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 . Increased opacity at the bilateral bases , left greater than right , is most prominent in the retrocardiac region . Additional patchy opacity is present in the right middle lobe , partially obscuring the right heart border Note is made of a small left - sided pleural effusion . There cardiac silhouette is unchanged . The aorta remains tortuous . There is no pneumothorax .
    OUTPUT:
    
1 . Bibasilar opacities favor atelectasis . Additional patchy right middle lobe opacity could reflect atelectasis or infectious pneumonia . Short - term followup radiographs may be helpful in this regard . . 2 . Small left pleural effusion .