Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Supine portable radiograph is obtained . Endotracheal tube is satisfactorily positioned within the trachea . Examination was slightly limited by motion with bilateral atelectasis and low lung volumes . No pneumothorax is seen with exaggeration of heart and mediastinal size likely due to supine positioning . Old clavicular fracture is noted .
    OUTPUT:
    
No acute intrathoracic process .