New visualization of cervical nerve roots by ultrasound: Identification by 0–1 sign

Introduction

Ultrasound-guided cervical nerve root block is an effective technique that avoids radiation exposure. However, there is currently no standard technique for visualizing cervical nerve roots using ultrasound. The most common method is to search for the cervical nerve by moving the transducer from the brachial plexus in the direction of the head, using nerves and the scalene muscle as landmarks. However, this approach often poses difficulties for novice ultrasound operators because it can be difficult to identify these landmarks. We propose a new technique to visualize the cervical nerve root by using the common carotid artery and the C6 anterior tubercle as landmarks. Our aim was to quantitatively measure the anatomical positions of these landmarks to facilitate identification by novice ultrasound operators.

Case reports

Included in this study were 32 healthy volunteers (19 men, 13 women; mean age, 34.5 ± 10.5 years) who provided informed consent to inclusion in the study. The new technique called the ‘0–1 sign’ as the common carotid artery and the C6 anterior tubercle are morphologically likened to ‘0’ and ‘1’, respectively. Our aim was to measure the distance between the ‘0’ and ‘1’ and the distance of ‘1’ from the skin so as to allow beginners in ultrasound to quickly locate these landmarks.

Conclusions

Our new procedure for cervical nerve root visualization under ultrasound uses the 0–1 sign as an indicator. The results suggested that the 0–1 sign technique is a simple and effective method for cervical nerve root visualization and may serve as a reliable reference for ultrasound-guided cervical nerve root blocks.