The Application Of Diffusion Tensor Imaging In Preterm Infants With Hypoxic-Ischemic Brain Injury

Part 1 Diagnostic Value of Diffusion Tensor Imaging in Preterm Infants with Hypoxic-Ischemic Brain InjuryObjectiveThis experiment used conventional magnetic resonance imaging sequence and diffusion tensor imaging(DTI)sequence to scan HIBD preterm and full-term infants.The fractional anisotropy(FA)and the apparent diffusion coefficient(ADC)of the brain region of interest(ROI)were measured,and the FA values and the ADC values among different groups and groups were statistically analyzed.The correlation between the posterior limb of the internal capsule of FA value and Apgar score at birth was analyzed.Discuss:(1)The value of DTI in the early diagnosis of hypoxicischemic brain damage in infants;(2)The correlation between the FA value of the posterior limb of the internal capsule and the Apgar score at birth in the HIBD group of premature infants.Materials and methodsWe selected 35 premature infants who were diagnosed as HIBD in our hospital in May 2016 to February 2017,the birth weight was 900 to 1650 g.The admission criteria are based on the criteria previously described by Volpe Joseph J et al.And 10 cases of normal term newborns(prenatal ultrasound indicated that the lateral ventricle or the transparent septum widened and the posterior cranial fossa fluid)were selected..The birth weight was 2645 to 3900 g.The MRI examination(the postnatal MRI only shows the cavum septum pellucidum)was 10~14 days old.All the subjects were scanned by 3.0T SIEMENS magnetic resonance scanner in our hospital.Independent sample t test,single factor analysis of variance(one-way,ANOVA)and least significant difference test(LSD-t)were used to analyze.Correlation between FA value and neonatal Apgar score was calculated by correlation analysis.ResultsThe FA values of posterior limb of internal capsule,corpus callosum,white matter of frontal lobe,occipital lobe and putamen had significant difference between the HIBD group(mild group,moderate group,severe group)and control group(P<0.05),the FA values of parietal white matter,thalamus and brain foot had significant difference between the HIBD group(moderate group,severe group)and control group(P<0.05).In group comparison,the FA values of three groups(HIBD mild group,moderate group and severe group)in each region of interest were analyzed by one-way ANOVA,the difference was statistically significant(P<0.05).Except for the cerebellum in the severe HIBD group,the ADC values in the other HIBD groups were significantly different from those in the control group(P<0.05).In group comparison,the ADC values of three HIBD groups(mild group,moderate group and severe group)in some region of interest(posterior limb of internal capsule,white matter of frontal lobe,white matter of occipital lobe,lenticular nucleus,cerebellum and caudate nucleus)were analyzed by one-way ANOVA,the difference was statistically significant(P<0.05).There was no significant correlation between the FA value of the posterior limb of internal capsule and the Apgar score(1 minutes and 5 minutes)(r=-0.179,P>0.05,r=-0.201,P>0.05).Conclusions(1)Diffusion tensor imaging has higher diagnostic value than conventional MRI for early diagnosis of HIBD in premature infants,and it can detect occult lesions which are difficult to be detected by conventional MRI.(2)There is no significant correlation between the FA value of the posterior limb of the internal capsule and the Apgar score,so it is not reasonable to use the Apgar score to diagnose whether or not the premature infants are suffocating.Prognosis of Preterm Infants with Hypoxic-Ischemic Brain Injury Part 2 The Value of Diffusion Tensor Imaging in Predicting theObjectiveIn this study,subjects were diagnosed in preterm infants with hypoxic-ischemic brain injury(HIBD)in new department of pediatrics in our hospital.After stable postnatal condition,we performed the scanning of diffusion tensor imaging(DTI),and delineated the region of interest(ROI).The children were followed up at 7~8 months of correct age.Follow up was conducted in our hospital department of health.The Bailey scales of infant development(BSID)was used to evaluate the neurobehavioral development score.According to the BSID scores,the patients were divided into good prognosis group and poor prognosis group.The fractional anisotropy(FA)of the brain region of interest(ROI)were measured,and the FA values among different groups were statistically analyzed.The receiver operating characteristic curves(ROC)are drawn to find the best truncation value for each region of interest.To explore: the value of diffusion tensor imaging in the prognosis evaluation of preterm infants with hypoxic-ischemic brain injury.Materials and methodsIn September 2016 to June 2017,we selected 74 premature infants(40 males and 34 females)who were diagnosed as HIBD in new department of pediatrics in our hospital.The gestational age was 26~32 weeks,and the birth weight was 900 g to 1942 g.The admission criteria are based on the criteria previously described by Volpe Joseph J et al.The correct fetal age was 31~38 weeks when the DTI sequence was carried out.When the corrected age of children was 7~8 months,BSID was used to conduct neurobehavioral development score in children's health care department of our hospital.According to the results of the grading,we divided them into two groups with better prognosis and poor prognosis.We compared the difference of the FA values between the two groups,and drew the ROC curve for each ROI to find the best cut-off value.Result(1)The FA value of the posterior capsule of inner capsule,corporis callosi splenium,white matter of frontal lobe,white matter of parietal lobe,white matter of occipital lobe,cerebral ganglia,cerebellum and caudex cerebri in the better prognosis group were higher than those in the poor prognosis group,and the difference was statistically significant(P < 0.05).(2)The area under the curve(AUC)of the FA value of the posterior limb of the inner capsule was the largest,and the diagnostic efficiency was the highest.Conclusions(1)The FA value can basically reflect the development of the prognosis.The higher the FA value,the better the prognosis..(2)The FA value of the posterior limb of internal capsule is the most effective,which can be used as a significant predictor of prognosis.