Is the spleen stiffness value acquired using acoustic radiation force impulse (ARFI) technology predictive of the presence of esophageal varices in patients with cirrhosis of various etiologies?

AIM: This study's aimwas to determine the accuracy of the spleen stiffness value acquired using acoustic radiation force impulse (ARFI) technology, to predict the presence of esophageal varices (EVs) in patients with liver cirrhosis of various etiologies. MATERIAL AND METHODS: Of the 366 enrolled patients, 192 had hepatitis B virus, 74 had hepatitis C virus, and 100 had alcohol-related cirrhosis. All patients underwent biochemical tests, gastrointestinal endoscopy, and liver and spleen elastography by ARFI. We evaluated the correlation between the presence of EVs and factors including liver and spleen stiffness measured by ARFI, biochemical tests, and other noninvasive measurements, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), platelet count (PLT), spleen diameter (SD), PLT to SD ratio, AST to ALT ratio (AAR) score, the AST to PLT ratio index (APRI) score. RESULTS: A univariate analysis revealed that the AAR score, APRI score, PLT, PLT/SD ratio, and spleen elastography variables were all independently associated with EVs (p<0.05). On multivariate analysis, only spleen elastography was associated with EVs (p=0.001). However, in cases of alcohol-induced liver cirrhosis, spleen stiffness was not reliable for the prediction of EVs. CONCLUSION: Spleen elastography measured using ARFI may serve as a non-invasive method for determining the presence of EVs. However, it is not an appropriate predictor for EVs in alcoholic cirrhosis.

Effect of visceral fat area on outcomes of laparoscopyassisted distal gastrectomy for gastric cancer: subgroup analysis by gender and parameters of obesity.

PURPOSE: The aim of this study was to investigate the impact of the visceral fat area (VFA) of patients with gastric cancer undergoing laparoscopic surgery on operative outcomes such as number of retrieved lymph nodes (LNs) and operative time. METHODS: We retrospectively reviewed the medical records and the CT scans of 597 patients with gastric cancer who underwent laparoscopy assisted distal gastrectomy (LADG) with partial omentectomy and LN dissection (>D1 plus beta). Patients were stratified by gender, VFA, and body mass index (BMI), and the clinicopathologic characteristics and operative outcomes were evaluated. Multiple linear regression analysis was used to assess the effects of VFA and BMI on the number of retrieved LNs and operative time in male and female patients. RESULTS: The mean number of retrieved LNs was significantly decreased for both male and female patients with high VFA. The operative time was significantly longer for both male and female patients with high VFA. The number of retrieved LNs had a statistically significant negative correlation with VFA in both men and women, but not with BMI. The operative time had a statistically significant positive correlation with VFA in men, whereas the operative time had a statistically significant positive correlation with BMI in women. CONCLUSION: The preoperative VFA of male patients with gastric cancer who undergo LADG may affect the number of retrieved LNs and operative time. VFA was more useful than BMI for predicting outcomes of LADG.

Initial phantom study comparing image quality in computed tomography using adaptive statistical iterative reconstruction and new adaptive statistical iterative reconstruction v.

PURPOSE: The purpose of this study was to assess the image quality of a novel advanced iterative reconstruction (IR) method called as "adaptive statistical IR V" (ASIR-V) by comparing the image noise, contrast-to-noise ratio (CNR), and spatial resolution from those of filtered back projection (FBP) and adaptive statistical IR (ASIR) on computed tomography (CT) phantom image. MATERIALS AND METHODS: We performed CT scans at 5 different tube currents (50, 70, 100, 150, and 200 mA) using 3 types of CT phantoms. Scanned images were subsequently reconstructed in 7 different scan settings, such as FBP, and 3 levels of ASIR and ASIR-V (30%, 50%, and 70%). The image noise was measured in the first study using body phantom. The CNR was measured in the second study using contrast phantom and the spatial resolutions were measured in the third study using a high-resolution phantom. We compared the image noise, CNR, and spatial resolution among the 7 reconstructed image scan settings to determine whether noise reduction, high CNR, and high spatial resolution could be achieved at ASIR-V. RESULTS: At quantitative analysis of the first and second studies, it showed that the images reconstructed using ASIR-V had reduced image noise and improved CNR compared with those of FBP and ASIR (P < 0.001). At qualitative analysis of the third study, it also showed that the images reconstructed using ASIR-V had significantly improved spatial resolution than those of FBP and ASIR (P < 0.001). CONCLUSIONS: Our phantom studies showed that ASIR-V provides a significant reduction in image noise and a significant improvement in CNR as well as spatial resolution. Therefore, this technique has the potential to reduce the radiation dose further without compromising image quality.

Serial change of liver stiffness measured by acoustic radiation force impulse imaging in chronic liver disease: correlation with biochemical markers.

PURPOSE: In patients with chronic diffuse liver diseases, liver fibrosis severity is an important element for prognosis and for selecting therapy. Acoustic radiation force impulse (ARFI) imaging techniques were recently developed to measure liver fibrosis, but their specificity is impaired by cholestasis, inflammation, or edema in acute hepatitis. Herein, our objectives were to evaluate serial changes in shear wave velocity (SWV) and to correlate these changes with biochemical activity. METHODS: This study included 108 patients who underwent ARFI because of viral hepatitis [hepatitis B (HBV) or C (HCV)] with serial follow-up after 3-6 months at our institution between August 2011 and May 2013. Based on baseline and follow-up ARFI, we divided patients with HBV and HCV into two groups: a decreasing SWV group and a non-decreasing SWV group. We evaluated serial SWV changes and correlated these changes with biochemical activity changes. RESULTS: The patients were divided into SWV groups as follows: decreasing SWV group (HBV, n = 23; HCV, n = 7) and non-decreasing SWV group (HBV, n = 40; HCV, n = 38). In both HBV and HVC patients, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were significantly decreased at follow-up in the decreasing SWV group. CONCLUSIONS: The liver stiffness value assessed by ARFI became lower over time in patients who had decreasing AST and ALT levels. According to this study, ARFI overestimates fibrosis grade in patients with high AST and ALT. Thus, assessment of liver fibrosis by ARFI elastography should include consideration of biochemical markers such as AST and ALT levels and additional follow-up using ARFI elastography.

Comparative study of shear wave velocities using acoustic radiation force impulse technology in hepatocellular carcinoma: the extent of radiofrequency ablation.

BACKGROUND/AIMS: The purpose of this study was to assess the value of acoustic radiation force impulse (ARFI) for predicting the extent of radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) by correlating the elasticity of HCC and peritumoral parenchyma (as measured by ARFI) with the extent of ablation determined by computed tomography (CT). METHODS: From September 2009 to June 2011, 158 patients underwent RFA ablation for HCC (single, ≤3 cm). We evaluated the data of a total of 38 prospectively enrolled patients who underwent both ARFI imaging and contrast-enhanced CT after one session of 12 minutes of RFA without a change in needle position. The ARFI imaging indices, including the mean shear wave velocity (SWV) of HCC, mean SWV of the peritumoral parenchyma and tumor size, were evaluated to determine the statistical correlation with RFA extent after one session of 12 minutes of RFA. RESULTS: A stiffer liver parenchyma in patients with cirrhosis results in a smaller ablation zone. CONCLUSIONS: SWV of ARFI in liver parenchyma was well correlated with RFA extent. After evaluating the correlation between ARFI and RFA extent, we suggest that the SWV in liver parenchyma might be a non-invasive supplementary tool for predicting the extent of RFA.

Acoustic radiation force impulse elastography for hepatocellular carcinoma-associated radiofrequency ablation.

AIM: To evaluate the potential usefulness of acoustic radiation force impulse (ARFI) images for evaluation of hepatocellular carcinomas (HCC)-associated radiofrequency ablation. METHODS: From January 2010 to June 2010, a total of 38 patients with HCC including recurred HCCs after RFA underwent ARFI elastography. The brightness of tumor was checked and the shear wave velocity was measured for the quantification of stiffness. According to the brightness, the tumors were classified as brighter, same color and darker compared with adjacent parenchyma. Using the same methods, 8 patients with recurred HCCs after RFA state were evaluated about the brightness compared with adjacent RFA ablation area. RESULTS: In the 38 patients with HCCs, 20 (52.6%) were brighter than surrounding cirrhotic parenchyma. Another 13 (34.2%) were darker. The others (5 cases, 13.2%) were seen as the same color as the adjacent liver parenchyma. Post-RFA lesions were darker than previous tumor and surrounding parenchyma in all 38 cases. However, recurred HCCs were brighter than the treated site in all 8 cases. CONCLUSION: Using ARFI technique is helpful for differential diagnosis in order to detect recurred HCCs more easily in patients with confusing status.

Actinomycosis of the appendix mimicking appendiceal tumor: a case report.

Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the appendix, is the most commonly involved site. In some reports, limited appendiceal actinomycosis has revealed a thickened appendiceal wall with peri-appendiceal inflammation as acute appendicitis or perforated appendicitis. We experienced pathologically confirmed intraluminal limited appendiceal actinomycosis without peri-appendiceal infiltration. Here, we report the computed tomography and ultrasound findings.

Ultrasonographic evidence of phenotypic instability during hepatocarcinogenesis in N-nitrosomorpholine-treated rats.

Carcinogen-induced hepatoma in immunocompetent animal models has shown a progress similar to the clinical course of human hepatoma. Ultrasonography (US) was used for consecutive evaluation of the phenotypic changes in Sprague-Dawley rats exposed for 8 weeks to N-nitrosomorpholine (NNM, 200 mg/L). Three distinctive US findings were ascites, coarseness (defined as small and heterogeneously widespread increased echogenecity), and nodularity (defined as a >0.6-cm-sized echogenic region and clearly showing a tumor-like mass). Abdominal ascites was observed in 5 of 26 rats at week 8 NNM posttreatment and the number of rats showing ascites gradually increased. Coarseness (22 of 26 rats) and nodularity (1 of 18) appeared at weeks 8 and 17 NNM posttreatment, respectively. The gross and histological findings indicated that coarseness and nodularity shown in US reflected fibrosis and hepatocellular carcinoma or cholangiofibroma, respectively. The computer-aided quantification of coarseness and nodularity showed that the regression-linked phenotypic instability was present in coarseness but not in nodularity. We conclude that the heterogeneity of preneoplasia in NNM-treated rats might be induced by phenotypic instability rather than random initiating events of preneoplastic lesion.