Apparent diffusion coefficient in normal fetal brain: a prenatal study / 中华放射学杂志

ABSTRACT

Objective To investigate the feasibility of ADC values in the evaluation of normal fetal brain development by measuring ADC values changes in specific regions with advancing gestational age.Methods Forty fetuses(gestational age24 to 41 weeks) with normal brain underwent DWI(b value were 0 and 600 s/mm2).ADC values of the frontal white matter(WM),occipital WM,thalamus,basal ganglia,and cerebellum were measured by post-processing software.The differences among different regions' ADC values were calculated by repeated measurements of ANOVA,and simple linear regression was used to evaluate the relationship between ADC values and gestational age.Results The mean ADC valuesof 40 fetuses were(1 800±214) ×10-6mm2/s in frontal WM,(1 400±100) ×10-6mm2/s in basal ganglia,(1 300±126) ×10-6mm2/s in thalamus,(1 700±133) ×10-6mm2/s in occipital WM and(1 400± 155) × 10-6mm2/s in cerebellum,respectively.There was significant difference in the ADC values among the five regions(F=80.813,P＜0.01).In pair-wise comparison,ADC values of basal ganglia,thalamus and cerebellum had no significant difference; however,others had significant difference between each other.With the increasing gestational age,ADC values of basal ganglia,thalamus,occipital WM and cerebellum decreased,and had significant negative correlations with gestational age(Pearson correlation coefficient were-0.568,-0.716,-0.830 and-0.700,respectively,all P＜0.01).In terms of ADC value,occipital WM declined fastest with gestational age,followed by cerebellum and thalamus,and the slowest was basal ganglia.Frontal ADC values showed no correlation with gestational age(P＞0.05).Conclusions Specific regions of fetal brain have specific ADC values,and ADC values of the region undergo regular change with advancing gestational age.ADC value is a specific quantitative parameter that could help to evaluate normal brain development and early diagnosis of fetal brain lesions.