Measurement of liver stiffness with two imaging techniques: Magnetic resonance elastography and ultrasound elastometry

Abstract

Purpose:To cross-validate the magnetic resonance elastography (MRE) technique with a clinical device, based on an ultrasound elastometry system called Fibroscan. Materials and Methods:Ten healthy subjects underwent an MRE and a Fibroscan test. The MRE technique used a round pneumatic driver at 60 Hz to generate shear waves inside the liver. An elastogram representing a map of the liver stiffness was generated allowing for the measurement of the average liver stiffness inside a region of interest. The Fibroscan technique used an ultrasound probe (3.5 MHz) composed of a vibrator that sent low-frequency (50 Hz) shear waves inside the right liver lobe. The probe acts as an emitter-receptor that measures the velocity of the waves propagated inside the liver tissue. Results:The mean shear stiffness measured with the MRE and Fibroscan techniques were 1.95 Ϯ 0.06 kPa and 1.79 Ϯ 0.30 kPa, respectively. A higher standard deviation was found for the same subject with Fibroscan. Conclusion:This study shows why MRE should be investigated beyond the Fibroscan. The MRE technique provided elasticity of the entire liver, meanwhile the Fibroscan provided values of elasticity locally.

Patient-Activated Three-Dimensional Multifrequency Magnetic Resonance Elastography for High-Resolution Mechanical Imaging of the Liver and Spleen

“…|G * | reflects the stiffness or softness of the tissue and is closely related to the shear wave speed measured by transient stimulation methods in ultrasound elastography. Our group mean value of |G * | = 1.27 ± 0.17 kPa for the liver falls in the range of shear modulus values (1.1 to 1.8 kPa) measured by Fibroscan [36,37] or ARFI [37,38] ultrasound devices. The phase angle of the complex modulus φ = arctan[Im(G * )/Re(G * )] is a relatively unexplored parameter within the field of elastography.…”

Characterization of frequency-dependent material properties of human liver and its pathologies using an impact hammer

“…FibroScan is commercially available, but this technique works best for separating patients with minimal or no fibrosis from those with significant fibrosis (Lucidarme et al, 2009). Moreover, Bensamoun et al (2008) demonstrates the sensitivity of the FibroScan technique to local measurements. They compare the liver stiffness measured by FibroScan with MRE and finds higher variability in FibroScan measurements.…”

Prediction of the Biomechanical Effects of Compression Therapy by Finite Element Modeling and Ultrasound Elastography

“…For example, magnetic resonance elastography has been used to explore the elasticity of soft tissue in large anatomical areas such as thighs [17] or livers [29] but due to a low spatial resolution, it is not appropriate to study subcutaneous tissues. Moreover, external vibrator is needed to generate low-frequency shear waves compared to SSI, where the ultrasonic probe remotely generates the shear wave inside the region of interest through pressure of radiation [18] allowing ease of use and minimal discomfort to the subject.…”