Anomalous Systemic Arterial Supply to Normal Basal Segments of Left Lower Lobe: Characteristic Imaging Findings

Abstract

PURPOSE: The purpose of this study was to describe the characteristic findings in each imaging modality of anomalous systemic arterial supply to normal basal segments of the left lower lobe of the lung. METHOD: Five patients with anomalous systemic arterial supply to normal basal segments of the left lower lobe were retrospectively reviewed. Chest radiography, contrast-enhanced CT scan, angiography, and other imaging modalities were analyzed. RESULTS: The imaging findings of this anomaly were characterized by three issues as follows: an anomalous systemic artery arising from the thoracic aorta, absence of pulmonary arterial supply, and normal bronchial system as well as normal pulmonary parenchyma in the affected segments. The anomalous systemic artery was demonstrated on chest radiography, contrast-enhanced CT scan, MRI, and thoracic aortography. Absence of pulmonary arterial supply was revealed by pulmonary angiography, radiolabeled perfusion scan, and CT scan. Normal bronchial system was confirmed by radiolabeled ventilation scan, bronchography, and CT scan. CONCLUSION: CT is useful in making the correct diagnosis of this anomaly because it is the only diagnostic method that can demonstrate the anomalous systemic artery, absence of pulmonary arterial supply, and normal bronchial system in the affected segments.