What did we learn from the first 3,459 cases of liver stiffness measurement by transient elastography (FibroScan®)?

Imaging-based noninvasive liver disease assessment for staging liver fibrosis in chronic liver disease: A systematic review supporting the AASLD Practice Guideline

BACKGROUND AND AIMS

Transient elastography (TE), shear wave elastography, and/or magnetic resonance elastography (MRE), each providing liver stiffness measurement (LSM), are the most studied imaging-based noninvasive liver disease assessment (NILDA) techniques. To support the American Association for the Study of Liver Diseases guidelines on NILDA, we summarized the evidence on the accuracy of these LSM methods to stage liver fibrosis (F).

APPROACH AND RESULTS

A comprehensive search for studies assessing LSM by TE, shear wave elastography, or MRE for the identification of significant fibrosis (F2-4), advanced fibrosis (F3-4), or cirrhosis (F4), using histopathology as the standard of reference by liver disease etiology in adults or children from inception to April 2022 was performed. We excluded studies with <50 patients with a single disease entity and mixed liver disease etiologies (with the exception of HCV/HIV coinfection). Out of 9447 studies, 240 with 61,193 patients were included in this systematic review. In adults, sensitivities for the identification of F2-4 ranged from 51% to 95%, for F3-4 from 70% to 100%, and for F4 from 60% to 100% across all techniques/diseases, whereas specificities ranged from 36% to 100%, 74% to 100%, and 67% to 99%, respectively. The largest body of evidence available was for TE; MRE appeared to be the most accurate method. Imaging-based NILDA outperformed blood-based NILDA in most comparisons, particularly for the identification of F3-4/F4. In the pediatric population, imaging-based NILDA is likely as accurate as in adults.

CONCLUSIONS

LSM from TE, shear wave elastography, and MRE shows acceptable to outstanding accuracy for the detection of liver fibrosis across various liver disease etiologies. Accuracy increased from F2-4 to F3-4 and was the highest for F4. Further research is needed to better standardize the use of imaging-based NILDA, particularly in pediatric liver diseases.

Hepatic and splenic sonographic and sonoelastographic findings in pulmonary arterial hypertension

Purpose

The aim of this study was to evaluate the associations of sonographic and sonoelastographic parameters with clinical cardiac parameters, as well as to assess their value in predicting survival in patients with pulmonary arterial hypertension (PAH).

Methods

Thirty-six patients with PAH and normal liver function were prospectively enrolled in this prospective study along with 26 healthy controls, all of whom underwent ultrasound and point shear wave elastography examinations. Additionally, the portal vein pulsatility index (PVPI), inferior vena cava collapsibility index, and clinical cardiac variables were obtained in PAH patients. The values of hepatic (LV_s) and splenic shear wave velocity (SV_s) were compared between PAH patients and controls. The relationships between all sonographic and clinical parameters in the PAH patients were analyzed. Furthermore, their prognostic value in predicting survival was investigated.

Results

LV_s values in PAH patients (median, 1.62 m/s) were significantly higher than in controls (median, 0.99 m/s), while no significant difference was observed in SV_s values. Patients with higher grades of tricuspid regurgitation (TR) had significantly different values of PVPI (P=0.010) and sonoelastographic parameters (P<0.001 for LV_s and P=0.004 for SV_s) compared to those with less severe TR. Tricuspid annular plane systolic excursion values were the only investigated parameter found to be associated with survival (hazard ratio, 0.814; 95% confidence interval, 0.694 to 0.954; P=0.011).

Conclusion

Our results demonstrated a direct association between cardiac congestion (i.e., the severity of TR) and liver stiffness, which should be kept in mind during the assessment of fibrosis in patients with PAH.

Transient elastography in clinical detection of liver cirrhosis: A systematic review and meta-analysis

BACKGROUND/AIMS

Transient elastography is a noninvasive method for measuring liver fibrosis. This meta-analysis assesses the diagnostic performance of transient elastography of detecting liver cirrhosis in patients with liver disease.

PATIENTS AND METHODS

We searched MEDLINE, Cochrane, EMBASE databases until Jan 31, 2015, using the following search terms: elastography and liver cirrhosis. Included studies assessed patients with a diagnosis of liver cirrhosis, with an index test of transient elastography, and with the reference standard being a histopathological exam by liver biopsy. Sensitivity analysis and assessment of risk of bias and publication bias were performed.

RESULTS

Fifty-seven studies were included in the meta-analysis with a total of 10,504 patients. The pooled estimate for the sensitivity of transient elastography for detecting liver fibrosis was 81% and the specificity was 88%. The imputed diagnostic odds ratio (DOR) was 26.08 and the area under the receiver-operating characteristic (AUROC) curve was 0.931.

CONCLUSION

Our findings indicate that transient elastography shows good sensitivity, specificity and a high accuracy for detecting liver cirrhosis. Transient elastography can be used as an additional method for the clinical diagnosis of liver fibrosis and cirrhosis.

A health technology assessment of transient elastography in adult liver disease

BACKGROUND

An estimated one in 10 Canadians have some form of liver disease. The reference standard for staging and monitoring liver fibrosis is percutaneous liver biopsy--an invasive procedure associated with risks and complications. Transient elastography (TE) represents a noninvasive, ultrasound-based alternative.

OBJECTIVE

To assess the efficacy of TE compared with liver biopsy for fibrosis staging in adults with five common types of liver disease: hepatitis B, hepatitis C, nonalcoholic fatty liver disease, cholestatic liver disease and complications post-liver transplantation.

METHODS

A systematic review of published and grey literature from 2001 to June 2011 was conducted. Included were observational studies evaluating the accuracy of TE using liver biopsy as the comparator. An economic model was developed to estimate the cost per correct diagnosis gained with liver biopsy compared with TE. Identification of moderate fibrosis (stages 2 to 4) and cirrhosis (stage 4) were considered.

RESULTS

Fifty-seven studies were included in the review. The diagnostic accuracy of TE for the five clinical subgroups had sensitivities ranging from 0.67 to 0.92 and specificities ranging from 0.72 to 0.95. Liver biopsy was associated with an additional $1,427 to $7,030 per correct diagnosis gained compared with TE. The model was sensitive to the sensitivity and specificity of TE and the prevalence of fibrosis.

CONCLUSIONS

TE is an accurate diagnostic method in patients with moderate fibrosis or cirrhosis. TE is less effective but less expensive than liver biopsy. Systemic implementation of TE should be considered for the noninvasive assessment of liver fibrosis.

Acoustic radiation force impulse and supersonic shear imaging versus transient elastography for liver fibrosis assessment

Our study compared three elastographic methods--transient elastography (TE), acoustic radiation force impulse (ARFI) imaging and supersonic shear imaging (SSI)--with respect to the feasibility of their use in liver fibrosis evaluation. We also compared the performance of ARFI imaging and SSI, with TE as the reference method. The study included 332 patients, with or without hepatopathies, in which liver stiffness was evaluated using TE, ARFI and SSI. Reliable measurements were defined as a median value of 10 (TE, ARFI imaging) or 5 (SSI) liver stiffness measurements with a success rate ≥60% and an interquartile range interval <30%. A significantly higher percentage of reliable measurements were obtained using ARFI than by using TE and SSI: 92.1% versus 72.2% (p < 0.0001) and 92.1% versus 71.3% (p < 0.0001). Higher body mass index and older age were significantly associated with inability to obtain reliable measurements of liver stiffness using TE and SSI. In 55.4% of patients, reliable liver stiffness measurements were obtained using all three elastographic methods, and ARFI imaging and TE were similarly accurate in diagnosing significant fibrosis and cirrhosis, with TE as the reference method.

Liver elastography, comments on EFSUMB elastography guidelines 2013

Recently the European Federation of Societies for Ultrasound in Medicine and Biology Guidelines and Recommendations have been published assessing the clinical use of ultrasound elastography. The document is intended to form a reference and to guide clinical users in a practical way. They give practical advice for the use and interpretation. Liver disease forms the largest section, reflecting published experience to date including evidence from meta-analyses with shear wave and strain elastography. In this review comments and illustrations on the guidelines are given.

Influence of different frequencies and insertion depths on the diagnostic accuracy of liver elastography by acoustic radiation force impulse imaging (ARFI)

BACKGROUND

Acoustic Radiation Force Impulse Imaging (ARFI) is an innovative elastography for staging of liver fibrosis. We evaluated the diagnostic accuracy of different probes to perform ARFI at different insertion depths.

METHODS

In a prospective study, 89 chronic HCV infected patients underwent ARFI elastography using both available probes (c-ARFI: C4-1-MHz; l-ARFI: L9-4 MHz) in comparison to Fibroscan(®). Variability of ARFI elastography at different insertion depths was systematically evaluated in 39 patients (44%). According to Fibroscan(®) elastography, 32 patients (36%) presented with liver cirrhosis, 23 patients (26%) had significant fibrosis and 34 patients (38%) had no significant fibrosis.

RESULTS

Mean propagation velocity with c-ARFI was 1.70±0.67m/s and 1.91±0.87m/s with l-ARFI. Results of both probes were correlated to each other (p<0.001; r=0.70) and to Fibroscan(®) (p<0.001, r=0.82 and 0.84, respectively). In patients with significant fibrosis or with cirrhosis, mean values by l-ARFI were significantly higher than by c-ARFI (p<0.001). For detection of liver cirrhosis, AUROC was 0.97 for c-ARFI (cut-off level 1.72m/s) and 0.90 for l-ARFI (cut-off 2.04m/s). Correlation coefficients of c-ARFI with Fibroscan(®) were highest at an insertion depth of 5-6cm (r=0.882 and 0.864, respectively, p<0.001) and at 3-4cm for l-ARFI (r=0.850 and 0.838, respectively, p<0.001).

CONCLUSIONS

ARFI elastography with the linear and with the convex probes showed comparable validity and accuracy in the estimation of liver stiffness. The linear probe gave higher ARFI values. The most accurate insertion depth was 5-6cm for c-ARFI and 3-4cm for l-ARFI indicating that measurements should not be performed close to the liver capsule.

Comparative study concerning the value of acoustic radiation force impulse elastography (ARFI) in comparison with transient elastography (TE) for the assessment of liver fibrosis in patients with chronic hepatitis B and C

Our aim was to compare liver stiffness (LS) measurements by means of acoustic radiation force impulse (ARFI) elastography and transient elastography (TE) in patients with chronic hepatitis B and C, according to the severity of fibrosis. We also compared the correlation strength of ARFI and TE measurements with liver fibrosis. We included 53 patients with hepatitis B and 107 with hepatitis C in which liver biopsy, ARFI and TE measurements were performed in the same session. The mean LS values measured with ARFI were similar in patients with chronic hepatitis B and C and depended on the stage of fibrosis. The correlation strength of LS measurements by ARFI and by TE with fibrosis was similar in chronic hepatitis B and C patients. In conclusion, for the same stage of fibrosis, the mean LS values by ARFI were similar in patients with chronic hepatitis B and C. ARFI had similar predictive value with TE in both chronic viral hepatitis.

Intra- and interoperator reproducibility of acoustic radiation force impulse (ARFI) elastography--preliminary results

Our study assessed acoustic radiation force impulse (ARFI) reproducibility and the factors influencing it. The intra- and interoperator reproducibility were studied in 33 and 58 patients, respectively. Intraclass correlation coefficient (ICC) was used to assess ARFI reproducibility. The overall intraoperator agreement was better than the interoperator one: ICC 0.90 vs. ICC 0.81. The correlation of repeated ARFI measurements was higher, but not significantly so, in cases in which intraoperator reproducibility was assessed compared with the ones in which interoperator reproducibility was studied: r = 0.848 vs. r = 0.694 (p = 0.08). For both intra- and interoperator reproducibility, the ICCs were smaller in women vs. men (0.88 vs. 0.91 and 0.67 vs. 0.86, respectively), in patients with high body mass index (BMI) ≥25 kg/m² vs. <25 kg/m² (0.88 vs. 0.91 and 0.79 vs. 0.82, respectively), in patients with ascites vs. no ascites (0.80 vs. 0.93 and 0.78 vs. 0.84, respectively) and in noncirrhotic vs. cirrhotic patients (0.77 vs. 0.82 and 0.70 vs. 0.83, respectively).