Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are compared to previous exam from ___ . Lung volumes are low , linear retrocardiac opacity seen only on the frontal , most likely due to atelectasis . Lungs are otherwise clear . Costophrenic angles are sharp . Cardiomediastinal silhouette is within normal limits as are osseous and soft tissue structures .
    OUTPUT:
    
No acute cardiopulmonary process .