Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Size of the patient 's left apical pneumothorax is unchanged very slightly slightly smaller compared to yesterday 's study . Taking into account differences in obliquity , there is no significant interval change in the appearance of the lungs or the heart and mediastinal contours . No central pulmonary vascular congestion is seen . Healed posttraumatic changes at the proximal humerus and acromioclavicular joint appear stable .
    OUTPUT:
    
Left apical pneumothorax is unchanged to slightly smaller