Combination Of FMRI And DTI In The Assessment Of Cortical Visual Impairment In The Children With Periventricular Leukomalacia

IntroductionPeriventricular leukomalacia is one of the most important factors that cause cerebral palsy.Cerebral visual injury would bad influence children's intellectual development and cognitive level improvement and is one of common complications of periventricular leukomalacia.Early evaluation of visual function and visual plasticity would provide an important guiding for treatment programmers.Blood-oxygen-level dependent Functional magnetic resonance imaging(BOLD-fMRI) can reflect regional blood stream and metabolism alteration relating with neuron release level and detect different encephalic region' activation and related physiological change under different stimulus condition.Diffusion tensor imaging(DTI) can clearly draw the line feed of white matter fiber bundles.In this study,fMRI and DTI were used in the assessment of cortical visual impairment in children with perivent ricular leukomalacia(PVL).PurposeIn this study,fMRI and DTI were used in the assessment of cortical visual impairment in children with perivent ricular leukomalacia(PVL).To investigate fMRI and DTI value in cortical visual impairment in hypoxic ischemic encephalopathy (HIE).Materials and MethodsTwenty-four children with PVL were enrolled.Meanwhile,24 age-matched normal controls were recruited for comparison,fMRI scan was performed using a 3.0T MR scanner.Data analysis was performed by Statistical Parametric Mapping software (SPM2).Activated voxels were identified in both groups,t test was used for statistical analysis.DTI was performed by MedINRIA software and DTI color maps were created from fractional anisotropy(FA) values and the three vector elements,FA values on diffusion tensor color maps were compared between the patients and the controls.All the FA values of these WM fibers were analyzed by paired t test.The correlations were calculated between FA values and activated voxels of visual cortex for PVL children using SPSS 10.0.ResultsIn all 24 normal children,the maximum response of blood oxygen level-dependent (BOLD) signal was located in the primary visuaI cortex(PVC).However,some of the 24 cases of PVL had deviated activation.The active voxels of patients in visual cortex were less than that of controls(P＜0.001).All 24 cases of PVL showed a significant mean FA reduction in PTR and ICPL in comparison to the ipsilateral regions of healthy controls(P＜0.01;P＜0.05).The significantly positive correlations were shown between FA values and activated voxels of visual cortex for PVL children(P＜0.05).ConclutionfMRI and DTI play an important role in the assessment of cortical visual impairment in children with PVL.The relationship between activation in visual cortex and diffusion of optic radiation was manifested by quantitive index.