Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Limited study due to underpenetration . Low lung volumes are unchanged from prior exam with crowding of vasculature . No overt pulmonary edema or pneumonia . Pleural surfaces are normal without pleural effusion or pneumothorax . Mediastinal and hilar contours are unremarkable . Visualized osseous structures are unremarkable . No evidence of rib fracture .
    OUTPUT:
    
1 . No overt pulmonary edema or pneumonia . Subtle abnormalities are difficult to exclude on this study . 2 . No evidence of rib fracture , however , if clinical concern , consider dedicated rib series .