Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild blunting of the left costophrenic angle seen on the frontal view which may be due to pleural thickening versus a trace pleural effusion . The right lung is clear . The lungs are hyperinflated suggesting underlying COPD . No focal consolidation is seen . There is no pneumothorax . The cardiac silhouette is top - normal . The aortic knob is calcified .
    OUTPUT:
    
Mild blunting of the left costophrenic angle on the frontal view may be due to pleural thickening , but a trace pleural effusion is not excluded .