Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest . The lungs are clear . There is no pneumothorax . Cardiomediastinal silhouette is within normal limits . There is persistent mild blunting of a posterior costophrenic angle potentially due to small effusion , unchanged . No acute osseous abnormality detected .
    OUTPUT:
    
No definite acute cardiopulmonary process .