Ultrasound images for ESP block showing ribs and transverse processes

It is important to identify the tip of the transverse process (TP) when performing ESP block. With the transducer in a parasagittal orientation, scan from lateral to medial, looking for the transition from rib to TP. Panel A shows ribs, which are rounded structures with pleura visible beneath and between the ribs. Panel B shows the TPs, which appear flatter than the ribs and without pleura visible. At the point of transition from rib to TP (ie, the costo-transverse angle), the TP is more superficial than the rib.