Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left PICC is in the upper to mid SVC . Lung volumes are low . Heart size is normal . The mediastinal and hilar contours are stable . Previous mild volume overload is improved . There is no pleural effusion or pneumothorax . Spinal fusion hardware is partially imaged in the lower cervical spine .
    OUTPUT:
    
Persistently low lung volumes . Previous mild volume overload is improved .