Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is subtle opacity projecting over the posterior left seventh rib , not see on the prior study . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Subtle opacity projecting over the posterior left seventh rib in the the left lower lung , may be due to overlapping structures , however , small focus of consolidation due to infection or aspiration is not excluded in the appropriate clinical setting . Recommend followup to resolution .