ABSTRACT
Planning/site selection The computed tomography (CT) scan of the thorax should be examined prior to TBNA and the site of aspiration should be predetermined (Fig. 6.2a). The simplest approach is to relate the airway to a clock face and plan the position of target sites in this manner (Fig. 6.2b). The CT scan is obtained by imaging from the feet upwards (Fig. 6.2c), whereas at bronchoscopy the patient is approached from the head downwards (Fig. 6.2d). It is therefore important to account for these differences. For patients who are being approached from the anterior side, the simple trick is to fl ip the image in the horizontal axis (Fig. 6.2e). The vertical position also needs to be determined and can be described in terms of cartilage spaces or rings above and below the carina (Fig. 6.2f). In some cases it may be necessary to relate the vertical position to the origin of the segmental bronchi. More detailed descriptions are given for the example lymph node stations in this chapter, but it should be emphasized that this is merely a guide and individual sites for aspiration are determined according to the patient’s CT scan. Modern multi-planar reformatting of CTs and software modules with virtual bronchoscopy (Fig. 6.2g) and lymph node highlighting (Fig. 6.2h) may help to determine
Fig. 6.2a CT scan with right paratracheal lymph node present.
