Carlo Filice

Accuracy of real-time shear wave elastography for assessing liver fibrosis in chronic hepatitis C: A pilot study

Real‐time shear wave elastography (SWE) is a novel, noninvasive method to assess liver fibrosis by measuring liver stiffness. This single‐center study was conducted to assess the accuracy of SWE in patients with chronic hepatitis C (CHC), in comparison with transient elastography (TE), by using liver biopsy (LB) as the reference standard. Consecutive patients with CHC scheduled for LB by referring physicians were studied. One hundred and twenty‐one patients met inclusion criteria. On the same day, real‐time SWE using the ultrasound (US) system, Aixplorer (SuperSonic Imagine S.A., Aix‐en‐Provence, France), TE using FibroScan (Echosens, Paris, France), and US‐assisted LB were consecutively performed. Fibrosis was staged according to the METAVIR scoring system. Analyses of receiver operating characteristic (ROC) curve were performed to calculate optimal area under the ROC curve (AUROC) for F0‐F1 versus F2‐F4, F0‐ F2 versus F3‐F4, and F0‐F3 versus F4 for both real‐time SWE and TE. Liver stiffness values increased in parallel with degree of liver fibrosis, both with SWE and TE. AUROCs were 0.92 (95% confidence interval [CI]: 0.85‐0.96) for SWE and 0.84 (95% CI: 0.76‐0.90) for TE (P = 0.002), 0.98 (95% CI: 0.94‐1.00) for SWE and 0.96 (95% CI: 0.90‐0.99) for TE (P = 0.14), and 0.98 (95% CI: 0.93‐1.00) for SWE and 0.96 (95% CI: 0.91‐0.99) for TE (P = 0.48), when comparing F0‐F1 versus F2‐ F4, F0‐ F2 versus F3‐F4, and F0 ‐F3 versus F4, respectively. Conclusion: The results of this study show that real‐time SWE is more accurate than TE in assessing significant fibrosis (≥F2). With respect to TE, SWE has the advantage of imaging liver stiffness in real time while guided by a B‐mode image. Thus, the region of measurement can be guided with both anatomical and tissue stiffness information. (HEPATOLOGY 2012;56:2125–2133)

WFUMB Guidelines and Recommendations for Clinical Use of Ultrasound Elastography: Part 2: Breast

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has produced these guidelines for the use of elastography techniques in liver disease. For each available technique, the reproducibility, results, and limitations are analyzed, and recommendations are given. Finally, recommendations based on the international literature and the findings of the WFUMB expert group are established as answers to common questions. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of liver diseases.

Percutaneous Ethanol Injection in the Treatment of Hepatocellular Carcinoma: A Multicenter Survey of Evaluation Practices and Complication Rates

BACKGROUND Percutaneous ethanol injection (PEI) has become a widely used procedure in the treatment of hepatocellular carcinoma (HCC). However, the criteria for selecting patients are not standardized, and little information is available about the complications of the procedure. METHODS A questionnaire was sent to 11 experienced Italian centers. It investigated: the size and the number of HCC nodules suitable for treatment and the Child-Pugh risk class of the associated cirrhosis; the performance of the procedure; the number and characteristics of the patients treated; and, finally, any complications. RESULTS Most of the centers performed PEI in single HCC nodules less than 5 cm in diameter or in multiple nodules if fewer than three, the larger being less than 3 cm. Patients in Child-Pughs classes A, B, and C with single nodules were generally considered for PEI. A prothrombin time of less than 40% and a platelet count of less than 40,000/mm3 contraindicated PEI in most of the centers. PEI was generally performed on outpatients, using Chiba or spinal needles. One thousand and sixty-six patients (8118 sessions) were enrolled; 74% had a single HCC nodule and 26% multiple nodules. All except four had cirrhosis; 53% were in Child class A, 38% in class B, and 9% in class C. The mean number of sessions needed to destroy an HCC nodule was 6.7 (range, 2-14), with a mean alcohol injection volume of 5.0 ml per session (range, 2-20 ml). One death (0.09%) and 34 complications (3.2%) were reported. Among the complications we call attention to the hemorrhagic ones (eight cases) and tumoral seeding (seven cases). Severe pain experienced during the maneuver led to discontinuation of the procedure in 3.7% of the patients; 13.5% of the patients required analgesics and 24% had fever after PEI. CONCLUSIONS Some procedural aspects of PEI treatment differ among the various centers a standardization is advisable. In the present survey PEI is a low-risk technique.

A New Therapeutic Approach for Hydatid Liver Cysts: Aspiration and Alcohol Injection Under Sonographic Guidance

The treatment of hydatid disease is still rather difficult; surgery is not always feasible, and there are no definite methods to evaluate the outcome of medical treatment. Although percutaneous needle aspiration of hydatid cysts has been discouraged because of potential complications, e.g., anaphylactic shock or spreading of daughter cysts, these risks have never been quantified. Therefore, it was decided to treat hydatid liver cysts by aspiration and alcohol injection under sonographic guidance using 95% sterile ethanol. Five patients are reported who were treated by this procedure without complications or relapses during a follow-up period ranging from 10-26 mo.

Reproducibility of real-time shear wave elastography in the evaluation of liver elasticity.

OBJECTIVE To evaluate the reproducibility of real-time shear wave elastography in assessing liver elasticity in healthy volunteers. METHODS Forty-two volunteers were studied in day 1. Shear wave elastography studies were performed by using the ultrasound system Aixplorer™ (SuperSonic Imagine S.A., Aix-en-Provence, France) with a convex broadband probe. Measurements were carried by two operators, an expert (operator 1) and a novice (operator 2). Examinations were performed on the right lobe of the liver. Each operator performed 10 consecutive measurements in each volunteer. In a subset of volunteers (n=18) measurements were performed twice on two different days (day 1 and day 2). Intraobserver and interobserver agreement were assessed by intraclass correlation coefficient. RESULTS Intraobserver agreement between measurements performed in the same subject in the same day (day 1 or day 2) showed intraclass correlation coefficient values of 0.95 (95% confidence interval, 0.93-0.98) and 0.93 (95% confidence interval, 0.90-0.96) for operator 1 and operator 2, respectively. Intraobserver agreement between measurements performed in the same subject in different days showed intraclass correlation coefficient values of 0.84 (95% confidence interval, 0.69-0.98) and 0.65 (95% confidence interval, 0.39-0.91) for operator 1 and operator 2, respectively. Interobserver agreement was 0.88 (95% confidence interval, 0.82-0.94). CONCLUSIONS The results of this study show that shear wave elastography is a reliable and reproducible noninvasive method for the assessment of liver elasticity. Expert operator had higher reproducibility of measurements over time than novice operator.

Use of PAIR in human cystic echinococcosis.

The authors report their experience with ultrasound (US)-guided percutaneous treatment of hydatid abdominal cysts (mainly hepatic). From November 1987 to January 1996 in Italy and in Kenya 231 cysts in 163 patients were treated with a technique called PAIR (puncture, aspiration, injection, re-aspiration), using 95% ethanol as a scolecide agent according to a routine protocol. In Kakuma, Turkana (Kenya) 141 cysts in 85 patients were treated with a simplified protocol and a portable US machine. No anaphylactic shock or peritoneal dissemination was observed. One failure was observed due to the proximity of the parasitic cyst to the gallbladder, resulting in a fistula between the two cavities; this complication was resolved by surgery. A few minor complications were observed. In all the other cases detachment of the germinal membrane and subsequent reduction in size was observed, with a more or less complete solidification of the cyst and reduction of serology titers. Only one cyst recurred after 4 years and was treated again by PAIR. Long-term results indicate that in type I, II and III cysts, according to the Gharbi classification, PAIR is a first-choice method for treatment of liver hydatid cysts, especially in developing countries.

Individual patient data meta-analysis of controlled attenuation parameter (CAP) technology for assessing steatosis

BACKGROUND & AIMS The prevalence of fatty liver underscores the need for non-invasive characterization of steatosis, such as the ultrasound based controlled attenuation parameter (CAP). Despite good diagnostic accuracy, clinical use of CAP is limited due to uncertainty regarding optimal cut-offs and the influence of covariates. We therefore conducted an individual patient data meta-analysis. METHODS A review of the literature identified studies containing histology verified CAP data (M probe, vibration controlled transient elastography with FibroScan®) for grading of steatosis (S0-S3). Receiver operating characteristic analysis after correcting for center effects was used as well as mixed models to test the impact of covariates on CAP. The primary outcome was establishing CAP cut-offs for distinguishing steatosis grades. RESULTS Data from 19/21 eligible papers were provided, comprising 3830/3968 (97%) of patients. Considering data overlap and exclusion criteria, 2735 patients were included in the final analysis (37% hepatitis B, 36% hepatitis C, 20% NAFLD/NASH, 7% other). Steatosis distribution was 51%/27%/16%/6% for S0/S1/S2/S3. CAP values in dB/m (95% CI) were influenced by several covariates with an estimated shift of 10 (4.5-17) for NAFLD/NASH patients, 10 (3.5-16) for diabetics and 4.4 (3.8-5.0) per BMI unit. Areas under the curves were 0.823 (0.809-0.837) and 0.865 (0.850-0.880) respectively. Optimal cut-offs were 248 (237-261) and 268 (257-284) for those above S0 and S1 respectively. CONCLUSIONS CAP provides a standardized non-invasive measure of hepatic steatosis. Prevalence, etiology, diabetes, and BMI deserve consideration when interpreting CAP. Longitudinal data are needed to demonstrate how CAP relates to clinical outcomes. LAY SUMMARY There is an increase in fatty liver for patients with chronic liver disease, linked to the epidemic of the obesity. Invasive liver biopsies are considered the best means of diagnosing fatty liver. The ultrasound based controlled attenuation parameter (CAP) can be used instead, but factors such as the underlying disease, BMI and diabetes must be taken into account. Registration: Prospero CRD42015027238.

Shear Wave Elastography for Evaluation of Liver Fibrosis

The prognosis and management of chronic viral hepatitis mainly depend on the extent of liver fibrosis, particularly in chronic hepatitis C. Liver histologic analysis is still considered the reference standard in the assessment of liver fibrosis despite the interobserver and interobserver variability in staging and some morbidity and mortality risks. Thus, noninvasive methods for assessing liver fibrosis are of great clinical interest. In the last decade, ultrasound‐based techniques to estimate the stage of liver fibrosis have become commercially available. They all have the capability to noninvasively evaluate differences in the elastic properties of soft tissues by measuring tissue behavior when a mechanical stress is applied. Shear wave elastography relies on the generation of shear waves determined by the displacement of tissues induced by the force of a focused ultrasound beam or by an external push. This article reviews the results that have been obtained with shear wave elastography for assessment of liver fibrosis.

Follow-up after percutaneous radiofrequency ablation of renal cell carcinoma: contrast-enhanced sonography versus contrast-enhanced CT or MRI.

OBJECTIVE The purpose of this study was to assess, with contrast-enhanced CT or MRI as the reference imaging technique, the diagnostic performance of low-mechanical-index contrast-enhanced sonography in detecting local tumor progression after percutaneous radiofrequency ablation of renal tumors. MATERIALS AND METHODS Twenty-nine patients with 30 renal tumors (18 men, 11 women; mean age, 73 years; range, 53-83 years) underwent percutaneous radiofrequency ablation at a single center between March 1998 and January 2007. The imaging follow-up schedule was both contrast-enhanced sonography and CT or MRI 4 months after completion of treatment and every 4 months for the first year. Thereafter, the follow-up schedule was contrast-enhanced sonography every 4 months with CT or MRI every 8 months. The chi-square test with Yates correction was used to evaluate positive and negative predictive values and accuracy. RESULTS One patient was scheduled to undergo surgical resection, and another patient was lost to follow-up. Twenty-seven patients with 28 renal tumors participated in follow-up. The concordance between contrast-enhanced sonographic and CT or MRI findings was 100% for 27 of 28 tumors (96.4%) that had a hypervascular pattern before treatment. In the case of the tumor that was hypovascular at imaging performed before percutaneous radiofrequency ablation, local tumor progression was missed at contrast-enhanced sonography. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of contrast-enhanced sonography were 96.6%, 100%, 100%, 95.8%, and 98.1%. CONCLUSION Contrast-enhanced sonography is an effective alternative to CT and MRI in the follow-up of renal tumors managed with percutaneous radiofrequency ablation.

Point shear wave elastography method for assessing liver stiffness

AIM To estimate the validity of the point shear-wave elastography method by evaluating its reproducibility and accuracy for assessing liver stiffness. METHODS This was a single-center, cross-sectional study. Consecutive patients with chronic viral hepatitis scheduled for liver biopsy (LB) (Group 1) and healthy volunteers (Group 2) were studied. In each subject 10 consecutive point shear-wave elastography (PSWE) measurements were performed using the iU22 ultrasound system (Philips Medical Systems, Bothell, WA, United States). Patients in Group 1 underwent PSWE, transient elastography (TE) using FibroScan (Echosens, Paris, France) and ultrasound-assisted LB. For the assessment of PSWE reproducibility two expert raters (rater 1 and rater 2) independently performed the examinations. The performance of PSWE was compared to that of TE using LB as a reference standard. Fibrosis was staged according to the METAVIR scoring system. Receiver operating characteristic curve analyses were performed to calculate the area under the receiver operating characteristic curve (AUC) for F ≥ 2, F ≥ 3 and F = 4. The intraobserver and interobserver reproducibility of PSWE were assessed by calculating Lins concordance correlation coefficient. RESULTS To assess the performance of PSWE, 134 consecutive patients in Group 1 were studied. The median values of PSWE and TE (in kilopascals) were 4.7 (IQR = 3.8-5.4) and 5.5 (IQR = 4.7-6.5), respectively, in patients at the F0-F1 stage and 3.5 (IQR = 3.2-4.0) and 4.4 (IQR = 3.5-4.9), respectively, in the healthy volunteers in Group 2 (P < 10(-5)). In the univariate analysis, the PSWE and TE values showed a high correlation with the fibrosis stage; low correlations with the degree of necroinflammation, aspartate aminotransferase and gamma-glutamyl transferase (GGT); and a moderate negative correlation with the platelet count. A multiple regression analysis confirmed the correlations of both PSWE and TE with fibrosis stage and GGT but not with any other variables. The following AUC values were found: 0.80 (0.71-0.87) for PSWE and 0.82 (0.73-0.89) for TE (P = 0.42); 0.88 (0.80-0.94) for PSWE and 0.95 (0.88-0.98) for TE (P = 0.06); and 0.95 (0.89-0.99) for PSWE and 0.92 (0.85-0.97) for TE (P = 0.30) for F ≥ 2, F ≥ 3 and F = 4, respectively. To assess PSWE reproducibility, 116 subjects were studied, including 47 consecutive patients scheduled for LB (Group 1) and 69 consecutive healthy volunteers (Group 2). The intraobserver agreement ranged from 0.83 (95%CI: 0.79-0.88) to 0.96 (95%CI: 0.95-0.97) for rater 1 and from 0.84 (95%CI: 0.79-0.88) to 0.96 (95%CI: 0.95-0.97) for rater 2. The interobserver agreement yielded values from 0.83 (95%CI: 0.78-0.88) to 0.93 (95%CI: 0.91-0.95). CONCLUSION PSWE is a reproducible method for assessing liver stiffness, and it compares with TE. Compared with patients with nonsignificant fibrosis, healthy volunteers showed significantly lower values.