The Application Value Of Diffusion Tensor Imaging In Neonatal Hypoxic-ischemic Encephalopathy

Background: Magnetic resonance(MR)is an important examination for neonatal hypoxic-ischemic encephalopathy(HIE),but in the early stages,conventional MR scans often appear normal.If the diagnosis is delayed,it may lead to undesirable consequences.However,even after active treatment,some children still develop motor disorders and neurological dysfunction later in life.The imaging principle of diffusion tensor imaging(DTI)is based on the diffusion of water molecules,which can detect the different physiological state water molecular diffusion and reflect the change of microscopic structures.In theory,DTI is better than MR scanning for HIE early and small lesions.The detection of HIE is more sensitive,and quantitative diagnosis can be achieved through quantitative indicators.The Neonatal Behavioral Neurological Assessment(NBNA)can assess the prognosis of children with HIE.The value of DTI in HIE diagnosis needs to be verified.Whether the quantitative indicators of DTI are correlated with NBNA score,that is,whether the measured value of DTI is related to the prognosis of children with HIE needs to be further explored.Objective: The brain DTI scan of HIE neonates were performed to investigate the diagnostic value of DTI in neonates with hypoxic-ischemic encephalopathy(HIE)and its predictive value in prognosis.Methods: A total of 62 full-term neonates diagnosed as HIE were divided into three groups of mild,moderate and severe,and 20 full-term normal neonates were selected as control group.All subjects underwent conventional MR scan(T1WI、T2WI、T2FLAIR),diffusion weighted imaging(DWI)and DTI scans by Philips Ingenia 3.0T MR scanner.The bilateral deep frontal lobe white matter,deep occipital lobe white matter,anterior capsule limb,interior capsule limb,caudate nucleus,lenticular nucleus,dorsal thalamus,splenium corpus callosum were selected as region of interest(ROI).After scanning,the DTI image was post-processed,the ROIs were standardized and accurately delineated on the basis of it.Neonates with HIE also need a behavioral neurological assessment(NBNA).FA values were calculated in each ROI and analyzed among groups.Whether the FA value was different between the HIE group and the control group,and between different clinical grades were explored.The correlation between FA values and clinical grades,NBNA score were analyzed.The ROI with the most diagnostic and predictive value was identified.Results: Compared with the control group,FA value of each ROI(except the lenticular nucleus)of HIE group was significantly different(P<0.05).The FA values of HIE neonates with different clinical grades were different.The FA value of each ROI(except the lenticular nucleus)was correlated with the NABA score(P<0.05).FA values of the deep occipital lobe white matter,anterior capsule limb,interior capsule limb,the dorsal thalamus,splenium corpus callosum were correlated with the clinical grades(P<0.05).Among all ROIs,the diagnostic value and predictive value of interior capsule limb were the highest(P<0.05).Conclusion:1.DTI can early,accurately and quantitatively assess HIE brain damage,evaluate myelination and damage,and is of great value in the auxiliary diagnosis of HIE.2.The FA value is different among HIE newborns with different clinical grading,and the FA value is correlated with the clinical grade,indicating that the FA value can reflect the severity of the disease.3.The FA value is correlated with the NBNA score,indicating that the FA value can predict the prognosis of children with HIE to a certain extent,and guide clinicians to implement intervention as soon as possible to avoid and reduce the impact of adverse prognosis as much as possible.