Fig. 1

Primary tumors of six patients encircled in red. a Axial T1 MRI image of a tumor in the left mandible of patient 1. b Axial ceCT image of a tumor in the floor of mouth of patient 2. c Axial ceCT image of a tumor in the right lateral tongue of patient 3. d Axial ceCT image of a tumor in the right mandible/floor of mouth/tongue of patient 4. e Axial ceCT image of a tumor in the floor of mouth in patient 5. f Axial T1 MRI image of tumor in left mid tongue base of patient 6. ceCT = contrast enhanced computed tomography