Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is top normal . The hilar and mediastinal contours are within normal limits . A faint left upper nodular opacity corresponds to a nodule , better seen on the CT examinations from ___ and ___ . There is no pneumothorax or pleural effusion . Linear bibasilar atelectasis is again seen .
    OUTPUT:
    
Left upper opacity , corresponding to known nodule in this region . No acute superimposed process seen .