Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal silhouette and hilar contours are normal . There is a new , subtle retrocardiac opacity which can also be seen posteriorly on the lateral view projecting over the vertebral bodies , worrisome for left lower lobe pneumonia . Right lung is clear . There is no effusion or pneumothorax .
    OUTPUT:
    
Retrocardiac opacity worrisome for left lower lobe pneumonia . Results were discussed over the telephone with ___ , RN by Dr . ___ at 5 :02 p .m . on ___ at time of initial review .