Place the probe in the axial plane at the level of the transverse proces of vertebral body C4
The needle is advanced with in-plane technique from the posterior end of the probe until it penetrates the prevertebral fascia and the needle tip is placed just posterior to the longus capitis muscle
Transverse process of vertebral body C4 (green asterix), longus capitis m. (yellow asterix), middle scalene m. (magenta asterix), longus colli m. (blue asterix), carotid sheath (yellow arrow), prevertebral fascia (cyan arrow), needle trajectory (magenta arrow), sternocleidomastoid m. (red asterix)
