Study Of Diffusion Tensor Imaging In Motor Aphasia After Ischemic Stroke At 3.0 Tesla MRI

Objective To investigate the the changes of white matter of language functional area and its clinical value in motor aphasia after ischemic stroke at 3.0Tesla magnetic resonance diffusion tensor imaging (MR-DTI).Methods MR data of heads were collected in 36 patients with motor aphasia after ischemic stroke and 29 healthy volunteers. Conventional MR scanning and DTI examination of heads were carried out using a 3.0 T superconductive magnetic resonance imaging system. The b values of DTI examination were 0s/mm2 and 800s/mm2 respectively. The conventional MR and DTI appearances were observed and ADC values and FA values were measured for statistically analysis in control and pathological group. Diffusion tensor imaging fiber tracking was used to show the white matter fiber tracts of motor speech area and contralateral mirror area as well as bilateral arcuate fascicle, to observe the normal and abnormal appearances.Results FA values were reduced and ADC values changed little at left 44, 45 areas and infarct areas in motor aphasia patients. Specific as follows: In control group, FA values of 44, 45 areas of left hemisphere and the right counterparts were 0.42±0.10, 0.41±0.08, 0.43±0.10 and 0.38±0.07 respectively; ADC values were (0.75±0.09, 0.77±0.07, 0.77±0.11, 0.79±0.08)×10-3 mm2/s. At the left 44, 45 areas of pathological group, FA values were both 0.37±0.09; ADC values were (0.78±0.17, 0.79±0.15)×10-3mm2/s. At the infarct areas and the contralateral mirror areas of pathological group, FA values were 0.31±0.17, 0.45±0.12; ADC values were (0.78±0.19, 0.83±0.18)×10-3mm2/s. By t test, FA values, ADC values at the bilateral 44 and 45 areas of control group were both no statistically significant (P>0.05). FA values of left 44 and 45 areas between pathological group and control group were both statistically significant (P<0.05); ADC values were both no statistically significant (P>0.05). FA values at infarct area and contralateral mirror area of pathological group were statistically significant (t=-4.267, P=0.000<0.05); ADC values were no statistically significant (t=-0.513, P=0.612>0.05). Fiber tracts of Broca areas and arcuate fascicle from normal people had left hemisphere advantages and individual differences; most patients of Broca aphasia with damage at different degrees while a few had no obvious abnormalities.Conclusion As an effective method in the study of motor aphasia after cerebral infarction in vivo, diffusion tensor imaging, through the analyses after measurement of different diffusion indexes and fiber tracking of white matter fiber tracts, can provide functional anatomy and quantitative basis for pathogenesis, rehabilitation programs and prognosis of motor aphasia after ischemic stroke.