Utility of virtual touch quantification in the diagnosis of pancreatic ductal adenocarcinoma.

This study aimed to compare the tissue stiffness of pancreatic ductal adenocarcinoma (PDAC) with that of pancreatic parenchyma using virtual touch quantification (VTQ). SWV was measured in 34 PDAC lesions and in pancreatic parenchyma of both controls and patients. SWVs in PDAC lesions were significantly higher than in pancreatic parenchyma in both healthy controls and in patients with PDAC. The area under the ROC for diagnosis of PDAC was 0.94 for pancreatic parenchyma in healthy controls, and 0.85 for pancreatic parenchyma in patients with PDAC. VTQ can provide a useful and additional information for diagnosis of PDAC.

Antifibrotic effects of ambrisentan, an endothelin-A receptor antagonist, in a non-alcoholic steatohepatitis mouse model.

AIM: To examine the effects of the endothelin type A receptor antagonist ambrisentan on hepatic steatosis and fibrosis in a steatohepatitis mouse model. METHODS: Fatty liver shionogi (FLS) FLS-ob/ob mice (male, 12 wk old) received ambrisentan (2.5 mg/kg orally per day; n = 8) or water as a control (n = 5) for 4 wk. Factors were compared between the two groups, including steatosis, fibrosis, inflammation, and endothelin-related gene expression in the liver. RESULTS: In the ambrisentan group, hepatic hydroxyproline content was significantly lower than in the control group (18.0 µg/g ± 6.1 µg/g vs 33.9 µg/g ± 13.5 µg/g liver, respectively, P = 0.014). Hepatic fibrosis estimated by Sirius red staining and areas positive for α-smooth muscle actin, indicative of activated hepatic stellate cells, were also significantly lower in the ambrisentan group (0.46% ± 0.18% vs 1.11% ± 0.28%, respectively, P = 0.0003; and 0.12% ± 0.08% vs 0.25% ± 0.11%, respectively, P = 0.047). Moreover, hepatic RNA expression levels of procollagen-1 and tissue inhibitor of metalloproteinase-1 (TIMP-1) were significantly lower by 60% and 45%, respectively, in the ambrisentan group. Inflammation, steatosis, and endothelin-related mRNA expression in the liver were not significantly different between the groups. CONCLUSION: Ambrisentan attenuated the progression of hepatic fibrosis by inhibiting hepatic stellate cell activation and reducing procollagen-1 and TIMP-1 gene expression. Ambrisentan did not affect inflammation or steatosis.

Kupffer phase image of Sonazoid-enhanced US is useful in predicting a hypervascularization of non-hypervascular hypointense hepatic lesions detected on Gd-EOB-DTPA-enhanced MRI: a multicenter retrospective study.

BACKGROUND: It remains unknown whether Kupffer-phase images in Sonazoid-enhanced ultrasonography (US) can be used to predict hypervascularization of borderline lesions. Therefore, we aimed to clarify whether Kupffer-phase images in Sonazoid-enhanced ultrasonography can predict subsequent hypervascularization in hypovascular borderline lesions detected on hepatobiliary-phase gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging. METHODS: From January 2008 to March 2012, 616 low-intensity hypovascular nodules were detected in hepatobiliary-phase images of Gd-EOB-DTPA-enhanced MRI at nine institutions. Among these, 167 nodules, which were confirmed as hypovascular by Gd-EOB-DTPA-enhanced MRI and Sonazoid-enhanced US, were evaluated in this study. Potential hypervascularization factors were selected based on their clinical significance and the results of previous reports. The Kaplan-Meier model and log-rank test were used for univariate analysis and the Cox regression model was used for multivariate analysis. RESULTS: The cumulative incidence of hypervascularization of borderline lesions was 18, 37, and 43 % at 1, 2, and 3 years, respectively. Univariate analyses showed that tumor size (p = 0.0012) and hypoperfusion on Kupffer-phase images in Sonazoid-enhanced US (p = 0.004) were associated with hypervascularization of the tumor. Multivariate analysis showed that tumor size [HR: 1.086, 95 % confidence interval = 1.027-1.148, p = 0.004] and hypo perfusion on Kupffer-phase images [HR: 3.684, 95 % confidence interval = 1.798-7.546, p = 0.0004] were significantly different. CONCLUSIONS: Kupffer-phase images in Sonazoid-enhanced US and tumor diameter can predict hypervascularization of hypointense borderline lesions detected on hepatobiliary-phase Gd-EOB-DTPA-enhanced MRI.

Clinical usefulness of the ablative margin assessed by magnetic resonance imaging with Gd-EOB-DTPA for radiofrequency ablation of hepatocellular carcinoma.

BACKGROUND & AIMS: The aim of this study was to investigate the feasibility of ablative margin (AM) grading by magnetic resonance imaging (MRI) with Gd-EOB-DTPA administered prior to radiofrequency ablation (RFA), and to identify factors for achieving a sufficient AM and predictors for local tumor progression. METHODS: A total of 124 hepatocellular carcinomas (HCCs) were treated by RFA after Gd-EOB-DTPA administration. MRI and enhanced CT were performed within seven hours and one month after RFA. The AM assessment was categorized using three grades: AM (+), low-intensity area with continuous high-intensity rim; AM zero, low-intensity area with discontinuous high-intensity rim; and AM (-), low-intensity area extends beyond the high-intensity rim. Patients were followed and local tumor progression was observed. RESULTS: AM (+), AM zero, AM (-), and indeterminate were found in 34, 33, 26, and 31 nodules, respectively. The overall agreement rate between MRI and enhanced CT for the diagnosis of AM was 56.8%. The κ coefficient was 0.326 (p<0.001), indicating moderate agreement. Multivariate logistic regression analysis showed that a significant factor for the achievement of AM (+) on MRI was no contiguous vessels. The cumulative local tumor progression rates (0% at 1, 2, and 3 years) in 33 AM (+) nodules were significantly lower than those (3.6%, 11.5%, and 18.3% at 1, 2, and 3 years respectively) in 32 AM zero nodules. A multivariate Cox proportional hazards model identified tumor size as an independent predictor for local tumor progression. CONCLUSION: Gd-EOB-DTPA-MRI enabled an early assessment of RFA effectiveness in the majority ofHCC nodules. Local tumor progression was not detected in AM (+) nodules during the follow-up.

Usefulness of contrast-enhanced ultrasound with Sonazoid for evaluating liver abscess in comparison with conventional B-mode ultrasound.

AIM: The purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasound (CEUS) with Sonazoid (perfluorobutane) in patients with liver abscess. Sonazoid is a contrast agent with a low mechanical index and is phagocytosed by Kupffer cells. METHODS: Twenty-two patients with liver abscess were evaluated with conventional US, real-time CEUS with Sonazoid, and enhanced computed tomography (CT). After 0.5 mL of Sonazoid was administrated i.v., CEUS images in the vascular and post-vascular phases were observed. RESULTS: Conventional US showed hypoechoic lesions in 13 (59.1%), isoechoic in four (18.2%), hyperechoic in two (9.1%), mixed echoic in two (9.1%) and undetected in one (4.8%) patient. CEUS showed perilesional enhancement in 19 (86.4%) lesions in the vascular phase and well-defined unenhanced areas in 22 (100%) lesions in the post-vascular phase. CEUS revealed that 18 abscesses were cystic type and three were honeycomb type. Twenty-one abscesses (95.5%) had clearer appearances on CEUS than on conventional US in regard to the extent of necrotic or liquefied lesions seen. We could confirm reduction of the lesions after therapy in 13 (92.9%) of 14 patients followed up by CEUS. CONCLUSION: Most of the liver abscesses showed perilesional enhancement in the vascular phase and unenhanced areas in the post-vascular phase. The appearance of liver abscesses was clearer on CEUS than on conventional US. CEUS with Sonazoid can be a more effective diagnostic and therapeutic tool for liver abscess.

Hypovascular hepatic nodules showing hypointense on the hepatobiliary-phase image of Gd-EOB-DTPA-enhanced MRI to develop a hypervascular hepatocellular carcinoma: a nationwide retrospective study on their natural course and risk factors.

OBJECTIVE: We aimed to investigate the natural outcome of nonhypervascular lesions detected in the hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI by performing a longitudinal study retrospectively enrolled in a nationwide manner. METHODS: Between February 2008 and March 2011, 224 patients with 504 nodules that were diagnosed as nonhypervascular by imaging were recruited from institutions that participated in the present study. We examined the natural outcome of nonhypervascular lesions and evaluated the risk factors. RESULTS: Of the 504 nodules, 173 (34.3%) showed hypervascular transformation. The overall cumulative incidence of hypervascular transformation was 14.9% at 12 months and 45.8% at 24 months. Multivariate analysis using the Cox regression model revealed previous treatment history for hepatocellular carcinoma (HCC; relative risk = 1.498; p = 0.036, 95% CI 1.03-2.19) and hyperintensity on T2-weighted images (relative risk = 1.724; p = 0.015, 95% CI 1.11-2.67) were identified as independent factors for hypervascular transformation. CONCLUSIONS: Patients who have a previous treatment history for HCC and with hypointense nodules showing hyperintensity on T2-weighted images need careful follow-up because of the high incidence of hypervascular transformation.

Ablative margin states by magnetic resonance imaging with ferucarbotran in radiofrequency ablation for hepatocellular carcinoma can predict local tumor progression.

BACKGROUND: Our aim was to determine how well ablative margin (AM) grading assessed by magnetic resonance imaging (MRI) with ferucarbotran administered prior to radiofrequency ablation (RFA) predicts local tumor progression in comparison with enhanced computed tomography (CT). METHODS: 101 hepatocellular carcinomas were treated by RFA after ferucarbotran administration. We performed T2*-weighted MRI after 1 week and enhanced CT after 1 month. The assessment was categorized in three grades: AM(+): high-intensity area with continuous low-intensity rim; AM zero: high-intensity area with discontinuous low-intensity rim; and AM(-): high-intensity area extending beyond the low-intensity rim. RESULTS: AM(+), AM zero, AM(-) and indeterminable were found in 47, 36, 8 and 10 nodules, respectively. The overall agreement rate between MRI and enhanced CT for the diagnosis of AM was 71.3%. The κ coefficient was 0.523 (p < 0.001), indicating moderate agreement. Multivariate logistic regression showed that a significant factor for the achievement of AM(+) on MRI was only segment location (odds ratio 5.9, non-segment 4 + 8 vs. segment 4 + 8). The cumulative local tumor progression rates (4.4, 7.6, and 7.6% in 1, 2, and 3 years) in 47 AM(+) nodules were significantly lower than those (13.9, 33.4, and 41.8% in 1, 2, and 3 years) in 36 AM zero nodules. A multivariate Cox proportional hazards model identified contiguous vessels (odds ratio 12.0) and AM(+) on MRI (odds ratio 0.19) as independent factors for local tumor progression. CONCLUSION: AM assessment by MRI using ferucarbotran can predict local tumor progression after RFA and enable early and less invasive diagnosis.

Assessment of ablative margin by unenhanced magnetic resonance imaging after radiofrequency ablation for hepatocellular carcinoma.

PURPOSE: The aim of this study was to evaluate the feasibility of magnetic resonance imaging (MRI) without a contrast agent to visualize the ablative margin after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), compared with enhanced CT. METHODS: Twenty-five HCCs in 19 patients were treated by RFA. T1-weighted MRI was performed before and after RFA, and the signal intensities of the tumors and surrounding liver tissues were measured. Treatment efficacy was assessed based on three grades: margin (+), a continuous high-intensity rim around the index tumor; margin zero, a partially discontinuous high-intensity rim; margin (-), the tumor extends beyond the high-intensity rim. RESULTS: Twelve (86%) of fourteen low-intensity tumors on the pre-MRI were visualized as low-intensity tumors on post-MRI, and the ablative margins were visualized as high-intensity rims. Two (67%) of three high-intensity tumors on pre-MRI were visualized as higher-intensity tumors in the high-intensity ablative margin. Because the signal intensities of tumors and surrounding tissues in 14 tumors that were low- or high-intensity tumors on pre-MRI increased to the same extent, the tumors and ablative margin could be distinguished on post images. In 6 (75%) of the 8 iso-intensity tumors on pre-MRI, the ablative margin and tumor could also not be discriminated on post-MRI. The overall agreement between MRI and CT for the ablative margin was good (κ coefficient=0.716, p=0.00002). CONCLUSION: In 82% of low- or high-intensity tumors on pre-MRI, post-MRI without a contrast agent enabled visualization of the ablative margin as a high-intensity rim, and it was possible to evaluate the ablative margin earlier and easier than with enhanced CT.