Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A Port - A - Cath again terminates in the superior vena cava . The cardiac , mediastinal and hilar contours appear stable . There is mild volume loss at the left lung base with mild elevation of the left hemidiaphragm and patchy retrocardiac opacity , although this appears unchanged and suggests chronic atelectasis rather than an acute process .
    OUTPUT:
    
Persistent volume loss at the left lung base and patchy opacity , probably consistent with unchanged chronic atelectasis , with no definite acute superimposed process .