颅内动脉瘤双源CT血管成像与常规和三维DSA结果的比较

Intracranial aneurysms on dual-source CT angiography： comparison with conventional and threedimensional DSA

目的评价双源CT血管成像（DSCTA）在颅内动脉瘤诊断中的价值，并与常规和三维旋转DSA进行对照研究。方法95例自发性蛛网膜下腔出血患者同时进行了DSCTA和DSA检查，用2种方法分别评价动脉瘤的检出率、形态、长轴及动脉瘤瘤颈／短轴（N／D）比值。动脉瘤N／D值比较采用配对t检验，长轴比较采用两相关样本的非参数检验。结果95例患者，DSA在63例患者中检出67个动脉瘤，DSCTA在60例患者中检出64个动脉瘤，32例患者未检测到动脉瘤。DSCTA检测动脉瘤总的诊断敏感性、特异性、阳性预测值及阴性预测值分别为94．2％、100．0％、100．0％、91．4％。DSCTA对长径／〉3mm动脉瘤的检出率与DSA一致，其诊断敏感性、特异性均为100％；长径〈3mm动脉瘤的诊断敏感性和特异性分别为80．0％和100．0％：DSA与DSCTA所测动脉瘤N／D比值分别为0．46±0．14、0．51±0．18，差异无统计学意义（t=3．20，P〉0．05）；长轴中位数分别为4．9、4．8mm，差异也无统计学意义（Z=-1．309，P〉0．05）。结论DSCTA在诊断颅内动脉瘤方面与常规和三维旋转DSA相比有很高的敏感性和特异性，提高了小动脉瘤的检出率，可作为一种无创性的常规筛查方法。

Objective To assess the value of dual-source computed tomography angiography （DSCTA） in detecting intracranial aneurysms by comparing with conventional and three-dimensional DSA. Methods In this study, 95 patients with subarachnoid hemorrhage （SAH） underwent both DSCTA and DSA examination. The detection rate, size, and ratio of the neck to the dome （ N/D ratio） of the aneurysms were evaluated. Statistical analysis was performed using a paired sample Student＇s t-test for the comparisons of the value of N/D and 2 Related Samples test for long axis. Results A total of 67 aneurysms in 63 patients at DSA and 64 aneurysms in 60 patients at DSCTA were detected, respectively; whereas no aneurysm was detected in 32 patients at DSA. Compared with DSA, the overall sensitivity, specificity, positive predictive value, and negative predictive value of DSCTA on a per-aneurysm basis were 94. 2%, 100. 0% ,100.0%, and 91.4%, respectively. For the aneurysms larger than 3 mm, the sensitivity and specificity of DSCTA in detecting intracranial aneurysms were equal to those of DSA ; For aneurysms smaller than 3 mm, however, the sensitivity and specificity of DSCTA is 80. 0% and 100.0%. The N/D ratio for DSA and DSCTA was 0.46 ± 0. 14 and 0. 51 ± 0. 18, respectively, and the median of long axis was 4. 9 mm and 4.8 mm, respectively. There was no significant difference in the N/D ratio （ t = 3.20 ; P 〉 0. 05 ） and the long axis （ Z = - 1. 309 ; P 〉 0. 05） between DSA and DSCT. Conclusions Compared with conventional and three-dimensional digital subtraction angiography, DSCTA has high sensitivity and specificity in the detection of intracranial aneurysms, especially for detection of small aneurysms（ 〈 3 mm）. It can be used as a routine screening technique.