Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are relatively low . Left basilar opacity is presumably secondary to atelectasis . Lungs are otherwise clear . There is no large effusion common pneumothorax or edema . The cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities .
    OUTPUT:
    
No definite acute cardiopulmonary process .