Diagnostic Value Of Amide Proton Transfer Magnetic Resonance Imaging In Neonatal Hypoxic-ischemic Encephalopathy

Part Ⅰ:Imaging of amide proton transfer in a model of hypoxic ischemic encephalopathy in newborn pigs under different time windowsOBJECTIVE:Because APT imaging is highly sensitive to protein concentration and intracellular pH.it is widely used in the central nervous system,including brain tumors and strokes.The aim of this study was to use APT imaging techniques to measure the APT values of basal ganglia in different time windows of neonatal porcine hypoxic ischemic encephalopathy model to explore the development of neonatal hypoxic ischemic brain damage.MATERIALS AND METHODS:Ten healthy newborn Tibetan mini-pigs were initially selected(3-7 days postpartum,1-1.5 kg body weight).Due to the death of the experimental process and the failure of the model establishment,2 animals were excluded and the remaining 8 newborns were born.Tibetan miniature pigs were randomly assigned to the control group(n=4)and the animal model group(n=4).APT imaging of 8 newborn Tibetan miniature pigs was performed using the Philips 3.0T Achieva magnetic resonance imaging system.Four HIE model pigs were in different time windows(0-2h,2-6h,6-12h,12-24h,and 24-48h)Scanning separately.APT image data was processed using in-house development software for interactive data speech and APT values were obtained for all newborn pig basal ganglia.ANOVA analysis was used to compare the statistical differences between the control group and the HIE model group at different time points.RESULTS:There was a statistically significant difference in APT between 0-2h,2-6h,6-12h and 24-48h after modeling in the control group and the HIE model group(P<0.05).-24h between groups(P>0.05).APT values decreased immediately within 0-2 hours after hypoxic-ischemic injury and remained low.Subsequently,the APT value gradually increased and finally exceeded the control group after 24-48 hours.CONCLUSION:Neonatal perinatal hypoxia-ischemia can cause changes in the pH of the brain.APT imaging technology can assess brain damage through changes in protein concentration and pH in the internal environment,in order to understand the neonatal hypoxic-ischemia.Sexual brain injury provides new ideas.Part Ⅱ:Study on repeatability and reliability of amide proton transfer imaging examination for normal full-term neonatal cerebrumObjective:To investigate the reproducibility and reliability of magnetic resonance amide proton transfer imaging in normal full-term neonatal cerebrum.MATERIALS AND METHODS:Using the Philips 3.0T Achieva magnetic resonance imaging system,21 healthy full-term neonates(including 13 males and 8 females,gestational age 37-41 weeks,mean birth weight 2.93±0.57 kg,age of examination)4.35±2.14 days.Two amide proton transfer imaging was performed.Image processing was performed using an internal development software for interactive data speech,and APT values of bilateral basal ganglia,deep white matter of the frontal lobe,cerebellum,and brainstem were measured.The intra-group correlation coefficient and Pearson correlation analysis were used to evaluate the consistency of the two measurements.The paired t-test was used to compare the differences between the two measurements.One-way ANOVA was used to compare the APT values of the two scans with different interestRESULTS:There were no statistically significant differences in APT values between the two regions of interest in the different regions of the brain(P>0.05).The intra-group correlation coefficients of’the neonatal brain basal ganglia,frontal white matter,cerebellum and brainstem were 0.886,0.800,0.818.and 0.910,respectively.Pearson correlation analysis also showed good repeatability of the two measurements.CONCLUSION:Magnetic resonance amide proton transfer imaging has good reproducibility and reliability in neonatal brain examination,and can be further used in the study of neonatal encephalopathy.Part Ⅲ:Early detection of neonatal mild hypoxic ischemic encephalopathy by amide proton transfer magnetic resonance imagingOBJECTIVE:This study was designed to investigate the value of amide proton transfer imaging in the evaluation of neonatal mild hy-poxic ischemic encephalopathy.MATERIALS AND METHODS:30 cases of mild HIE full-term neonates(16 males,14 females;average postpartum 4.2 days,age 2-7 days),12 normal newborns(6 males and 6 females;average 3.3 days after birth),age range 2-5 days)routine MR and APT imaging.APT measurements were performed in multiple brain regions of interest,including bilateral caudate nucleus,bilateral globus pallidus/shell nucleus,bilateral thalamus,bilateral semi-ovoid centers,and brainstem.The independent sample t test was used to compare the statistical difference between the AHT values of mild HIE and normal newborns in different interests,and to analyze the correlation between APT values in different interests and neonatal gestational age.RESULTS:Of the 30 mild HIE neonates,10%(3/30)of HIE patients had normal MRI findings.The mean MRI score in the mild HIE group was 5.67 ± 3.76.Compared with the control group,the APT values of the bilateral caudate nucleus,bilateral thalamus,bilateral semi-oval center,and left globus pallidus/hard nucleus were significantly different in the HIE group(p<0.05).There were no significant differences in APT values between the two groups in the right globus pallidus/nucleus(p=0.051)and brainstem(p=0.073).There was a linear positive correlation between APT values in the bilateral caudate nucleus,bilateral white/nuclear nucleus,bilateral thalamus and brainstem in the control group and gestational age(p<0.05),but no significant correlation in the bilateral semi-oval center.(Right:Pearson’s r = 0.554,p = 0.062;left:Pearson’s r = 0.561,p = 0.058).There was no significant correlation between APT values and gestational age in the regions of interest in the brain of the mild HIE group.CONCLUSION:APT imaging is a feasible and practical technique for the diagnosis of neonatal hypoxic ischemic encephalopathy.