Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is chronic mild cardiomegaly and a vague ground - glass opacity projecting over the left upper lung . There is no pleural effusion or focal airspace consolidation . There is no pneumothorax . AICD and its lead are unchanged .
    OUTPUT:
    
Ground - glass opacity projecting over the left upper lung better characterized on the subsequent chest CTA .