Shear wave elastography

Shear wave elastography measures the mechanical and elastic properties of tissue. A high intensity ultrasound pulse produces shear waves that cause tissue displacement. These shear waves are then tracked via low-intensity pulses to determine shear velocity. Because shear waves move faster through stiffer tissue, the distribution of shear wave velocities can be used to measure tissue elasticity.

The most common anatomy evaluated with shear wave elastography is the liver, where it is used for parenchyma evaluation. Clinical indications include history of hepatitis C, abnormal liver function tests or an enlarged liver. Shear wave elastography is also used to stage liver fibrosis, track liver disease progress and assess treatment.

Other uses of shear wave elastography are breast, prostate, thyroid nodule and musculoskeletal ultrasound.

Shear wave elastography is widely used in many countries. Payment for liver elastography depends on the healthcare organization’s location, examination procedures and local payer rules. In the USA, there are several two CPT codes for liver parenchyma evaluation.

Shear wave liver elastography provides an objective, quantitative value of liver disease, rather than relying on qualitative image assessment that can vary among readers. The 2020 Society of Radiologists in Ultrasound (SRU) Consensus Statement on Liver Elastography and the World Federation of Ultrasound in Medicine Biology’s (WFUMB)Update to the 2018 Guidelines on Liver Ultrasound Elastography provide shear wave liver elastography protocols and clinical management guidelines based on measured values.^[3,4]

Shear wave elastography measures liver stiffness to assess fibrosis (scarring). Liver fat quantification measures attenuation of the ultrasound signal to assess steatosis (fat content). In short: stiffness = fibrosis, attenuation = fat. They evaluate different aspects of liver health and are often used together for a more complete assessment. In addition to shear wave elastography, Philips also offers attenuation imaging and Hepatorenal Index (HRI) for steatosis assessment. These three assessments are complementary and combine for a multi-parametric view of liver health.

Auto ElastQ is an automated measurement capability for use with Philips Ultrasound 2D Shear Wave Imaging (ElastQ) that delivers precision, reproducibility and ease-of-use. With 99% reliability,^[5] Auto ElastQ can reduce liver shear wave elastography exam time by up to 60%^[5] and reduce the number of steps to acquire liver shear wave measurements by up to 29%.^[5]

It automatically selects frames within a cineloop of the liver to use for measurements, based on the temporal stability of the frames. Within these selected frames, Auto ElastQ analyzes the ElastQ image and automatically places the measurement ROI in an appropriate location within the image based on various image analysis metrics.

Yes. If you have the ElastQ package and the Elevate release, you can add Auto ElastQ to your EPIQ Elite or Affiniti 70 system for no charge. If you do not have the ElastQ package and the Elevate release, you may add Auto ElastQ when you purchase that software.

Many options are available, including in-person courses taught by clinical thought-leaders, on-site training, virtual training and videos. Options vary by region. Contact your local sales representative to learn more.