Horseshoe lung associated with left-lung hypoplasia, left pulmonary artery sling and bilateral agenesis of upper lobe bronchi.

Horseshoe lung, a rare congenital anomaly, is almost always associated with unilateral (usually right-sided) lung hypoplasia, and, in most cases, in conjunction with the scimitar syndrome. We present an 8-month-old boy with horseshoe lung associated with left-lung hypoplasia, left pulmonary artery sling and bilateral agenesis of the upper lobe bronchi, diagnosed by multidetector CT (MDCT) imaging. The study also revealed an anomalous origin of the left vertebral artery as the last branch of the aortic arch, distal to the left subclavian artery, and an anomalous origin of the left common carotid artery from the brachiocephalic trunk. A hemivertebral anomaly of the seventh cervical vertebra was incidentally detected. MDCT with high-quality multiplanar and three-dimensional reconstructions is a noninvasive and rapid technique for detecting the complex combination of vascular, tracheobronchial and parenchymal anomalies, and any potential bone anomalies, in one imaging study.