Liver Stiffness Measured by 2‐Dimensional Shear Wave Elastography: Prospective Evaluation of Healthy Volunteers and Patients With Liver Cirrhosis

Abstract

Objectives-We aimed to establish normal values for liver stiffness measurement, performed by 2-dimensional shear wave elastography (LOGIQ E9; GE Healthcare, Wauwatosa, WI), in healthy volunteers, patients with nonhepatic morbidities, and patients with histologically confirmed liver cirrhosis.Methods-A total of 175 participants were included between July 2016 and February 2018. Three cohorts were analyzed: healthy volunteers (n = 68), patients with healthy livers but nonhepatic morbidities (n = 57), and patients with liver cirrhosis (n = 50). Liver stiffness measurement was performed by 2 observers with different levels of experience to determine interobserver agreement.Results-Of the 175 participants included, 91 were male, and the mean age ± SD was 44.4 ± 19.4 years. The success rate for 175 liver stiffness measurements was 95.4%. The number of unsuccessful measurements was significantly higher in the liver cirrhosis cohort (P = .04). The interobserver agreement was excellent (intraclass correlation coefficient, 0.87). Liver stiffness in the healthy-liver patient cohort (4.93 ± 0.83 kPa) was not significantly different from that in the healthy-volunteer cohort (5.19 ± 1.03 kPa; P = .13). Apart from male sex in the healthy-volunteer cohort, age, body mass index, mild steatosis, and nonhepatic morbidities had no significant impact on liver stiffness. Liver stiffness values in participants without liver disease (healthy volunteers and healthy-liver patients; n = 125) ranged from 3.62 to 7.02 kPa (2.5th-97.5th percentiles). Notably, there was no overlap of liver stiffness measurements between the patients without liver disease and the cirrhosis cohort ).Conclusions-Liver stiffness values in healthy individuals vary widely and are not dependent on age, body mass index, or specific nonhepatic comorbidities. Liver stiffness values within the normal range can noninvasively rule out cirrhosis, as liver stiffness is significantly higher in cirrhotic patients (P < .001). Twodimensional shear wave elastography has excellent interobserver agreement.

Diagnostic Performance of Point Shear Wave Elastography (pSWE) Using Acoustic Radiation Force Impulse (ARFI) Technology in Mesenteric Masses: A Feasibility Study

“…In point shear wave elastography (pSWE), such as acoustic radiation force impulse (ARFI) pSWE, the resulting shear waves propagate in a direction perpendicular to the axial stimulating acoustic beam, and the speed of propagation of these shear waves is measured within a region of interest (ROI) by estimating the time needed to travel from the border near to the stimulus to the border away from the stimulus [ 33 ]. Both pSWE and 2D-SWE have excellent performance in assessing liver fibrosis and cirrhosis [ 34 , 35 , 36 ], with good reproducibility [ 34 , 37 ], and both modalities perform similarly well in differentiating malignant and benign lesions [ 38 , 39 , 40 ]. The feasibility of performing examinations in ascites and obesity is considered among the advantages of pSWE.…”

Comparison of point and two-dimensional shear wave elastography of the spleen in healthy subjects

“…Also no information on unsuccessful mesaurements was collected during the study. However, due to the predominantly healthy young and slim probands, a low number of unsuccessful measurements can be assumed[ 45 ]. Histological examination could not be performed either, as this was ethically unacceptable in young healthy subjects.…”

Utility of transient elastography in determining liver fibrosis

“…there was no overlap of liver stiffness measurements between the patients without liver disease and the cirrhosis cohort (p < 0.001). 19…”