(A) Parasagittal scan of thoracic paravertebral space (TPVS); (B) Transverse/oblique scan of TPVS after 75-degree anti-clockwise rotation from A. The needle tip’s target is TPVS, which, after probe rotation, appears enlarged and lies anteriorly to superior costotransverse ligament (SCTL)/IIMb (see text).TM, trapezius muscle; RM, rhomboid muscle; ESM, erector spinae muscle; EIM, external intercostal muscle; IIM, internal intercostal muscle; TP, transverse vertebral process; SCTL, superior costotransverse ligament; IIMb, internal intercostal membrane; TPVS, thoracic paravertebral space.