Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A subtle ground - glass and nodular opacity is visualized within the region of the right upper lobe and corresponds with findings seen on recent outside hospital chest CT . Appearance is nonspecific , but could represent focus of infection or aspiration in the appropriate clinical setting . No other confluent opacity is identified . There is no pulmonary edema or pleural effusions . No pneumothorax is evident . Cardiomediastinal and hilar contours are within normal limits . There is calcification of the aortic arch .
    OUTPUT:
    
Subtle right upper lung ground - glass nodular opacity , better characterized on recent outside hospital chest CT .