稀疏欠采样和迭代重建的3.0T时间飞跃法磁共振血管成像用于颅内未破裂动脉瘤诊断

Application of 3.0T Time-of-flight Magnetic Resonance Angiography with Sparse Undersampling and Iterative Reconstruction in the Diagnosis of Unruptured Intracranial Aneurysms

目的以数字减影血管造影(digital subtraction angiography,DSA)检查为金标准,探讨使用稀疏欠采样和迭代重建的3.0T时间飞跃法磁共振血管成像(time-of-flight with sparse undersampling and iterative reconstruction magnetic resonance angiography,TOFu-MRA)对颅内未破裂动脉瘤的诊断价值。方法前瞻性纳入我院65例疑似动脉瘤患者,进行TOFu-MRA、DSA检查,以DSA为金标准,计算TOFu-MRA诊断动脉瘤的敏感度、特异度、阳性预测值及阴性预测值,并计算2名医生间检查的一致性。在最大信号强度投影和容积再现的重建图像上比较两方法在测量动脉瘤形态学参数间的一致性,包括动脉瘤颈宽度(Dneck)、动脉瘤高度(H)和动脉瘤宽度(Dwidth)。结果 DSA检测出46例确诊患者,共计55个动脉瘤。两名医生利用TOFu-MRA诊断颅内动脉瘤的敏感度、特异度、阳性预测值及阴性预测值分别为基于患者(95.7%,95.7%)、(94.7%,94.7%)、(97.8%,97.8%)及(90.0%,90.0%);基于动脉瘤(96.4%,94.5%)、(94.7%,94.7%)、(98.1%,98.1%)及(90.0%,85.7%),且两者间的诊断一致性较高,kappa值分别为0.93、0.97。Bland-Altman分析发现,在Dneck、H及Dwidth的测量中,超过95%以上的点位于一致限范围内,两种检查方式对动脉瘤形态学参数测量的一致性较好。结论 TOFu-MRA对颅内未破裂动脉瘤具有较好的诊断效能,并在颅内未破裂动脉瘤形态学参数的测量方面与影像金标准之间有较好的一致性,可用作颅内未破裂动脉瘤诊断的首选无创检查方案。

Objective To evaluate the diagnostic value of 3.0 T time-of-flight MR angiography with sparse undersampling and iterative reconstruction(TOFu-MRA)for unruptured intracranial aneurysms(UIAs)on the basis of using digital subtraction angiography(DSA)as the reference standard.Methods A total of 65 patients with suspected UIAs were prospectively enrolled and all patients underwent TOFu-MRA and DSA.Relying on DSA as the reference standard,the sensitivity(SEN),specificity(SPE),positive predictive value(PPV)and negative predictive value(NPV)of using TOFu-MRA in UIA diagnosis were calculated,and the inter-observer agreement between two doctors was determined.Comparison of maximum intensity projection(MIP)and volume rendering(VR)image datasets was made to evaluate the agreement between DSA results and TOFu-MRA in the measurement of UIA morphological parameters,including the neck width(Dneck),height(H),and width(Dwidth)of UIAs.Results The study covered 55 UIAs from 46 patients.The SEN,SPE,PPV and NPV of the two doctors using TOFu-MRA in UIA diagnosis were as follows:(95.7%,95.7%),(94.7%,94.7%),(97.8%,97.8%)and(90.0%,90.0%),respectively for patient-based assessment;(96.4%,94.5%),(94.7%,94.7%),(98.1%,98.1%)and(90.0%,85.7%),respectively,for aneurysm-based assessment.There is a strong interobserver agreement(Kappa=0.93 for patient-based assessment and 0.96 for aneurysm-based assessment)between the two doctors.Moreover,Bland-Altman analysis showed that more than 95%points fell within the limits of agreement(LoA),suggesting strong agreement between the two examination methods for the measurement of UIAs morphological parameters.Conclusion TOFu-MRA showed good diagnostic efficacy for UIAs and the results were in good agreement with those of DSA,the reference standard,for assessing UIA morphological parameter.TOFu-MRA can be used as a first choice for noninvasive diagnostic evaluation of UIAs.