Imaging of the axillary vein.

Editor—In figure 3a of the recent article on imaging of the axillary vein, from a radiological point of view and according to line A in figure 2, the bright structure that you named rib cage may be either rib cage or lung pleural interface. You can differentiate between them by their posterior shadowing as the rib cage has dark shadow and the lung pleural interface has a bright layering shadow with linear comet tail artifacts and as you cannot ask the patient to catch his breath you may see both of them alternately so the posterior shadowing is important. The lung pleural interface carries the risk of pneumothorax if penetrated by the needle then the vein in line C is safer for puncture than line A and B C.