3 spaces.
On sagittal images, Medial to lateral - interscalene triangle, costoclavicular space and retropectoralis minor space
1. Interscalene space:
Medial most compartment
Boundaries:
Anterior - anterior scalene
Posterior - middle and posterior scalene
Inferior - first rib
Contents:
Subclavian artery - anteroinferiorly
Upper trunk (C5-6) - upper part
Middle trunk (C7) - upper part
Lower trunk (C7-T1) - inferior part, posterior to subclavian artery
Subclavian vein is situated anterior to anterior scalene and is not part of interscalene triangle
2. Costoclavicular space:
Intermediate compartment
Boundaries:
Superior - clavicle
Anterior - subclavius muscle
Posterior - first rib and middle scalene
Contents:
Subclavian vein - anteriorly
Subclavian artery - imeediately posterior to subclavian vein
Bracial plexus - triangular
Lateral cord (anterior division of upper and middle trunk) - superior to subclavian, anterior to medial cord
Medial cord (anterior division of lower trunk) - superior to subclavians, posterior to lateral cord
Posterior cord (posterior divisions of all 3 trunks) - Posterior edge of the space
Retropectoralis minor space:
Lateral most compartment
Boundaries:
Anterior - pectoralis minor
Posterosuperior - subscapularis
posteroinferior - anterior chest wall
Contents:
Similar to costoclavucular space
References:
Demondion X et al. Imaging Assessment of Thoracic Outlet Syndrome. RadioGraphics 2006;26:1735-1750
