Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal silhouette is normal . There is no pleural effusion or pneumothorax . There is irregularity of the posterior left fourth rib but no fractures seen in this region on torso CT scan . There is loss of vertebral body height at L1 .
    OUTPUT:
    
Compression fracture of L1 .