Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2016 Sep-Oct;17(5):750-7.
doi: 10.3348/kjr.2016.17.5.750. Epub 2016 Aug 23.

Prospective Comparison of Liver Stiffness Measurements between Two Point Shear Wave Elastography Methods: Virtual Touch Quantification and Elastography Point Quantification

Hyunsuk Yoo  1 , Jeong Min Lee  2 , Jeong Hee Yoon  1 , Dong Ho Lee  1 , Won Chang  1 , Joon Koo Han  2
Affiliations
Comparative Study

Prospective Comparison of Liver Stiffness Measurements between Two Point Shear Wave Elastography Methods: Virtual Touch Quantification and Elastography Point Quantification

Hyunsuk Yoo et al. Korean J Radiol. 2016 Sep-Oct.

Abstract

Objective: To prospectively compare technical success rate and reliable measurements of virtual touch quantification (VTQ) elastography and elastography point quantification (ElastPQ), and to correlate liver stiffness (LS) measurements obtained by the two elastography techniques.

Materials and methods: Our study included 85 patients, 80 of whom were previously diagnosed with chronic liver disease. The technical success rate and reliable measurements of the two kinds of point shear wave elastography (pSWE) techniques were compared by χ(2) analysis. LS values measured using the two techniques were compared and correlated via Wilcoxon signed-rank test, Spearman correlation coefficient, and 95% Bland-Altman limit of agreement. The intraobserver reproducibility of ElastPQ was determined by 95% Bland-Altman limit of agreement and intraclass correlation coefficient (ICC).

Results: The two pSWE techniques showed similar technical success rate (98.8% for VTQ vs. 95.3% for ElastPQ, p = 0.823) and reliable LS measurements (95.3% for VTQ vs. 90.6% for ElastPQ, p = 0.509). The mean LS measurements obtained by VTQ (1.71 ± 0.47 m/s) and ElastPQ (1.66 ± 0.41 m/s) were not significantly different (p = 0.209). The LS measurements obtained by the two techniques showed strong correlation (r = 0.820); in addition, the 95% limit of agreement of the two methods was 27.5% of the mean. Finally, the ICC of repeat ElastPQ measurements was 0.991.

Conclusion: Virtual touch quantification and ElastPQ showed similar technical success rate and reliable measurements, with strongly correlated LS measurements. However, the two methods are not interchangeable due to the large limit of agreement.

Keywords: Liver fibrosis; Liver stiffness; Shear wave elastography; Ultrasound elastography.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1. Flow diagram of study population.
*One patient who had technical failure on VTQ also had unreliable measurement on ElastPQ. ElastPQ = elastography point quantification, LS = liver stiffness, VTQ = virtual touch quantification
Fig. 2
Fig. 2. LS measurements by two pSWE techniques.
VTQ (A) and ElastPQ (B). For both measurements, operator placed predefined measuring box in liver. ElastPQ = elastography point quantification, LS = liver stiffness, pSWE = point shear wave elastography, VTQ = virtual touch quantification
Fig. 3
Fig. 3. Histogram showing distribution of mean LS measurements by two pSWE techniques.
VTQ (A) and ElastPQ (B). Skewness/standard error of skewness was 3.10 for VTQ vs. 4.96 for ElastPQ. Black line = normal distribution fit. ElastPQ = elastography point quantification, LS = liver stiffness, pSWE = point shear wave elastography, VTQ = virtual touch quantification
Fig. 4
Fig. 4. Bland-Altman plot shows agreement in VTQ and ElastPQ LS measurements.
X-axis shows means of repeated LS measurements, and y-axis shows difference between VTQ and ElastPQ LS measurements. Red line = mean difference, Green line = 95% limits of agreement. ElastPQ = elastography point quantification, LS = liver stiffness, VTQ = virtual touch quantification
Fig. 5
Fig. 5. Bland-Altman plot shows intraobserver agreement of ElastPQ measurement.
X-axis shows means of repeated LS measurements, and y-axis shows difference between repeat ElastPQ LS measurements. Red line = mean difference, Green line = 95% limits of agreement. ElastPQ = elastography point quantification, LS = liver stiffness
See this image and copyright information in PMC

References

    1. Wong GL, Espinosa WZ, Wong VW. Personalized management of cirrhosis by non-invasive tests of liver fibrosis. Clin Mol Hepatol. 2015;21:200–211. - PMC - PubMed
    1. Rockey DC. Hepatic fibrosis, stellate cells, and portal hypertension. Clin Liver Dis. 2006;10:459–479. - PubMed
    1. Castera L. Invasive and non-invasive methods for the assessment of fibrosis and disease progression in chronic liver disease. Best Pract Res Clin Gastroenterol. 2011;25:291–303. - PubMed
    1. Bravo AA, Sheth SG, Chopra S. Liver biopsy. N Engl J Med. 2001;344:495–500. - PubMed
    1. Piccinino F, Sagnelli E, Pasquale G, Giusti G. Complications following percutaneous liver biopsy. A multicentre retrospective study on 68,276 biopsies. J Hepatol. 1986;2:165–117. - PubMed

Publication types