[Hhigh-frequency ultrasound research on the normal adult sciatic nerve].

Objective: To explore the application value of the high-frequency ultrasound examination of the normal adult sciatic nerve.

Methods: The high frequency ultrasound was used to examine 60 cases ,a total of 120 normal adult sciatic nerve (28 males and 32 females ranging in age from 19 to 38 years old, averaged 23.8 years old). The age between men and women, height and weight showed no significant difference. The cross-sectional scanning and longitudinal scanning, if necessary, Panoramic Imaging were conducted. The cross section area of sciatic nerve was measured at the hip line, the middle of the thigh, the edge of the popliteal fossa, and the relationship betwen the sciatic nerve and surrounding muscle group was observed in each cross-section. Probe was rotated 90 degree to display the long axis of sciatic nerve, to get the longitudinal section along the long axis from top to bottom. So the sciatic nerve in the vertical axis and the surrouunding muscles was displayed by above method combined with panoramic imaging. The data of coss-sectional area of sciatic nerve were obtained at the central of hip line, the middle of the thigh, the edge of the popliteal fossa, and then were divided into different groups by gender and sides to do statistical analysis.

Results: The applicatic nerve in thigh can be clearly displayed by high-frequency ultrasound in this group of 60 people with 120 nerves, but low display rate of sciatic nerve in hip, approximatley 31.4% (21/66). The longitudinal section of the sciatic nerve displayed as the banded isoechoic or slightly hyperechoic, parallel partial hyperechoic line could be seen in it; in the cross-section, it showed a clear edge of the sieve-like isoechoic or slightly hyperechnie, which could be oval ,trapezoidal, triangular and irregular in shape; the sciatic nerve bad visible passive movement and shape change when muscle contracted. There were statistically significant differences of cross-sectional area of sciatic nerves at the hip line ,the middle of thigh and edge of the popliteal fossa between 56 sciatic nerves in 28 males and 64 sciatic nerves in 32 females (P< 0.05); but there were no significant differences between left and right sides (P>0.05).

Conclusion: High frequency ultrasound can be used as the first choice of the sciatic nerve when an imaging method preferred.