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BACKGROUND Red dichromatic imaging (RDI) is a novel image-enhanced endoscopy released in 2020, which increases the visibility of deeper vessels. In this study, we retrospectively investigated whether RDI can shorten treatment times of endoscopic injection sclerotherapy (EIS), and which operational procedure times are affected compared with white light imaging (WLI). METHODS A total of 155 patients (RDI, 70; WLI, 85) with risky esophageal varices (EV), who were treated with EIS were analyzed. Treatment times were compared, and predictors associated with treatment time were analyzed by multivariate analysis. For 24 cases (RDI, 12; WLI, 12) in which treatment videos were recorded, the procedure times of each step (observation of EV, needle flush, positioning, puncture, observation of bleeding, hemostasis, observation after hemostasis) were measured. Regarding the seven patients with EV bleeding, color differences were calculated between the bleeding point and the blood pool using the CIE (L*a*b*) color measurement method, and results were compared between using RDI and WLI. RESULTS Treatment times were shorter in the RDI group (RDI vs. WLI = 35.1 vs. 42.2 min; P

Background Nonalcoholic steatohepatitis (NASH) is diagnosed with histopathologic testing, but noninvasive surrogate markers are desirable for screening patients who are at high risk of NASH. Purpose To investigate the diagnostic performance of dispersion slope, attenuation coefficient, and shear-wave speed measurements obtained using two-dimensional (2D) shear-wave elastography (SWE) in assessing inflammation, steatosis, and fibrosis and in the noninvasive diagnosis of NASH in patients suspected of having nonalcoholic fatty liver disease (NAFLD). Materials and Methods This prospective study collected data from 120 consecutive adults who underwent liver biopsy for suspected NAFLD and were enrolled between April 2017 and March 2019. Three US parameters (dispersion slope [(m/sec)/kHz], attenuation coefficient [dB/cm/MHz], and shear-wave speed [in meters per second]) were measured using a 2D SWE system immediately before biopsy. The biopsy specimens were scored by one expert pathologist according to the Nonalcoholic Steatohepatitis Clinical Research Network criteria (119 participants underwent a histologic examination). Diagnostic performance was assessed using the area under the receiver operating characteristic curve (AUC) for the categories of inflammation, steatosis, and fibrosis. Results One hundred eleven adults (mean age, 53 years ± 18 [standard deviation]; 57 men) underwent a US examination. Dispersion slope enabled the identification of lobular inflammation, with an AUC of 0.95 (95% confidence interval [CI]: 0.91, 0.10) for an inflammation grade greater than or equal to A1 (mild), 0.81 (95% CI: 0.72, 0.89) for an inflammation grade greater than or equal to A2 (moderate), and 0.85 (95% CI: 0.74, 0.97) for an inflammation grade equal to A3 (marked). Attenuation coefficient enabled the identification of steatosis, with an AUC of 0.88 (95% CI: 0.80, 0.97) for steatosis grade greater than or equal to S1 (mild), 0.86 (95% CI: 0.79, 0.93) for steatosis grade greater than or equal to S2 (moderate), and 0.79 (95% CI: 0.68, 0.89) for steatosis grade equal to S3 (severe). Shear-wave speed enabled the identification of fibrosis, with an AUC of 0.79 (95% CI: 0.69, 0.88) for fibrosis stage greater than or equal to F1 (portal fibrosis), 0.88 (95% CI: 0.82, 0.94) for fibrosis stage greater than or equal to F2 (periportal fibrosis), 0.90 (95% CI: 0.84, 0.96) for fibrosis stage greater than or equal to F3 (septal fibrosis), and 0.95 (95% CI: 0.91, 0.99) for fibrosis stage equal to F4 (cirrhosis). The combination of dispersion slope, attenuation coefficient, and shear-wave speed showed an AUC of 0.81 (95% CI: 0.71, 0.91) for the diagnosis of NASH. Conclusion Dispersion slope, attenuation coefficient, and shear-wave speed were found to be useful for assessing lobular inflammation, steatosis, and fibrosis, respectively, in participants with biopsy-proven nonalcoholic fatty liver disease. © RSNA, 2020

Irreversible electroporation (IRE) is a novel form of soft tissue ablation therapy that uses high-current electrical pulses to induce the formation of pores in the cell membrane, leading to cell death. Although outcome data for the ablation of hepatocellular carcinoma (HCC) by IRE are limited, early results are encouraging and may suggest equivalency to the outcomes achieved by thermal ablation methods such as radiofrequency ablation (RFA) and microwave ablation (MWA). However, IRE can be a challenging and very time-consuming procedure compared to RFA and MWA. In this review article, we not only evaluate the efficacy and safety of IRE for the treatment of HCC, but also discuss imaging guidance, ablation monitoring, and endpoint assessment, with a particular focus on ultrasonography.

To investigate the efficacy of application of VCM powder to surgical wounds. A total of 314 patients who underwent posterior spinal instrumentation with local application of VCM (VCM group) were compared to 354 patients without VCM (control). The wound drainage tube was submitted for bacterial culture. The number of positive cultures, types of bacteria, and incidence of surgical site infections (SSI) were investigated. Drainage tube culture was positive in 1.6% (5/314 cases) and 7.3% (26/354 cases) of the VCM and control groups, respectively (P = 0.004). Among the five positive cases in the VCM group, one had an SSI, compared to three of 26 in the control group. Among the culture-negative cases, 0 and six, respectively, had an SSI. Finally, the incidence of SSI was 0.3% (1/314 cases) and 2.5% (9/354 cases), respectively. SSI occurred significantly less often in the VCM than in the control group (P = 0.01). The pathogenic bacterium was P. aeruginosa in the VCM group and MSSE, S. marcescens, methicillin-resistant S. aureus (MRSA), etc., in the control group. This study indicates that the amount of bacteria in the operative field was decreased by local application of VCM. However, the incidence of positive culture of VCM-resistant bacteria was not decreased by VCM. Importantly, pathogenic bacteria in the VCM group were only VCM-resistant, supporting the efficacy of VCM. In conclusion, local application of VCM decreases the amount of bacteria in the operative field and leads to fewer SSIs.

Background & Aims: Direct-acting antiviral agents (DAAs) and the risk of hepatocellular carcinoma (HCC) is controversially reported in the literature. The primary endpoints of this study were to clarify the cumulative incidence and recurrence rate of HCC after DAA treatment. The secondary endpoints were to identify the factors associated with the occurrence or recurrence of HCC after DAAs treatment.Methods: Of 234 HCV patients, 211 with no history of HCC (no-HCC-history group) and 23 with previous treated HCC history (HCC-history group) were treated with DAAs and followed for more than 24 weeks to determine the incidence of HCC. Platelet count, albumin, α-fetoprotein (AFP) level, L3%, the FIB-4 index and APRI scores were analyzed as possible factors associated with HCC occurrence and recurrence. An intergroup comparison was made of the cumulative incidence of HCC. Cox proportional hazards regression was used to determine associations between blood test values and risk of HCC.Results: The median observation period was 21 months. Cumulative incidence of HCC was higher in the HCChistory group than in the no-HCC-history group (p < 0.0001, 19.0 and 0.52 per 100 patient-years, respectively). Univariate analysis revealed platelet count, albumin, α-fetoprotein (AFP) level, AFP-L3%, and FIB-4 index and APRI scores at the end of DAA treatment as being significantly associated with occurrence/recurrence of HCC. Multivariate analysis revealed that AFP levels before and after the administration of DAAs and AFP-L3% after DAA were independently associated with the occurrence/recurrence of HCC (p = 0.045, 0.043, 0.005, respectively).Conclusion: The HCC occurrence rate after DAA treatment was very low, and the recurrence rate lower than that in previous interferon reports. The AFP level and AFP-L3% were identified as important factors in predicting occurrence/recurrence of HCC. Careful observation is needed when increased levels of AFP or AFP-L3% after DAAs treatment are observed.

Measurement of spleen stiffness (SS) using ultrasound (US) elastography is useful for predicting portal hypertension. However, the mechanism leading to increased SS remains unclear. We jointly developed a new US elastography system (Aplio i-series, Canon Medical Systems) that can easily measure organ viscosity (dispersion slope: DS). We analyzed the cause of increased SS by calculating the shear wave speed (SWs, which reflects fibrosis) and DS of the spleen in carbon tetrachloride (CCL4) rat liver cirrhosis models. A total of 13 Sprague–Dawley rats were randomly divided into four groups (C group: 3 rats as control, 2D group: 3 rats injected with CCL4 twice in 1 week, 4D group: 4 rats injected 4 times in 1 week, 6W group: 3 rats injected twice a week for 6 weeks). The SWs and the DS of each group were calculated, and histopathological analysis was performed. The spleen SWs of the 6W group was significantly higher than that of the C group (p = 0.044). The spleen DS did not change after CCL4. The liver SWs of the 4D and 6W groups was significantly higher than that of the C group (p = 0.012 and 0.007, respectively) with fibrosis change on histopathology, and the DS of the 4D group was significantly higher than that of the C group (p = 0.033). Splenic fibrosis was confirmed in the 6W group, but inflammation and necrosis were not seen. SS increased due to fibrosis and can be predicted based on SWs and DS values.

The Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) was introduced for classifying suspected hepatocellular carcinoma (HCC). However, it cannot be applied to Sonazoid. We assessed the diagnostic usefulness of a modified CEUS LI-RADS for HCC and non-HCC malignancies based on sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Patients with chronic liver disease at risk for HCC were evaluated retrospectively. Nodules ≥1 cm with arterial phase hyperenhancement, no early washout (within 60 s), and contrast defects in the Kupffer phase were classified as LR-5. Nodules showing early washout, contrast defects in the Kupffer phase, and/or rim enhancement were classified as LR-M. A total of 104 nodules in 104 patients (median age: 70.0 years; interquartile range: 54.5–78.0 years; 74 men) were evaluated. The 48 (46.2%) LR-5 lesions included 45 HCCs, 2 high-flow hemangiomas, and 1 adrenal rest tumor. The PPV of LR-5 for HCC was 93.8% (95% confidence interval (CI): 82.8–98.7%). The 22 (21.2%) LR-M lesions included 16 non-HCC malignancies and 6 HCCs. The PPV of LR-M for non-HCC malignancies, including six intrahepatic cholangiocarcinomas, was 100% (95% CI: 69.8–100%). In conclusion, in the modified CEUS LI-RADS for Sonazoid, LR-5 and LR-M are good predictors of HCC and non-HCC malignancies, respectively.

Background Despite repeated efforts for accurate cervical pedicle screw insertion, malpositioning of the inserted screw is commonly noted. To avoid neurovascular complications during cervical pedicle screw insertion, we have developed a new patient-specific screw guide system. This study aimed to evaluate the accuracy of cervical PS placement using the new patient-specific screw guide system. Methods This study is a retrospective clinical evaluation of prospectively enrolled patients. Seventeen consecutively enrolled patients who underwent posterior cervical fusion using the guide system were included. Firstly, three-dimensional planning of pedicle screw placement was done using simulation software. A screw guide for each vertebra was constructed preoperatively. A total of 77 screws were inserted with the guides. Postoperative computed tomography was used to evaluate pedicle perforation, and screw deviations, between the planned and actual screw positions, were measured. Results A total of 76 screws (98.7%) were completely inside the pedicle (C3-7), without neurovascular injuries. The mean screw deviations from the planned trajectory at the narrowest point of the pedicle and at the entry point in the axial and sagittal planes were 0.56 ± 0.43 mm and 0.43 ± 0.35 mm and 0.43 ± 0.30 mm and 0.63 ± 0.50 mm, respectively. There were no significant differences in any parameter at different spinal levels. Angular deviations in the sagittal and axial planes were 2.94 ± 2.04° and 2.53 ± 1.85°, respectively. Sagittal angular deviations tended to increase in the cranial vertebra (C3 and C4) compared to the middle cervical spine. Conclusions We demonstrated that our patient-specific screw guide is vital for guiding precise screw insertion in the cervical pedicle. This technique may be an effective solution for achieving precise screw insertion and reducing the incidence of complications.

To investigate the usefulness of shear-wave speed and dispersion slope measurements obtained, using an ultrasound elastography system in rat livers with various degrees of necroinflammation and fibrosis. A total of 25 male Sprague Dawley rats were randomly divided into 5 groups of 5 rats each: G0 (control), G1 (CCl4 injected twice a week for 1 wk), G2 (CCl4 injected four times a wk for 1 wk), G3 (CCl4 injected twice a wk for 6 wk) and G4 (CCl4 injected twice a wk for 10 wk). The shear-wave speed (m/s) and the dispersion slope ([m/s]/kHz) were measured. Histologic features (inflammation, necrosis and fibrosis) were used as reference standards. In multivariable analysis with histologic features as independent variables, the fibrosis grade was significantly related to shear-wave speed (p < 0.05) and the necrosis grade was significantly related to dispersion slope (p < 0.05). Dispersion slope is more useful than shear-wave speed for predicting the degree of necroinflammation.

A 27-year-old woman with colon cancer and liver metastasis was referred to our hospital. Colectomy and colostomy were performed to improve her ileus. Following 13 sessions of oxaliplatin-based chemotherapy (OC) with mFOLFOX6 + bevacizumab, thrombocytopenia and frequent peristomal bleeding occurred. Computed tomography showed severe ascites, splenomegaly, significant collateral veins around the stoma, and severe stenosis of the hepatic veins (HV) and inferior vena cava (IVC). Ultrasound elastography showed high liver (and spleen) stiffness values. Repeated OC appeared to cause IVC stenosis as a result of worsening sinusoidal obstruction syndrome (SOS), and peristomal variceal bleeding. After ultrasound-guided percutaneous embolization, bleeding did not recur. Unfortunately, the patient died of liver dysfunction caused by severe SOS. The incidence of OC-induced SOS is reported to be about 50%; however, there is apparently no report of OC-induced HV and IVC stenosis, and in most cases, portal hypertension is improved after OC cessation. This is the first report of OC-induced severe HV and IVC stenosis resulting in refractory peristomal variceal bleeding and eventual death.

Hepatic adrenal rest include ectopic adrenal tissue in the liver and adrenohepatic fusion. Long-lasting hyperstimulation of that tissue induces hyperplasia sometimes simulating true tumors. True autonomic tumors originating from ectopic adrenal tissue with or without hyperfunction are rare. Hepatic adrenal rest sometimes has similar imaging findings to lipid-rich hepatocellular carcinoma or angiomyolipoma, containing obvious lipid component. But in our cases, tumors showed hypervascular patterns similar to hepatocellular adenoma or carcinoma. Therefore, adrenocortical scintigraphy with SPECT/CT should be taken into consideration to diagnose tumoral lesions in the posterior segment of the right hepatic lobe with or without an obvious lipid component.

Shear wave (SW) dispersion imaging is a newly developed imaging technology for assessing the dispersion slope of SWs, which is related to tissue viscosity in diffuse liver disease. Our preclinical and preliminary clinical studies have shown that SW speed is more useful than dispersion slope for predicting the degree of fibrosis and that dispersion slope is more useful than SW speed for predicting the degree of necroinflammation. Thus, dispersion slope, which reflects viscosity, may provide additional pathophysiological insight into diffuse liver disease.

Purpose Irreversible electroporation (IRE) differs from thermal radiofrequency (RF) ablation, especially in terms of the reparative process in the ablation zone induced. To elucidate this, the systemic immune responses after 2 mechanistically different types of ablation (IRE and RF ablation) were evaluated in patients with hepatocellular carcinoma (HCC). Materials and Methods Twenty-one patients with HCC who underwent either RF ablation (n = 11) or IRE (n = 10) were studied. Peripheral blood samples were collected from all patients at 4 timepoints: before ablation, within 1 hour after ablation, 1 day after ablation, and 4 days after ablation. The phenotypes and functions of immune cells in peripheral blood and serum levels of cytokines and chemokines were monitored and analyzed using the mixed-effects model. Follow-up radiological images were also obtained to assess temporal changes in the ablation zone. Results The most significant difference was seen in the levels of macrophage migration inhibitory factor (MIF) in the IRE group compared to the RF ablation group (P = .0011): the serum levels of MIF in the IRE group significantly increased immediately after IRE and then rapidly decreased to the pre-ablation range 1 day after IRE, but, in contrast, no consistent trend was observed in the RF ablation group. The axial diameter (P = .0009) and area (P = .0192) of the ablation zone of IRE were significantly smaller than those of RF ablation 1 year after ablation. Conclusions IRE was found to be associated with a significant early increase in MIF levels, which may facilitate the early reparative process and result in significant shrinkage of the ablation zone.

Shear wave elastography (SWE) has been validated in chronic hepatitis C and B; however, limited data are available in non-alcoholic fatty liver disease (NAFLD). This study aimed to evaluate the accuracy of SWE and FIB4 index for the diagnosis of fibrosis in a cohort of consecutive patients with biopsy-proven NAFLD, and to evaluate the effects of other histologic parameters on SWE measurement. Written informed consent was obtained from all patients, and this study was approved by our internal review board and ethics committee. Seventy-one patients with histologically proven NAFLD (mean age 50.8 years ± 15.7) were examined. All patients underwent SWE (Aixplorer™; SuperSonic Imagine) and FIB4 index (based on age, aspartate aminotransferase and alanine aminotransferase levels, and platelet counts) measurements. SWE measurements were compared with the histologic features based on the NAFLD activity score and FIB4 index. The area under the ROC curve for the diagnosis of hepatic fibrosis stage 3 or higher was 0.821 (optimal cut-off value 13.1 kPa, sensitivity 62.5%, specificity 57.4%) for SWE and 0.822 (optimal cut-off value 1.41, sensitivity 71.9%, specificity 53.9%) for FIB4 index. The median liver stiffness values measured using SWE showed a stepwise increase with increasing hepatic fibrosis stage (P

A 58-year-old man with hepatitis B cirrhosis noticed black stools and underwent an endoscopy at a community hospital. The presence of esophageal varices (EVs) was confirmed, but the bleeding point was not found. He was referred to our institution and underwent a second endoscopy. Extensive white patches of esophageal candidiasis were visible on endoscopy by white-light imaging (WLI), but it was difficult to find the fibrin cap of the EVs. This was easier under narrow-band imaging (NBI), however, as the color turned red from absorption by hemoglobin adhered to it. We retrospectively measured the color differences (CD) between the fibrin cap and the surrounding mucosa 10 times using the CIE (L*a*b*) color space method. The median value of CD increased after NBI (13.9 → 43.0, p < 0.001), with increased visibility. However, the median CD between the white patch and surrounding mucosa decreased after NBI (44.8 → 30.3, p < 0.001). The fibrin cap was paler than the white patch of candidiasis, but the increased visibility of the fibrin cap by NBI enabled it to be found more easily. This is the first report of a case in which NBI was helpful in locating a fibrin cap of EVs.

Dual red imaging (DRI) is a new technology that can increase the visibility of deeper veins compared with narrow band imaging (NBI). As esophageal varices (EVs) are a vascular disease occurring in the submucosal layer, their visibility might be increased by DRI. We prospectively clarified whether the visibility of EVs with red color sign (RCS) can be increased by DRI, and clarified the relation between the visibility scores and the obtained endoscopic ultrasound (EUS) images. Forty patients were enrolled. The visibility of the EVs on DRI and NBI endoscopic images was evaluated by five observers in a blinded manner and was compared with a white light image (bad, 0; equal, 1; good, 2). The diameter of the lumen and the depth of the EVs and RCS from the epithelium were measured by EUS. The relation between the visibility scores and the EUS findings was investigated. The DRI scores were 1.66 ± 0.34 for the EV substance and 1.79 ± 0.28 for the RCS, whereas the NBI scores were 0.68 ± 0.38 and 0.41 ± 0.28, respectively. A significant negative correlation was found between the depth and the visibility score (r = −0.505, p = 0.001 for EVs; r = −0.458, p = 0.003 for RCS). DRI increased the visibility of the EVs and RCS. The visibility of the EVs or RCS in the shallower position was more enhanced by DRI. Visual recognition of the changing degrees of visibility by DRI enables the prediction of the depth of EVs.

Objective To determine the optimal bolus injection rate of ultrasound (US) contrast agent in vascular imaging for focal liver lesions. Methods Thirteen patients with 13 focal liver lesions (5 hepatocellular carcinomas (HCCs) with cirrhosis, 4 liver metastases, 2 hemangiomas, 1 intrahepatic cholangiocarcinoma, 1 focal nodular hyperplasia) received two bolus injections of Sonazoid (at 0.5 and 2.0 mL/s) using an automatic power injector. The lesion-to-liver contrast ratio at peak enhancement was quantitatively evaluated. Enhancement of the lesions compared to liver parenchyma was assessed by two independent readers using a five-point scale and qualitatively evaluated by receiver operating characteristic (ROC) analysis. Results For all lesions, the contrast ratio was not significantly different between the two injection rates. For HCCs, the contrast ratio was higher at 0.5 mL/s (7.41 ± 6.56) than at 2.0 mL/s (4.28 ± 4.66, p = 0.025). For all lesions, the mean area under the ROC curve (AUC) was not significantly different between the two injection rates. For HCCs, the AUC was greater at 0.5 mL/s than at 2.0 mL/s (AUC: 0.86, p = 0.013). Conclusion In contrast-enhanced US, an injection rate of 0.5 mL/s is superior to an injection rate of 2.0 mL/s for the quantitative and qualitative analysis of HCCs in the cirrhotic liver.