by Doppler ultrasonography between 166 cirrhosis (87 males and 79 females; mean age ± standard deviation, 62.5 ± 11.8 years; age range, 20–89 years) and 14 IPH patients (3 males and 11 females; mean age ± standard deviation, 64.2 ± 6.6 years; age range, 51–78 years). Both groups comprised of consecutive patients from November 2007 through February 2013 and were studied retrospectively. The median observation period was 33.4 months for ascites and 34.5 months for survival.Ascites was detected in 60/166 (36.1%) and 116/166 (69.9%) cirrhosis patients and in 7/14 (50%) and 9/14 (64.3%) IPH patients, at baseline and at the end of the observation period, respectively. The cumulative incidence of ascites was 12.3% at 1 year, 35.9% at 3 years, and 59.9% at 5 years in cirrhosis, and 25% at 3 years, and 50% at 5 years in IPH (P = 0.36). Deterioration of ascites in patients showing mild ascites at baseline was found in 32.4% of cirrhosis patients and 42.9% of IPH patients (P = 0.41). Serum creatinine (mg/dl) at baseline was significantly higher in IPH patients who developed ascites (n = 2, 0.74 ± 0.14) than in those who did not (n = 5, 0.526 ± 0.06, P = 0.029). The overall survival rate appeared to favor IPH (100% at 1 year, 92.9% at 3 and 5 years; P = 0.2) more than cirrhosis (87.7% at 1 year, 75.2% at 3 years, and 63.6% at 5 years), but did not reach statistical significance. However, in patients with ascites at baseline, the survival rate was significantly better in IPH (100% at 1, 3, and 5 years, P = 0.04) than in cirrhosis (69.1% at 1 year, 43% at 3 years, 34.4% at 5 years).The presence of ascites at baseline correlated with worse survival rates in patients with cirrhosis as compared to those with IPH as the underlying etiology.

Pretreatment Microbubble-Induced Enhancement in Hepatocellular Carcinoma Predicts Intrahepatic Distant Recurrence After Radiofrequency Ablation

OBJECTIVE The purpose of this study is to examine whether pretreatment findings in hepatocellular carcinoma (HCC) using contrast-enhanced ultrasound can predict local or distant recurrence after radiofrequency ablation (RFA). SUBJECTS AND METHODS Subjects of the prospective study were 54 patients with HCC lesions treated by RFA. Intensity differences between lesion and liver parenchyma at early arterial (4 seconds) and peak enhancement times and washout at late phase were provided on contrast-enhanced sonograms with perflubutane microbubble agent. The pretreatment findings were examined with respect to intrahepatic local and distant recurrence. RESULTS Univariate analysis showed that intensity differences at the early arterial time (hazard ratio [HR], 2.2; 95% CI, 1.0-4.6; p = 0.042) and lesion frequency (HR, 2.3; 95% CI, 1.0-5.0; p = 0.044) were risk factors for distant recurrence. Multivariate analysis showed that intensity differences at the early arterial time (HR, 2.7; 95% CI, 1.2-5.8; p = 0.014) and lesion frequency (HR, 2.9; 95% CI, 1.3-6.5; p = 0.015) were risk factors for distant recurrence. The cumulative distant recurrence rate for patients with intensity differences at the early arterial time was greater at less than 10 dB than at 10 dB or higher (33.3% and 91.3% vs 23.9% and 65.1% at 1 and 2 years, respectively; p = 0.035). The cumulative distant recurrence rate was 16.5% and 61.1% at 1 and 2 years, respectively, in patients with solitary lesions and 54.7% and 77.4% at 1 and 2 years, respectively, in patients with multiple lesions (p = 0.0296). No pretreatment findings were predictive for local recurrence. CONCLUSION HCC lesions with gradual enhancement in the early arterial time displayed potential distant recurrence risk after RFA, requiring careful posttreatment surveillance.

Heterogeneity of microbubble accumulation: a novel approach to discriminate between well-differentiated hepatocellular carcinomas and regenerative nodules.

This prospective study aimed to elucidate the possibility of differentiating well-differentiated hepatocellular carcinoma (wHCC) from regenerative nodule (RN) on the basis of the heterogeneity of microbubble accumulation. Intensity analysis was conducted on early-phase and late-phase (60 s and 900 s post-injection; perflubutane microbubble) harmonic sonograms in 33 focal hepatic lesions (≤ 15 mm; 30 patients with chronic liver disease) that were histologically proven as wHCC or RN. Heterogeneity of enhancement, an average of standard deviation of late-phase enhancement in three different sections in the lesions with late-phase iso-enhancement, was examined with respect to the histologic findings. Heterogeneity of enhancement was higher in wHCC (28.7 ± 3.8) than RN (19.8 ± 2.1, p = 0.0213) in the 29 late-phase iso-enhancement lesions. The best cut-off value of the heterogeneity for the diagnosis of wHCC was 25.58, and the sensitivity and specificity were 77.8% and 100%, respectively. A novel parameter, heterogeneity of microbubble accumulation, facilitates differentiation between wHCC and RN showing a late-phase, iso-enhancement appearance.