Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Previously noted right sided dual lumen venous catheter is no longer visualized . Low lung volumes are noted with secondary crowding of the bronchovascular markings . There is no large effusion or pneumothorax . The cardiomediastinal silhouette is grossly unchanged .
    OUTPUT:
    
Right - sided dialysis catheter no longer visualized .