The Study Of Diffusion Tensor Imaging In Hypoxic-ischemic Encephalopathy

Objective To study the value of diffusion tensor imaging (DTI) in early diagnosis of hypoxie--ischemic. Quantitative determination of ADC values and FA value by diffusion tensor imaging (DTI),1.To evaluate the utility of using apparent diffusion cofficient (ADC) and fractional anisotropy (FA) for detection of brain injury caused by hypoxie-isehemic encephalopathy (HIE) in term neonates;2.To evaluate the follow up value of DTI on full term HIE and the effect of HIE on myelination.Materials and Methods1.Diffusion Tensor MR images were performed in26infants who had been clinically diagnosed as HIE before, including11mild cases,9moderate cases,6severe cases. ADC values and FA value were calculated in deep frontal white matter, corona radiata, posterior limb of internal capsule (PLIC), thalami, lentiform necleus and head of caudate nuclei, and were compared between two groups.2. Follow-up15infants who had been clinically diagnosed as HIE before, including6mild cases,9moderate cases and severe cases. FA values in the frontal white matter, corona radiate, PLIC were analyzed.Results1. FA values of the three groups were significantly different in all regions of intrest ing (ROI):the frontal white matter, corona radiate, PLIC, thalami (P<0.05); the ADC values and FA value in PLIC were paralleled with NBNA score; there is no significant difference of FA value in lentiform necleus and head of caudate nuclei.2. The FA value in frontal white matter, corona radiate and PLIC were increased from early to late, but the range was different; The FA value in mild HIE group was mroe than moderate HIE group and severe HIE group in frontal white matter,corona radiate and PLIC (P<0.05)Conclusion1. Quantitative diffusion anisotropy imaging can provide an objective measure of hypoxic and improve conspicuity of hypoxic-ischemic injury, especially for the white matter.2. FA value can provide an object measure of hypoxic-ichemic injury on myelination of white matters. Calculation of anisotropy values may prov ide a valuable marker index for the severity of hypoxic-ischemic injury and a predictor of prognosis.