LKnative - PECS blocks 
Axillary artery (A), rib 2 (r2), rib 3 (r3), major pectoral muscle (red asterix), minor pectoral muscle (green asterix), serratus anterior muscle (magenta asterix)
12 – Sonoanatomy: Identify the ribs
Below the lateral third of the clavicle the axillary artery is typically located on top of the second rib
Ribs III and IV can be identified by sliding caudad and counting

