OBJECTIVE

Transient elastography has been studied in a multitude of liver diseases for the staging of liver fibrosis with variable results. A meta-analysis was performed to assess the overall performance of transient elastography for the diagnosis of liver fibrosis and to analyze factors influencing the diagnostic accuracy.

METHODS

Literature databases and international conference abstracts were searched. Inclusion criteria were as follows: evaluation of transient elastography, liver biopsy as reference, and assessment of the area under the receiver operating characteristic curve (AUROC). The meta-analysis was performed using the random-effects model for the AUROC, summary receiver operating curve techniques, as well as meta-regression approaches.

RESULTS

Fifty studies were included in the analysis. The mean AUROC for the diagnosis of significant fibrosis, severe fibrosis, and cirrhosis were 0.84 (95% confidence interval [CI], 0.82-0.86), 0.89 (95% CI, 0.88-0.91), and 0.94 (95% CI, 0.93-0.95), respectively. For the diagnosis of significant fibrosis a significant reduction of heterogeneity of the AUROC was found when differentiating between the underlying liver diseases (P < .001). Other factors influencing the AUROC were the scoring system used and the country in which the study was performed. Age, body mass index, and biopsy quality did not have a significant effect on the AUROC.

CONCLUSIONS

Transient elastography can be performed with excellent diagnostic accuracy and independent of the underlying liver disease for the diagnosis of cirrhosis. However, for the diagnosis of significant fibrosis, a high variation of the AUROC was found that is dependent on the underlying liver disease.

Transient elastography (TE, FibroScan) is a novel non-invasive method that has been proposed for the assessment of hepatic fibrosis in patients with chronic liver diseases, by measuring liver stiffness. TE is a rapid and user-friendly technique that can be easily performed at the bedside or in the outpatient clinic with immediate results and good reproducibility. Limitations include failure in around 5% of cases, mainly in obese patients. So far, TE has been mostly validated in chronic hepatitis C, with diagnostic performance equivalent to that of serum markers for the diagnosis of significant fibrosis. Combining TE with serum markers increases diagnostic accuracy and as a result, liver biopsy could be avoided for initial assessment in most patients with chronic hepatitis C. This strategy warrants further evaluation in other aetiological types of chronic liver diseases. TE appears to be an excellent tool for early detection of cirrhosis and may have prognostic value in this setting. As TE has excellent patient acceptance it could be useful for monitoring fibrosis progression and regression in the individual case, but more data are awaited for this application. Guidelines are needed for the use of TE in clinical practice.

OBJECTIVE

Recently, transient elastography (FibroScan) has been introduced for noninvasive staging of liver fibrosis. Here, we investigated a novel approach for noninvasive assessment of liver fibrosis using sonography-based real-time elastography, which can be performed with conventional ultrasound probes during a routine sonography examination.

METHODS

Real-time elastography was performed in 79 patients with chronic viral hepatitis and known fibrosis stage and in 20 healthy volunteers. A specially developed program was used for quantification of tissue elasticity. Stepwise logistic regression analysis was performed to define an elasticity score using variables with high reproducibility in a preceding analysis of data from 16 different patients. In addition, aspartate transaminase-to-platelet ratio index (APRI) and routine laboratory values were included in the analysis.

RESULTS

The Spearman's correlation coefficient between the elasticity scores obtained using real-time elastography and the histologic fibrosis stage was 0.48, which is highly significant (p < 0.001). The diagnostic accuracy expressed as areas under receiver operating characteristic (ROC) curves were 0.75 for the diagnosis of significant fibrosis (fibrosis stage according to METAVIR scoring system [F]>> or = F2), 0.73 for severe fibrosis (F>> or = F3), and 0.69 for cirrhosis. For a combined elasticity-laboratory score, the areas under the ROC curves were 0.93, 0.95, and 0.91, respectively.

CONCLUSIONS

Real-time elastography is a new and promising sonography-based noninvasive method for the assessment of liver fibrosis in patients with chronic viral hepatitis.

The accurate diagnosis and staging of hepatic fibrosis is crucial for prognosis and treatment of liver disease. The current gold standard, liver biopsy, cannot be used for population-based screening, and has well known drawbacks if used for monitoring of disease progression or treatment success. Our objective was to assess performance and promise of radiologic modalities and techniques as alternative, noninvasive assessment of hepatic fibrosis. A systematic review was conducted. Six hundred twenty-eight studies were identified via electronic search. One hundred fifty-three papers were reviewed. Most described techniques that could differentiate between cirrhosis or severe fibrosis and normal liver. Accurate staging of fibrosis or diagnosis of mild fibrosis was often not achievable. Ultrasonography is the most common modality used in the diagnosis and staging of hepatic fibrosis. Elastographic measurements, either ultrasonography-based or magnetic resonance-based, and magnetic resonance diffusion weighted imaging, show the most promise for accurate staging of hepatic fibrosis. Most currently available imaging techniques can detect cirrhosis or significant fibrosis reasonably accurately. However, to date only magnetic resonance elastography has been able to stage fibrosis or diagnose mild disease. Utrasonographic elastography and magnetic resonance diffusion weighted appear next most promising.