Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A left apical pneumothorax is not significantly changed though remains small . A left chest pacemaker with a single right ventricular lead is unchanged . The lung volumes remain somewhat low , though are improved compared with prior . There is a probable small right pleural effusion with bibasilar atelectasis . The pulmonary vasculature is normal . The cardiac silhouette and mediastinal contours are unchanged .
    OUTPUT:
    
Residual small left apical pneumothorax .