Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph obtained . Port - A - Cath is in unchanged position with tip residing at the low SVC . The lungs are clear with interval improvement of interstitial edema seen previously . No effusion or pneumothorax . Cardiomediastinal silhouette is normal . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
No acute intrathoracic process . Interval resolution of previously detected interstitial edema .