Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single semi upright AP portable chest radiograph demonstrates an endotracheal tube , its tip which terminates approximately 4 .9 cm above the level of the carina in appropriate position . An enteric tube descends the thorax in uncomplicated course , its tip below the level of the hemidiaphragm projecting over the left upper quadrant , new since prior study . Relative to prior study , there is improved aeration of the left hemithorax . There persists a large opacification at the left lung base with mild shift of mediastinal structures leftward to suggest a component of volume loss . The right costophrenic angle is incompletely imaged . There is no large pneumothorax .
    OUTPUT:
    
1 . Interval placement of enteric tube its tip terminating below the level of the diaphragm . 2 . Improved aeration of the left hemithorax suggesting improved atelectasis with persistent significant opacification at the left lung base . Possible etiologies include underlying effusion and atelectasis though infection is possible .