Figure 1.

A — Ultrasonographic view of the lumbosacral (LS) space in parasagittal approach in the cat; B — Positioning of ultrasound transducer at the LS space and needle at the sacrococcygeal (SC) space; C — Ultrasonographic view of the LS space in transverse approach in the cat; D — Sonoanatomy of the LS space in transverse plane — note that, in the lower image, there is an increase in the LS epidural space enlarged by SC epidural injection of local anesthetic (LA).

ISL — Interspinous ligament; LF — ligamentum flavum; VC — vertebral canal; VB — vertebral body; ES — epidural space; SP — Spinal process; L7 — 7th lumbar vertebra; S1, S2, and S3 — 1st, 2nd, and 3rd sacral vertebrae; Co1 — 1st coccygeal vertebra; IC — Iliac crest; LM — longissimus muscle; MM — multifidus muscle; APFJ — articular process/facet joint.