[Application of apparent diffusion coefficient histogram in moderate to severe neonatal hypoxic-ischemic...

Objective: To investigate the diagnostic value of apparent diffusion coefficient (ADC) histogram in quantifying moderate to severe neonatal hypoxic-ischemic encephalopathy (HIE). Methods: A total of 49 children with moderate to severe HIE admitted to the Children's Hospital Affiliated to Nanjing Medical University from July 2015 to September 2018 were retrospectively analyzed. Cranial magnetic resonance imaging (MRI) data of 31 full-term neonates without neurological symptoms and signs who visited the hospital during the same period were recruited as the control group. ImgJ software was used to delineate the whole brain area at the thalamus/basal ganglia level as the area of interest, and MRIcron software was used to obtain ADC histogram parameters. The differences of ADC histogram parameters between HIE group and control group were compared. The correlation between ADC histogram parameters and neonatal neurobehavioral neurological assessment (NBNA) in HIE group was analyzed. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficiency of each parameter. Results: The mean value, minimum value, maximum value, mode-value, variance, heterogeneity and 10%-90% ADC values of HIE group were all greater than those of the control group(634±65,310±36,1 683±18,711±87,66 928±921,5 907±204,477±50,513±53,542±56,568±59,591±61,625±92,661±97,709±105,811±119),the differences were statistically significant(all P<0.05), while mode-count of HIE group was smaller than that of the control group(272±22 to 395±83), and the difference was statistically significant (t=2.996,P<0.05). All the above parameters with statistical differences were correlated with NBNA score, among which mode-count was negatively correlated with NBNA score(r=-0.369,P<0.05), and the rest were positively correlated(all P<0.05). The area under the ROC curve (AUC) of variance had the highest diagnostic efficiency (0.881), followed by 90% ADC value and ADC maximum value. Conclusion: ADC histogram is helpful for the diagnosis of HIE, objectively and quantitatively reflecting the diffusion information of brain, and assessing the severity of HIE.