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Validity of measurement of shear modulus by ultrasound shear wave elastography in human pennate muscle.

Miyamoto N, Hirata K, Kanehisa H, Yoshitake Y - PLoS ONE (2015)

Bottom Line: Shear modulus in seven specially-designed tissue-mimicking phantoms, and in eleven human in-vivo biceps brachii and medial gastrocnemius were determined by using ultrasound shear wave elastography.The reproducibility of shear modulus measurements was high for both parallel and oblique conditions.These findings indicate that the ultrasound shear wave elastography is a valid tool for evaluating the mechanical property of pennate muscles along the fascicle direction.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Fitness and Sports in Kanoya, Kagoshima, Japan.

ABSTRACT
Ultrasound shear wave elastography is becoming a valuable tool for measuring mechanical properties of individual muscles. Since ultrasound shear wave elastography measures shear modulus along the principal axis of the probe (i.e., along the transverse axis of the imaging plane), the measured shear modulus most accurately represents the mechanical property of the muscle along the fascicle direction when the probe's principal axis is parallel to the fascicle direction in the plane of the ultrasound image. However, it is unclear how the measured shear modulus is affected by the probe angle relative to the fascicle direction in the same plane. The purpose of the present study was therefore to examine whether the angle between the principal axis of the probe and the fascicle direction in the same plane affects the measured shear modulus. Shear modulus in seven specially-designed tissue-mimicking phantoms, and in eleven human in-vivo biceps brachii and medial gastrocnemius were determined by using ultrasound shear wave elastography. The probe was positioned parallel or 20° obliquely to the fascicle across the B-mode images. The reproducibility of shear modulus measurements was high for both parallel and oblique conditions. Although there was a significant effect of the probe angle relative to the fascicle on the shear modulus in human experiment, the magnitude was negligibly small. These findings indicate that the ultrasound shear wave elastography is a valid tool for evaluating the mechanical property of pennate muscles along the fascicle direction.

No MeSH data available.


Scatter plots of shear elastic modulus between Parallel and Oblique conditions.
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pone.0124311.g003: Scatter plots of shear elastic modulus between Parallel and Oblique conditions.

Mentions: For BB data, in the Parallel condition, the intra-day CV, ICC, and absolute difference were 1.6%, 1.00, and 0.4 kPa, respectively (Table 2). In the Oblique condition, these values were 2.7%, 1.00, and 0.5 kPa, respectively. Furthermore, the regression lines obtained from the ICC analysis were close to the identity line in both conditions. A two-way ANOVA revealed significant main effects of Joint angle (P < 0.001, observed power = 1.000) and Probe angle (P = 0.048, observed power = 0.528) with no significant interaction (P = 0.230). The ICC(1,2) between Parallel and Oblique conditions was 0.979 (P < 0.001; Fig 3). The absolute difference between Parallel and Oblique conditions was 0.5 ± 0.6 kPa.


Validity of measurement of shear modulus by ultrasound shear wave elastography in human pennate muscle.

Miyamoto N, Hirata K, Kanehisa H, Yoshitake Y - PLoS ONE (2015)

Scatter plots of shear elastic modulus between Parallel and Oblique conditions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390150&req=5

pone.0124311.g003: Scatter plots of shear elastic modulus between Parallel and Oblique conditions.
Mentions: For BB data, in the Parallel condition, the intra-day CV, ICC, and absolute difference were 1.6%, 1.00, and 0.4 kPa, respectively (Table 2). In the Oblique condition, these values were 2.7%, 1.00, and 0.5 kPa, respectively. Furthermore, the regression lines obtained from the ICC analysis were close to the identity line in both conditions. A two-way ANOVA revealed significant main effects of Joint angle (P < 0.001, observed power = 1.000) and Probe angle (P = 0.048, observed power = 0.528) with no significant interaction (P = 0.230). The ICC(1,2) between Parallel and Oblique conditions was 0.979 (P < 0.001; Fig 3). The absolute difference between Parallel and Oblique conditions was 0.5 ± 0.6 kPa.

Bottom Line: Shear modulus in seven specially-designed tissue-mimicking phantoms, and in eleven human in-vivo biceps brachii and medial gastrocnemius were determined by using ultrasound shear wave elastography.The reproducibility of shear modulus measurements was high for both parallel and oblique conditions.These findings indicate that the ultrasound shear wave elastography is a valid tool for evaluating the mechanical property of pennate muscles along the fascicle direction.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Fitness and Sports in Kanoya, Kagoshima, Japan.

ABSTRACT
Ultrasound shear wave elastography is becoming a valuable tool for measuring mechanical properties of individual muscles. Since ultrasound shear wave elastography measures shear modulus along the principal axis of the probe (i.e., along the transverse axis of the imaging plane), the measured shear modulus most accurately represents the mechanical property of the muscle along the fascicle direction when the probe's principal axis is parallel to the fascicle direction in the plane of the ultrasound image. However, it is unclear how the measured shear modulus is affected by the probe angle relative to the fascicle direction in the same plane. The purpose of the present study was therefore to examine whether the angle between the principal axis of the probe and the fascicle direction in the same plane affects the measured shear modulus. Shear modulus in seven specially-designed tissue-mimicking phantoms, and in eleven human in-vivo biceps brachii and medial gastrocnemius were determined by using ultrasound shear wave elastography. The probe was positioned parallel or 20° obliquely to the fascicle across the B-mode images. The reproducibility of shear modulus measurements was high for both parallel and oblique conditions. Although there was a significant effect of the probe angle relative to the fascicle on the shear modulus in human experiment, the magnitude was negligibly small. These findings indicate that the ultrasound shear wave elastography is a valid tool for evaluating the mechanical property of pennate muscles along the fascicle direction.

No MeSH data available.