Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes results in crowding of the bronchovascular structures . A mild , nonspecific interstitial abnormality may have increased since ___ . There is no lobar consolidation , pleural effusion , pneumothorax , or pulmonary edema . The cardiac size is stable . The descending thoracic aorta is mildly tortuous .
    OUTPUT:
    
Interval increase in degree of an interstitial abnormality . Although there is no evidence of bacterial pneumonia , an opportunistic infection or reaction to inhaled substances should be considered clinically .