Unilateral Coexisting Intralobar and Extralobar Pulmonary Sequestrations.

Pulmonary sequestration is a focal area of nonfunctioning, dysplastic lung parenchyma that lacks communication with the normal tracheobronchial tree. It is supplied by the systemic arterial circulation and has two types, intralobar and extralobar, that can be differentiated from each other by the pleural covering and the venous drainage. Their coexistence is extremely rare. We report the imaging findings of a patient who had coexisting but completely separate intralobar and extralobar sequestrations at the left lower lung. We elucidated the complex vascular anatomy using three dimensional volume rendering and multiplanar reconstructions from a 64-detector helical CT scanner.