Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is at the upper limits of normal . The mediastinal and hilar contours are normal . A small - to - moderate right - sided pleural effusion is present , some of which appears to track laterally . Right basilar opacity is noted . No large pneumothorax is present .
    OUTPUT:
    
Small - to - moderate right pleural effusion . Right basilar opacity may be attributed to atelectasis however - underlying pneumonia or post biopsy changes can not be excluded ; no visualized pneumothorax .