A comparative study of the effects of multi-slice spiral CT (MSCT) automatic bone removal and subtraction technique on the quality of head angiography

HU Xin; LIU Qian; DAI Guidong; LAN Yongshu

Abstract：Objective To investigate the effects of different post-processing methods on image quality.Methods The imaging results of 88 patients underwent brain digital subtraction CT angiography (DSCTA) examination were processed and analyzed by the subtraction technique and automatic bone removal procedure.VR images obtained from above two methods were scored by two physicians, scoring results of the qualified rate and excellent rate were evaluated using a 2 test.Vessel diameters of the left internal carotid artery cavernous segment and petrous segment were measured utilizing vessel analysis.Paired t test was used to examine the obtained blood vessel diameters.Results There was no significant difference regarding qualified rates between subtraction technique and automatic bone removal procedure (P>0.05).The excellent rate of subtraction technique was higher than that of automatic bone removal procedure, with statistically difference (P<0.05).Vessel analysis results revealed that the subtraction technique measured vessel diameters of the left internal carotid cavernous segment and petrous segment were (3.527±1.027) and (3.980±1.119), respectively;further, diameters of the left internal carotid cavernous segment and petrous segment were (3.901±0.848) and (4.308±0.731) determined by automatic bone removal procedure, respectively.The vessel diameters of the left internal carotid cavernous segment and petrous segment were smaller by subtraction technique than by automatic bone removal procedure, showing statistical differences (t =-4.054, P<0.05;t=-3.260, P=0.002;respectively).Conclusion Both the subtraction technique and automatic bone removal procedure had their own advantages and should be selected according to clinical needs and patient's condition in the clinical application.