Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac and mediastinal silhouettes demonstrate calcification of the aortic arch but otherwise appear grossly unremarkable . There is slight blunting of the right costophrenic angle , probably representing changes of atelectasis . No definite consolidative process is seen . No other focal pulmonary opacity , pleural effusion , or evidence of pneumothorax . Examination of osseous structures demonstrate mild anterior shortening of a mid thoracic vertebral body , but are otherwise unremarkable .
    OUTPUT:
    
Probable atelectasis at the right lung base . No definite consolidation .