Top left: probe is positioned in the longitudinal paramedian plane. Top right: sacrum is seen as a continuous hyperechoic line parallel to the skin, approximately 5 cm deep continuing as "cracks" (interspaces) alternating with "lumps" (lamina of different vertebrae). Bottom: close up at a lumbar "crack" (interspace), with lamina of two different vertebrae on the right (caudad) and on the left (cephalad). The elements of the interspace can be easily identified, including distinct images of the posterior dura mater, the epidural space and the ligamentum flavum. The vertebral body-posterior longitudinal ligament-anterior dura mater is seen as a single unit. #PainManagement #Anatomy #POCUS #Spinal #Epidural #Anesthesia #Paramedian #Longitudinal #Parasagittal #Lumbar #Sacrum
