Differences in liver stiffness values obtained with new ultrasound elastography machines and Fibroscan: A comparative study

TLDR: The present results showed only moderate concordance of the majority of elastography machines with the Fibroscan results, preventing the possibility of the immediate universal adoption of fibroscan thresholds for defining liver fibrosis staging for all new machines.

About: This article is published in Digestive and Liver Disease.The article was published on 2017-07-01 and is currently open access. It has received 51 citations till now. The article focuses on the topics: Transient elastography & Elastography.

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Table 1 Patients characteristics.

Table 3 Concordance analysis for liver stiffness measurement taken in two different intercostal spaces and success rate.

Fig. 3. Comparison of each SWE technique versus Fibroscan in determining liver stiffness from two intercostal spaces. Scatter plots obtained considering liver stiffness as the median of all 20 samplings achieved in the reference (10 measurements) and alternative (10 measurements) intercostal s Fibros a n’s co

Fig. 2. Comparison of each SWE technique versus Fibroscan in determining liver stiffness sampled in the reference intercostal space. Liver stiffness sampled with each SWE machine (x axis) is plotted against the respective Fibroscan values (y axis). The regression line (thick) and the reference line (y = x; dashed) are drawn on each plot. Reports of the regression equation (y = ax + by), sample size (n), Pearson’s coefficient (r) and p value (P) for each comparison are reported in the box for each diagram.

Fig. 1. Demo plots to better illustrate Lin’s analysis. a: Same accuracy but different precision: two different samples (circles and dots) are plotted on the graph; the regression line (continuous line) and the median (square) are exactly the same for the two samples, but the two sets of samples differ overtly when considering the scattering of data from the regression line. As a consequence, notwithstanding the same accuracy (indicated by the regression line), Lin’s analysis is able to demonstrate a different concordance of the two sample sets by including the precision (indicated by the Pearson’s coefficient) which would be higher in the circles than in the dots. b: Same precision but different accuracy: three different sets of data are represented with circles; each set of data is perfectly aligned to the respective regression line (I, II and III); thus, Pearson’s analysis (an index of precision) would give the same result in the three samples in spite of the different slopes and intercepts of the regression lines. Conversely, accuracy would be very high for set III, and lower for sets I and II. The box indicates the median value, which is identical in the I and the III lines, indicating that the median value is not sufficient to confirm that two techniques produce the same data.

Frequently asked questions

Q1. What contributions have the authors mentioned in the paper "Differences in liver stiffness values obtained with new ultrasound elastography machines and fibroscan: a comparative study" ?

The aim of the present study was to test the concordance of the findings obtained from 7 of the most recent ultrasound elastography machines with respect to Fibroscan.