Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes . Heart size top - normal . No pulmonary edema . Vague increased density in the lower lung zones . No pleural effusion . No hilar adenopathy .
    OUTPUT:
    
Vague increased density in the bilateral lower lung zones may represent micro atelectasis ( secondary to low lung volumes ) or early airspace consolidation . Unfortunately a pneumonic process can not be excluded with absolute certainty and clinical correlation is advised .