Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is blunting of the right costophrenic angle , concerning for a small right pleural effusion versus pleural thickening . The left lung is clear . The cardiac silhouette is top normal to mildly enlarged . The aortic knob is calcified .
    OUTPUT:
    
Blunted right costophrenic angle with opacity along the right mid to lower pleura could be due to pleural thickening and / or pleural effusion . No prior available for comparison .