scholarly journals Influencing Factors of 2D Shear Wave Elastography of the Muscle – An Ex Vivo Animal Study

2018 ◽  
Vol 04 (02) ◽  
pp. E54-E60 ◽  
Author(s):  
Marga Rominger ◽  
Pascal Kälin ◽  
Monika Mastalerz ◽  
Katharina Martini ◽  
Volker Klingmüller ◽  
...  

AbstractTo evaluate measurement confounders on 2D shear wave elastography (2D-SWE) elastography of muscle. Ex vivo, porcine muscle was examined with a GE LOGIQ E9 ultrasound machine with a 9 L linear (9 MHz) and C1-6 convex probe (operating at 2.5 or 6 MHz). The influence of different confounders on mean shear wave velocity (SWVmean) was analyzed: probes, pressure applied by probe, muscle orientation, together with the impact of different machine settings such as frequency, placement depth and size of region of interest (ROI). The mean of twelve repeated SWVmean measurements (m/s) and coefficient of variation (CV; standard deviation/mean in %) were assessed for each test configuration. Reproducibility (CV) and maximum possible tissue depth of the linear probe were inferior to the convex probe. With the linear probe, there was a linear decrease of SWVmean with placement depth from 4.56 m/s to 1.81 m/s. A significant increase of SWVmean (p<0.001) was observed for larger ROI widths (range 3.96 m/s to 6.8 m/s). A change in the machine operation mode ('penetration' instead of 'general') led to a significant increase of SWVmean (p=0.04). SWVmean in the longitudinal direction of muscle was significantly higher than in cross section (p<0.001) (e. g. 4.56 m/s versus 3.42 m/s). An increase of linear probe pressure significantly increased muscle SWVmean from 5.29 m/s to 7.21 m/s (p<0.001). 2D-SWE of muscle is influenced by a wealth of parameters. Therefore, standardization of measurement is advisable before application in clinical research studies and routine patient assessment.

Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 795
Author(s):  
Mauro Giuffrè ◽  
Michela Giuricin ◽  
Deborah Bonazza ◽  
Natalia Rosso ◽  
Pablo José Giraudi ◽  
...  

Background: Obesity is a primary limiting factor in liver stiffness measurement (LSM). The impact of obesity has always been evaluated in terms of body mass index (BMI), without studying the effects of skin-to-liver distance (SLD) on LSM. We studied the impact of SLD on LSM in a cohort of obese patients undergoing bariatric surgery and intra-operatory liver biopsy. Materials and Methods: 299 patients underwent LSM by point-shear wave elastography (ElastPQ protocol), with two different ultrasound machines. SLD was measured as the distance between the skin and the liver capsule, perpendicular to where the region of interest (ROI) was positioned. We used the following arbitrary cut-offs: <5.7 kPa, F0–1; 5.7–7.99 kPa, F2; ≥8 kPa, F3–4. Results: We developed two logistic regression models using elastography–histology agreement (EHA) as the dependent variable and SLD as the independent variable. The model based on the second machine showed strongly more performant discriminative and calibration metrics (AIC 38.5, BIC 44.2, Nagelkerke Pseudo-R2 0.894, AUROC 0.90). The SLD cut-off value of 34.5 mm allowed a correct EHA with a sensitivity of 100%, a specificity of 93%, negative predictive value of 100%, positive predictive value of 87%, an accuracy of 96%, and positive likelihood ratio of 3.56. Conclusion: The impact of SLD is machine-dependent and should be taken into consideration when interpreting LSM. We believe that our findings may serve as a reference point for appropriate fibrosis stratification by liver elastography in obese patients.


2017 ◽  
Vol 59 (6) ◽  
pp. 657-663 ◽  
Author(s):  
Jin Hee Moon ◽  
Ji-Young Hwang ◽  
Jeong Seon Park ◽  
Sung Hye Koh ◽  
Sun-Young Park

Background Shear wave elastography (SWE) using a region of interest (ROI) can demonstrate the quantitative elasticity of breast lesions. Purpose To prospectively evaluate the impact of two different ROI sizes on the diagnostic performance of SWE for differentiating benign and malignant breast lesions. Material and Methods A total of 154 breast lesions were included. Two types of ROIs were investigated: one involving an approximately 2-mm diameter, small round ROIs placed over the stiffest area of the lesion, as determined by SWE (ROI-S); and another ROI drawn along the margin of the lesion using a touch pen or track ball to encompass the entire lesion (ROI-M). Maximum elasticity (Emax), mean elasticity (Emean), minimum elasticity (Emin), and standard deviation (SD) were measured for the two ROIs. The area under the receiver operating characteristic curve (AUC) as well as the sensitivity and specificity of each elasticity value were determined. Results The AUCs for ROI-S were higher than those for ROI-M when differentiating benign and malignant breast solid lesions. The Emax, Emean, Emin, and SD of the elasticity values for ROI-S were 0.865, 0.857, 0.816, and 0.849, respectively, and for ROI-M were 0.820, 0.780, 0.724, and 0.837, respectively. However, only Emax ( P = 0.0024) and Emean ( P = 0.0015) showed statistically significant differences. For ROI-S, the sensitivity and specificity of Emax were 78.8% and 84.3%, respectively, and those for Emean were 80.8% and 81.4%, respectively. Conclusion Using ROI-S with Emax and Emean has better diagnostic performance than ROI-M for differentiating between benign and malignant breast lesions.


Author(s):  
Francesca Del Signore ◽  
Stefania De Dominicis ◽  
Giovanni Mastromatteo ◽  
Francesco Simeoni ◽  
Pier Augusto Scapolo ◽  
...  

AbstractShear wave elastography (SWE) is a feasible and newly developed ultrasonographic technique which is able to assess elasticity of tissues. The aim of this work was to assess the feasibility of SWE on the normal canine common calcaneal tendon (CCT) evaluating the intra-operator repeatability and reproducibility of single measurements and stiffness of different anatomic CCT portions was examined. Tendons were first evaluated with B-mode ultrasound with a linear probe 8.5 to 10 MHz in longitudinal section with slight flexed tarsocrural joint and a gel-pad. Common calcaneal tendon was divided into three different anatomical regions. Shear wave elastography was performed in each region by two operators and quantitative evaluation (m/s and kPa) was performed on the most representative images. Region of interest (0.15 cm) was settled. Intraclass correlation coefficient (ICC) results were classified using the following scale: 0.00 to 0.20 = poor; 0.20 to 0.40 = fair; 0.40 to 075 = good; >0.75 = excellent. Ten adult dogs were enrolled. Intra-operator ICC values were >0.75 for both operators in every tendon portion. Inter-operator SWE ICC values for m/s measurements were 0.3, 0.61 and 0.61 for the enthesis, intermediate portion and the myotendinous junction respectively; for kPa measurements, values were respectively 0.3, 0.7 and 0.81. The three CCT portions were significantly different in stiffness (p-value < 0.001 for both m/s and kPa measurements). These preliminary results provide evidence that SWE is potentially appliable to assess mechanical properties of canine CCT affected by tendinopathies.


Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.


Author(s):  
Cyprian Olchowy ◽  
Anna Olchowy ◽  
Aleksander Pawluś ◽  
Mieszko Więckiewicz ◽  
Luca Maria Sconfienza

In children, the quality and muscle function are altered in many pathologic conditions, including temporomandibular disorders. Although several methods have been used to evaluate muscle tonus, none became a golden standard. Moreover, the masseter muscle characteristics in children have not been investigated to date. This study aimed to measure the stiffness of the masseter muscle using shear-wave elastography in healthy children. We enrolled 30 healthy children (mean age 10.87 ± 3.38 years). The stiffness of masseter muscles was measured with shear wave elastography. Stiffness for the total sample was 6.37 ± 0.77 kPa. A comparison of the measurements did not show significant differences between the right and the left masseter muscles (left—6.47 ± 0.78 kPa; right—6.24 ± 0.76 kPa; p = 0.3546). A significant difference was seen between boys and girls (boys—5.94 ± 0.50 kPa; girls—6.63 ± 0.80; p = 0.0006). Shear-wave elastography is a promising diagnostic tool. It may help to detect changes in the stiffness of the masseter muscle and draw attention to pathological processes within the jaw muscles. Directions for further research shall include determining stiffness values in pathological conditions and the impact of biological and functional factors on the stiffness of the masseter muscle.


2018 ◽  
Vol 63 (23) ◽  
pp. 235008 ◽  
Author(s):  
David Marlevi ◽  
Elira Maksuti ◽  
Matthew W Urban ◽  
Reidar Winter ◽  
Matilda Larsson

Author(s):  
Terry K. Koo ◽  
Jingyi Guo ◽  
Jeffrey H. Cohen ◽  
Kevin J. Parker

As a skeletal muscle is being stretched, it reacts with increasing passive resistance. This passive force component is important for normal muscle function [1]. Unfortunately, direct measurement of muscle force is still beyond the current state-of-the-art. In the present study, we investigate the feasibility of using Supersonic shear wave elastography (SWE) to indirectly measure passive muscle force using an ex-vivo chicken model.


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