Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low . Retrocardiac opacity is most likely atelectasis . No focal consolidation , edema , effusion , or pneumothorax . The heart is mildly enlarged . The thoracic aorta is slightly tortuous . Aortic knob calcifications are moderate . No mediastinal widening . Degenerative changes in both AC joints are mild . Moderate degenerative changes are seen in the right glenohumeral joint . Multilevel degenerative changes in the thoracic spine are mild .
    OUTPUT:
    
No focal pneumonia . Mild cardiomegaly .