Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest . Mildly indistinct pulmonary vascular markings are seen . More dense left retrocardiac opacity is identified . Small bilateral pleural effusions are seen . The cardiac silhouette is enlarged , but unchanged . Atherosclerotic calcifications seen in the thoracic aorta . No acute osseous abnormality is identified .
    OUTPUT:
    
Small bilateral effusions and mild interstitial edema . Retrocardiac opacity could be secondary to atelectasis , although superimposed infection is also possible .