Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is difficult to assess given the presence of small bilateral pleural effusions , left greater than right . The pleural effusion on the left appears slightly increased in size while the effusion on the right is unchanged . Mediastinal contour is unchanged with mild atherosclerotic calcification noted at the aortic knob . Prosthetic aortic valve is again demonstrated . The pulmonary vasculature is normal . There is compressive atelectasis at the lung bases . No pneumothorax is detected . No acute osseous abnormality is identified .
    OUTPUT:
    
Small bilateral pleural effusions , increased in size on the left , and unchanged in size of the right with associated compressive bibasilar atelectasis .