Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heterogeneous area of opacification in the posterior aspect of the left lower lobe , seen only on the lateral view , suggests pneumonia . No pleural effusion . No pneumothorax . Mild cardiomegaly is stable . Mild elevation of right hemidiaphragm is chronic .
    OUTPUT:
    
Probable left lower lobe pneumonia . Follow - up chest radiographs in ___ weeks to ensure resolution .