Objective To employ spinal virtual surgery system (SVSS) for preoperative planning of thoracolumbar pedicle screw fixation, and to establ ish the measurement method for pedicle screw-related parameters. Methods Eight thoracicand lumbar spine specimens (T11-L3) were selected. First of all, SVSS was used for the preoperative planning of pedicle screw and the parameters of both sides of pedicle were measured in every vertebral segment, including angle of axial view (Aa), angle of sagittal view (As), x-direction entrance (XE), total pedicle length of axial view (TLa), total pedicle length of sagittal view (TLs), pedicle height (PH), pedicle width (PW), and pedicle spongy width (PSW). Then the corresponding parameters of the right and left pedicle screws of the specimens were measured actually. Finally, its accuracy was verified by comparing the data by virtual measurement and actual measurement. Results There was no significant difference in the parameters of virtual measurement (Aa, As, TLa, TLs, XE, PW, PSW, and PH) and actual measurement (Aa, As, TLa, XE, PW, PSW, and PH) between the right and left sides (P gt; 0.05). Except XE of the L3 vertebral segment and PSW of T11 and T12 vertebral segments (P lt; 0.05), the differences in other parameters of other segments were not significant (P gt; 0.05). Conclusion After statistical analysis and comparison, the feasibil ity of preoperative planning of thoracolumbar pedicle screw fixation and the accuracy of the measurement of the SVSS is verified.
目的:研究多层螺旋CT多平面图像重组技术(multiplanar reformation,MPR)对肺部病变定位诊断的价值。方法:398例患者行胸部多层螺旋CT薄层扫描后,采用MPR技术将横断面图像重组,分别获得矢状和冠状位的MPR图像。三位高年资医师分别在横断和矢冠状重组图像上确定病变部位,两位或两位以上均诊断为同一位置者确定为病变部位,纳入统计分析。所有资料用χ2检验。结果:398例中,矢冠状重组图像组无定位诊断错误,横断图像组有22例定位诊断错误。两者间差异无统计学意义(Pgt;005)。结论:多层螺旋CT MPR图像定位准确性较高,对少数横断图像难以定位的病变可加作MPR重组图像。