Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is likely unchanged , though assessment is limited due to the presence of a moderate to large right pleural effusion , as noted on the prior CT . There is adjacent right basilar compressive atelectasis . Pulmonary vascularity is normal . The mediastinal and hilar contours are unremarkable though the right hila is this partly obscured . Left lung is grossly clear . No left - sided pleural effusion is present . There is no pneumothorax . No acute osseous abnormalities are detected .
    OUTPUT:
    
Moderate to large right pleural effusion with associated right basilar compressive atelectasis .