Shear wave elastography is a rapidly evolving US imaging technique that allows quantification of mechanical and elastic tissue properties and serves as an adjunct to conventional US techniques, aiding in initial characterization and treatment follow-up of various traumatic and pathologic conditions of the musculoskeletal system.

Shear-Wave Elastography: Basic Physics and Musculoskeletal Applications.

Ultrasound elastography: the new frontier in direct measurement of muscle stiffness.

Shear wave elastography of passive skeletal muscle stiffness: Influences of sex and age throughout adulthood

This manuscript describes the use of ultrasound elastography, with the exception of liver applications, and represents an update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography.

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The EFSUMB Guidelines and Recommendations for the Clinical Practice of Elastography in Non-Hepatic Applications: Update 2018

Deep learning based classification of breast tumors with shear-wave elastography.

Standardization on Shear wave ultrasound elastography (SWUE) technical settings will not only ensure that the results are accurate, but also detect any differences over time that may be attributed to true physiological changes. The present study evaluated the variations of elastic modulus of muscle and tendon using SWUE when different technical aspects were altered. The results of this study indicated that variations of elastic modulus of muscle and tendon were found when different transducer’s pressure and region of interest (ROI)’s size were applied. No significant differences in elastic modulus of the rectus femoris muscle and patellar tendon were found with different acquisition times of the SWUE sonogram. The SWUE on the muscle and tendon should be performed with the lightest transducer’s pressure, a shorter acquisition time for the SWUE sonogram, while measuring the mean elastic modulus regardless the ROI’s size.

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0044348&type=printable

Elastic Modulus of Muscle and Tendon with Shear Wave Ultrasound Elastography: Variations with Different Technical Settings

Background: Patellar tendinopathy (PT) is one of the most common knee disorders among athletes. Changes in morphology and elasticity of the painful tendon and how these relate to the self-perceived pain and dysfunction remain unclear. Objectives: To compare the morphology and elastic properties of patellar tendons between athlete with and without unilateral PT and to examine its association with self-perceived pain and dysfunction. Methods: In this cross-sectional study, 33 male athletes (20 healthy and 13 with unilateral PT) were enrolled. The morphology and elastic properties of the patellar tendon were assessed by the grey and elastography mode of supersonic shear imaging (SSI) technique while the intensity of pressure pain, self-perceived pain and dysfunction were quantified with a 10-lb force to the most painful site and the Victorian Institute of Sport Assessment-patella (VISA-P) questionnaire, respectively. Results: In athletes with unilateral PT, the painful tendons had higher shear elastic modulus (SEM) and larger tendon than the non-painful side (p,0.05) or the dominant side of the healthy athletes (p,0.05). Significant correlations were found between tendon SEM ratio (SEM of painful over non-painful tendon) and the intensity of pressure pain (rho =0.62; p=0.024), VISA-P scores (rho = 20.61; p=0.026), and the sub-scores of the VISA-P scores on going down stairs, lunge, single leg hopping and squatting (rho ranged from 20.63 to 20.67; p,0.05). Conclusions: Athletes with unilateral PT had stiffer and larger tendon on the painful side than the non-painful side and the dominant side of healthy athletes. No significant differences on the patellar tendon morphology and elastic properties were detected between the dominant and non-dominant knees of the healthy control. The ratio of the SEM of painful to nonpainful sides was associated with pain and dysfunction among athletes with unilateral PT.

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Changes in morphological and elastic properties of patellar tendon in athletes with unilateral patellar tendinopathy and their relationships with pain and functional disability.

Characterization of the elastic properties of a tendon could enhance the diagnosis and treatment of tendon injuries. The purpose of this study was to examine the correlation between the shear elastic modulus on the patellar tendon captured from a Supersonic Shear Imaging (SSI) and the tangent traction modulus computed from a Material testing system (MTS) on 8 fresh patellar pig tendons (Experiment I). Test–retest reliability of the shear elastic modulus captured from the SSI was established in Experiment II on 22 patellar tendons of 11 healthy human subjects using the SSI. Spearman Correlation coefficients for the shear elastic modulus and tangent traction modulus ranged from 0.82 to 1.00 (all p<0.05) on the 8 tendons. The intra and inter-operator reliabilities were 0.98 (95% CI: 0.93–0.99) and 0.97 (95% CI: 0.93–0.98) respectively. The results from this study demonstrate that the shear elastic modulus of the patellar tendon measured by the SSI is related to the tangent traction modulus quantified by the MTS. The SSI shows good intra and inter-operator repeatability. Therefore, the present study shows that SSI can be used to assess elastic properties of a tendon.

/pdf/shear-elastic-modulus-on-patellar-tendon-captured-from-548hfx3gq8.pdf

Shear elastic modulus on patellar tendon captured from supersonic shear imaging : correlation with tangent traction modulus computed from material testing system and test–retest reliability

Introduction Neovascularization of tendon is one of the characteristics in patellar tendinopathy. It had been hypothesised that the vessels or the nerves accompanying the vessels were involved in the pain mechanism in this chronic pathology. [Cook, 2004] Due to the different methods used to categorise or quantify the vascularity change by researchers [Hoksrud, 2009], the relationship between vascularity and pain is still controversial. The aim of this study was to correlate findings on vascularity using power Doppler ultrasonography (PDU) and pain measured by visual analogue scale (VAS) in patients with patellar tendinopathy. Methods PDU was performed on thirty-five jumping athletes (age range: 18–35 years, mean age 22.9 years) with patellar tendinopathy (21 unilateral, 14 bilateral). The vascularity was quantified using ultrasound images by a customised software program. Vascular index (VI) was calculated as the ratio of the number of colour pixels to the total number of pixels within a standardised selected area of proximal patellar tendon. The higher VI, the more vascular is the region. The tendons were further categorised into minimal- or moderate-vascularized groups with reference to classification rated by an experienced sonographer. The athlete then rated their knee pain level using VAS on a 10-cm continuous line marked “no pain” on one end and “worst pain” on the other, recalling the maximal pain level during activities in the last 7 days. Results Tendons VI were positively correlated to pain level in both groups (r = 0.49; p = 0.03 in minimal-vascularized group; r = 0.57; p = 0.03 in moderate-vascularized group). However, when combining both groups, the correlation was not significant (r = 0.26, p = 0.14). Discussion The computerised vascular index could be one of the indicators to reflect the severity or subjective pain level of athletes suffering from patellar tendinopathy. This study suggested that categorization was indicated to reflect this correlation. The pain mechanism in tendinopathy might be different in tendons with minimal- or moderate-vascularisation. References Cook, et al . Clin J Sport Med. 2004;14:296–299 Hoksrud, et al . Am J Sports Med. 2009;36:1813–1820

https://bjsm.bmj.com/content/bjsports/48/Suppl_2/A34.2.full.pdf

Zhi Jie Zhang

Papers

Elastic Modulus of Muscle and Tendon with Shear Wave Ultrasound Elastography: Variations with Different Technical Settings

Changes in morphological and elastic properties of patellar tendon in athletes with unilateral patellar tendinopathy and their relationships with pain and functional disability.

Shear elastic modulus on patellar tendon captured from supersonic shear imaging : correlation with tangent traction modulus computed from material testing system and test–retest reliability

Correlation between vascularity with power doppler ultrasonography assessment and pain In patients with patellar tendinopathy