Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The aorta is mildly tortuous . The aortic arch is calcified . The pulmonary interstitium appears irregular and there is a patchy peripheral opacification suggesting a substantial interstitial abnormality . Although lung volumes are low , there may be an emphysematous component noting relative lucency and attenuation of bronchovascular structures in the upper lung . Associated with slight elevation of the left hemidiaphragm is predominantly streaky focal opacification in the left lower lobe , which may be due to chronic scarring or atelectasis , although an infectious cause is hard to completely exclude . There is no pneumothorax or pleural effusion . The bones appear demineralized . There are mild degenerative changes along the thoracic spine .
    OUTPUT:
    
1 . Findings suggesting interstitial lung disease and perhaps coinciding emphysema . 2 . Focal opacity in the left lower lung , not specific although compatible with atelectasis . Particularly if pulmonary symptoms are chronic and of uncertain etiology , a chest CT may be considered depending on clinical evaluation , particularly if the cause of lung disease depicted on the radiographs is unknown and prior imaging is not available .