Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Volume loss and opacification of the left lung base appears compatible with round atelectasis , scarring , and pleural plaque formation , not significantly changed . Calcified pleural plaques are present more broadly along the left hemithorax . The right lung remains clear . There is no pneumothorax . The cardiac , mediastinal , and hilar contours also appear unchanged . Mild degenerative changes are similar along the thoracic spine .
    OUTPUT:
    
Persistent left basilar opacification compatible with chronic findings with no definite superimposed process .