Surface landmarks of brachial plexus: ultrasound and magnetic resonance imaging for supraclavicular approach with anatomical correlation.

The present study is able to describe a certain line, under which brachial plexus (BP) lies underneath in the supraclavicular region. A line drawn between midpoint of the sternocleidomastoid muscle to the midpoint of the clavicle was considered for BP. Surface landmarks were evaluated by applying ultrasound (US) on 30 volunteers (15 female, 15 male). Axial and sagittal views of BP were taken and distances between skin and BP were measured. Coronal magnetic resonance (MR) sections were taken from 7 volunteers according to the second line after applying two fat capsules on each line. The sonographic views were seen at the same line. Mean distances from skin were found as 16.5+/-0.7 mm for male and 14.5+/-0.5 mm for female volunteers. MR images were obtained bilaterally, which were parallel and posterior from sonographic lines. Surface landmarks, as presented in this study, are simple to accomplish and are not dependent on structural variations as external jugular vein.