Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: When compared to the prior studies the lungs appear hyperinflated with flattening of the diaphragm bilaterally consistent with patient 's known history of COPD . There are no focal opacifications . The cardiomediastinal silhouette is stable . The hila and pleura are unremarkable .
    OUTPUT:
    
No evidence of pneumonia .