Radiology Respiratory Radiology c7a0adfc Luftsichel sign is seen in A Right upper lobe collapse B Right middle lobe collapse C Left upper lobe collapse D Left lower lobe collapse High-Yield Explanation Luftsichel sign is a sickle shaped lucency of air seen On Chest Radiographs, Seen in Left Upper lobe collapse with Compensatory Left Lower lobe hyperinflation.