Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouettes are within normal limits . The bilateral hila are unremarkable . Irregular opacity at the right cardiophrenic angle likely represents combination of basal atelectasis in conjunction with crowding of bronchovascular structures in the setting of low lung volumes . Otherwise , the lungs are clear . There is no evidence of pulmonary vascular congestion . There is no pneumothorax or pleural effusion . Evidence of multiple old left posterolateral rib fractures , at least involving ribs 6 , 7 , and 8 , are noted .
    OUTPUT:
    
No acute cardiopulmonary process . Multilevel old left posterolateral rib fractures .