Ultrasound shear wave speed measurements correlate with liver fibrosis in children

Abstract

Background: Little published research has shown the relationship between noninvasive US shear wave speed (SWS) measurements and degree of liver fibrosis as established by percutaneous biopsy in children.

Objective: To assess the relationship between liver US shear wave speed (SWS) measurements and parenchymal fibrosis in children.

Materials and methods: Sixty-two children (0-18 years old) with known or suspected liver disease underwent same-day US shear wave elastography (SWE) and clinically ordered percutaneous core needle biopsy. SWE was performed just before the liver biopsy in the area targeted for sampling, using an Acuson S3000 US system with a 9L4 transducer; six SWS measurements were acquired using Virtual Touch Quantification (VTQ) and Virtual Touch IQ (VTIQ) modes. Biopsy specimens were scored for histological fibrosis and inflammation. Bivariate relationships were assessed using Pearson correlation, while multiple linear regression analysis was used to establish the relationship between SWS and predictor variables. Receiver operating characteristic (ROC) curves were created to assess the abilities of VTQ and VTIQ to discern low vs. high liver fibrosis (histological fibrosis scores 0-2 vs. 3-6).

Results: There were significant positive correlations between liver histological fibrosis score and VTQ (n = 49) and VTIQ (n = 48) mean shear wave speed measurements (r = 0.68 and r = 0.73; P-values <0.0001). There also were significant positive correlations between liver histological inflammation score and VTQ and VTIQ mean shear wave speed measurements (r = 0.47 and r = 0.44, and P = 0.0006 and P = 0.0016, respectively). For VTQ, both histological fibrosis (P < 0.0001) and inflammation (P = 0.04) scores were significant predictors of shear wave speed (model adjusted R (2) = 0.49). For VTIQ, only histological fibrosis score (P < 0.0001) was a significant predictor of shear wave speed (model adjusted R (2) = 0.56). ROC areas under the curve were 0.84 and 0.86 for VTQ and VTIQ, respectively.

Conclusion: Liver US shear wave speed measurements increase with increasing parenchymal fibrosis in children.

Conflict of interest statement

Conflicts of interest None

Figures

Fig. 1

Shear wave elastography. Virtual Touch Quantification (VTQ) mode images in (a) a 5-year-old boy and (b) a 17-year-old girl. Virtual Touch IQ (VTIQ) shear wave elastography mode images in (c) the same girl and (d) the same boy as (a and b). Higher shear wave speed measurements (and elastogram heterogeneity on VTIQ imaging) correlate with increasing parenchymal fibrosis

Fig. 2

Comparison of shear wave speed (SWS) and fibrosis. Box plots show increasing liver mean SWS measurements with increasing parenchymal fibrosis using (a) VTQ and (b) VTIQ shear wave elastography modes. VTIQ Virtual Touch IQ, VTQ Virtual Touch Quantification

Fig. 3

Correlations between Virtual Touch Quantification (VTQ) and Virtual Touch IQ (VTIQ) shear wave speed measurements. Scatter plot (with fit line and 95% confidence interval) shows the relationship between VTQ and VTIQ mean shear wave speed (SWS) measurements in 44 children (r=0.79; P<0.0001)

Fig. 4

Shear wave speed measurements compared to histological fibrosis scores. Box plots show mean shear wave speed (SWS) measurements for children with differing amounts of liver fibrosis using (a) VTIQ and (b) VTQ modes. Both imaging modes demonstrate increases in SWS with increasing histological fibrosis score (P<0.0001 for both VTQ and VTIQ). VTIQ Virtual Touch IQ, VTQ Virtual Touch Quantification

Fig. 5

Receiver operating characteristic (ROC) curves for discriminating low (histological fibrosis scores 0–2) vs. high (histological fibrosis scores 3–6) liver fibrosis using mean shear wave speed. a Area under the curve for VTQ is 0.84 (95% CI: 0.70–0.98). b Area under the curve for VTIQ is 0.86 (95% CI: 0.72–1.0). VTIQ Virtual Touch IQ, VTQ Virtual Touch Quantification