Diagnosis of arterial sequestration using multidetector CT angiography

Arterial sequestration is a rare congenital disorder. The diagnostic evaluation of this condition using multidetector computerized tomography (MDCT) has not been described previously. The purpose of this study was to describe the characteristic features of this disorder and to assess the use of MDCT in visualizing the characteristic anatomic features.

We retrospectively reviewed the records of seven patients with anomalous systemic blood supply to left lower lobe of the lung. All the patients had undergone MDCT angiography. To evaluate the lung parenchyma, bronchial branching pattern, and vascular anatomy, four series of images were systematically reconstructed as follows: contiguous transverse CT scans viewed at mediastinal and pulmonary window settings, oblique coronal and sagittal maximum intensity projections (MIP), multiplanar reconstruction (MPR), and three-dimensional volume-rendered images (VR) of airway and thoracic vascular structures.

All 7 cases had isolated and tortuous arterial anatomy from the descending thoracic aorta to the basal segment of the left lower lobe; however, variable distribution of branches was observed. Characteristic findings of anomalous systemic arterial (ASA) supply were distinct from those seen in other pulmonary sequestration syndromes and were well visualized by the use of noninvasive MDCT.

Complex CT findings allow clear imaging of arterial sequestration and the ASA blood supply; MDCT angiography has demonstrated its value and accuracy in diagnosing this condition, obviating the use of digital subtraction angiography and magnetic resonance angiography for the diagnosis of arterial sequestration.