Radial EBUS allows physicians to diagnose and sample suspicious areas in the lungs locaded in the periphery of the lungs.  Radial EBUS is performed by inserting an ultrasound miniature probe through the instrument channel of a standard bronchoscope.  The physician moves the probe forward and backward throughout the airway to obtain images of the surrounding tissue, so the physician can assess the internal structure of the lesion, determining its size, location and depth of penetration.