Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is borderline in size . The mediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax . Vague opacification of the left mid to lower lung spares the left cardiac border , which appear sharp ; although the opacities are not well seen on the lateral view , it is probably in the left lower lobe . Although the density is not very elevated , the extent of the abnormality may be significant .
    OUTPUT:
    
Findings suggest pneumonia in the left lung , probably in the left lower lobe . Follow - up radiographs are suggested to show resolution within ___ weeks .