Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . Heterogeneous opacities are present in the left lower lobe with otherwise clear lungs . . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Heterogeneous left lower lobe opacities may reflect pulmonary hemorrhage or infection . No conventional radiographic evidence of obstructing lesion .