Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouettes are stable and within normal limits . The bilateral hila are unremarkable . There is no pulmonary vascular congestion . Subtle diffuse mild interstitial prominence may reflect some component of underlying mild chronic interstitial lung disease , however this is unchanged in appearance since ___ . There is no focal lung consolidation . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
1 . No acute cardiopulmonary process . No focal lung consolidation . 2 . Subtle diffuse interstitial prominence may reflect some underlying mild chronic interstitial lung disease , but this is not appreciably changed in appearance since at least ___ .