Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiograph demonstrates hypoinflated lungs with crowding of vasculature . Right lung is clear . Heterogeneous opacity within the left lower lobe with elevation of the left hemidiaphragm is noted . No definite pleural effusion . No pneumothorax . Top normal heart size is accentuated due to low lung volumes and patient positioning . Mediastinal contour and hila are otherwise unremarkable .
    OUTPUT:
    
Subtle left lower lobe opacity could reflect pneumonia in the appropriate clinical setting .