Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral chest radiographs were obtained , but are limited due to poor penetration likely in part due to body habitus . The lungs are reasonably well expanded and clear with improved linear left midlung atelectasis . There is no pleural effusion or pneumothorax identified on these limited films . The cardiac silhouette remains mild to moderately enlarged with otherwise normal cardiomediastinal and hilar contours .
    OUTPUT:
    
No acute intrathoracic process .