Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been interval placement of a right pigtail chest tube along the right lateral lung apex . There is a residual trace right apical pneumothorax . The lungs are clear without focal consolidation , pleural effusion or pulmonary edema . The heart is normal in size . A spinal stimulator device is again noted .
    OUTPUT:
    
Trace right apical pneumothorax following right pigtail catheter placement along the right lateral lung apex .