磁敏感加权成像与TOF-MR血管成像对急性脑梗死中大脑中动脉内血栓检测的对比研究

目的：比较研究磁敏感加权成像与TOF-血管成像(MRA)两种方法对检查急性脑梗死中大脑中动脉主要血管段内急性血管闭塞的诊断准确性。材料与方法61例大脑中动脉供血区急性脑梗死患者均行常规磁共振(MRI)和DWl、SWI、TOF-MRA检查。对SWI检测到的磁敏感血管征象(SVS)与MRA检测的大脑中动脉主要血管段不同程度狭窄或闭塞频率通过McNemar检验进行比较。结果61例脑梗死病变在DW I图像上均显示高信号，47例患者的患侧大脑深髓静脉较对侧明显扩张。59例患者在SWI上明确清晰显示SVS，其中有56例患者的SVS与MRA显示的闭塞或狭窄位置相匹配。两种技术在检测M1段内血栓性闭塞的灵敏度没有明显差异(SWI：98.1%；MRA：98.1%)，而在检测M2/M3段血管内血栓的灵敏度存在显著差异(SWI：75.0%；MRA：37.5%；P<0.001)。结论 SWI和MRA均能检测到急性脑梗死中血管内血栓性闭塞或狭窄，其在检测主要血管狭窄或闭塞方面的灵敏性没有差别，但是在检测较小、迂曲动脉段及髓静脉方面SWI更具有优越性。

Comparison of susceptibility weighted imaging and TOF-MR angiography for the detection of middle cerebral artery thrombi in acute ischemic stroke

Objectives:The aim of this study was to compare the diagnostic accuracy of both methods of susceptibility weighted imaging (SWI) and time-of-flight MR angiography (TOF-MRA) in determining middle cerebral artery occlusion in patients with acute ischemic stroke. Materials and Methods:Sixty-one patients who presented with clinical symptoms for acute ischemic stroke in the territory of the middle (M1, M2/M3) cerebral artery (MCA) were performed with conventional MRI, DWI, SWI and TOF-MRA. The frequency of hypointense susceptibility vessel signs (SVS) on SWI and vessel occlusion or stenosis on TOF-MRA were compared using the McNemar test. Results:All of the 61 patients displayed hyperintention on DWI in the infarction area. Forty-seven patients showed larger deep medullary vein than the contralateral. Fifty-nine patients displayed a clearly deifnable SVS on SWI. In 56 patients the SVS was associated with occlusion or stenosis on TOF-MRA. Sensitivity for detection of thrombi within M1 did not show any signiifcant difference between both techniques (98.2%for both SWI and TOF-MRA) while the sensitivity for detection of thrombi within M2/M3 was significantly different (75.0% for SWI versus 37.5% for TOF-angiography, P<0.05). Conclusions:SWI and TOF-MRA provide similar sensitivity for acute embolic occlusion in stroke while SWI is superior for the detection of embolic occlusion in small, tortuous arterial vessel segments and deep medullary vein.