Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Upright AP and lateral views of the chest demonstrate low lung volumes . The lungs are clear , with no evidence of pneumothorax , pulmonary edema or focal airspace opacity . No large pleural effusion is identified . The heart is moderately enlarged , best appreciated on the lateral view . No displaced rib fractures are identified on the AP and lateral views .
    OUTPUT:
    
1 . Moderate cardiomegaly . 2 . No displaced rib fractures identified on these views ; however , assessment is limited secondary to body habitus . If clinical suspicion remains for occult rib fracture , dedicated rib series radiographs or chest CT is recommended .