Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . This accentuates the size of the cardiac silhouette which appears borderline enlarged . Additionally , low lung volumes cause apparent widening of the superior mediastinum , but the aortic knob appears distinct . Crowding of the bronchovascular structures is noted without overt pulmonary edema . No focal consolidation , pleural effusion or pneumothorax is present . No acute osseous abnormality is detected .
    OUTPUT:
    
Low lung volumes . Apparent superior mediastinal widening is likely related to the presence of low lung volumes , but repeat PA and lateral views with improved inspiratory effort is recommended . No acute cardiopulmonary abnormality otherwise noted .