Fig. 2From: CT for estimating adequacy of lymph node dissection in patients with squamous cell carcinoma of the head and neckSegmentation protocol. A Fat mask based on tissue attenuation (green highlight). B Interpolation mask based on boundaries of nodal levels II–IV (yellow highlight). C Intersection mask generated from overlap of fat and interpolation masks (blue highlight). D Intersection mask edited to include lymphatic tissue and exclude vessels and lymphatic tissue outside the operative field to produce the final mask (purple highlight)Back to article page