With this chapter, the authors discuss the sonoanatomy of the posterior triangle of the neck. The basic sonoanatomy is approached from two angles, the first from a static ultrasound point of view to give the reader the opportunity to study the different structures in detail. Secondly, a video production has been produced to explain the dynamic ultrasound of this area. In both instances, the ultrasound transducer probe is placed so that the initial view is that of a known structure. In the anterolateral approach, the probe is placed on the cricoid cartilage and moved posterior to bring the thyroid gland into view; slightly more posterolateral, the common carotid artery comes into view, followed by the large anterior tubercle of the transverse process of the 6th cervical vertebra. From this known position, the probe is moved cephalad and caudad to identify the other structures of the cervical vertebrae and brachial plexus. In the lateral approach, the probe is placed in the supraclavicular area where the subclavian artery and vein are clearly visible, and from there, the trunks of the brachial plexus are followed cephalad to view the transverse processes of the vertebrae and the spinal nerve roots and trunks as they exit the neuroforamens and form the trunks. The sonoanatomy of the supraclavicular fossa is discussed in detail.
Keywords: Anterior scalene muscle, Brachial plexus, Brachial plexus trunks, Cervical paravertebral block, Cervical spinal roots, Chassaignac’s tubercle, Circumneural sheath, Dorsal scapular artery, Dorsal scapular nerve, Dynamic ultrasound, Interscalene block, Longus colli muscle, Middle cervical sympathetic ganglion, Middle scalene muscle, Neuroforamens, Paraneural sheath, Phrenic nerve, Posterior scalene muscle, Sonoanatomy, Static ultrasound, Stellate ganglion, Sternocleidomastoid muscle, Superficial cervical plexus, Transverse process, Ultrasound.