Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior exam the large left pleural effusion has significantly improved although a small amount of residual fluid and pleural thickening remain . Areas of atelectasis are noted at the left lung base . The right lung is clear . Cardiomediastinal silhouette is normal . There is no pneumothorax . Right upper extremity PICC terminates at the mid SVC .
    OUTPUT:
    
Significant improvement in left pleural effusion with small amount of residual pleural thickening and fluid remaining .