Fig. 3

Occult pneumothorax size on CT scan classification by Wolfman et al. [15]. Minuscule pneumothorax is defined as a thin collection of air up to 1 cm thick in the greatest slice and seen on no more than 4 cm length. Anterior pneumothorax is categorized as a collection of pleural air more than 1 cm thick, located anteriorly, not extending to the mid-coronal line, and which may be seen on 4 cm or more length. Anterolateral pneumothorax is defined as pleural air extending to the mid-coronal line at least