Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph obtained . The heart is moderately enlarged . No pleural effusion or pneumothorax . No definite signs of pneumonia . No overt signs of CHF . There is mild prominence of the aortic knob , but this is likely due to tortuosity with faint atherosclerotic calcifications noted . Bony structures are intact .
    OUTPUT:
    
Cardiomegaly with unfolded thoracic aorta likely accounting for prominence of the mediastinum . Please refer to subsequent CTA for further details .