Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The study is severely limited by body habitus . Within these limitations , the lungs are moderately well expanded . There is no definite focal airspace opacity to suggest pneumonia . Heart size is exaggerated by known pericardial fat , better seen on CT of ___ . Given extrapleural and pericardial fat , widening of the mediastinum is also likely due to mediastinal fat . There is no large pneumothorax . Blunting of the costophrenic sulcus posteriorly likely reflects small left pleural effusion .
    OUTPUT:
    
1 . Severely limited study , but no definite evidence of pneumonia . 2 . Small left pleural effusion .