Unilateral Coexisting Intralobar and Extralobar Pulmonary Sequestrations

Abstract

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.

Keywords: CT, computed tomography; MRI, magnetic resonance imaging.

Figure 1A-B

Three-dimensional volume-rendered images with surface shading in A) sagittal and B) posterior views. The celiac artery origin of the large caliber artery (1) is clearly seen as well its smaller caliber branch (2). An anomalous artery originates directly from the thoracic aorta (3). The anomalous systemic vein (4) associated with the extralobar sequestration is seen originating from the sequestration (s) and draining into the incompletely filled left brachiocephalic vein (LBCV). Left inferior pulmonary vein (LIPV) is draining the intralobar sequestration.

Figure 2

Coronal maximum intensity projection (MIP) image in soft tissue window. The sequestration is seen as an abnormal enhancing soft tissue mass at the left lower lobe. The large caliber artery (1) is arising from the abdomen. The left inferior pulmonary vein (LIPV) is seen draining the sequestration.

Figure 3

Coronal reformatted image with 50% overlapping slices in lung window. There is emphysematous area (E) surrounding the sequestration (s). The large caliber artery originating from the aorta (1) and anomalous systemic vein originating from the sequestration (2) are seen.