Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post mitral valve replacement . The cardiac , mediastinal and hilar contours appear stable , including borderline cardiomegaly . There are new small - to - moderate sized bilateral pleural effusions with patchy parenchymal densities and low lung volumes , a setting suggestive that opacities are probably due to associated atelectasis .
    OUTPUT:
    
New small bilateral pleural effusions and associated opacities due to probable atelectasis .