Abstract
Ultrasound elastography (USE) is a recent technology that has experienced major developments in the past two decades. The assessment of the main mechanical properties of tissues can be made with this technology by characterisation of their response to stress. This article reviews the two major techniques used in musculoskeletal elastography, compression elastography (CE) and shear-wave elastography (SWE), and evaluates the studies published on major electronic databases that use both techniques in the context of tendon pathology. CE accounts for more studies than SWE. The mechanical properties of tendons, particularly their stiffness, may be altered in the presence of tendon injury. CE and SWE have already been used for the assessment of Achilles tendons, patellar tendon, quadriceps tendon, epicondylar tendons and rotator cuff tendons and muscles. Achilles tendinopathy is the most studied tendon injury with USE, including the postoperative period after surgical repair of Achilles rupture tendon. In relation to conventional ultrasound (US), USE potentially increases the sensitivity and diagnostic accuracy in tendinopathy, and can detect pathological changes before they are visible in conventional US imaging. Several technical limitations are recognised, and standardisation is necessary to ensure repeatability and comparability of the results when using these techniques. Still, USE is a promising technique under development and may be used not only to promote an early diagnosis, but also to identify the risk of injury and to support the evaluation of rehabilitation interventions.Key Points• USE is used for the assessment of the mechanical properties of tissues, including the tendons.• USE increases diagnostic performance when coupled to conventional US imaging modalities.• USE will be useful in early diagnosis, tracking outcomes and monitoring treatments of tendon injury.• Technical issues and lack of standardisation limits USE use in the assessment of tendon injury.
Highlights
Ultrasound (US)-based methods are of particular interest due to their inherent advantages, such as wide availability, relatively low cost and quick procedures [1]
A bibliographic research was made on PubMed, Ovid MEDLINE, Cochrane Library, EMBASE and PEDro for articles published up to February 2018 related to the assessment of pathologic tendons, ruptured tendons, tendons with tendinopathy and on systemic diseases, using compression elastography (CE) or shear-wave elastography (SWE) techniques
In what concerns the set of limitations related with Ultrasound elastography (USE), it is necessary to standardise the following: technical parameters, examination protocols, variables and classification systems
Summary
Ultrasound (US)-based methods are of particular interest due to their inherent advantages, such as wide availability, relatively low cost and quick procedures [1]. The elastic modulus has larger variation compared to the parameters of other imaging modalities, allowing higher discrimination between different tissues and between normal and pathologic tissues [7]. This elastic modulus can be defined as the slope of a stress–strain curve, during elastic strain, reflecting the elastic properties of the tissues, and it is inversely proportional to the degree of strain, assuming that applied stress is uniform [10]. Given a certain amount of applied stress, softer tissues have more deformation and, experience larger strain than stiffer tissues These strains are obtained by the variation of longitudinal distance, calculated from the time taken by the US waves to return to the transducer before and after compression (Fig. 1). Some limitations must be considered, the limited size, shape and depth of the ROI [26]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
