Inter-platform Variability of Liver Elastography: Pairwise Comparisons of Four Devices

This study was aimed at determining whether liver stiffness measurements by 2-D shear wave elastography using GE's (2D-SWE-GE) and Canon's (2D-SWE-Canon) newest apparatus and vibration-controlled transient elastography (VCTE) share the same distribution of values compared with Hologic Supersonic Imagine (2D-SWE-SSI). In participants with chronic liver disease recruited in two university centers from August 2020 to February 2021, liver stiffness was measured the same day by the same operator with 2D-SWE-SSI plus one of the following devices: 2D-SWE-GE (n = 314), 2D-SWE-Canon (n = 311), and VCTE-M probe (n = 812). VCTE-M and 2D-SWE-SSI values shared the highest correlation and concordance coefficients (0.933 and 0.920, respectively) and a coefficient of variation below 20%, whatever the range of values. 2D-SWE-GE had the lowest variations, with 2D-SWE-SSI values below 13 kPa. However, both 2D-SWE-GE and 2D-SWE-Canon exhibited a frank underestimation of the high percentiles' 2D-SWE-SSI values with coefficients of variation of -21.7% and -25.8% from 13- to 17-kPa values, and -44.3% and -32.4% from 17-kPa values, respectively. In conclusion, knowledge of the vendor-specific distribution of values is mandatory for interpreting results obtained with different machines. If all four techniques behave closely in low values allowing excluding advanced chronic liver diseases in larger populations, discrepancies are observed in high percentile values.

Transient Versus Two-Dimensional Shear-Wave Elastography in a Multistep Strategy to Detect Advanced Fibrosis in NAFLD

BACKGROUND AND AIMS

The combination of laboratory and elastography tests allows the accurate diagnosis of advanced liver fibrosis in patients with NAFLD. In this study, we compared the diagnostic performances of a two-step strategy (laboratory tests and vibration-controlled transient elastography [VCTE] or two-dimensional shear-wave elastography with SuperSonic Imagine [2D-SWE-SSI]) and the added value of a three-step strategy (laboratory tests and two elastography methods).

APPROACH AND RESULTS

From a prospective registry, we retrospectively selected 577 consecutive patients with suspicion of NAFLD who underwent laboratory tests to calculate the Fibrosis-4 (FIB-4) score, liver stiffness evaluation by VCTE (M and XL probes) and 2D-SWE-SSI, and liver biopsy. The diagnostic performances and need for liver biopsy in unclassified patients for the diagnosis of advanced fibrosis (F ≥ 3) in multistep strategies were compared. The area under the curve of FIB-4, VCTE, and 2D-SWE-SSI was 0.74, 0.82, and 0.88, respectively. Using the same thresholds, the FIB-4/2D-SWE-SSI and FIB-4/VCTE diagnostic performances were comparable (sensitivity, 71.4% and 66%; specificity, 91.4% and 91.5%; and accuracy, 83.7% and 81.4%; all P = not significant). Conversely, more patients required liver biopsy after 2D-SWE-SSI (24.6% versus 15.3%, P < 0.001). Performing a second elastography technique in patients with unreliable or gray zone (between 8 and 10 kPa) results greatly decreased the need for liver biopsy (42/577, 7.3%). The diagnostic performances (accuracy, sensitivity, and specificity) of FIB-4/2D-SWE-SSI/VCTE and FIB-4/VCTE/2D-SWE-SSI were comparable (81.1%, 71.5%, and 87.9% versus 81.3%, 69.7%, and 89.5%, respectively; all P = not significant).

CONCLUSIONS

Using the same cutoff values, 2D-SWE-SSI is as accurate as VCTE for advanced liver fibrosis diagnosis in NAFLD. The three-step strategy in selected patients strongly decreased the need for liver biopsy while maintaining excellent accuracy.

Assessment of hepatic steatosis by controlled attenuation parameter using the M and XL probes: an individual patient data meta-analysis

BACKGROUND

Diagnostic tools for liver disease can now include estimation of the grade of hepatic steatosis (S0 to S3). Controlled attenuation parameter (CAP) is a non-invasive method for assessing hepatic steatosis that has become available for patients who are obese (FibroScan XL probe), but a consensus has not yet been reached regarding cutoffs and its diagnostic performance. We aimed to assess diagnostic properties and identify relevant covariates with use of an individual patient data meta-analysis.

METHODS

We did an individual patient data meta-analysis, in which we searched PubMed and Web of Science for studies published from database inception until April 30, 2019. Studies reporting original biopsy-controlled data of CAP for non-invasive grading of steatosis were eligible. Probe recommendation was based on automated selection, manual assessment of skin-to-liver-capsule distance, and a body-mass index (BMI) criterion. Receiver operating characteristic methods and mixed models were used to assess diagnostic properties and covariates. Patients with non-alcoholic fatty liver disease (NAFLD) were analysed separately because they are the predominant patient group when using the XL probe. This study is registered with PROSPERO, CRD42018099284.

FINDINGS

16 studies reported histology-controlled CAP including the XL probe, and individual data from 13 papers and 2346 patients were included. Patients with a mean age of 46·5 years (SD 14·5) were recruited from 20 centres in nine countries. 2283 patients had data for BMI; 673 (29%) were normal weight (BMI <25 kg/m²), 530 (23%) were overweight (BMI ≥25 to <30 kg/m²), and 1080 (47%) were obese (BMI ≥30 kg/m²). 1277 (54%) patients had NAFLD, 474 (20%) had viral hepatitis, 285 (12%) had alcohol-associated liver disease, and 310 (13%) had other liver disease aetiologies. The XL probe was recommended in 1050 patients, 930 (89%) of whom had NAFLD; among the patients with NAFLD, the areas under the curve were 0·819 (95% CI 0·769-0·869) for S0 versus S1 to S3 and 0·754 (0·720-0·787) for S0 to S1 versus S2 to S3. CAP values were independently affected by aetiology, diabetes, BMI, aspartate aminotransferase, and sex. Optimal cutoffs differed substantially across aetiologies. Risk of bias according to QUADAS-2 was low.

INTERPRETATION

CAP cutoffs varied according to cause, and can effectively recognise significant steatosis in patients with viral hepatitis. CAP cannot grade steatosis in patients with NAFLD adequately, but its value in a NAFLD screening setting needs to be studied, ideally with methods beyond the traditional histological reference standard.

FUNDING

The German Federal Ministry of Education and Research and Echosens.

Agreement Between 2-Dimensional Shear Wave and Transient Elastography Values for Diagnosis of Advanced Chronic Liver Disease

BACKGROUND & AIMS

Inter-platform variation in liver stiffness evaluation (LSE) could hinder dissemination and clinical implementation of new ultrasound methods. We aimed to determine whether measurements of liver stiffness by bi-dimensional shear wave elastography (2D-SWE) with a Supersonic Imagine apparatus are comparable to those made by vibration-controlled transient elastography (VCTE).

METHODS

We collected data from 1219 consecutive patients with chronic liver disease who underwent LSE by VCTE and 2D-SWE (performed by blinded operators), on the same day, at a single center in France from September 2011 through June 2019. We assessed the ability of liver stiffness value distributions and 2D-SWE performances to identify patients with compensated advanced chronic liver disease (cACLD) according to the Baveno VI criteria, based on VCTE cut-off values.

RESULTS

VCTE and 2D-SWE values correlated (Pearson's correlation coefficient, 0.882; P < .0001; Lin concordance coefficient, 0.846; P < .0001). The median stiffness values were 6.7 kPa with VCTE (interquartile range, 4.8-11.6 kPa) and 7.1 kPa with 2D-SWE (interquartile range, 5.4-11.1 kPa) (P = .736). 2D-SWE values were slightly higher in the low percentiles and lower in the high percentiles; the best match with VCTE values were at approximately 7-9 kPa. The area under the curve of 2D-SWE for identifying of VCTE values below 10 was 0.964 (95% CI, 0.952-0.976) and for VCTE values above 15 kPa was 0.976 (95% CI, 0.963-0.988), with Youden index-associated cut-off values of 9.5 and 13kPa and best accuracy cut-off values of 10 kPa and 14 kPa, respectively. A 2D-SWE cut-off value of 10 kPa detected VCTE values below 10k Pa with 92% sensitivity, 87% specificity, and 91% accuracy.

CONCLUSIONS

Measurement of liver stiffness by VCTE or 2D-SWE produces comparable results. 2D-SWE accurately identifies patients with cACLD according to the Baveno VI criteria based on VCTE cut-off values. A 10 kPa 2D-SWE cut-off value can be used to rule out cACLD.

No Change in Determining Crohn's Disease Recurrence or Need for Endoscopic or Surgical Intervention With Modification of the Rutgeerts' Scoring System

The postoperative endoscopic recurrence score, commonly referred to as the Rutgeerts score, was designed to predict clinical recurrence risk in Crohn's disease (CD) patients undergoing ileocolonic resection based on early endoscopic findings at the anastomosis and in the neoterminal ileum.¹ In the pivotal publication, the i2 category, including aphthous lesions in the terminal ileum as well as ileocolonic anastomosis lesions, had a heterogeneous recurrence risk. Because anastomotic ulcers were suspected to be postsurgical ischemic lesions and less predictive of progressive disease,² a modified Rutgeerts score (mRS) was proposed: i2a, lesions confined to the anastomosis ±<5 isolated aphthous ulcers in the ileum; i2b, more than 5 aphthous ulcers in the ileum with normal mucosa in between, ± anastomotic lesions.^3,4.