Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A Port - A - Cath terminates in the mid to lower superior vena cava . The cardiac , mediastinal and hilar contours appear changed . Streaky opacities at the lung bases are more coalescent , corresponding to decreased lung volumes , suggesting waxing and waning atelectasis rather than pneumonia . The pulmonary vasculature appears within normal limits . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No evidence of acute disease .