ANGULATED NEEDLE PLACEMENT IN CT-GUIDED PERCUTANEOUS NEEDLE-BIOPSY OFTHE THORAX

Computed tomography (CT)-guided percutaneous needle biopsy is often ne cessary to evaluate small intrathoracic lesions. Not infrequently, an overlying structure such as a rib or vessel precludes insertion of the biopsy needle within the CT slice containing the lesion. Insertion an d angulation of the needle at a site within an adjacent CT slice is th en required. In order to determine the optimal skin-entry site and deg ree of angulation for biopsy needle insertion, we analyzed the geometr ic relationship between lesion depth, needle length, and needle angula tion.