TY - JOUR T1 - Mapping Human Fetal Brain Maturation In Vivo Using Quantitative MRI JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. DO - 10.3174/ajnr.A7286 AU - V.U. Schmidbauer AU - G.O. Dovjak AU - M.S. Yildirim AU - G. Mayr-Geisl AU - M. Weber AU - M.C. Diogo AU - G.M. Gruber AU - F. Prayer AU - R.-I. Milos AU - M. Stuempflen AU - B. Ulm AU - J. Binder AU - D. Bettelheim AU - H. Kiss AU - D. Prayer AU - G. Kasprian Y1 - 2021/09/23 UR - http://www.ajnr.org/content/early/2021/09/23/ajnr.A7286.abstract N2 - BACKGROUND AND PURPOSE: On the basis of a single multidynamic multiecho sequence acquisition, SyMRI generates a variety of quantitative image data that can characterize tissue-specific properties. The aim of this retrospective study was to evaluate the feasibility of SyMRI for the qualitative and quantitative assessment of fetal brain maturation.MATERIALS AND METHODS: In 52 fetuses, multidynamic multiecho sequence acquisitions were available. SyMRI was used to perform multidynamic multiecho–based postprocessing. Fetal brain maturity was scored qualitatively on the basis of SyMRI-generated MR imaging data. The results were compared with conventionally acquired T1-weighted/T2-weighted contrasts as a standard of reference. Myelin-related changes in T1-/T2-relaxation time/relaxation rate, proton density, and MR imaging signal intensity of the developing fetal brain stem were measured. A Pearson correlation analysis was used to detect correlations between the following: 1) the gestational age at MR imaging and the fetal brain maturity score, and 2) the gestational age at MR imaging and the quantitative measurements.RESULTS: SyMRI provided images of sufficient quality in 12/52 (23.08%) (range, 23 + 6–34 + 0) fetal multidynamic multiecho sequence acquisitions. The fetal brain maturity score positively correlated with gestational age at MR imaging (SyMRI: r = 0.915, P < .001/standard of reference: r = 0.966, P < .001). Myelination-related changes in the T2 relaxation time/T2 relaxation rate of the medulla oblongata significantly correlated with gestational age at MR imaging (T2-relaxation time: r = –0.739, P = .006/T2-relaxation rate: r = 0.790, P = .002).CONCLUSIONS: Fetal motion limits the applicability of multidynamic multiecho–based postprocessing. However, SyMRI-generated image data of sufficient quality enable the qualitative assessment of maturity-related changes of the fetal brain. In addition, quantitative T2 relaxation time/T2 relaxation rate mapping characterizes myelin-related changes of the brain stem prenatally. This approach, if successful, opens novel possibilities for the evaluation of structural and biochemical aspects of fetal brain maturation.GAgestational ageMDMEmultidynamic multiechoPDproton densityR1T1-relaxation rateR2T2-relaxation rateSIsignal intensityT1RT1-relaxation timeT2RT2-relaxation time ER -