Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear without focal consolidation , effusion , or edema . There is a rounded nodular opacity in the retrocardiac region which may project behind the heart on the lateral view . The cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities identified .
    OUTPUT:
    
No acute cardiopulmonary process . Suggestion of retrocardiac nodular opacity .