Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size is normal . Atherosclerotic calcifications are noted in the aortic knob . Mediastinal and hilar contours are unchanged . Crowding of bronchovascular structures is present without overt pulmonary edema . Patchy and linear opacities in the lung bases most likely reflect areas of atelectasis , but infection is not excluded . Attenuation of pulmonary vascular markings towards the apices indicates underlying emphysema . No pleural effusion or pneumothorax is identified . Evidence of prior kyphoplasty is seen within the lower thoracic spine .
    OUTPUT:
    
Low lung volumes with patchy opacities the lung bases most likely reflective of atelectasis . Infection , however , is not excluded in the correct clinical setting .