Fig. 2From: A systemic ultrasound positioning protocol for nasointestinal tube in critically ill patientsAcoustic signs of the nasointestinal tube (NIT) on ultrasound. a Double-track sign: white arrows; b Five lines sign: red dotted box; Guidewire: yellow arrows; Wall of the NIT: white arrows; c Bar shadow sign: white arrows; NIT: yellow arrow; d: Bright band sign: white arrows; e Gas bead-like sign: white arrows; NIT: yellow arrow; f: Dynamic water flow sign: white arrows; g: Short-axis acoustic shadow sign: white arrows. NIT: yellow arrow. DB, duodenal bulb; GB, gallbladder; LL, left liver; PH, pancreatic head; PY, pylorusBack to article page