Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph is obtained . The lung volumes are low . The heart is markedly enlarged . There is obscuration of the retrocardiac space , which could reflect technique . The possibility of tiny bilateral pleural effusions is not excluded . While there is no overt pulmonary edema , there may be minimal interstitial edema . The mediastinal contour is stable . Bony structures are intact .
    OUTPUT:
    
Cardiomegaly with possible mild interstitial edema and tiny pleural effusions . Limited exam due to low lung volumes .