Principle of contrast-enhanced ultrasonography.

Sonazoid, an ultrasound contrast agent, has been covered by insurance in Japan since January 2007 for the diagnosis of hepatic mass lesions and is widely used for diagnosing not only primary liver cancer but also liver metastases such as those from breast cancer and colorectal cancer. Contrast-enhanced ultrasound for breast mass lesions has been covered by insurance since August 2012 after phase II and phase III clinical trials showed that the diagnostic performance was significantly superior to that of B-mode and contrast-enhanced magnetic resonance imaging. This paper describes the principles of imaging techniques in contrast-enhanced ultrasonography including the filter, pulse inversion, amplitude modulation, and amplitude-modulated pulse inversion methods. The pulse inversion method, which visualizes the second-harmonic component using the nonlinear scattering characteristics of the contrast agent, is widely used regardless of the contrast agent and target organ because of its high resolution. Sonazoid has a stiffer shell and requires a higher acoustic amplitude than Sonovue to generate nonlinear vibrations. The higher transmitted sound pressure generates more tissue harmonic components. Since pulse inversion allows visualization of the tissue harmonic components, amplitude modulation and amplitude-modulated pulse inversion, which include few tissue harmonic components, are primarily used. Amplitude modulation methods detect nonlinear signals from the contrast agent in the fundamental band. The mechanism of the amplitude modulation is considered to be changes in the echo signal's phase depending on the sound pressure. Since the tissue-derived component is minor in amplitude modulation methods, good contrast sensitivity can be obtained.

Multiparametric US for Identifying Patients with High-Risk NASH: A Derivation and Validation Study.

Background Nonalcoholic fatty liver disease (NAFLD) is common in the general population but identifying patients with high-risk nonalcoholic steatohepatitis (NASH) who are candidates for pharmacologic therapy remains a challenge. Purpose To develop a score to identify patients with high-risk NASH, defined as NASH with an NAFLD activity score (NAS) of 4 or greater and clinically significant fibrosis (stage 2 [F2] or higher). Materials and Methods This was a cross-sectional secondary analysis of data prospectively collected between April 2017 and March 2019 for a group of patients with NAFLD in Japan (Japan NAFLD, the derivation data set) with contemporaneous two-dimensional shear-wave elastography and biopsy-proven NAFLD (age range, 20-89 years). Three US markers (liver stiffness [LS, measured in kilopascals], attenuation coefficient [AC, measured in decibels per centimeter per megahertz], and dispersion slope [DS, measured in meters per second per kilohertz]) were determined, together with aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the AST-to-ALT ratio. The best-fit multivariate logistic regression model for identifying patients with high-risk NASH was determined. Diagnostic performance was assessed by using the area under the receiver operating characteristic curve (AUC). The findings were validated in an independent data set (Korea NAFLD; age range, 20-78 years). Results The Japan NAFLD data set included 111 patients (mean age, 53 years ± 18 [standard deviation]; 57 men), 84 (76%) with NASH. The Korea NAFLD data set included 102 patients (mean age, 48 years ± 18; 43 men), 55 (36%) with NASH. The most predictive model (LAD NASH score) combined LS, AC, and DS. Performance was satisfactory in both the derivation sample (AUC, 0.86; 95% CI: 0.79, 0.93) and the validation sample (AUC, 0.88; 95% CI: 0.80, 0.95). The LAD NASH score showed a positive predictive value of 86.5% and a negative predictive value of 87.5% for high-risk NASH in the derivation sample. Conclusion A score combining three US markers may be useful for noninvasive identification of patients with high-risk nonalcoholic steatohepatitis for inclusion in clinical trials and pharmacologic therapy. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lockhart in this issue.

Quantification of Liver Fat Content with Ultrasound: A WFUMB Position Paper.

New ultrasound methods that can be used to quantitatively assess liver fat content have recently been developed. These quantitative ultrasound (QUS) methods are based on the analysis of radiofrequency echoes detected by the transducer, allowing calculation of parameters for quantifying the fat in the liver. In this position paper, after a section dedicated to the importance of quantifying liver steatosis in patients with non-alcoholic fatty liver disease and another section dedicated to the assessment of liver fat with magnetic resonance, the current clinical studies performed using QUS are summarized. These new methods include spectral-based techniques and techniques based on envelope statistics. The spectral-based techniques that have been used in clinical studies are those estimating the attenuation coefficient and those estimating the backscatter coefficient. Clinical studies that have used tools based on the envelope statistics of the backscattered ultrasound are those performed by using the acoustic structure quantification or other parameters derived from it, such as the normalized local variance, and that performed by estimating the speed of sound. Experts' opinions are reported.

Guidelines and Good Clinical Practice Recommendations for Contrast Enhanced Ultrasound (CEUS) in the Liver - Update 2020 - WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS.

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS), first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications.The 2012 guideline requires updating as previously the differences of the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including the United States Food and Drug Administration (FDA) approval as well as the extensive Asian experience, to produce a truly international perspective.These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCA) and are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis to improve the management of patients.

Guidelines and Good Clinical Practice Recommendations for Contrast-Enhanced Ultrasound (CEUS) in the Liver-Update 2020 WFUMB in Cooperation with EFSUMB, AFSUMB, AIUM, and FLAUS.

The present, updated document describes the fourth iteration of recommendations for the hepatic use of contrast-enhanced ultrasound, first initiated in 2004 by the European Federation of Societies for Ultrasound in Medicine and Biology. The previous updated editions of the guidelines reflected changes in the available contrast agents and updated the guidelines not only for hepatic but also for non-hepatic applications. The 2012 guideline requires updating as, previously, the differences in the contrast agents were not precisely described and the differences in contrast phases as well as handling were not clearly indicated. In addition, more evidence has been published for all contrast agents. The update also reflects the most recent developments in contrast agents, including U.S. Food and Drug Administration approval and the extensive Asian experience, to produce a truly international perspective. These guidelines and recommendations provide general advice on the use of ultrasound contrast agents (UCAs) and are intended to create standard protocols for the use and administration of UCAs in liver applications on an international basis to improve the management of patients.

The Role of Multiparametric US of the Liver for the Evaluation of Nonalcoholic Steatohepatitis.

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 Online supplemental material is available for this article.

Clinical utilization of shear wave dispersion imaging in diffuse liver disease.

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.

Irreversible Electroporation versus Radiofrequency Ablation: Comparison of Systemic Immune Responses in Patients with Hepatocellular Carcinoma.

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.

Irreversible Electroporation for Nonthermal Tumor Ablation in Patients with Locally Advanced Pancreatic Cancer: Initial Clinical Experience in Japan.

Objective To evaluate irreversible electroporation (IRE) for locally advanced pancreatic cancer (LAPC). Methods This study was approved by our local review board. Eight patients with histologically proven LAPC ≤5 cm were prospectively enrolled to undergo ultrasound-guided IRE. The primary endpoint was complications within 90 days. Secondary outcomes were the overall survival (OS) and time to local progression. Safety was assessed using Common Terminology Criteria for Adverse Events Version 4.0. Results All patients were treated successfully. The median procedure time was 150 min. The median largest tumor diameter was 29.5 mm (20.0-48.0 mm) in the pancreatic head (n=5) and body (n=3). Open (n=4) and percutaneous (n=4) approaches were used. No patients died within 90 days after IRE. There were 5 minor complications in 3 patients and 4 major complications in 3 patients. The incidence rates of major complications did not differ significantly between the approaches. The median time to local progression after IRE was 12.0 months, and the median OS was 17.5 months from IRE and 24.0 months from the diagnosis, with no significant differences between the approaches. Conclusions Percutaneous and open IRE may be acceptable for patients with LAPC (despite some major adverse events) and may represent a useful new therapeutic option.

Viscoelasticity Measurement in Rat Livers Using Shear-Wave US Elastography.

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.

How to perform Contrast-Enhanced Ultrasound (CEUS).

"How to perform contrast-enhanced ultrasound (CEUS)" provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

Efficacy and safety of rifaximin in Japanese patients with hepatic encephalopathy: A phase II/III, multicenter, randomized, evaluator-blinded, active-controlled trial and a phase III, multicenter, open trial.

AIM: The efficacy and safety of rifaximin in the treatment of hepatic encephalopathy (HE) are widely known, but they have not been confirmed in Japanese patients with HE. Thus, two prospective, randomized studies (a phase II/III study and a phase III study) were carried out. METHODS: Subjects with grade I or II HE and hyperammonemia were enrolled. The phase II/III study, which was a randomized, evaluator-blinded, active-comparator, parallel-group study, was undertaken at 37 institutions in Japan. Treatment periods were 14 days. Eligible patients were randomized to the rifaximin group (1200 mg/day) or the lactitol group (18-36 g/day). The phase III study was carried out in the same patients previously enrolled in the phase II/III study, and they were all treated with rifaximin (1200 mg/day) for 10 weeks. RESULTS: In the phase II/III study, 172 patients were enrolled. Blood ammonia (B-NH3 ) concentration was significantly improved in the rifaximin group, but the difference between the two groups was not significant. The portal systemic encephalopathy index (PSE index), including HE grade, was significantly improved in both groups. In the phase III study, 87.3% of enrolled patients completed the treatment. The improved B-NH3 concentration and PSE index were well maintained from the phase II/III study during the treatment period of the phase III study. Adverse drug reactions (ADRs) were seen in 13.4% of patients who received rifaximin, but there were no severe ADRs leading to death. CONCLUSION: The efficacy of rifaximin is sufficient and treatment is well tolerated in Japanese patients with HE and hyperammonemia.

Specific clones of Staphylococcus lugdunensis may be associated with colon carcinoma.

Staphylococcus lugdunensis produces a tannase with activity that may be associated with the onset of colon carcinoma. To clarify this feature of colon carcinoma-associated S. lugdunensis, we obtained isolates from healthy subjects and patients with colon adenomas and carcinomas and analyzed their genetic backgrounds. In total, 40 S. lugdunensis isolates from 288 rectal swabs collected between 2002 and 2008 were used. These isolates were classified into four groups according to the diseases of the subjects: healthy (n=13), colon carcinoma (n=13), colon adenoma (n=9), and unknown (n=5). The isolates were also classified by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing. In addition, an antimicrobial susceptibility test and detection of resistance genes were performed for all isolates. According to the PFGE analysis, 40 isolates could be classified into five groups. Among the groups, carcinoma and colon adenoma patients were significantly more frequently (40.9%) classified into group D (p<0.05), whereas healthy subjects were more frequently (38.5%) classified into group A. All isolates in group D were typed as ST27, which was clearly different than isolates in the other groups. All isolates were susceptible to the antimicrobial agents tested, including ß-lactams, although seven strains produced ß-lactamase. Our data suggest that a specific clone of S. lugdunensis might be associated with colon carcinoma and colon adenoma. This clone showed high susceptibility to many antimicrobial agents. Therefore, eradication therapy may lead to a decreased risk of colon carcinoma.

Serum Metabolomic Profiles for Human Pancreatic Cancer Discrimination.

This study evaluated the clinical use of serum metabolomics to discriminate malignant cancers including pancreatic cancer (PC) from malignant diseases, such as biliary tract cancer (BTC), intraductal papillary mucinous carcinoma (IPMC), and various benign pancreaticobiliary diseases. Capillary electrophoresismass spectrometry was used to analyze charged metabolites. We repeatedly analyzed serum samples (n = 41) of different storage durations to identify metabolites showing high quantitative reproducibility, and subsequently analyzed all samples (n = 140). Overall, 189 metabolites were quantified and 66 metabolites had a 20% coefficient of variation and, of these, 24 metabolites showed significant differences among control, benign, and malignant groups (p < 0.05; Steel-Dwass test). Four multiple logistic regression models (MLR) were developed and one MLR model clearly discriminated all disease patients from healthy controls with an area under receiver operating characteristic curve (AUC) of 0.970 (95% confidential interval (CI), 0.946-0.994, p < 0.0001). Another model to discriminate PC from BTC and IPMC yielded AUC = 0.831 (95% CI, 0.650-1.01, p = 0.0020) with higher accuracy compared with tumor markers including carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), pancreatic cancer-associated antigen (DUPAN2) and s-pancreas-1 antigen (SPAN1). Changes in metabolomic profiles might be used to screen for malignant cancers as well as to differentiate between PC and other malignant diseases.

Multimodality imaging to assess immediate response following irreversible electroporation in patients with malignant hepatic tumors.

PURPOSE: To assess the diagnostic accuracy of contrast-enhanced ultrasound (CEUS), contrast-enhanced multiphase CT (CECT), and gadoxetic acid-enhanced MRI (EOB-MRI) in identifying residual tumor in the subacute follow-up of patients with malignant hepatic tumors treated by irreversible electroporation (IRE). METHODS: We enrolled 16 patients with 21 hepatic lesions treated by IRE and examined by CEUS and CECT at 1 day after IRE and by EOB-MRI at 7 days after IRE. Follow-up examinations by EOB-MRI or CECT and CEUS were performed at 3-month intervals. Two radiologists independently reviewed the images and assessed the probability of residual tumor using a five-point scale with receiver operating characteristic (ROC) curve analysis. The sensitivity and specificity were also evaluated. Verifiable local recurrence was assessed using follow-up imaging as the reference standard. RESULTS: The mean area under the ROC curve was significantly higher for CEUS (0.980) than for CECT (0.742, P < 0.01) and EOB-MRI (0.806, P < 0.01), as were the sensitivity and specificity (mean 85.7 and 85.7% for CEUS, respectively, vs 64.3 and 46.4% for CECT and 78.6 and 64.3% for EOB-MRI). CONCLUSION: CEUS was found to be superior to CECT and EOB-MRI for the diagnosis of residual tumor in the subacute phase following IRE.

Dual red imaging (novel advanced endoscopy) can increase visibility and can predict the depth in diagnosing esophageal varices.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Effectiveness of contrast-enhanced endoscopic ultrasound for detecting mural nodules in intraductal papillary mucinous neoplasm of the pancreas and for making therapeutic decisions.

BACKGROUND AND OBJECTIVES: There have been few studies to date evaluating the effectiveness of contrast-enhanced endoscopic ultrasound (CE-EUS) for detecting mural nodules in patients with branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) of the pancreas. We aim to evaluate the effectiveness of CE-EUS for detecting mural nodules in BD-IPMN. PATIENTS AND METHODS: Of the 427 BD-IPMN patients, 21 patients (4.9%) in whom the presence of mural nodules was suggested by CE computed tomography (CT) or magnetic resonance imaging (MRI), or in whom the presence of nodule-like lesions as shown by fundamental EUS, were examined by CE-EUS. RESULTS: The mean diameter of cystic lesions was 29.8 ± 12.8 mm. The mean diameter of mural nodules was 9.5 ± 5.7 mm. BD-IPMN was detected in the pancreatic head in 16 cases, pancreatic body in 2 cases, and pancreatic tail in 3 cases. The mean follow-up period was 17.2 ± 11.9 months. The detection rates of mural nodule-like lesions in BD-IPMN patients on CT, MRI, and fundamental EUS were 36.8%, 63.2%, and 100%, respectively. The detection rates of true mural nodules in BD-IPMN patients on CT, MRI, and fundamental EUS were 85.7%, 71.4%, and 100%, respectively. The echo levels of mural nodule-like lesions on fundamental EUS were hyperechoic in 6 patients, isoechoic in 9 patients, and hypoechoic in 6 patients. The final diagnosis was mucus lumps in 14 patients and mural nodules in 7 patients. The contrast patterns observed were avascular, isovascular, and hypervascular in 14, 3, and 4 patients, respectively. No patients showed a hypovascular pattern. Fourteen patients showing an avascular pattern were diagnosed as having mucus lumps, and they were able to avoid surgical resection. Of the 7 patients who were diagnosed as having mural nodules, 5 underwent surgical resection. The pathological findings were adenocarcinoma in 2 patients and adenoma in 3 patients. Of the 3 adenoma patients, fundamental EUS demonstrated a hypoechoic area in 1 patient and an isoechoic area in 2 patients. Of the 2 adenocarcinoma patients, 1 each showed a hypoechoic area and a hyperechoic area. It was difficult to distinguish between patients with adenoma and patients with adenocarcinoma using the echo levels obtained from fundamental EUS. CONCLUSIONS: CE-EUS may be useful for avoiding the overdiagnosis of BD-IPMN with mural nodule-like lesions. However, it has difficulty in distinguishing between clearly benign and malignant lesions in BD-IPMN.

Strongyloides stercoralis Infection Causing Obstructive Jaundice and Refractory Pancreatitis: A Lesson Learned from a Case Study.

A 58-year-old Japanese woman came to our institution because of leg edema and abdominal distention. She had developed acute pancreatitis 5 times in the past 3 years. Dilation of the bile duct and main pancreatic duct without obstruction was observed on computed tomography and magnetic resonance cholangiopancreatography. The presence of Strongyloides stercoralis was highly suspected from the biopsy sample from the duodenal papilla. Polymerase chain reaction amplification and sequencing of small subunit rDNA from paraffin-embedded specimens identified the worm as S. stercoralis. All of the symptoms were considered to be associated with S. stercoralis infection. Therefore, the patient was treated with oral administration of ivermectin. Subsequently, symptoms and laboratory data improved. There has been no recurrence of the symptoms to date.

Optimal injection rate of ultrasound contrast agent for evaluation of focal liver lesions using an automatic power injector: a pilot study.

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.

Barium impaction therapy with balloon occlusion for deep colonic diverticular bleeding: a three-case series.

BACKGROUND AND AIMS: In hemostasis for colonic diverticular bleeding, the incidence of recurrent bleeding is higher in deep colonic diverticulum than in shallow. We aimed to improve and evaluate barium impaction therapy using an enteroscopic overtube with balloon. PATIENTS AND METHOD: We performed barium impaction therapy in three patients with a diagnosis of deep colonic diverticular bleeding. The tip of the overtube was inserted to reach the cecum using the conventional method. After deflating the colon, the enteroscope was removed. The balloon in the tube was inflated, followed by barium filling via the tube. Sufficient pressure was applied by ensuring no regurgitation into the small intestine side. The entire colon was continuously filled with barium in stages. RESULTS: Post-treatment bleeding was controllable without adverse events in all three patients. CONCLUSION: This novel barium impaction therapy using an enteroscopic overtube with balloon was effectively performed without adverse events.