Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable AP upright chest radiograph demonstrates clear lungs allowing for significant patient rotation . These status post left rib plate and screw fixations through the mobile left rib fractures . Heart is enlarged though no overt pulmonary edema is appreciated . There is no pneumothorax . There is blunting of the left hemidiaphragm , possibly reflective of atelectasis or alternatively a small pleural effusion . No air under the right hemidiaphragm is seen . Patient is status post right shoulder arthroplasty .
    OUTPUT:
    
Large heart without overt pulmonary edema . Obscuration of the left hemidiaphragm may reflect atelectasis or a small pleural effusion .