Multi-slice spiral CT evaluation of the styloid process and diagnosis of styloid process syndrome

LIU Kai; QIN Geng-geng; LONG Jian-sheng; ZENG Hui; SHI Chang-bing; DAI Zheng; CHEN Wei-guo

Abstract：Objective To measure styloid shape, length and azimuth of healthy individuals by three-dimension-al post-hoc processing technology of the multi-slice spiral CT (MSCT), and evaluate its value in diagnosis of styloid process syndrome ( SPS) .Methods Volume reproduction ( VR) and multi-planar reconstruction ( MPR) technology of 64-slice spiral CT were used to evaluate styloid process of 146 healthy individuals and 46 SPS patients for morphology, length and azimuth.Results The control group was divided into three groups by ages,<20 years old, 20 to 40 years old and above 40 years old.Average length of styloid process in the three groups was (21.27 ±17.44) mm, (32.00 ±8.52) mm and (30.33 ±7.77)mm, respectively.Length in the <20 years old group was less than in the other groups (P<0.05).The average inward deflection angle in the above 40 years old group was (71.27 ±4.55) degrees and the average forward angle was (68.49 ±4.66) degree.The average length of styloid in the SPS group was (36.26 ±8.47) mm,the average inward deflection angle (68.12 ±3.65) degrees, and the average forward deflection angle (70.05 ±5.04) de-grees.The length of styloid process in the SPS group was longer than in the control group of above 40 years old and the in-ward deflection angle was less (P<0.05.Forward angle in the two groups were similar (P=0.059).The morphology of styloid process in the three age groups had statistically significant differences ( within-group P<0.05 ) .With growing age, cases of complete type increased.Morphology of styloid process in the control group above 40 ages old and SPS group were similar (=0.133) .Conclusions MSCT is currently the most accurate method to observe and measure the styloid process.It should be measured with MPR technology.In observation of styloid process morphology, VR and MPR should be combined.There is an increasing trend of hyperplasia and ossification of styloid process with growing ages.Elongated styloid process and smaller inward deflection angle are important bases for the diagnosis of SPS.And the increased of ossi-fication is another pathogenic factor for SPS.