CAJ | 학술논문

目的：利用MR扩散张量成像（ DTI）动态观察大鼠急性脑缺血再灌注（ IR）扩散系数的变化。方法18只SD大鼠随机分为两组，假手术组6只、IR组12只，其中IR组随机平均分成3组，于缺血2 h再灌注后24、72、7 d行连续DTI检查，测量缺血区的相对平均扩散系数（rDCavg）和相对部分各向异性（rFA）值，分析脑白质纤维束示踪图。结果假手术组DCavg、FA图未见异常信号，双侧脑白质束对称、连续、密集。 IR组DCavg、FA图上均可见右侧大脑皮层及纹状体出现异常低信号；24 h脑缺血区rDCavg下降，72 h、7 d逐渐上升，至7 d时rDCavg值出现假正常化；24 h rFA值下降，72 h、7 d逐渐降低，7 d达到较低水平；脑白质纤维束示踪图显示病灶区白质束断裂、稀疏、缺失。结论 DTI可以准确反映超急性期、急性期脑缺血区水分子扩散各向异性的改变，脑白质纤维示踪图可以清晰地显示脑缺血区及其远端神经纤维束的走向和完整性，DTI对脑梗死早期诊断、预后评估具有重要的意义。
목적：이용MR확산장량성상（ DTI）동태관찰대서급성뇌결혈재관주（ IR）확산계수적변화。방법18지SD대서수궤분위량조，가수술조6지、IR조12지，기중IR조수궤평균분성3조，우결혈2 h재관주후24、72、7 d행련속DTI검사，측량결혈구적상대평균확산계수（rDCavg）화상대부분각향이성（rFA）치，분석뇌백질섬유속시종도。결과가수술조DCavg、FA도미견이상신호，쌍측뇌백질속대칭、련속、밀집。 IR조DCavg、FA도상균가견우측대뇌피층급문상체출현이상저신호；24 h뇌결혈구rDCavg하강，72 h、7 d축점상승，지7 d시rDCavg치출현가정상화；24 h rFA치하강，72 h、7 d축점강저，7 d체도교저수평；뇌백질섬유속시종도현시병조구백질속단렬、희소、결실。결론 DTI가이준학반영초급성기、급성기뇌결혈구수분자확산각향이성적개변，뇌백질섬유시종도가이청석지현시뇌결혈구급기원단신경섬유속적주향화완정성，DTI대뇌경사조기진단、예후평고구유중요적의의。
Objective To observe dynamicaIIy the changing discipIine of parameters in acute cer-ebraI schemia reperfusion ( IR) rats by diffusion tensor imaging( DTI) .Methods Modified Longa thread emboIism method is used to estabIish the focaI cerebraI ischemia-reperfusion( IR) mod-eI.Eighteen maIe Sprangue DawIey rats were divided randomIy into controI group (n=6),IR group ( n=12) ,DTI was performed in 24 hours,72 hours,7 days respectiveIy after reperfusion, measuring the reIative DCavg( r DCavg) and the reIative FA ( rFA) in cerebraI infarction area, anaIyzing the white matter fiber tracking picture.Results There is no abnormaI Iow-intensity in contrIo group,the white fiber bundIe on doubIe sides were symmetricaI,continuous,dense.Ab-normaI Iow-intensity was found in the right brain cortex and striatum on DCavg map and FA map in IR group,the rDCavg decIined in cerebraI infarction area in 24 hours after reperfusion,in-creased graduaIIy in 72 hours,7 days,rDCavg appear faIse normaIization in 7 days;the rFA de-cIined in cerebraI infarction area in 24 hours after reperfusion,decIined graduaIIy in 72 hours,7 days,rFA reach to Iower IeveI in 7 days;the white matter fiber bundIe of the ischemic area was broken,scattered,deIeted.Conclusion The diffusion anisotropic features in super acute and a-cute ischemia can be accurateIy refIected by DTI ,the direction and integrity of white fiber bun-dIe in ischemic areas and distant areas can be cIearIy showed,DTI has great significance to ear-Iy diagnosis and prognosis assessment of cerebraI infarction.