Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs demonstrate moderate cardiomegaly , which is likely unchanged but accentuated by lower lung volumes compared to prior radiographs . There is also results in bronchovascular crowding . There is mild vascular congestion . The left hemidiaphragm is obscured , consistent with a retrocardiac opacity , which may be due to a small left pleural effusion . There is no pneumothorax .
    OUTPUT:
    
1 . Retrocardiac opacity , new since ___ . This may represent a small left pleural effusion . 2 . Moderate cardiomegaly . 3 . Mild vascular congestion .