Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient upright position . Analysis is performed in direct comparison with the next preceding PA and lateral chest examination of ___ . Appearance of cardiovascular mediastinal structures is unaltered in comparison with the preceding chest examination . No evidence of new pulmonary infiltrates . A mildly blunted left lateral pleural sinus is again noted that appears unchanged . The previously remaining tiny left - sided apical pneumothorax can not be identified anymore . Lungs appear well ventilated bilaterally .
    OUTPUT:
    
Disappearance of previously identified residual pneumothorax .