Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Upright frontal chest / abdominal radiograph demonstrates a Dobbhoff tube ending in the left upper quadrant . The curvature of the Dobbhoff tube suggests that it is within the fourth portion of the duodenum . There is a right central venous catheter line ending in the right atrium . The bowel gas pattern is unremarkable . There is retrocardiac opacity in the left lung base , perhaps in large part an effusion .
    OUTPUT:
    
The curvature of the Dobbhoff tube suggests that its tip is within the fourth portion of the duodenum . A radiograph could be considered after injection of contrast into the tube for definite confirmation of tip location .