16层螺旋CT头颈部血管减影成像技术初探

Preliminary investigation of 16-slice helical computed tomography subtraction angiography of head

目的:探讨16层螺旋CT血管减影成像技术显示头颈部血管的能力及优势。方法:对20例行头颈部CT灌注的脑梗塞或(和)短暂性脑缺血发作(transient ischemic attack,TIA)患者进行CT血管减影成像检查。常规平扫后,选取基底节区进行静脉团注对比剂CT灌注(CT Perfusion imaging,CTP)扫描;然后根据CT灌注扫描获得动脉内对比剂峰值时间,用以设定平扫后动脉期的延迟时间,进而进行增强前后的同步薄层扫描,将增强前后(动脉期)的图像相减,即可获得动脉血管的原始图像,进行三维重建后显示动脉。结果:20例减影图像均能清晰显示颈内动脉颅内段、海绵窦段及颅内大动脉及其主要分支,其中15例无颅底骨质干扰,动脉显示良好,余5例因患者头部轻微运动,颅底骨质未能完全减去,但动脉尚能显示完整,不影响诊断。结论:16层螺旋CT血管减影成像,图像后处理简易省时,能提供类似MRA和DSA的血管图像,可广泛应用于临床,结合CTP资料,可有效预测颅内缺血性病变的发生。

Objective：To investigate the role and advantages of 16-slice helical computed tomography subtraction angiography in displaying cranial arteries. Methods： Cranial subtraction angiography was performed in 20 patients with ischemic cerbral infarction or transient ischemic attack （TIA） after CT perfusion imaging（CTP） using a 16-slice helical computed tomography. After the plain scan, the CTP was performed with bolus injection of contrast media to obtain the peak time of contrasted artery. And then, the subtracted images were extracted with pre-and-pest-enhenced thin slices which scanned synchronously. The cranial arteries were observed with the techniques of volume rendering （VR） and maximum intensity projection （MIP） from the subtracted images using the software in AW4.3. Resuits：The cranial arteries and their main branches could be displayed well without bony contamination from skull base. In other 5 cases, the arteries were clearly displayed but the skull base could not completely removed due to slightly motion of head, but riot precluding a correct diagnosis. Conclusion： 16-slice helical computed tomography subtraction angiaghaphy, with its availablity and less time of reconstruction, could display cranial arteries similar to magnetic resonance angiography （MRA） and digital subtraction angiography （DSA）. Ttherefore, it is worthy to be widely applied in clinical settings. Together with CTP, it is effective for a better apprehension of ischemic cerebral infarction.