Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Large bullae are seen in the upper lobes , left greater than right . These have well - defined , thin walls , with convex margins that are uncharacteristic of pneumothorax . In the right lower lobe , there is a cluster of hyperdense nodules , which may represent calcifications or mucus - impacted bronchi . Left lung is clear . Cardiomediastinal and hilar contours are normal . There are no pleural effusions . A small hiatal hernia is present . Clips in the left upper quadrant are likely from Nissen fundoplication . There is no free air beneath the diaphragm .
    OUTPUT:
    
1 . Bilateral upper lobe bullae , left greater than right . 2 . Right lower lobe aspiration versus calcified nodules .