Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is mild hyperexpansion . There is no focal consolidation , pleural effusion , pulmonary edema , or pneumothorax . The cardiomediastinal silhouette is within normal limits with a tortuous descending aorta . Focal narrowing of the upper trachea is unchanged from the prior study and may be due to an enlarged thyroid gland .
    OUTPUT:
    
1 . No evidence of acute cardiopulmonary process . 2 . Unchanged mild narrowing of the upper trachea , potentially related to an enlarged thyroid gland .