Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates low lung volumes , which results in bronchovascular crowding . Retrocardiac and right basalar opacities are concerning for pneumonia . Relative lucencies in the bilateral upper lobes likely represents blebs . The heart appears enlarged . No pneumothorax .
    OUTPUT:
    
Retrocardiac and right basalar opacities are concerning for pneumonia .