Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph is obtained . Evaluation is limited given patient rotation to the right , as well as low lung volumes . There is a markedly abnormal mediastinal contour with significant widening . Given the suboptimal technique and patient rotation , this may result in slight distortion of the mediastinal silouhette . This widening may reflect aortic tortuosity and ectasia , though appears new from prior . There are subtle ground glass opacities in the lungs , which could reflect pulmonary edema . No large pleural effusion is seen . No pneumothorax . Heart size can not be assessed . Bony structures appear intact .
    OUTPUT:
    
Markedly limited with marked mediastinal widening which could in part reflectt an ectatic unfolded thoracic aorta , though given the significant change from prior exam , further evaluation with dedicated PA and lateral CXR and / or CT chest is recommended .