256层螺旋CT三维血管成像与三维DSA诊断颅内动脉瘤的对比分析

目的对比256层螺旋CT三维血管成像（3D．CTA）与三维数字减影血管造影（3D-DSA）诊断颅内动脉瘤的价值。方法回顾性分析46例就诊时临床表现疑似为蛛网膜下腔出血（SAH）或MR血管成像检查怀疑为颅内动脉瘤的患者，全部行头颈联合3D-CTA及3D-DSA检查，两名影像科医师使用盲法独立判读所有患者的3D-CTA图像，3D．DSA的图像由1名从事血管介入的神经科医师和1名介入影像科医师共同判读确定。以3D-DSA检出动脉瘤的数目为标准，评估3D-CTA的敏感性、特异性以及两名3D-CTA阅片者、3D-CTA与3D-DSA技术之间，在动脉瘤检出数量的一致性；测量动脉瘤瘤体最大径，以3D．DSA图像测量值为标准，比较两名3D-CTA阅片者用3D．CTA容积重建图像测量瘤体最大径的差异以及3D-CTA容积重建与3D-DSA图像在瘤体最大径测量上的差异。结果3D-DSA对46例患者中的37例共检出49个动脉瘤，其余9例未被发现动脉瘤。①3D-CTA在检出动脉瘤数目方面的敏感性为91．8％-93．9％，特异性为77．8-100％。②对〈3mm的动脉瘤，3D-CTA的敏感性均为83．3％，特异性为77．8％-100％。③从动脉瘤的检出率方面，3D-CTA阅片者以及3D．CTA与3D．DSA技术之间一致性均较高（分别为K=0．730，K=0．686-0．777）。④两名医师采用3D-CTA法测量的瘤体最大径与3D-DSA法的测量值，以及两名医师的3D-CTA测量值之间均存在高度相关性，均r值=0．996，均P值〈0．001。结论256层螺旋CT3D-CTA对动脉瘤检出的敏感性和特异性均较高，3D-CTA对动脉瘤的检出率和瘤体最大径测量与3D-DSA一致性较高，可以作为疑似动脉瘤患者的首选筛查方法。但其对瘤体最大径〈3mm的动脉瘤仍有假阴性的表现。在高度怀疑动脉瘤而3D-CTA结果显示为阴性时，仍需进一步行3D-DSA检查。

Comparative analysis of 256-slice CT angiography and 3D digital subtraction angiography in the diagnosis of intracranial aneurysms

Objective To compare the values of 256-slice CT angiography(3D-CTA) and 3D digital subtraction angiography(3D-DSA) in the diagnosis of intracranial aneurysms.Methods Forty-six patients whose clinical manifestations were highly suspected as subarachnoid hemorrhage(SAH) or suspected as aneurysms on magnetic resonance angiography(MRA) were analyzed retrospectively.Both head 3D-CTA and 3D-DSA were performed in all the patients.Two radiologists independently interpreted the 3D-DSA images of all the patients using double blind method,and the 3D-DSA was interpreted and judged by a neurologist and a radiologist.With the number of aneurysms detected by 3D-DSA as the standard,the sensitivity and specificity of 3D-CTA as well as the consistency of the number of aneurysms detected between the two 3D-CTA readers and between 3D-CTA and 3D-DSA techniques were assessed.In the measurement of the maximum diameter of aneurysms,the measured values of 3D-DSA images were used as the standard to compare the differences of the maximum diameter of aneurysms in the 3D-CTA VR images between the two 3D-CTA readers and to compare those between the 3D-CTA VR images and the 3D-DSA images. Results Among the 46 patients,3D-DSA revealed 49 aneurysms in 37 patients and no aneurysm was revealed in the remaining 9 patients.①The sensitivity and specificity of 3D-CTA in detecting the number of intracranial aneurysms were 91.8%-93.9%and 77.8%- 100%respectively.②As for the aneurysms less than 3 mm,the sensitivity were 83.3%and specificity of 3D-CTA were 77.8%- 100%respectively.③From the aspect of the detection rate of aneurysms,the consistency was high between the 3 D-CTA readers and between the techniques of 3D-CTA and 3D-DSA(k =0.730 and k =0.686 -0.777 respectively ).④The maximum diameter of aneurysms detected with CTA and the measured values of DSA,as well as the measured values of CTA between the two doctors had a high correlation(r = 0.996,all P < 0.001). Conclusion Both the sensitivity and specificity of aneurysm detection with 256-slice 3D-CTA are high. The aneurysm detection rate and the maximum diameter measurement of 3 D-CTA are as high as 3D-DSA, which can be used as the screening method for patients with suspected aneurysm,but the aneurysms with maximum diameter < 3 mm may still have false-negative result.When the aneurysms are highly suspected in clinical practice but the results of 3D-CTA suggest negative,3D-DSA examination is still to be needed.