ZTE-MRA与TOF-MRA对脑动脉狭窄诊断价值对比研究

目的探讨零回波时间磁共振血管成像(zero echo time MR angiography,ZTE-MRA)及时间飞跃法磁共振血管成像(time of fight MR angiography,TOF-MRA)的图像质量以及对脑动脉狭窄诊断的价值。材料与方法纳入19例拟诊断为脑动脉狭窄的患者,同时进行ZTE-MRA及TOF-MRA检查,以数字减影血管造影(digital subtraction angiography,DSA)作为金标准,评估两种MRA成像技术诊断脑动脉狭窄的准确度、敏感度、特异度。结果ZTE-MRA和TOF-MRA的优良图像占比和信噪比(signal-to-noise ratio,SNR)平均值分别为84%、74%和14.2、19.4,差异均无统计学意义(P=0.583、0.175);诊断脑动脉狭窄ZTE-MRA的敏感度和特异度为100%和98%,TOF-MRA相应为85%和96%,ZTE-MRA的Kappa值为0.898优于TOF-MRA;ZTE-MRA诊断1~2级动脉狭窄和3~4级动脉狭窄准确度分别为57%和81%。TOF-MRA相应为46%和31%。诊断1~2级动脉狭窄差异无统计学意义(P=0.427),3~4级狭窄差异具有统计学意义(P=0.017)。结论ZTE-MRA和TOF-MRA的图像质量无明显差异,两者对于1~2级脑动脉狭窄诊断价值无差别,对于3~4级脑动脉狭窄ZTE-MRA较TOF-MRA更为准确。

Compared study of the cerebral artery stenosis assessed by ZTE-MRA and TOF-MRA

Objective:To compare the image quality and the diagnostic value of zero-echo-time MR angiography(ZTE-MRA)and time-of-flight MR angiography(TOF-MRA)in the evaluation of cerebral artery stenosis.Materials and Methods:Nineteen cases of cerebral artery stenosis were examined by ZTE-MRA and TOF-MRA at the same time.DSA examination was conducted within one week of MRA examination,to evaluate the accuracy,reliability and specificity of ZTE MRA and TOF-MRA.Results:Among the images obtained by ZTE-MRA and TOF-MRA,the proportion of the images with good score was 84%and 74%.There was no significant difference in the image quality score between the two methods(P>0.05).The average SNR of ZTE-MRA and TOF-MRA were 14.2 and 19.4,respectively.The rank sum test of the two groups of independent samples showed no statistical difference(P>0.05).Based on the diagnosis of cerebral artery stenosis,the sensitivity and specificity of ZTE-MRA were 100%and 98%.The sensitivity and specificity of TOF-MRA in the diagnosis of cerebral arterial stenosis were 85%and 96%,respectively.Compared the consistency of TOF-MRA and DSA,the Kappa value was 0.776,indicating a good consistency between the two.The accuracy rate of grade 1—2 and grade 3—4 arterial stenosis diagnosed by ZTE-MRA was 57%and 81%.Among the TOF-MRA,the accuracy rate of grade 1—2 and grade 3—4 arterial stenosis was 46%and 31%.There was no statistical difference between the two methods in the diagnosis of grade 1—2 arterial stenosis(P>0.05),and there was statistical difference between the two methods in the diagnosis of grade 3—4 arterial stenosis(P<0.05).Conclusions:ZTE-MRA had comparative image quality with TOF-MRA.There was no significant difference between the two methods in the diagnosis of grade 1—2 cerebral arterial stenosis.ZTE-MRA had high value in the diagnosis of grade 3—4 cerebral artery stenosis,accuracy is higher than TOF-MRA.