Résumé
Objective:To analyze the influence of different factors on the entropy and grayscale values extracted from the ultrasonic original radio-frequency signals of normal human gastrocnemius.Methods:The ultrasonic original radio-frequency signals of 10 healthy men and 10 healthy women admitted to the Department of Ultrasound of First Affiliated Hospital of Nanjing Medical University from October to December 2019 in natural ankle joint position, maximum plantar flflexion and maximum dorsiflflexion position were collected, and the entropy and grayscale values were obtained by processing these signals with MATLAB software to analyze the differences of parameters in different positions and sections, and to discuss the influence of age, gender and BMI on them.Results:Comparison of the values between different sections: the differences between longitudinal extraction entropy values and transverse extraction entropy values at the maximum dorsiflexion position were statistically significant ( P<0.05), the differences between longitudinal extraction grayscale values and transverse extraction grayscale values at the natural position were statistically significant ( P<0.05) and both of values extracted in the longitudinal plane were higher than those extracted in the transverse plane. Comparison of the values among different positions of the ankle joints: the values of the maximal metatarsal flexion were statistically different from those of the natural position and the maximal dorsiflexion ( P<0.05), and the values of the maximal metatarsal flexion were the lowest, while the entropy and gray values of the natural position and the maximal dorsiflexion were not statistically different ( P>0.05). There was no significant difference in ultrasonic characteristic parameters between different genders and different age groups ( P>0.05). There was no correlation between BMI and characteristic parameters ( P>0.05). Conclusions:The entropy and grayscale values extracted from the original radio-frequency ultrasonic signals of healthy persons′ gastrocnemius can quantitatively reflect the difference in muscle structure from different positions and setions. As a result, this method can be considered in the quantitative evaluation of neuromuscular diseases.