外流角辅助技术在MRA诊断脑侧壁动脉瘤中的应用

Application of outflow angle-assisted approach in diagnosing cerebral sidewall aneurysms with MRA

目的探讨外流角辅助技术对脑侧壁动脉瘤诊断和鉴别诊断的价值。方法采用MRA外流角技术与DSA分别检测438例疑似脑侧壁动脉瘤及其它脑血管疾病患者。外流角≥90°考虑为脑侧壁动脉瘤,从患者、动脉瘤数及动脉瘤大小层次评价外流角技术诊断脑侧壁动脉瘤的准确度、灵敏度及特异度。结果 DSA显示267例301枚脑侧壁动脉瘤,171例未发现脑侧壁动脉瘤,其中有52例55枚动脉圆锥;MRA外流角技术显示267例300枚脑侧壁动脉瘤(1枚漏检),其中238例271枚动脉瘤外流角≥90°(90.3%真阳性),29例29枚外流角<90°(9.7%假阴性)。基于患者、动脉瘤数、动脉瘤大小的外流角诊断均获得较高准确度、灵敏度及特异度。51例54枚圆锥(98.2%)外流角均<90°,1例1枚≥90°(假阳性)。结论 MRA检查中采用外流角辅助技术诊断脑侧壁动脉瘤具有较高的准确度及鉴别动脉圆锥能力,可初步替代DSA用于脑侧壁动脉瘤诊断和鉴别诊断。

Objective To assess the value of outflow angle-assisted（OA-assisted） approach in diagnosing and differentiating sidewall cerebral aneurysms（SCAs） with magnetic resonance angiography（MRA）. Methods A total of 438 patients with suspected SCAs and other cerebrovascular diseases were separately evaluated by OA-assisted approach MRA and digital subtraction angiography（DSA）. An OA of ≥90° was considered to represent SCA. The diagnostic accuracy, sensitivity, and specificity of SCAs with OAassisted approach were evaluated with the number of aneurysms and the size of aneurysms. Results DSA revealed 301 SCAs in 267 patients, and no SCAs was detected in the remaining 171 patients, among them a total of 55 infundibulae were observed in 52 patients. OA-assisted approach MRA revealed 300 SCAs in 267 patients, among which 271 aneurysms in 238 patients had an OA of ≥90°（true positive of 90.3%） and 29 aneurysms in 29 patients had an OA of 90°（false negative of 9.7%）. Based on the patient, the number of aneurysms and the size of aneurysms, OA-assisted approach MRA had higher accuracy, sensitivity and specificity in diagnosing SCAs. The OA of all 54 infundibulae observed in 51 patients was 90°（98.2%）, and only one infundibula in one patient was ≥90°（false positive）. Conclusion MRA with OA-assisted approach has higher accuracy in diagnosing SCAs and in differentiating SCAs with infundibula, therefore, it can substitute DSA for the diagnosis and differentiation of SCAs.