Radiographs of different types of nodular lesions. (A) Solitary nodule. (B) Nodule with surrounding ground-glass halo. (C) Mass-like consolidation with surrounding halo of ground-glass opacity. (D) Peripheral pleural-based nodule with pleural effusion. (E) Large central irregular speculated density with surrounding ground-glass opacity and smaller more peripheral speculated lesion. (F) Cavitary nodule with sequestrum (air-crescent sign).