Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear stable . There is a layering pleural effusion about the right hemithorax which is probably at least moderate and possibly moderate to large in size . The left lung appears clear without pleural effusion . There is at least a moderate - sized hiatal hernia suspected along the lower mediastinum . A lower thoracic vertebroplasty has been performed . There is moderate rightward curvature centered along the mid thoracic spine . Bones appear demineralized .
    OUTPUT:
    
Substantial pleural effusion on the right , difficult to compare to the most recent prior radiographs due to differences in technique , although the right lung is probably better aerated .