Possible Bronchopulmonary Sequestration

This is a chest CT image of a young male with fever, recurrent cough. CT chest shows well defined area in left lower lobe with cystic component. Possibility of  sequestration was suggested in view of location and appearance, and CT angiography was suggested.  The most common appearance of sequestration  is a solid mass sometimes with cystic changes. Less frequent findings include a large cavitary lesion with an air-fluid level, a collection of many small cystic lesions containing air or fluid, or a well-defined cystic mass. Conventional CT does not consistently demonstrate the aberrant systemic artery,  Lack of visualization was thought to be due to the small size  or unfavorable orientation of the vessel.  CT angiography is the procedure of choice.