Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouettes are stable allowing for differences due to a suboptimal inspiratory effort . There is a tortuous thoracic aorta , as on prior exam . The hila are within normal limits . There is evidence of prior right rotator cuff repair . Slightly increased opacity projecting over the right mid lung on AP view likely represents crowding of normal structures . Otherwise the lungs are clear . There is no pulmonary vascular congestion or pulmonary edema . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
Subtle right lower lobe opacity likely represents crowding of normal bronchovascular structures in the setting of low lung volumes . No pneumothorax or effusion .