Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable chest radiograph demonstrate low lung volumes . There is a new retrocardiac opacification which may represent atelectasis or developing pneumonia in the left lower lobe . The right lung is grossly clear . There is no appreciable pleural effusion . No pneumothorax . A VP shunt is redemonstrated . An enteric tube is descending in an uncomplicated course with its terminal tip in the stomach .
    OUTPUT:
    
New retrocardiac opacification concerning for atelectasis or developing pneumonia . These findings were discussed with the house staff caring for the patient by Dr . ___ ___ telephone at 11 :36 on ___ .