轻度认知功能障碍的脑白质扩散峰度成像研究

Diffusion kurtosis imaging of cerebral white matter in patients with mild cognitive impairment

目的应用磁共振扩散峰度成像(diffusion kurtosis imaging,DKI)技术观察轻度认知功能障碍患者脑白质微细结构的改变。方法轻度认知功能障碍患者20例为观察组,体检健康者20例为对照组,2组均行常规MRI平扫及DKI扫描,测量双侧额叶、顶叶、枕叶、颞叶、扣带回后部及胼胝体压部的各向异性分数(fractional anisotrophy,FA)、平均弥散率(mean diffusivity,MD)、平均扩散峰度(mean kurtosis,MK),并进行比较。结果观察组左侧额叶、左侧顶叶、左侧枕叶、右侧枕叶、左侧颞叶、右侧颞叶、左侧后扣带回、右侧后扣带回FA值(0.372±0.047)、(0.359±0.040)、(0.359±0.040)、(0.367±0.038)、(0.332±0.044)、(0.342±0.046)、(0.379±0.039)、(0.375±0.028)mm2/s)低于对照组((0.401±0.025)、(0.399±0.036)、(0.391±0.038)、(0.395±0.040)、(0.384±0.033)、(0.382±0.036)、(0.422±0.032)、(0.410±0.040)mm2/s)(P<0.05),左侧额叶、右侧顶叶、左侧枕叶、右侧枕叶、左侧颞叶、左侧后扣带回MD值((0.979±0.113)、(1.018±0.123)、(0.991±0.101)、(0.994±0.061)、(1.030±0.083)、(0.991±0.071)mm2/s)高于对照组((0.888±0.042)、(0.936±0.061)、(0.913±0.063)、(0.908±0.073)、(0.962±0.068)、(0.936±0.051)mm2/s)(P<0.05),左侧颞叶、右侧颞叶、左侧后扣带回MK值((0.659±0.100)、(0.716±0.093)、(0.885±0.125)mm2/s)低于对照组((0.838±0.095)、(0.847±0.073)、(0.964±0.056)mm2/s)(P<0.05)。结论轻度认知功能障碍患者脑白质损害具有一定的选择性,DKI技术可为其诊断提供有价值的影像依据。

Objective To explore the changes of cerebral white matter in patients with mild cognitive impairment by diffusion kurtosis imaging（DKI）technique.Methods Twenty patients with mild cognitive impairment（observation group）and 20 healthy volunteers（control group）received conventional MRI and DKI respectively to measure and compare the values of fractional anisotrophy（FA）,mean diffusivity（MD）and mean kurtosis（MK）of bilateral frontal lobe,parietal lobe,occipital lobe,temporal lobe,posterior cingulated cortex and splenium of corpus callosum.Results The values of FA of left frontal lobe,left parietal lobe,left and right occipital lobes,left and right temporal lobes,and left and right posterior cingulate were lower in observation group（（0.372±0.047）,（0.359±0.040）,（0.359±0.040）,（0.367±0.038）,（0.332±0.044）,（0.342±0.046）,（0.379±0.039）,（0.375±0.028）mm2/s）than those in control group（（0.401±0.025）,（0.399±0.036）,（0.391±0.038）,（0.395±0.040）,（0.384±0.033）,（0.382±0.036）,（0.422±0.032）,（0.410±0.040）mm2/s）（P〈0.05）.The values of MD of left frontal lobe,right parietal lobe left and right occipital lobes,left temporal lobe and left posterior cingulate were higher in observation group（（0.979±0.113）,（1.018±0.123）,（0.991±0.101）,（0.994±0.061）,（1.030±0.083）,（0.991±0.071）mm2/s）than those in control group（（0.888±0.042）,（0.936±0.061）,（0.913±0.063）,（0.908±0.073）,（0.926±0.068）、（0.936±0.051）mm2/s）（P〈0.05）.The values of MK of left and right temporal lobes,and left posterior cingulate were lower in observation group（（0.659±0.100）,（0.716±0.093）,（0.885±0.125）mm2/s）than those in control group（（0.838±0.095）,（0.847±0.073）,（0.964±0.056）mm2/s）（P〈0.05）.Conclusion Cerebral white matter damage in patients with mild cognitive impairment has certain selectivity.DKI technique can provide valuable imaging information for the diagnosis.