Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Overlying EKG leads are present . There is upper lung lucency with splaying of bronchovascular markings compatible with emphysema . There is mild linear atelectasis versus scarring in the mid to lower lungs . No convincing signs of pneumonia . No large effusion or pneumothorax . No worrisome nodule or mass . Cardiomediastinal silhouette is stable . Atherosclerotic calcification of the aortic knob noted . Bony structures are intact .
    OUTPUT:
    
Linear densities in the mid to lower lungs likely represent atelectasis versus scarring . Emphysema .