Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is subsegmental atelectasis at the left lung base . No focal consolidation , pleural effusion or pneumothorax . Mild pulmonary vascular congestion is noted . Heart remains enlarged . There is also an enlarged and tortuous thoracic aorta , similar to the prior study on the frontal view . No acute osseous abnormalities are identified . There are several healed rib fractures on the right .
    OUTPUT:
    
1 . Mild pulmonary vascular congestion , without overt pulmonary edema . 2 . Tortuous and enlarged thoracic aorta , similar to prior studies on the frontal view .