Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright chest radiograph was provided . The heart is enlarged , though patient is known to have extensive mediastinal and epicardial fat deposition likely also accounting for prominent cardiomediastinal silhouette . The lungs appear essentially clear . No evidence of effusion or pneumothorax . Bony structures are intact .
    OUTPUT:
    
No definite signs of acute intrathoracic process . Prominent cardiomediastinal silhouette likely due to prominent mediastinal and epicardial fat deposition as seen on prior CT . Please refer to subsequent CTA chest for further details .