PT  - JOURNAL ARTICLE
AU  - Schmidbauer, V.U.
AU  - Dovjak, G.O.
AU  - Yildirim, M.S.
AU  - Mayr-Geisl, G.
AU  - Weber, M.
AU  - Diogo, M.C.
AU  - Gruber, G.M.
AU  - Prayer, F.
AU  - Milos, R.-I.
AU  - Stuempflen, M.
AU  - Ulm, B.
AU  - Binder, J.
AU  - Bettelheim, D.
AU  - Kiss, H.
AU  - Prayer, D.
AU  - Kasprian, G.
TI  - Mapping Human Fetal Brain Maturation In Vivo Using Quantitative MRI
AID  - 10.3174/ajnr.A7286
DP  - 2021 Nov 01
TA  - American Journal of Neuroradiology
PG  - 2086--2093
VI  - 42
IP  - 11
4099  - http://www.ajnr.org/content/42/11/2086.short
4100  - http://www.ajnr.org/content/42/11/2086.full
SO  - Am. J. Neuroradiol.2021 Nov 01; 42
AB  - 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