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Axial post-contrast CT scan (mediastinal and lung windows) with coronal and sagittal reformatting study shows the mediastinal shift to the right with a small right lung volume and cardiac dextroposition. There is anomalous venous drainage from the right lower lobe to the IVC just before its confluence with the right atrium (scimitar vein).

Associated ASD, absent normal right-sided pulmonary veins and systemic arterialization of the right lower lobe through an additional branch that originated just proximal to the celiac trunk are noticed.

Well-aerated lung tissue extended from the right lower lobe and crosses the midline through the retrocardiac space with systemic arterial supply and venous drainage to the IVC that forming the horseshoe lung.