Applicability and accuracy improvement of transient elastography using the M and XL probes by experienced operators

Accuracy of a sequential algorithm based on FIB-4 and ELF to identify high-risk advanced liver fibrosis at the primary care level

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease, and liver fibrosis is the strongest predictor of morbimortality. We aimed to assess the performance of a sequential algorithm encompassing the Fibrosis 4 (FIB-4) and Enhanced Liver Fibrosis (ELF) scores for identifying patients at risk of advanced fibrosis. This cross-sectional study included one hospital-based cohort with biopsy-proven NAFLD (n = 140) and two primary care cohorts from different clinical settings: Type 2 Diabetes (T2D) follow-up (n = 141) and chronic liver disease (CLD) initial study (n = 138). Logistic regression analysis was performed to assess liver fibrosis diagnosis models based on FIB-4 and ELF biomarkers. The sequential algorithm retrieved the following accuracy parameters in predicting stages F3-4 in the biopsy-confirmed cohort: sensitivity (85%), specificity (73%), negative predictive value (79%) and positive predictive value (81%). In both T2D and CLD cohorts, a total of 28% of patients were classified as stages F3-4. Furthermore, of all F3-4 classified patients in the T2D cohort, 80% had a diagnosis of liver disease and 44% were referred to secondary care. Likewise, of all F3-4 classified patients in the CLD cohort, 71% had a diagnosis of liver disease and 44% were referred to secondary care. These results suggest the potential utility of this algorithm as a liver fibrosis stratifying tool in primary care, where updating referral protocols to detect high-risk F3-4 is needed. FIB-4 and ELF sequential measurement is an efficient strategy to prioritize patients with high risk of F3-4 in populations with metabolic risk factors.

Variability of transient elastography-based spleen stiffness performed at 100 Hz

BACKGROUND

Spleen stiffness measurement (SSM) performed by transient elastography at 100 Hz is a novel technology for the evaluation of portal hypertension in advanced chronic liver disease, but technical aspects are lacking. We aimed to evaluate the intraexamination variability of SSM and to determine the best transient elastography protocol for obtaining robust measurements to be used in clinical practice.

METHODS

We analyzed 253 SSM exams with up to 20 scans for each examination, performed between April 2021 and June 2022. All SSM results were evaluated according to different protocols by dividing data into groups of n measurements (from 2 to 19). Considering as reference the median SSM values across all the 20 measurements, we calculated the distribution of the absolute deviations of each protocol from the reference median. This analysis was repeated 1,000 times by resampling the data. Distributions were also stratified by etiology (chronic liver disease versus clinically significant portal hypertension) and different SSM ranges: < 25 kPa, 25-75, and > 75 kPa.

RESULTS

Overall, we observed that the spleen stiffness exam had less variability if it exceeded 12 measurements, i.e., absolute deviations ≤ 5 kPa at 95% confidence. For exams with higher SSM values (> 75 kPa), as seen in clinically significant portal hypertension, at least 15 measurements are highly recommendable.

CONCLUSIONS

Fifteen scans per examination should be considered for each SSM exam performed at 100 Hz to achieve a low intraexamination variability within a reasonable time in clinical practice.

RELEVANCE STATEMENT

Performing at least 15 scans per examination is recommended for 100 Hz SSM in order to achieve a low intraexamination variability, in particular for values > 75 kPa compatible with clinically significant portal hypertension.

KEY POINTS

• Spleen stiffness measurement by transient elastography is used for stratification in patients with portal hypertension. • At 100 Hz, this method may have intraexamination variability. • A minimum of 15 scans per examination achieves a low intraexamination variability.

Clinical practice guidelines of the Catalan Society of Gastroenterology about hepatic elastography 2022

INTRODUCTION

After almost 20 years using transient elastography (TE) for the non-invasive diagnosis of liver fibrosis, its use has been extended to population screening, evaluation of steatosis and complications of cirrhosis. For this reason, the «Catalan Society of Gastroenterology» commissioned a group of experts to update the first document carried out in 2011.

MATERIAL AND METHODS

The working group (8 doctors and 4 nurses) prepared a panel of questions based on the online survey «Hepatic Elastography in Catalonia 2022» following the PICO structure and the Delphi method.

RESULTS

The answers are presented with the level of evidence, the degree of recommendation and the final consensus after being evaluated by two external reviewers.

CONCLUSION

Transient elastography uses the simplest and most reliable elastographic method to quantify liver fibrosis, assess steatosis, and determine the risk of complications in patients with cirrhosis. The document has been endorsed by the "Catalan Society of Gastroenterology" and the "Col·legi Oficial d'Infermeres i Infermers de Barcelona".

Follow-up evaluation of patients with liver test abnormalities detected during SARS-CoV2 infection

Abnormal liver function tests (A-LFTs) during admission for coronavirus disease-19 (COVID-19) are frequent, but its evolution after COVID-19 resolution remains unexplored. We evaluated factors related to A-LFTs during COVID-19 and assessed the liver outcome after patients' discharge. This is a observational study including: (1) retrospective analysis of variables related to A-LFTs during COVID-19; and (2) follow-up evaluation with blood test, transient elastography and liver biopsy in those with persistent A-LFTs. A-LFTs were defined according to CTCAEv4.0. Among 595 patients, 366 (61.5%) showed A-LFTs. The ratio of partial pressure of oxygen and inspired oxygen fraction (P/F) below 200, ferritin ≥1000 ng/mL, male gender and antibiotic and immunomodulatory treatments were related to A-LFTs. Follow-up evaluation was performed in 153 individuals. Persistent A-LFTs at follow-up was similar in patients with/without A-LFTs during admission (14.1% vs. 4.9%, p = 0.104). Fifteen (93%) and 58 (39%) patients with/without A-LFTs at follow-up showed metabolic fatty liver disease criteria (p < 0.001), which were histologically confirmed. In conclusion, A-LFTs during COVID-19 were related to infection severity. Abnormalities remitted at follow-up in >80% of patients, and no correlation between A-LFTs at admission and at follow-up was found. Most patients with A-LFTs at follow-up had non-invasive and histologically proven fatty liver disease.

Quality criteria for the measurement of liver stiffness

Liver elastography offers the possibility of a quick, non-invasive, and painless evaluation of the liver with immediate results at bedside. Transient elastography is the most validated technology, and many others such as point shear wave elastography, 2D-shear wave elastography, or magnetic resonance elastography have been developed. To ensure the best evaluation, several conditions of examination must be respected for liver stiffness measurement. Indeed, patient, operator and examination characteristics have all been shown to influence the result of liver stiffness measurement. Food intake increases liver stiffness, whereas withdrawal in alcoholics is associated with a decrease in elastography results. Inter-observer reproducibility of the measurement seems suboptimal, and the influence of the operator experience is still being debated. The measurement site and the FibroScan® probe must be correctly chosen. Finally, the intrinsic characteristics and quality criteria of the measurement, especially the interquartile range/median ratio, must be carefully checked to avoid overestimation of liver stiffness. Most of the results come from studies which have evaluated transient elastography, with less data available for the other technologies. Liver stiffness measurement could appear as a simple way to explore the liver, but several conditions must be met before deciding the patient management according to its result.

Elastography is unable to exclude cirrhosis after sustained virological response in HCV-infected patients with advanced chronic liver disease

BACKGROUND

Liver fibrosis and transient elastography (TE) correlation in hepatitis C virus (HCV)-infected patients with compensated advanced chronic liver disease (cACLD) after the sustained virological response (SVR) is unknown.

AIMS

To evaluate TE accuracy at identifying cirrhosis 3 years after HCV-eradication.

METHODS

Prospective, multi-centric study including HCV-cACLD patients before direct-acting antivirals (DAA). Diagnostic accuracy of TE (area under ROC, AUROC) to identify cirrhosis 3 years after SVR was evaluated.

RESULTS

Among 746 HCV-infected patients (95.4% with TE ≥10 kPa), 76 (10.2%) underwent a liver biopsy 3 years after SVR. Before treatment, 46 (63%) showed a TE>15 kPa. The TE before DAA was the best variable for predicting cirrhosis (METAVIR, F4) after SVR (AUROC = 0.79). Liver function parameters, serological non-invasive tests (APRI and FIB-4), and TE values improved after SVR. However, liver biopsy 3 years after HCV elimination (median time = 38.4 months) showed cirrhosis in 41 (53.9%). Multivariate analysis (OR (95% CI), P) showed that HCV-genotype 3 (20.81 (2.12-201.47), .009), and TE before treatment (1.21 (1.09-1.34), <.001) were the only variables associated with cirrhosis after SVR. However, the accuracy of TE after SVR was poor (AUROC = 0.75) and 6 (27.3%) out of 22 patients with a TE <8 kPa had cirrhosis. Similar results were found with APRI and FIB-4 scores.

CONCLUSIONS

Cirrhosis is present, 3 years after SVR, in more than half of HCV-cACLD patients even with the normalisation of liver function parameters, serological non-invasive tests and TE values. The low diagnostic accuracy of non-invasive methods after SVR reinforces the need for long-term surveillance.

What does liver elastography measure? Technical aspects and methodology

Elastography can be thought as an extension of the ancient technique of palpation. After giving a short introduction to the history of elastography, the different technologies that are nowadays available and the physics behind them, the article focuses on the assessment of liver stiffness in patients with diffuse liver disease using shear wave elastography (SWE). Practical advices on how to perform the SWE techniques and on the factors that should be considered for a correct interpretation of the results are given. This paper aimed to provide a practical guide for beginners and advanced clinical users to better understand technical aspects, methodologies and terminology.

The Use of Transient Elastography Technology in the Bariatric Patient: a Review of the Literature

Transient elastography (TE) is a non-invasive technology that demonstrates promise in assessing liver steatosis and fibrosis without the risks of traditional percutaneous liver biopsy. Many studies have examined its reliability in respect to liver biopsy, but fewer have examined using TE in obese and bariatric surgery patients. With evidence showing that bariatric surgery can lead to improvement of liver steatosis and fibrosis, TE has the potential to provide a simple avenue of hepatic assessment in patients before and after procedures. This review article investigates what is known about the reliability of TE and its implementation in obese and bariatric surgery patients.

Impact of sustained virological response with DAAs on gastroesophageal varices and Baveno criteria in HCV-cirrhotic patients

BACKGROUND

Direct-acting antivirals (DAAs) show high efficacy and safety in HCV-cirrhotic patients, but most maintain clinically significant portal hypertension after sustained virological response (SVR). Non-invasive Baveno and expanded-Baveno criteria can identify patients without high-risk gastroesophageal varices (GEV) who have no need for endoscopic surveillance. However, data after SVR are scarce. We performed a multicenter study to evaluate SVR effects over GEV and diagnostic accuracy of non-invasive criteria after SVR.

METHODS

HCV-cirrhotic patients receiving DAAs and baseline endoscopic evaluation were included (November 2014-October 2015). GEV were classified as low risk (LR-GEV) (< 5 mm) or high risk (HR-GEV) (≥ 5 mm or with risk signs). Transient elastography (TE) and endoscopy were performed during follow-up.

RESULTS

SVR was achieved in 230 (93.1%) of 247 included patients, 151 (65.7%) with endoscopic follow-up. Among 64/151 (42.4%) patients without baseline GEV, 8 (12.5%) developed GEV after SVR. Among 50/151 (33.1%) with baseline LR-GEV, 12 (24%) developed HR-GEV. Patients with GEV progression showed TE ≥ 25 kPa before treatment (64.7%) or ≥ 20 kPa after SVR (66.7%). Only 6% of patients without GEV and LSM < 25 kPa before treatment, and 10% of those with baseline LSM < 25 kPa and LSM < 20 kPa after SVR showed GEV progression after 36 months. The negative predictive value of Baveno and expanded-Baveno criteria to exclude HR-GEV was maintained after SVR (100% and 90.7%, respectively).

CONCLUSIONS

HCV-cirrhotic patients can develop HR-GEV after SVR. Surveillance is especially recommended in those with GEV before antiviral treatment. Baveno and expanded-Baveno criteria can be safely applied after SVR. https://clinicaltrials.gov: NCT02758509.

Transient elastography: should XL probe be used in all overweight patients?

Background: Obesity is one of the main factors of transient elastography (TE) failure, considering body mass index (BMI) ≥28 kg/m² as a limiting factor. The XL probe was designed to overcome this limitation. Aim: To compare the feasibility of the M and XL probes in patients with BMI ≥ 28 kg/m², to evaluate differences in mean values of controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) between the two probes and find predictive factors of TE failure. Material and methods: Prospective study, including all patients with BMI ≥ 28 kg/m² consecutively admitted for TE. Results: Included 161 patients. Measurements with M probe were reliable in 69.6% of the patients, with 68.2% of valid measurements in obese population and 58.9% in patients with skin-capsule distance (SCD) >25 mm. In 40 patients (81.6%) with an invalid M probe measurement, a reliable result was obtained with XL probe. We found that SCD >25 mm was the only predictor of M probe failure (OR: 4.9, CI: 1.64-14.63, p = .004). In those patients in which TE was possible with both probes (n = 112), mean CAP was 304 ± 49 dB/m² with M probe and 301 ± 50 dB/m² with XL probe (p = .59). Regarding liver stiffness, a mean value of 7.58 ± 3.47 kpas was obtained with the M probe and 6.21 ± 3.44 kpas with the XL probe (p < .001). Conclusion: There is a reliable applicability of the M probe in a high number (68.2%) of patients with a BMI ≥30 kg/m². A SCD >25 mm was the only predictive factor of M probe failure. Mean values of LSM with XL probe were lower than those obtained with M probe.

Recommendations for the detection, diagnosis and follow-up of patients with non-alcoholic fatty liver disease in primary and hospital care

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases, with a prevalence of 20-30% in the general population and 60-80% in at-risk populations. In a not negligible percentage of patients, NAFLD progresses from steatosis to different stages of fibrosis and cirrhosis. Due to its high prevalence, NAFLD has become a significant health problem that requires specific action in detection, diagnosis, follow-up and treatment. Furthermore, given that NAFLD presents an increased risk of cardiovascular morbidity and mortality, a multidisciplinary approach is required for its treatment and follow-up. Patients with early stages of the disease, without fibrosis, can be diagnosed and receive treatment in the Primary Care setting, while those with more advanced liver disease benefit from specialised follow-up in the hospital setting to prevent and treat liver complications. This consensus document, prepared by the Catalan Societies of Digestology, Primary Care, Endocrinology, Diabetes and Internal Medicine, arises from the need to design strategies to guide patient flows between Primary and Hospital Care in order to offer patients with NAFLD the best care according to the stage of their disease. The consensus document describes the most commonly used non-invasive diagnostic methods for patient diagnosis and two algorithms have been designed for patient management in both Primary Care and Hospital Care.

Eight weeks of Paritaprevir/r/Ombitasvir + Dasabuvir in HCV genotype 1b with mild-moderate fibrosis: Results from a real-world cohort

BACKGROUND & AIMS

The interferon-free regimen paritaprevir/ritonavir, ombitasvir + dasabuvir (PTV/r/OBV/DSV) has shown high efficacy in patients with hepatitis C virus (HCV) genotype 1b infection when administered for 8 or 12 weeks, but data regarding the 8-week treatment are scarce. The aim of our study was to assess the efficacy and safety of the 8-week administration of PTV/r/OBV/DSV in a real-world cohort.

METHODS

We performed a multicentre observational study from Spanish Hepa-C database including patients receiving 8 weeks of PTV/r/OBV/DSV (October 2016-November 2017). Those with advanced fibrosis, with non-genotype 1b or who were treatment-experienced were excluded.

RESULTS

A total of 211 patients were registered from 23 Spanish centres; eleven were excluded. At baseline, 42.5% (n = 85) were male, median (range) age was 57 (23-86), ALT was 45 (11-494) IU/mL, viral load was 6.1 (3.3-8.2) log10 IU/mL, and 74.5% had mild liver fibrosis (F0-F1) and 25.5% moderate fibrosis (F2). At the end of treatment (EOT), HCV viral load was undetectable in 100% (200/200). Seven patients relapsed after treatment discontinuation. Sustained virological response (SVR12) rates by intention-to-treat analysis were 96% (192/200). Regarding treatment safety, 2 patients developed ALT elevation >5x ULN, but there were no treatment discontinuations. One patient died 7 weeks after EOT.

CONCLUSION

Treatment with PTV/r/OBV/DSV in genotype 1b-infected treatment-naive patients with mild-moderate fibrosis shows excellent efficacy and safety in real life, similarly to clinical trials. Clinicaltrials.gov, number: NCT03122132.

Chronic Hepatitis C Patients with Obesity: Do we Need two Operators for Accurate Evaluation of Liver Stiffness?

INTRODUCTION AND AIM

Transient elastography is gaining popularity as a non-invasive method for predicting liver fibrosis, but inter observer agreement and factors influencing reproducibility have not been adequately assessed.

MATERIAL AND METHODS

This cross-sectional study was conducted at Specialized Medical Hospital and the Egyptian Liver Foundation, Mansoura, Egypt. The inclusion criteria were: age older than 18 years and chronic infection by hepatitis C. The exclusion criteria were the presence of ascites, pacemaker or pregnancy. Three hundred and fifty-six patients participated in the study. Therefore, 356 pairs of exams were done by two operators on the same day.

RESULTS

The overall inter observer agreement ICC was 0.921. The correlation the two operators was excellent (Spearman's value q = 0.808, p < 0.001). Inter-observer reliability values were κ = 0.557 (p < 0.001). A not negligible discordance of fibrosis staging between operators was observed (87 cases, 24.4%). Discordance of at least one stage and for two or more stages of fibrosis occurred in 60 (16.9%) and 27 cases (7.6%) respectively. Obesity (BMI ≥ 30 kg/m2) is the main factor associated with discordance (p = 0.002).

CONCLUSION

Although liver stiffness measurement has had an excellent correlation between the two operators, TE presented an inter-observer variability that may not be negligible.

Usefulness of virtual touch quantification for staging liver fibrosis in patients with hepatitis C, and factors affecting liver stiffness measurement failure compared with liver biopsy

AIM

The assessment of liver fibrosis in patients with hepatitis C is important to predict carcinogenesis. In this study, we evaluated the usefulness of virtual touch quantification (VTQ) for staging liver fibrosis, and investigated factors causing discrepancies between the estimated fibrosis stage using VTQ and the pathological fibrosis stage.

METHODS

Patients with hepatitis C (n = 302) were assessed using VTQ and underwent pathological liver investigation within 1 week before and after VTQ. A receiver operator characteristic (ROC) curve was obtained for VTQ, fibrosis-4 (FIB-4) index, and aspartate aminotransferase-to-platelet ratio index (APRI), and each area under the ROC curve (AUROC) was compared to predict fibrosis stage. We used univariate and multivariate analyses to investigate the factors related to the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage.

RESULTS

At any stage, VTQ was the most accurate for staging liver fibrosis. The VTQ cut-off values were 1.33 m/s (AUROC = 0.822) for ≥F2, 1.51 m/s (AUROC = 0.836) for ≥F3, and 1.92 m/s (AUROC = 0.890) for F4. Skin liver capsule distance (SCD) was the most relevant factor for the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage. The SCD cut-off value was 17.5 mm.

CONCLUSIONS

Virtual touch quantification is a non-invasive, simple method that is more accurate for staging liver fibrosis than the FIB-4 index and APRI. However, when the SCD is longer than 17.5 mm, there may be measurement failures.

Enhanced liver fibrosis test using ELISA assay accurately discriminates advanced stage of liver fibrosis as determined by transient elastography fibroscan in treatment naïve chronic HCV patients

Evaluation of liver fibrosis stage is crucial in the assessment of chronic HCV patients, regarding decision to start treatment and during follow-up. Our aim was to assess the validity of the enhanced liver fibrosis (ELF) score in discrimination of advanced stage of liver fibrosis in naïve chronic HCV patients. We prospectively evaluated liver fibrosis stage in one hundred eighty-one naïve chronic HCV Egyptian patients by transient elastography (TE)-FibroScan. Patients were categorized into mild to moderate fibrosis (≤F2) group and advanced fibrosis (≥F3) group. The ELF score components, hyaluronic acid (HA), amino-terminal propeptide of type-III-procollagen (PIIINP) and tissue inhibitor of metalloproteinase type-1 (TIMP-1), were done using ELISA test. The mean values of ELF and its individual components significantly correlated with the hepatic fibrosis stage as measured by TE-FibroScan (P value 0.001). ELF cutoff value of 9.8 generated a sensitivity of 77.8%, specificity of 67.1%, area under the receiver operator characteristic curve (AUROC) of 0.76 with 95% confidence interval [CI] (0.68-0.83) for detecting advanced fibrosis (F ≥ 3). ELF panel is a good, reliable noninvasive test and showed comparable results to TE-FibroScan in detecting liver fibrosis stage in treatment naïve chronic HCV patients.

Diagnostic Accuracy of the Enhanced Liver Fibrosis (ELF®) Score Using HCV-Infected Serum Samples Cryopreserved for up to 25 Years

Introduction & Aims

Cryopreservation of serum samples is a standard procedure for biomedical research in tertiary centers. However, studies evaluating the long-term biological stability of direct liver fibrosis markers using cryopreserved samples are scarce.

Methods

We compared the stability of hyaluronic acid (HA), tissue inhibitor of metalloproteinases (TIMP-1) and amino-terminal propeptide of type III procollagen (PIIINP) in 225 frozen serum samples of HCV-infected patients with a paired liver biopsy for up to 25 years (1990–2014). Moreover, we assessed the diagnostic accuracy (AUROC) of the Enhanced Liver Fibrosis (ELF^®) score to identify significant fibrosis (F2-4) and its predictive capacity to identify clinical events during follow-up.

Results

Seventy-six patients (39,8%) had mild fibrosis (F0-1) and 115 (60,2%) significant fibrosis (F2-4). HA, PIIINP and TIMP-1 values remained stable during the period from 1995 to 2014 while those of 1990–94 were slightly higher. We did not find significant differences in the median ELF^® values during the 20-year period from 1995–2014 in patients with mild (from 8,4 to 8,7) and significant fibrosis (from 9,9 to 10,9) (p = ns between periods and fibrosis stages). The AUROCs of ELF^® to identify significant fibrosis were high in all the periods (from 0,85 to 0,91). The ELF^® score showed a good predictive capability to identify clinical events during follow-up.

Conclusions

The biological stability of direct serum markers (HA, PIIINP and TIMP-1) using HCV-infected samples cryopreserved for 20 years is good. Therefore, the diagnostic accuracy of the ELF^® score to identify significant fibrosis and clinical events during follow-up is very high.

Feasibility of transient elastography versus real-time two-dimensional shear wave elastography in difficult-to-scan patients

BACKGROUND AND AIMS

Transient elastography (TE) is hampered in some patients by failures and unreliable results. We hypothesized that real time two-dimensional shear wave elastography (2D-SWE), the FibroScan XL probe, and repeated TE exams, could be used to obtain reliable liver stiffness measurements in patients with an invalid TE examination.

METHODS

We reviewed 1975 patients with 5764 TE exams performed between 2007 and 2014, to identify failures and unreliable exams. Fifty-four patients with an invalid TE at their latest appointment entered a comparative feasibility study of TE vs. 2D-SWE.

RESULTS

The initial TE exam was successful in 93% (1835/1975) of patients. Success rate increased from 89% to 96% when the XL probe became available (OR: 1.07, 95% CI 1.06-1.09). Likewise, re-examining those with a failed or unreliable TE led to a reliable TE in 96% of patients. Combining availability of the XL probe with TE re-examination resulted in a 99.5% success rate on a per-patient level. When comparing the feasibility of TE vs. 2D-SWE, 96% (52/54) of patients obtained a reliable TE, while 2D-SWE was reliable in 63% (34/54, p < 0.001). The odds of a successful 2D-SWE exam decreased with higher skin-capsule distance (OR = 0.77, 95% CI 0.67-0.98).

CONCLUSIONS

Transient elastography can be accomplished in nearly all patients by use of the FibroScan XL probe and repeated examinations. In difficult-to-scan patients, the feasibility of TE is superior to 2D-SWE.

Appropriate use of virtual touch quantification and FibroScan M and XL probes according to the skin capsular distance

BACKGROUND

Appropriate utilization of different diagnostic modalities is essential for the accurate liver stiffness measurements (LSM) in patients with chronic liver diseases. The aim of this study was to evaluate the efficacy of Virtual Touch Quantification (VTQ) and the FibroScan M and XL probes in term of accurate LSM and to identify factors associated with inadequate measurements in obese and non-obese Japanese patients.

METHODS

A total of 664 consecutive patients with chronic liver disease were prospectively enrolled. LSM were evaluated concurrently with VTQ and the FibroScan M and XL probes. LSM quality was categorized as inadequate (success rate <60% and/or interquartile range/median value of ≥30%) or adequate.

RESULTS

No significant differences in the rate of inadequate LSM were observed among the three diagnostic modalities. In multivariate analysis, skin capsule distance (SCD) was strongly associated with inadequate rates obtained with VTQ and the M probe [odds ratio (OR) 1.28, P < 0.0001 and OR 1.20, P < 0.0001, respectively]. Inadequate LSM rates with both VTQ and the M probe increased with longer SCD, with a significant difference between subgroups at an SCD of ≥22.5 mm (VTQ 54.0%; M probe 51.1%; XL probe 25.2%; P < 0.0001). The rates of inadequate LSM rates with VTQ were significantly lower than those with the XL probe at an SCD of <17.5 mm. A total of 15 liver biopsy specimens obtained from nonalcoholic fatty liver disease patients confirmed the diagnostic accuracy and high applicability of the XL probe.

CONCLUSIONS

Long SCD reduced the diagnostic performance of the FibroScan® M probe and VTQ. LSM modalities should be selected according to SCD.

Factors Associated with the Quality of Transient Elastography

BACKGROUND

Transient elastography is a noninvasive method for the evaluation of fibrosis in chronic liver disease. However, its reliability is variable, and the factors associated with its accuracy have not been identified completely.

AIMS

To identify the factors associated with the reliability of transient elastography.

METHODS

A total of 2033 transient elastography measurements were taken from March 2009 to October 2013. Reliability was determined according to the interquartile range/median (IQR/M < 0.30 = reliable; IQR/M < 0.10 = very reliable). Other indicators such as the percentage of successful measurements (>60 %), time of performance, and probe size were recorded. Potential factors that could affect the reliability of the procedure were analyzed using multivariate logistic regression.

RESULTS

Slightly less than 5 % of the measurements were unsuccessful, and 83 % of the successful measurements were found to be reliable. Factors associated with an unsuccessful measurement were female gender, incorrect probe size, and the presence of HCV infection. Unreliable measurements were associated with use of the procedure as part of a clinical study and success rate. Very reliable evaluations were associated with >10 measurements, the presence of chronic hepatic disease, and a success rate of >60 %.

CONCLUSIONS

The operator and clinical and anthropometric characteristics are factors that influence the success and reliability of transient elastography. Improvements in the quality of the procedure are needed to provide better diagnostic accuracy in clinical practice.