Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior exam , the patient has undergone a right thoracentesis . The right pleural effusion has significantly decreased in size . A trace pleural effusion likely persists . There is no evidence of pneumothorax . There is no new opacity or pulmonary edema . There is no left pleural effusion . The cardiomediastinal silhouette is stable with unchanged moderate cardiomegaly . The patient is status post cardiac bypass . Sternal wires are intact .
    OUTPUT:
    
Interval decrease in size of the right pleural effusion . No evidence of pneumothorax .