Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been no significant interval change in a small left apical pneumothorax . Small left pleural effusion is persistent with adjacent mild atelectasis . The cardiomediastinal silhouette is unremarkable . No displaced rib fractures are identified . There is no focal airspace opacity .
    OUTPUT:
    
Persistent small left apical pneumothorax , overall unchanged compared to the prior exam .