Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiographs are obtained . Moderate left pleural effusion is noted . There is no pleural effusion on the right . Cardiac silhouette is top normal . Lungs demonstrate prominent interstitial markings without focal areas of consolidation or pulmonary edema . There is no pneumothorax .
    OUTPUT:
    
Moderate left pleural effusion . Underlying infection can not be excluded . No ptx .