Figure 12a. Paravertebral approach for biopsy of a right paratracheal mass. (a) CT scan shows a right paratracheal mass (M) that lacks an extrapleural window (arrowhead). (b) CT scan shows an extrapleural window (thin arrows) created by injection of saline solution through an 18-gauge needle (thick arrow). This extrapleural window allowed safe biopsy of the mass (M) with a coaxially placed 22-gauge needle (arrowhead).