颅脑64排螺旋CTA与高场强MRA效果对比及影响因素研究

目的 探讨64排螺旋CT颅脑计算机断层血管成像（CTA）和高场强磁共振成像血管（MRA）的效果及影响图像质量的因素.方法 对1 128例脑CTA患者中的138例和1 558例脑MRA患者中的208例1周内行数字减影血管造影（DSA）检查.CTA与MRA图像分为5级,得分1～5分.颅内动脉瘤按瘤体长径分为：小型（＜5 mm）,中型（5～10 mm）,大型（10～25 mm）,巨大型（＞25 mm）;动脉狭窄按直径分：轻度（＜50%）,中度（50%～74%）,严重（75%～99%）,闭塞（100%）.结果 以DSA为标准,CTA、MRA评估小型、中型、大型、巨大型动脉瘤的灵敏度分别为：（72%、60.9%）,（83.7%、78.3%）,（92.6%、87.5%）,（100%、100%）;评估动脉狭窄轻度、中度、严重、闭塞的灵敏度分别为（50%、44.8%）,（80%、78.9%）,（88.9%、84.6%）,（100%、100%）.影响CTA的因素有成像技术、延迟时间、旋转时间/螺距、造影剂单位剂量与注射速度、血管钙化、重建技术等;影响MRA的因素有饱和带、磁化传递、TR/TE/FA、激励次数/采集矩阵、成像技术、动脉钙化等.结论 颅脑CTA检出动脉瘤和动脉狭窄的灵敏度高于MRA而低于DSA.CTA、MRA能满足临床检出动脉瘤和血管狭窄的要求.

Study on the effect compare and influence factors of brain artery imaging with 64 slice spiral CT and high field MRA

Objective To study the effect of brain artery imaging with 64-slice spiral CT and high field MR and influence factors of the image quality.Methods 138 cases of 1128 patients with brain CTA and 208 cases of 1558 patients with brain MRA were examined with brain DSA within a week.The image qualities of CTA and MRA were divided into five degree,scoring 1 to 5.Intracranial aneurysms were divided into four degree according to the tumor length:small(＜5 mm),medium(5～10 mm),large(10～25 mm),giant(＞ 25 mm).Artery stenosis was divided into four degrees according to the diameters:mild (＜50%),moderate(50%～74%),serious (75%～99%) and occlusion (100%).Results Using DSA as comparison standard,the sensitivities of CTA/MRA in small,medium,large and giant aneurysms were (72%,60.9%),(83.7%,78.3%),(92.6%,87.5%),( 100%,100% ),respectively.The sensitivity of artery stenosis in mild,moderate,severe,occlusion were (50%,44.8%),(80%,78.9% ),(88.9%,84.6%),(100%,100%),respectively.The influence factors of CTA image quality include imaging technique,the delay time,rotation time/pitch,the unit dose of contrast medium and injection speed,vascular calcification,reconstruction,and so on.The influence factors of MRA image quality include unsaturated zone settings,magnetization transfer,TR/TE/FA,NEX/Matrix,imaging technology,arterial calcification,and so on.Conclusion The sensitivity of brain CTA to detect aneurysms and arterial stenosis is higher than that of MRA,but lower than DSA.CTA and MRA,however it can meet the clinical requirements of vascular stenosis and aneurysms detection.