Fig. 1: The zone system of pleura for assessment pleural tumor index.

A, B Coronal view of the thorax; C axial view of the thorax (left); D axial view of the thorax (right). Zone I, rib and chest wall zone; Zone II, diaphragm zone; Zone III, mediastinum zone; Zone IV, lower pulmonary zone (below oblique fissure); Zone V, upper pulmonary zone (above oblique fissure).