Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The tracheostomy tube is in situ . Lower cervical spinal fusion hardware and postsurgical ___ are again noted . The heart is top - normal in size . Mediastinal silhouette is unchanged however there is mediastinal shift towards the left consistent with left lower lobe collapse as demonstrated by the persistent retrocardiac opacity , obscuration of left hemidiaphragm , and compensatory hyperinflation of the left upper lobe . There is mild subsegmental atelectasis at the right lung base , improved compared to prior study . No pneumothorax .
    OUTPUT:
    
Persistent left lower lobe collapse .