Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral chest radiographs were obtained . The lungs are well expanded with linear left lung opacity most consistent with atelectasis . Rounded nodules seen in the left upper and lower lobes are better demonstrated on the recent thoracic spine CT as nodules with areas of central , benign - appearing calcification . There is no pleural effusion or pneumothorax . The heart and mediastinal contours are unremarkable . Lumbar fusion hardware is incompletely assessed . Old right rib fracture is again noted .
    OUTPUT:
    
No acute intrathoracic process with left midlung opacity , most likely atelectasis .