Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and left lateral decubitus radiographs were obtained . The volume of the left - sided pneumothorax has decreased since the prior study . Small pneumothorax remains . There is no consolidation , effusion or effusion . The cardiac and mediastinal contours are normal . The incompletely formed pigtail catheter remains in stable position .
    OUTPUT:
    
Decreased size of left apical pneumothorax .