Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph demonstrates low lung volumes . There is a non displaced fractures are identified within the posterior ___ left rib . Linear lucency within the posterior fifth rib is thought to be artifactual . There is no focal consolidation . Heart size is within upper limits of normal . Mediastinal and hilar contours are unremarkable . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
Nondisplaced fracture through the posterior fourth rib . No pneumothorax .