Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable chest radiograph is provided . ET tube is located approximately 3 cm above the carina in appropriate position . An NG tube courses right to the GE junction and should be advanced . There is no pneumothorax . There is a retrocardiac opacity with decreased lung volume on the left consistent possibly due to left lower lobe atelectasis . There may be a small left pleural effusion . There is prominence of the pulmonary vasculature , consistent with mild pulmonary edema . Cardiomediastinal silhouette appears shifted towards the left unchanged since the prior exam and may be due to volume loss on the left . Osseous structures are intact .
    OUTPUT:
    
1 . ET tube in appropriate position . 2 . NG tube should be advanced into the stomach . 3 . Retrocardiac opacity with shift of the mediastinum towards the left , possibly due to volume loss in the left lower lobe . Possible small left pleural effusion or superimposed infection .