Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a retrocardiac opacity silhouetting the medial hemidiaphragm which may be due to atelectasis . The lungs are otherwise clear without focal opacity , pulmonary edema , pleural effusion or pneumothorax . Cardiomegaly is mild . The aorta is tortuous . Mid thoracic vertebral body height loss is noted , age indeterminate .
    OUTPUT:
    
Mild cardiomegaly . Retrocardiac opacity , potentially atelectasis noting infection can not be excluded . Mid thoracic compression deformities , age indeterminate .