128 slice multidetector ct scanner

CT scans (0.6 mm each slice) were obtained for each CMI patient, with the neck in a neutral position, on a 128slice multi-detector CT scanner (Siemens, Germany). The images in DICOM format were reconstructed in three orthogonal planes using RadiAnt DICOM Viewer, version 5.5.0. (Medixant, Poland) software. The images of the control group obtained from the CT angiography were also analyzed using the same methods. Eight linear and 9 angular parameters (Table 1) were measured on the mid-sagittal image, according to our previous method [14] (Fig. 2), using RadiAnt or iPhotoDraw V2.6 software (Simen Wu, Canada). The first author evaluated all of the exams to minimize variations in measurements.
The volume of the bony PCF was calculated using Mimics Research, version 18.0.0.525 (Materialise NV, Leuven, Belgium), according to a previous method [14] . Briefly, a mask was constructed to define the bony boundary in the axial, sagittal and coronary planes, and the tool of region growing was used to reconstruct a 3-D model. Thus, the volume of the bony PCF was calculated automatically (Fig. 3).