Application of magnetic resonance diffusion tensor imaging technology in neonates with hypoxic-ischemic encephalopathy in the subacute stage

Abstract

Objective To discuss the value of magnetic resonance (MR) diffusion tensor imaging (DTI) technology in the diagnosis of the apparent diffusion coefficient (ADC) and the fraction anisotropy (FA) of neonates with hypoxic-ischemic encephalopathy (HIE) in the subacute stage. Methods Ten cases of normal full-term neonates and 34 term neonates diagnosed with HIE in the subacute stage were investigated with conventional MR and DTI.Of the 34 cases, 15 cases were mild HIE, 12 cases were moderate HIE, 7 cases were severe HIE.ADC/FA values in different parts of the brain were analyzed.And the receiver operating characteristic (ROC) curve was used, the sensitivity and specificity of the FA in specific parts were also analyzed. Results (1)On convention MRI: according to the MRI scoring system, score of mild group was(2.6±1.7) points, moderate group was (3.0±1.5) points, severe group was (5.8±1.3) points.There was significant difference between mild group and severe group, moderate and severe group(P 0.05). FA values in posterior limb of internal capsule (PLIC), splenium had statistic difference between the HIE group and the controls.FA values in mild group were (0.317±0.018, 0.339±0.025), moderate group (0.295±0.025, 0.324±0.026) and severe group (0.252±0.039, 0.253±0.036) and control group (0.455±0.047, 0.372±0.032). (3) ROC analysis of the neonates diagnosed with HIE: the area under the ROC curve of FA values in PLIC, Splenium had statistic difference between mild group and moderate group (P<0.05). The area under the ROC curve in each group was 0.744(P=0.032), 0.658 (P=0.164). ROC curve was used to evaluate the diagnostic accuracy of FA values in PLIC between HIE group and control group, when FA value was lower than 0.337, 0.803 was the largest area under the ROC curve, and there was significant difference between them(P<0.01). Conclusions FA values can reflect the brain white matter WM injury of HIE neonates quantitatively, and its diagnostic veracity is better than ADC value and conventional MR during the subacute phase of HIE.The diagnostic veracity of FA values in PLIC is higher than other parts.When the FA value is lower than 0.337, there is good sensitivity and specificity in diagnosis of HIE, so DTI technology can provide accurate and objective basis for clinical treatment with good sensitivity and specificity about the diagnosis of HIE in early stage. Key words: Infant, newborn; Hypoxic-ischemic encephalopathy; Diffusion tensor imaging; Fraction anisotropy