Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Coarsened interstitial markings suggest fibrosis . No lobar consolidation . Given background fibrosis , difficult to exclude a subtle infectious process . No large effusion or pneumothorax . No convincing signs of edema . Cardiomediastinal silhouette appears within normal limits . No free air below the right hemidiaphragm .
    OUTPUT:
    
Coarsened lung markings concerning for pulmonary fibrosis .