Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . No focal consolidation , pleural effusion , or pneumothorax . The cardiomediastinal silhouette is within normal limits and overall unchanged from the prior exam . Stable appearance of the hila . Posterior spinal fixation device is incompletely visualized but appears similar to the prior exam . A tubular opacity is seen only on the lateral view and is likely external to the patient . Multi - level degenerative changes in the visualized spine are overall unchanged .
    OUTPUT:
    
No acute intrathoracic process .