The Application Of Apparent Diffusion Coefficient In Normal Fetal Brain In Uterus

Objective: The aim of our study is to investigate regular patterns and characteristicsof normal fetal brain’s apparent diffusion coefficient (ADC) values with thegestational age increasing, and to establish normal ranges of fetal brain differentregional apparent diffusion coefficient (ADC) values, which may provide importantreference information on the diagnosis and evaluation of the fetal brain disorders inpreterm infants brain development.METHODS:40singleton nonsedated fetuses (gestational age range:24-41weeks,means±SD:31.35±3.86W) with normal or questionably abnormal results onsonography and normal fetal MR imaging results performed DWI on1.5T MRscanner, with3directories. ADC values in the frontal white matter (WM), occipitalWM, thalamus, basal ganglia, and cerebellum were measured on functool software.The differences among different regional ADC values were calculated by one-wayANOVA, and we used a linear regression to evaluate the regular pattern of ADC withgestational age increasing.RESULTS:40singleton nonsedated fetuses (gestational age range:24-41weeks,means±SD:31.35±3.86W)，mean ADC values were1800±214×10-6mm~2/s in frontalWM,1400±100×10-6mm~2/sin basal ganglia,1300±126×10-6mm~2/s in thalamus,1700±133×10-6mm~2/s in occipital WM and1400±155×10-6mm~2/s in cerebellum.There was a significant difference between frontal WM ADC values and the other4regions’(p<0.01). ADC values of basal ganglia showed significantly different among frontal and occipital WM (p<0.01), but no differences among thalamus andcerebellum (p>0.05). ADC values of thalamus had significant difference amongfrontal WM, occipital WM and cerebellum’s (p<0.01).There was a significantdifference between occipital WM ADC values and the other4regions’(p<0.01). ADCvalues of cerebellum showed significantly different among frontal WM, thalamus andoccipital WM (p<0.01).We found that ADC values of basal ganglia, thalamus,occipital WM and cerebellum decreased with the gestational age increasing. All the4regions’ ADC values has a strong negative correlation with gestational age, andoccipital WM declined fastest with gestational age, then thalamus and cerebellum, theslowest is basal ganglia. Frontal ADC values showed no correlation with gestationalage (p>0.05).CONCLUSION: The regular pattern of fetal brain different regional ADC valueswith gestational age reflects different regions of fetal brain evolution and is able to animportant indicator to evaluate normal fetal brain development. We establishednormal ranges of fetal brain different regional apparent diffusion coefficient (ADC)values to provide important reference information on diagnosis and evaluation of thefetal brain disorders in preterm infants brain development.