Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP semi-upright chest radiograph was provided . Port - A - Cath again noted residing over the right mid chest with the catheter tip extending into the expected region of the superior vena cava . Lung volumes are quite low , which limits the evaluation . Bronchovascular crowding likely accounts for the left lung base opacity . No definite signs of pneumonia or CHF . No large pleural effusion or pneumothorax is seen . The imaged osseous structures appear intact .
    OUTPUT:
    
Low lung volumes without definite signs of acute intrathoracic process .