Sequestration lung is best diagnosed by

Pulmonary sequestration:It is an embryonic mass of lung tissue that has no identifiable bronchial communication and that receives blood supply from 1 or more anomalous systemic aeriesClassified as extralobar (25%) and intralobar (75%)Demonstration of dominant feeding vessel, usually from the aoa or its major vessels, and venous drainage to the pulmonary veins suggests the diagnosisThe definitive diagnosis is made by using angiography ( conventional, CTA, MRA)(Ref: Sumer Sethi 4/e p35)