Comparison of Ablation Performance between Octopus Multipurpose Electrode and Conventional Octopus Electrode

Objective@#To compare Octopus multipurpose (MP) electrodes, which are capable of saline instillation and direct tissue temperature measurement, and conventional electrodes for radiofrequency ablation (RFA) in porcine livers in vivo. @*Materials and Methods@#Sixteen pigs were used in this study. In the first experiment, RFA was performed in the liver for 6 minutes using Octopus MP electrodes (n = 15 ablation zones) and conventional electrodes (n = 12 ablation zones) to investigate the effect of saline instillation. The ablation energy, electrical impedance, and ablation volume of the two electrodes were compared. In the second experiment, RFA was performed near the gallbladder (GB) and colon using Octopus MP electrodes (n = 12 ablation zones for each) with direct tissue temperature monitoring and conventional electrodes (n = 11 ablation zones for each). RFA was discontinued when the temperature increased to > 60°C in the Octopus MP electrode group, whereas RFA was performed for a total of 6 minutes in the conventional electrode group. Thermal injury was assessed and compared between the two groups by pathological examination. @*Results@#In the first experiment, the ablation volume and total energy delivered in the Octopus MP electrode group were significantly larger than those in the conventional electrode group (15.7 ± 4.26 cm3 vs. 12.5 ± 2.14 cm3 , p = 0.027; 5.48 ± 0.49 Kcal vs. 5.04 ± 0.49 Kcal, p = 0.029). In the second experiment, thermal injury to the GB and colon was less frequently noted in the Octopus MP electrode group than that in the conventional electrode group (16.7% [2/12] vs. 90.9% [10/11] for GB and 8.3% [1/12] vs. 90.9% [10/11] for colon, p < 0.001 for all). The total energy delivered around the GB (2.65 ± 1.07 Kcal vs. 5.04 ± 0.66 Kcal) and colon (2.58 ± 0.57 Kcal vs. 5.17 ± 0.90 Kcal) were significantly lower in the Octopus MP electrode group than that in the conventional electrode group (p < 0.001 for all). @*Conclusion@#RFA using the Octopus MP electrodes induced a larger ablation volume and resulted in less thermal injury to the adjacent organs compared with conventional electrodes.

Quantitative Ultrasound Radiofrequency Data Analysis for the Assessment of Hepatic Steatosis in Nonalcoholic Fatty Liver Disease Using Magnetic Resonance Imaging Proton Density Fat Fraction as the Reference Standard

Objective@#To investigate the diagnostic performance of quantitative ultrasound (US) parameters for the assessment of hepatic steatosis in patients with nonalcoholic fatty liver disease (NAFLD) using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard. @*Materials and Methods@#In this single-center prospective study, 120 patients with clinically suspected NAFLD were enrolled between March 2019 and January 2020. The participants underwent US examination for radiofrequency (RF) data acquisition and chemical shift-encoded liver MRI for PDFF measurement. Using the RF data analysis, the attenuation coefficient (AC) based on tissue attenuation imaging (TAI) (AC-TAI) and scatter-distribution coefficient (SC) based on tissue scatterdistribution imaging (TSI) (SC-TSI) were measured. The correlations between the quantitative US parameters (AC and SC) and MRI-PDFF were evaluated using Pearson correlation coefficients. The diagnostic performance of AC-TAI and SC-TSI for detecting hepatic fat contents of ≥ 5% (MRI-PDFF ≥ 5%) and ≥ 10% (MRI-PDFF ≥ 10%) were assessed using receiver operating characteristic (ROC) analysis. The significant clinical or imaging factors associated with AC and SC were analyzed using linear regression analysis. @*Results@#The participants were classified based on MRI-PDFF: < 5% (n = 38), 5–10% (n = 23), and ≥ 10% (n = 59). AC-TAI and SC-TSI were significantly correlated with MRI-PDFF (r = 0.659 and 0.727, p < 0.001 for both). For detecting hepatic fat contents of ≥ 5% and ≥ 10%, the areas under the ROC curves of AC-TAI were 0.861 (95% confidence interval [CI]: 0.786– 0.918) and 0.835 (95% CI: 0.757–0.897), and those of SC-TSI were 0.964 (95% CI: 0.913–0.989) and 0.935 (95% CI: 0.875–0.972), respectively. Multivariable linear regression analysis showed that MRI-PDFF was an independent determinant of AC-TAI and SC-TSI. @*Conclusion@#AC-TAI and SC-TSI derived from quantitative US RF data analysis yielded a good correlation with MRI-PDFF and provided good performance for detecting hepatic steatosis and assessing its severity in NAFLD.

Quantitative Ultrasound Radiofrequency Data Analysis for the Assessment of Hepatic Steatosis in Nonalcoholic Fatty Liver Disease Using Magnetic Resonance Imaging Proton Density Fat Fraction as the Reference Standard

Objective@#To investigate the diagnostic performance of quantitative ultrasound (US) parameters for the assessment of hepatic steatosis in patients with nonalcoholic fatty liver disease (NAFLD) using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard. @*Materials and Methods@#In this single-center prospective study, 120 patients with clinically suspected NAFLD were enrolled between March 2019 and January 2020. The participants underwent US examination for radiofrequency (RF) data acquisition and chemical shift-encoded liver MRI for PDFF measurement. Using the RF data analysis, the attenuation coefficient (AC) based on tissue attenuation imaging (TAI) (AC-TAI) and scatter-distribution coefficient (SC) based on tissue scatterdistribution imaging (TSI) (SC-TSI) were measured. The correlations between the quantitative US parameters (AC and SC) and MRI-PDFF were evaluated using Pearson correlation coefficients. The diagnostic performance of AC-TAI and SC-TSI for detecting hepatic fat contents of ≥ 5% (MRI-PDFF ≥ 5%) and ≥ 10% (MRI-PDFF ≥ 10%) were assessed using receiver operating characteristic (ROC) analysis. The significant clinical or imaging factors associated with AC and SC were analyzed using linear regression analysis. @*Results@#The participants were classified based on MRI-PDFF: < 5% (n = 38), 5–10% (n = 23), and ≥ 10% (n = 59). AC-TAI and SC-TSI were significantly correlated with MRI-PDFF (r = 0.659 and 0.727, p < 0.001 for both). For detecting hepatic fat contents of ≥ 5% and ≥ 10%, the areas under the ROC curves of AC-TAI were 0.861 (95% confidence interval [CI]: 0.786– 0.918) and 0.835 (95% CI: 0.757–0.897), and those of SC-TSI were 0.964 (95% CI: 0.913–0.989) and 0.935 (95% CI: 0.875–0.972), respectively. Multivariable linear regression analysis showed that MRI-PDFF was an independent determinant of AC-TAI and SC-TSI. @*Conclusion@#AC-TAI and SC-TSI derived from quantitative US RF data analysis yielded a good correlation with MRI-PDFF and provided good performance for detecting hepatic steatosis and assessing its severity in NAFLD.

No-Touch Radiofrequency Ablation of VX2 Hepatic Tumors In Vivo in Rabbits: A Proof of Concept Study

OBJECTIVE: In a proof of concept study, we compared no-touch radiofrequency ablation (NtRFA) in bipolar mode with conventional direct tumor puncture (DTP) in terms of local tumor control (LTC), peritoneal seeding, and tumorigenic factors, in the rabbit VX2 subcapsular hepatic tumor model. MATERIALS AND METHODS: Sixty-two rabbits with VX2 subcapsular hepatic tumors were divided into three groups according to the procedure: DTP-RFA (n = 25); NtRFA (n = 25); and control (n = 12). Each of the three groups was subdivided into two sets for pathologic analysis (n = 24) or computed tomography (CT) follow-up for 6 weeks after RFA (n = 38). Ultrasonography-guided DTP-RFA and NtRFA were performed nine days after tumor implantation. LTC was defined by either achievement of complete tumor necrosis on histopathology or absence of local tumor progression on follow-up CT and autopsy. Development of peritoneal seeding was also compared among the groups. Serum hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) were measured via ELISA (Elabscience Biotechnology Co.) after RFA for tumorigenic factor evaluation. RESULTS: Regarding LTC, there was a trend in NtRFA (80%, 20/25) toward better ablation than in DTP-RFA (56%, 14/25) (p = 0.069). Complete tumor necrosis was achieved in 54.5% of DTP-RFA (6/11) and 90.9% of NtRFA (10/11). Peritoneal seeding was significantly more common in DTP-RFA (71.4%, 10/14) than in NtRFA (21.4%, 3/14) (p = 0.021) or control (0%). Elevations of HGF, VEGF or IL-6 were not detected in any group. CONCLUSION: No-touch radiofrequency ablation led to lower rates of peritoneal seeding and showed a tendency toward better LTC than DTP-RFA.

Prospective Validation of Intra- and Interobserver Reproducibility of a New Point Shear Wave Elastographic Technique for Assessing Liver Stiffness in Patients with Chronic Liver Disease

OBJECTIVE: To assess intra- and inter-observer reproducibility of a new point shear wave elastography technique (pSWE, S-Shearwave, Samsung Medison) and compare its accuracy in assessing liver stiffness (LS) with an established pSWE technique (Virtual Touch Quantification, VTQ). MATERIALS AND METHODS: Thirty-three patients were enrolled in this Institutional Review Board-approved prospective study. LS values were measured by VTQ on an Acuson S2000 system (Siemens Healthineer) and S-Shearwave on an RS-80A (Samsung Medison) in the same session, followed by two further S-Shearwave sessions for inter- and intra-observer variation at 8-hour intervals. The technical success rate (SR) and reliability of the measurements of both pSWE techniques were compared. The intra- and inter-observer reproducibility of S-Shearwave was determined by intraclass correlation coefficients (ICCs). LS values were measured by both methods of pSWE. The diagnostic performance in severe fibrosis (F ≥ 3) and cirrhosis (F = 4) was evaluated using the receiver operating characteristics curve analysis and the Obuchowski measure with the LS values of transient elastography as the referenced standard. RESULTS: The VTQ (100%, 33/33) and S-Shearwave (96.9%, 32/33) techniques did not display a significant difference in technical SR (p = 0.63) or reliability of LS measurements (96.9%, 32/33; 93.9%, 30/32, respectively, p = 0.61). The inter- and intra-observer agreement for LS measurements using the S-Shearwave technique was excellent (ICC = 0.98 and 0.99, respectively). The mean LS values of both pSWE techniques were not significantly different and exhibited a good correlation (r = 0.78). To detect F ≥ 3 and F = 4, VTQ and S-Shearwave showed comparable diagnostic accuracy as indicated by the following outcomes: areas under receiver operating characteristics curve (AUROC) = 0.87 (95% confidence intervals [CI] 0.70–0.96), 0.89 for VTQ (95% CI 0.74–0.97), respectively; and AUROC = 0.84 (95% CI 0.67–0.94), 0.94 (95% CI 0.80–0.99) for S-Shearwave (p > 0.48), respectively. The Obuchowski measures were similarly high for S-Shearwave and VTQ (0.94 vs. 0.95). CONCLUSION: S-Shearwave shows excellent inter- and intra-observer agreement and diagnostic effectiveness comparable to VTQ in detecting LS.

Correlation between peripheral venous and arterial blood gas measurements in patients admitted to the intensive care unit: A single-center study

BACKGROUND: The objective of this study was to examine the correlation between arterial blood gas (ABG) and peripheral venous blood gas (VBG) samples for all commonly used parameters in patients admitted to a medical intensive care unit (ICU). METHODS: A single-center, prospective trial was carried out in a medical ICU in order to determine the level of correlation of ABG and peripheral VBG measurements. A maximum of five paired ABG-VBG samples were obtained per patient to prevent a single patient from dominating the data set. RESULTS: Regression equations were derived to predict arterial values from venous values as follows: arterial pH=-1.108+1.145xvenous pH+0.008xPCO2-0.012xvenous HCO3+0.002xvenous total CO2 (R2=0.655), arterial PCO2=88.6-10.888xvenous pH+0.150xPCO2+0.812xvenous HCO3+0.124xvenous total CO2 (R2=0.609), arterial HCO3=-89.266+12.677xvenous pH+0.042xPCO2+0.675xvenous HCO3+0.185xvenous total CO2 (R2=0.782). The mean ABG minus peripheral VBG differences for pH, PCO2, and bicarbonates were not clinically important for between-person heterogeneity. CONCLUSION: Peripheral venous pH, PCO2, bicarbonates, and total CO2 may be used as alternatives to their arterial equivalents in many clinical contexts encountered in the ICU.

Correlation between peripheral venous and arterial blood gas measurements in patients admitted to the intensive care unit: A single-center study

BACKGROUND: The objective of this study was to examine the correlation between arterial blood gas (ABG) and peripheral venous blood gas (VBG) samples for all commonly used parameters in patients admitted to a medical intensive care unit (ICU). METHODS: A single-center, prospective trial was carried out in a medical ICU in order to determine the level of correlation of ABG and peripheral VBG measurements. A maximum of five paired ABG-VBG samples were obtained per patient to prevent a single patient from dominating the data set. RESULTS: Regression equations were derived to predict arterial values from venous values as follows: arterial pH=-1.108+1.145xvenous pH+0.008xPCO2-0.012xvenous HCO3+0.002xvenous total CO2 (R2=0.655), arterial PCO2=88.6-10.888xvenous pH+0.150xPCO2+0.812xvenous HCO3+0.124xvenous total CO2 (R2=0.609), arterial HCO3=-89.266+12.677xvenous pH+0.042xPCO2+0.675xvenous HCO3+0.185xvenous total CO2 (R2=0.782). The mean ABG minus peripheral VBG differences for pH, PCO2, and bicarbonates were not clinically important for between-person heterogeneity. CONCLUSION: Peripheral venous pH, PCO2, bicarbonates, and total CO2 may be used as alternatives to their arterial equivalents in many clinical contexts encountered in the ICU.

The Efficacy of Antiviral Agents in Patients with Hepatitis B-related Liver Cirrhosis / 고신대학교의과대학학술지

OBJECTIVES: Improvement of liver synthetic function and the incidence of complication in the patients with hepatitis B-related liver cirrhosis is important. In this study, we study whether antiviral therapy was effective in patients with hepatitis B-related liver cirrhosis. METHODS: 103 patients with hepatitis B-related liver cirrhosis treated with lamivudine 100mg daily over 6 months and followed up over 30 months. 71 patients were positive for serum HBeAg. HBeAg, HBV DNA , CBC, prothrombin time, biochemistry, ultrasonography and endoscopy were tested every 6 months. RESULTS: The medians of ALT, albumin improved after 6 months and then aggravated after 18 months, but they didn't aggravated at 30 months compared with initial test. The median of Child-turcotte-pugh (CTP) score imporved after 6 months and then aggravated after 12 months, but they didn't aggravated at 30 months compared with initial test. The CTP score improved (2 point reduction) in 29 patients. The finding of ultrasonography didn't aggravaed (improved or didn't changed) in 58 patients. The 5 year incidence rate of hepatocelluar carcinoma was 8.3%. CONCLUSIONS: The antiviral therapy in patients with hepatitis B-related liver cirrhosis is improved CTP score and biochmical data. The improvement is more useful in decompensated cirrhosis the compensated cirrhosis. The incidence of hepatocellular carcinoma decreases than other studies. Therefore, the antiviral medication in patients with hepatitis B-related liver cirrhosis is helpful to consider more aggressively.

A Case of Mediastinal Ectopic Thyroid Tissue Diagnosed by Endobronchial Ultrasound Guided Transbronchial Needle Aspiration / 고신대학교의과대학학술지

A 77-year old woman was referred to hospital with dyspnea and chest dull pain for 5 months. The chest radiograph showed a mass located in the mediastinum. Trachea was deviated to right side. Chest computed tomography showed an enhancing large mass at the middle mediastinum. Endobronchial ultrasonography showed hyperechoic mediastinal mass. We performed endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA). Histologic finding was thyroid tissue with a benign looking papilla. Ectopic thyroid is an uncommon embryological aberration characterized by the presence of thyroid tissue in a site other than in its usual pretracheal region. It occurs along the path of descent of the developing thyroid primodium from the foramen cecum. It is extremely rare for mediastinal ectopic thyroid tissue diagnosised by EBUS-TBNA, so we report here on a case of mediastinal ectopic thyroid and we review the relevant medical literature.

A Case of Pancreatic Dual Wirsung Ducts in a Patient with von Hippel-Lindau Disease / 대한소화기내시경학회지

Rare autosomal dominant disorders associated with various tumors and cysts, and several kinds of pancreatic lesions have been described in patients with von Hippel- Lindau (VHL) disease, but there have been few studies concerned with the variations of the pancreatic duct. We experienced a case of pancreatic dual Wirsung ducts in a patient with VHL disease. Computed tomography scans showed that multiple cysts had nearly completely replaced the pancreas, there was a solid tumor on the uncinate process of the pancreas and a left renal mass suggested renal cell carcinoma. ERCP shows that the Santorini duct and Wirsung duct were fused in a normal fashion, and another Wirsung duct had shrub-like branches that are commonly seen in pancreatic divisum.