Establishing Reliability Criteria for Liver ElastPQ Shear Wave Elastography (ElastPQ-SWE): Comparison Between 10, 5 and 3 Measurements

Abstract

Purpose ElastPQ is a new elastography technique for non-invasive liver fibrosis staging. However, it does not have validated reliability criteria. We tested the reliability of a different number of measurements in patients with chronic liver disease and explored whether the application of quality criteria improves the diagnostic performance. Materials and Methods All patients underwent liver stiffness assessment (LSM) with ElastPQ and Fibroscan (F-TE). The mean, median, standard deviation (SD) and interquartile range (IQR) of 10, 5 and 3 measurements were retrospectively collected for each patient and compared to each other. Liver histology was available in a subset of patients. Results Overall, 400 patients met the inclusion criteria. Non-alcoholic fatty liver disease (NAFLD) was the most represented etiology (75 %), followed by primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH). The correlation of medians was significantly better between 10 and 5 measurements than between 10 and 3. The difference of medians was significant only in the comparison between 10 and 3 measurements. The correlation between ElastPQ and F-TE was equally good for 10 and 5 measurements and significantly improved after an IQR/median ≤ 30 % was applied. The diagnostic performance of ElastPQ was better with the median value of 10 and 5 measurements and improved if LSM values were obtained with IQR/M ≤ 30 %. Conclusion The median value of 5 valid LSMs suffices for the reliable estimation of liver stiffness using ElastPQ. The quality criterion of IQR/M ≤ 30 % should also be followed when using this technique.

Update to the Society of Radiologists in Ultrasound Liver Elastography Consensus Statement

“…pSWE.-Ten measurements are still recommended; however, studies have shown that there is no loss in accuracy with five measurements when the quality criterion of IQR/M is fulfilled (25)(26)(27)(28). In the study by Fang et al (25), six measurements were recommended; however, when only the values obtained with a high reliability (IQR/M, ≤30%) were considered, there was no difference between five and six measurements.…”

How to perform shear wave elastography. Part I

“…The most important criterion for a measurement of good quality seems an IQR/M ≤30% when the results are reported in Young's modulus [29]. This ratio, in fact, is a measure of the variability between consecutive acquisitions, and studies have reported a decrease in accuracy when this criterion is not fulfilled [37][38][39][40][41]. For measure-ment reported in m/s the IQR/M should be ≤15% because the conversion between the two is not linear [29].…”

“…Based on literature data, for the pSWE technique the EFSUMB and WFUMB guidelines have recommended to use the median value of 10 acquisitions [3,4,9]. However, some studies have shown that the accuracy does not decrease when fewer acquisitions (up to five) are obtained [38][39][40]42]. For 2D-SWE, the EFSUMB updated guidelines have recommended to obtain at least three acquisitions [3,4].…”

Liver stiffness quantification in biopsy-proven nonalcoholic fatty liver disease patients using shear wave elastography in comparison with transient elastography

“…Moreover, our study assessed the performance of the p-SWE technique with fewer measurements. In agreement with other recent evidence evaluating cohorts with different etiologies of chronic liver disease, we observed that SWE-5 provided the highest diagnostic performance (AUROC), sensitivity, and specificity for both significant (0.809, 77.8%, and 73.4%, respectively) and advanced fibrosis (0.809, 77.8%, and 75.0%, respectively) with respect to SWE-10 and for significant fibrosis with respect to TE, even if the differences were not statistically significant [22,23]. Interestingly, when exploring alternative cutoffs for maximizing sensitivity and specificity, SWE-5 with a cutoff of ≥7.6 kPa yielded an increase in sensitivity to 94.4%, with only a slight drop in specificity (60.7%) for the diagnosis of advanced fibrosis.…”