Improved Ultrasound Attenuation Measurement Method for the Non-invasive Evaluation of Hepatic Steatosis Using FibroScan.

Controlled attenuation parameter (CAP) is a measurement of ultrasound attenuation used to assess liver steatosis non-invasively. However, the standard method has some limitations. This study assessed the performance of a new CAP method by ex vivo and in vivo assessments.

Liver Steatosis Assessed by Controlled Attenuation Parameter (CAP) Measured with the XL Probe of the FibroScan: A Pilot Study Assessing Diagnostic Accuracy.

To assess liver steatosis, the controlled attenuation parameter (CAP; giving an estimate of ultrasound attenuation ∼3.5 MHz) is available with the M probe of the FibroScan. We report on the adaptation of the CAP for the FibroScan XL probe (center frequency 2.

Maximum likelihood estimation of shear wave speed in transient elastography.

Ultrasonic transient elastography (TE), enables to assess, under active mechanical constraints, the elasticity of the liver, which correlates with hepatic fibrosis stages. This technique is routinely used in clinical practice to assess noninvasively liver stiffness. The Fibroscan system used in this work generates a shear wave via an impulse stress applied on the surface of the skin and records a temporal series of radio-frequency (RF) lines using a single-element ultrasound probe.

Evaluation of in vivo liver tissue characterization with spectral RF analysis versus elasticity.

Ultrasonic elastography, via vibration-controlled transient elastography (VCTE), enables to assess, under active mechanical constraints, the elasticity of the liver, correlating with fibrosis stages. On the other hand, the same VCTE probe can also be used in passive mode, acquiring RF lines at different locations in the liver. This paper presents a thorough evaluation of passive-mode RF spectral parameters (integrated backscatter coefficient, power spectral index, effective scattering size and spectral variance), for tissue characterization on a large cohort of volunteers with various ranges of elasticity measures.

Measurement of the skin-liver capsule distance on ultrasound RF data for 1D transient elastography.

Vibration-controlled transient elastography (VCTETM) technique is routinely used in clinical practice to assess non-invasively the liver stiffness which is correlated to hepatic fibrosis. Adequate use of the VCTETM probe requires the knowledge of the distance between the skin and the liver parenchyma. This paper compares two methods to estimate this distance using spatial variations of the spectral content of ultrasound radiofrequency (RF) lines, obtained from a probe consisting of a single element ultrasound transducer placed in front of the liver right lobe.