Measuring shear-wave speed with point shear-wave elastography and MR elastography: a phantom study

Abstract

ObjectivesTo compare shear-wave speed (SWS) measured by ultrasound-based point shear-wave elastography (pSWE) and MR elastography (MRE) on phantoms with a known shear modulus, and to assess method validity and variability.Methods5 homogeneous phantoms of different stiffnesses were made. Shear modulus was measured by a rheometer, and this value was used as the standard. 10 SWS measurements were obtained at 4 different depths with 1.0–4.5 MHz convex (4C1) and 4.0–9.0 MHz linear (9L4) transducers using pSWE. MRE was carried out once per phantom, and SWSs at 5 different depths were obtained. These SWSs were then compared with those from a rheometer using linear regression analyses.ResultsSWSs obtained with both pSWE as well as MRE had a strong correlation with those obtained by a rheometer (R2>0.97). The relative difference in SWS between the procedures was from −25.2% to 25.6% for all phantoms, and from −8.1% to 6.9% when the softest and hardest phantoms were excluded. Depth dependency was noted in the 9L4 transducer of pSWE and MRE.ConclusionsSWSs from pSWE and MRE showed a good correlation with a rheometer-determined SWS. Although based on phantom studies, SWSs obtained with these methods are not always equivalent, the measurement can be thought of as reliable and these SWSs were reasonably close to each other for the middle range of stiffness within the measurable range.

Liver fibrosis detection and staging: a comparative study of T1ρ MR imaging and 2D real-time shear-wave elastography

“…They observed higher AUROC using MRE vs. TE for predicting F 2– F 4 fibrosis (0.91 vs. 0.82; P = 0.01) and cirrhosis (0.97 vs. 0.92; P = 0.49). A good correlation between US- and MR-based ultrasonography has also been determined in previous studies [ 44 , 45 ]. Yonon [ 46 ] compared MRE and SWE for the staging of hepatic fibrosis in the same individuals.…”

Potential of Using Shear Wave Elastography in the Clinical Evaluation and Monitoring of Changes in Masseter Muscle Stiffness

“…Moreover, a portable muscle hardness meter has been used in clinical research [ 10 ], and shear-wave elastography can be seen to be a very promising method. Elastography has been validated in studies using phantoms of known hardness and has also been compared to other methods [ 11 , 12 ]. Results of studies on other organs show that agreement between radiologists is statistically significant [ 13 ].…”

Dispersion in Tissue-Mimicking Gels Measured with Shear Wave Elastography and Torsional Vibration Rheometry

“…Okamoto et al (2011) compared magnetic resonance elastography (MRE) measurements in the 100-400 Hz frequency range to a novel dynamic shear test (20-200 Hz range) and found reasonable agreement in the shear storage modulus estimates (about 10% variation) but significant differences in the shear loss modulus estimates. Kishimoto et al (2017) compared ultrasound-based point SWE and MRE to rheometry on 5 homogeneous phantoms and found a relative difference between −25% to +25% in SWS estimates. In all of these cases, dispersion may be responsible for differences between values reported by different methods.…”