Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are again noted . There are subtle opacities over the left lung base , specifically overlying the posterior left ___ and 8th ribs which demonstrate subtle contour abnormality suggesting prior fractures . Moderate hiatal hernia is noted . The lungs are grossly clear . There is no effusion . Cardiomediastinal silhouette is within normal limits given low inspiratory effort . No acute osseous abnormality is noted .
    OUTPUT:
    
No definite acute cardiopulmonary process .