Cross‐sectional area reference values for nerve ultrasonography

Abstract

Ultrasound allows for a non-invasive structural assessment of nerves, muscles, and surrounding tissues, and therefore it is increasingly being used as a supplement to traditional electrodiagnostic studies. As investigators have begun to use ultrasound to explore peripheral nerves, it has become clear that conditions such as entrapment, hereditary neuropathies, acquired neuropathies, trauma, and nerve tumors result in an increase in nerve cross-sectional area. Reference values have not been published for the cross-sectional area of many nerves commonly studied in diseases of the peripheral nervous system, so our goal was to obtain reference values for the nerve cross-sectional area at the following sites: radial at antecubital fossa; radial at distal spiral groove; musculocutaneous in upper arm; trunks of the brachial plexus; vagus at carotid bifurcation; sciatic in distal thigh; tibial in popliteal fossa; tibial in proximal calf; tibial at ankle; peroneal in popliteal fossa; peroneal at fibular head; and sural in distal calf. Mean cross-sectional area, as well as side-to-side differences, are reported for each site, and qualitative data are provided to guide imaging at each site. The information provided in this study should serve as the starting point for quantitatively evaluating these nerve sites with ultrasound.

High-Resolution Ultrasonography of Peripheral Nerves: Measurements on 14 Nerve Segments in 56 Healthy Subjects and Reliability Assessments

“…Similarly to our results, Heinemeyer et al found no correlation between nerve size parameters and age, height and body weight, but reported thicker nerves on the upper limbs in males [15]. Cartwright et al [16] reported that nerve size correlated with body weight and body mass index, and that these correlations were most pronounced in the nerves of the proximal leg. They also found that females had smaller nerves than males.…”

“…However, we did not measure femoral and sciatic nerves, which are considerably larger, with CSA as high as 41 mm 2 in case of the sciatic nerve [25]. Table 4 also shows that CSA values across these studies are consistent for the major upper limb nerves, with the exception of the radial nerve in the spiral groove reported by Cartwright et al [16]. However, in the most recent study of Won et al [17] and in previous studies reporting reference values for the radial nerve [8,19] in that the C5 root is the smallest among the cervical roots.…”

“…Several reports have been published on reference values for the cross-sectional areas of the median and ulnar nerves [10][11][12][13][14][15][16][17], with a good agreement among the measurements. On the other hand, data are less abundant concerning normal values for cervical roots, radial nerve, lower limb nerves and pure sensory nerves [15][16][17][18][19][20][21][22][23][24][25], and they show more variation among studies. Some studies have reported values for intra-and inter-rater reliability [24][25][26][27], but inter-equipment reliability has not been hitherto addressed.…”

Challenges in sciatic nerve repair: anatomical considerations

“…To correlate our results with in vivo studies we reviewed ultrasound and MRI data from sciatic and sural nerves in healthy controls (Table 3). 9,16,23,26,42,44 These studies also demonstrate a large variability with regard to CSA, especially of the sural nerve. 9,15,16,26,44 Specifically, the sural nerve CSA as measured by ultrasound ranged from 1.44 to 5.3 mm 2 .…”

Ultrasonographic evaluation of peripheral nerves in Diabetic and it`s correlation with nerve conduction

“…Several recent articles focus on the use of ultrasound in diagnosing or mapping peripheral nerve injuries 11 . Even in animal studies the correlation between anatomical measurements and ultrasound measurements have been established.…”