正常小儿桡神经超声检查方法研究

Ultrasonography techniques in scanning normal radial nerve in children

目的探讨正常小儿桡神经的超声检查方法。方法采用8、12及14MHz3种不同超声频率,对41例健康小儿行桡神经扫查,以上臂中1/2、上臂中下1/3、肘关节及前臂上1/4作为A、B、C、D4个观察平面,对所显示神经的图像清晰度进行分级;选用最佳超声扫查频率测量4个平面桡神经灰阶超声模式及CDFI模式下的神经横截面积(CSA),分别记为CSA-Ⅰ和CSA-Ⅱ。比较不同超声频率对桡神经图像显示清晰度及不同超声模式下测得神经横截面积的准确性。结果与频率为8MHz比较,以12MHz或14MHz超声频率检查时,A、B、C、D4个平面的桡神经主干、浅支和深支的清晰度高,差异有统计学意义(P<0.01);在12MHz及14MHz两种频率改变时各平面的神经显示清晰度无明显差异(P>0.05);A和B平面桡神经主干的CSA-Ⅰ分别为(10.11±3.12)mm2和(10.37±3.74)mm2,C和D平面桡神经浅支、深支的CSA-Ⅰ分别为(4.77±0.93)mm2、(4.99±1.02)mm2和(4.72±0.82)mm2、(4.97±0.92)mm2;A和B平面桡神经主干CSA-Ⅱ分别为(6.44±0.95)mm2和(6.94±0.99)mm2,C和D平面桡神经浅支和深支CSA-Ⅱ分别为(3.21±0.71)mm2、(3.30±0.82)mm2和(3.11±0.87)mm2、(3.17±1.05)mm2。4个平面的桡神经主干、浅支和深支CSA-Ⅰ均大于CSA-Ⅱ,差异有统计学意义(P<0.01)。结论小儿桡神经超声扫查中,选择12～14MHz超声频率,并采用CDFI检查模式有利于准确识别神经旁营养血管和测量桡神经横截面积。

Objective To evaluate the uhrasonographic examination method of normal radial nerve in children. Methods The ultrasound examination of radial nerve was performed on 41 normal pediatric volunteers. Four ultrasonographic planes were defined： A, midway in the upper arm; B, in lower one-third of the upper arm; C, articulatio cubiti ; D, in upper one-forth of the forearm. Sonograms were obtained when the radial nerve demonstrated clearly in A, B, C and D planes with the frequency of 8 MHz, 12 MHz and 14 MHz. The sanograms were classified according to the distinctness of the radial nerve. The trackball was traced along with the epineurium to measure nerve cross-sectional area by gray scale ultrasound （CSA-I） and color Doppler flow ultrasound （CSA-Ⅱ）. Results The distinctness of the radial nerve with uhrasonographie frequency of 12 MHz or 14 MHz was significantly increased than with that of 8 MHz （P 〈 0.01）. No difference was found in the distinctness of the radial nerve between 12 MHz and 14 MHz （P 〉 0.05）. The CSA-Iof radial nerve trunk in plane A and B were 10. 11 ±3.12 mm2 and 10.37 ± 3.74 mm2, respectively. The CSA-Iof superficial radial nerve and deep radial nerve in plane C and D were 4.77 ± 0.93 mm2, 4.99 ±1.02 mm2 and 4.72 ± 0.82 mm2, 4.97 ± 0.92 mm2, respectively. The CSA-Ⅱ of radial nerve trunk in plane A and B were 6.44 ± 0.95 mm2 and 6.94± 0.99 mm2, respectively. The CSA-Ⅱ of superficial radial nerve and deep radial nerve in plane C and D were 3.21 ±0.71 mm2, 3.30±0.82 mm2 and 3.11±0.87 mm2, 3.17 ± 1.05 rnmz, respectively. CSA-Iof the radial nerve obtained in all the four planes were significantly greater than CSA-11 （P〈0.01）. Conclusion A linear array transducer working at a high frequency range of 12-14 MHz is recommended when scanning the pediatric radial nerve and the use of color Doppler technique can help identify the feeding vessel around the radial nerve and measure the cross-sectional area of radial nerve.