Ultrasonographic measurement of the cross‐sectional area of the axillary nerve

Abstract

Introduction The objectives of this study were to determine normal reference values for ultrasonographic measurement of the cross‐sectional area (CSA) of the axillary nerve and to standardize the measurement methods. Methods Sixty healthy volunteers were evaluated. Ultrasonography was performed with the shoulder positioned in 100°–120° abduction and 90° external rotation. The CSA of the axillary nerve was measured bilaterally. Results The normal CSA of the right axillary nerve was 2.9 ± 1.1 mm2. The side‐to‐side discrepancy was 22.8% ± 17.8%. Discussion These reference values may be helpful for investigating pathologies involving the axillary nerve.

Sonographic peripheral nerve cross‐sectional area in adults, excluding median and ulnar nerves: A systematic review and meta‐analysis

“…Five groups (axillary, femoral, long thoracic, saphenous, and suprascapular-supraspinatus fossa) were comprised of just one study. 8,[33][34][35] Fourteen studies reported multiple means at a given anatomical site, such as separate means for males and females, or for right and left sides. 20,[34][35][36][37][38][39][40][41][42][43][44][45][46] The greatest variability in nerve CSA was seen in the brachial plexus, tibial-popliteal fossa, and all three sciatic nerve small groups.…”

“…8,[33][34][35] Fourteen studies reported multiple means at a given anatomical site, such as separate means for males and females, or for right and left sides. 20,[34][35][36][37][38][39][40][41][42][43][44][45][46] The greatest variability in nerve CSA was seen in the brachial plexus, tibial-popliteal fossa, and all three sciatic nerve small groups. When combining all anatomical locations for individual nerve measurements, the tibial nerve (n = 2916 nerves) was the most assessed, followed by the common fibular nerve (n = 2580 nerves), radial nerve (n = 2326 nerves), sciatic nerve (n = 1470 nerves), sural nerve (n = 1316 nerves), and brachial plexus (n = 1314 nerves).…”

“…The remainder of studies did not indicate the methods utilized to determine CSA (6.4% of nerve measures), 33,34,[86][87][88][89][90][91][92] or used tracing, but did not specify the precise technique (9.4% of nerve measures). 38,40,43,45,46,[93][94][95][96] Full details regarding CSA technique and ultrasound equipment utilized are included in Appendix S1.…”

“…Twelve of the groups included at least 500 nerves, whereas only one group included fewer than 100 nerves. Five groups (axillary, femoral, long thoracic, saphenous, and suprascapular–supraspinatus fossa) were comprised of just one study 8,33–35 . Fourteen studies reported multiple means at a given anatomical site, such as separate means for males and females, or for right and left sides 20,34–46 .…”

“…Furthermore, although tracing within the hyperechoic epineural rim is the most commonly used method for determining the sonographic CSA of nerves, two studies did not do so, 35,79 and nine others omitted CSA technique information entirely. 33,34,[86][87][88][89][90][91][92] A total of 69 studies were included; however, additional studies may be found in other databases. Finally, we included only English-language studies.…”