Learning objectives
An incorrect usage of Shear Wave technology,
without properly following the updated Guidelines and not knowing the steps which characterize a specific solution,
may lead the operator to a misleading analysis and a wrong diagnosis.
This educational paper provides an easy-to-follow protocol in the usage of shear wave Sound Touch Elastography (STE) technology and describes the technical highlights and practical recommendations in applying STE in patients with CLD and interprets the results for a correct assessment.
Background
Shear Wave Elastographyis a non-invasive method that ensures good reproducibility and highly consistent quantitative elastic results in patients with chronic liver diseases (CLD),
to assess liver disease severity (fibrosis) before therapy at a safe level of predictability as an alternative to liver biopsy procedures.
Elasticity Evaluation in the Liver
Tissue has different mechanical properties and elasticity is one of these components.
Elasticity is the property of a material or a tissue to deform under a given stress (for example,
due to external forces applied) and...
Findings and procedure details
The scanning protocol consists of recommended steps that any clinician should perform in order to achieve reliable and reproducible STE examinations,
avoid pitfalls,
and recognize artefacts.
This includes fasting,
intercostal approach,
ROI placement,
stability-immobility tips,
STE activation,
reliability indicators interpretation,
measurements,
and cut-off values.
As recommended by EFSUMB and WFUMB guidelines on liver Shear Wave Elastography [2,4],
proper training in the acquisition of real time 2D with simultaneous Shear Wave Elastography is required to obtain better accuracy and intra-observer and inter-observer reproducibility of liver stiffness...
Conclusion
STE technology provides a new method for quantifying the elasticity information of the liver tissue for grading fibrosis in CLD.
It is a non-invasive technique,
easy to use after proper training,
and without any discomfort to the patient.
An STE measurement of liver stiffness within the normal range can rule out significant liver fibrosis if in agreement with the clinical and laboratory data.
Knowledge of the etiology of the CLD of a specific patient (HBV,
HCV,
ALD,
NASH) and the degree of necro-inflammation is a...
References
Sarvazyan AP,
Rudenko OV,
Swanson SD,
Fowlkes JB,
Emelianov SY.
Shear wave elasticity imaging: A new ultrasonic technology of medical diagnostic.
Ultr.
Med Biol 1998;20:1419 –1436
Dietrich CF,
Bamber J,
Berzigotti A,
Bota S,
Cantisani V,
Castera L,
Cosgrove D,
Ferraioli G,
Friedrich-Rust M,
Gilja OH,
Goertz RS,
Karlas T,
de Knegt R,
de Ledinghen V,
Piscaglia F,
Procopet B,
Saftoiu A,
Sidhu PS,
Sporea I,
Thiele M.
EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography,
Update 2017 (Long Version).
Ultraschall...