颅内动脉开窗畸形伴脑动脉瘤的MRA诊断价值

Magnetic Resonance Angiography in Diagnosis of Fenestrations Accompanied with Intracranial Aneurysms

目的：应用3D．TOFMRA对颅内动脉开窗畸形伴发脑动脉瘤解剖分型并探讨颅内动脉开窗畸形与脑动脉瘤发生的相关性。方法：2008年6月至2010年10间的4，652例患者纳入研究，年龄在23～73岁，疑似因颅内动脉瘤或其他脑血管疾患行磁共振血管成像检查（3D—TOF—MRA），并对所有图像行容积重建（VR）及最大密度投影（MIP），以明确颅内动脉开窗畸形、脑动脉瘤存在与否，如果存在开窗畸形及脑动脉瘤，则根据颅内动脉开窗畸形与脑动脉瘤的解剖关系，将其分为三种类型：I型，动脉瘤与开窗畸形紧邻但不位于窗内；Ⅱ型，动脉瘤位于开窗畸形窗内；Ⅲ型，动脉瘤与开窗畸形较远，无明确联系。结果：141例存在开窗畸形（13％），其中24例存在脑动脉瘤（17％），24例中，I型例，II型3例；III型14例。结论：VR3D—TOF-MRA可以清晰地显示颅内动脉开窗畸形与脑动脉瘤的解剖细节及毗邻关系，颅内动脉开窗畸形伴有较高的脑动脉瘤发生可能性。

Purpose： The aim of this study was to evaluate the anatomical changes and investigate the prevalence in intracranial aneurysm with fenestrations using magnetic resonance angiography （MRA）. Methods： Between June 2008 and October 2010, 4,652 patients （aged 23 to 73 years） with suspected intracranial aneurysm or other cerebrovascular diseases underwent MRA examination. MRA was performed using a three-dimensional time-of-flight technique （3D-TOF） with volume rendering （VR） and maximum intensity projection （MIP） reconstruction methods. The presence and location of fenestrations and aneurysms was reviewed. When fenestrations were present in combination with aneurysms, we noted the relationship of the locations. The classification of fenestration accompanied by intracranial aneurysm was divided into three types according to their anatomical relationship as follows： type I, aneurysm adjacent to but not on a fenestration; type II, aneurysm located on the fenestration; type III, aneurysm located at a position remote from a fenestration. Results： Among the 4,652 examined patients, 141 patients were identified with fenestrations, and twenty-four of these patients were confirmed with intracranial aneurysms. Seven cases were classified as type I, three as type II, and fourteen as type III. The prevalence of fenestrations accompanied by aneurysms could reach up to 17.0%, with significant statistical difference compared to aneurysms unaccompanied with fenestrations （P=0.0064）. Conclusion： The anatomical relationship between fenestrations and intracranial aneurysms was visualized by MRA with VR, which displayed pathologies with sufficient clarity to enable diagnosis. Furthermore, the results of this study suggest that physicians should be alerted to the occurrence of intracranial aneurysm following the detection of fenestrations by MRA.