Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left basilar atelectasis is seen . No definite focal consolidation . There are relatively low lung volumes . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable . The patient is status post median sternotomy , CABG , and cardiac valve replacement . . Degenerative changes are partially imaged along the spine .
    OUTPUT:
    
No acute cardiopulmonary process .