Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates well - expanded , clear lungs . There is a curvilinear structure in the upper left hemithorax which may represent the pleural surface , but vessels are seen extending superior to this line , making pneumothorax unlikely . Cardiomediastinal and hilar contours are unremarkable . There is no pleural effusion . Again seen is a nodular opacity in the left upper lung , consistent with area of biopsy today .
    OUTPUT:
    
Left apical curvilinear structure may represent pleural surface , but vessels are seen coursing superior to this structure , making pneumothorax unlikely .