Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared with the prior exam , there has been interval slight worsening of bilateral diffuse interstitial opacities as well as upper vascular redistribution , concerning for mild pulmonary edema . Mild - to - moderate cardiomegaly is not significantly changed from prior . Cardiac silhouette is grossly stable given differences in technique and inspiration . There is no pleural effusion or pneumothorax . Mediastinal contours are stable with tortuous aorta . A vague amorphous lucency measuring 5 cm in length , up to 2 .9 cm transverse projecting over the cardiac silhouette in the midline , just inferior to the left main bronchus may represent air within a hiatal hernia , a distended esophagus , or may relate to external artifact . Not well localized on the lateral view . Consider repeat frontal view .
    OUTPUT:
    
Findings compatible with mild interstitial edema in the setting of stable moderate cardiomegaly . Vague amorphous lucency projecting over the cardiac silhouette in the midline , just inferior to the left main bronchus may represent air within a hiatal hernia , a distended esophagus , or may relate to external artifact . Not well localized on the lateral view . Consider repeat frontal view .