Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: This is a subtle linear opacity at the right base , which appears stable from the prior exams , and most likely represents atelectasis . No focal airspace opacities identified . There is no pulmonary edema , pleural effusion , or pneumothorax . The hila remain prominent , although unchanged from the prior exam . The mediastinal contours are normal . The heart size is normal .
    OUTPUT:
    
No acute cardiopulmonary process .