From the Department of Biomedical Imaging and Image-guided Therapy (V.U.S., M.S.Y., G.O.D., M.W., F.P., M.S., F.L., F.S., C.L., D.P., G.K.).
Comprehensive Center for Pediatrics (K.G., J.B., V.G., V.L., S.G., K.K.-S., A.B.), Department of Pediatrics and Adolescent Medicine, Division of Neonatology, Pediatric Intensive Care and Neuropediatrics.
AJNR Am J Neuroradiol. 2022 Apr;43(4):611-619. doi: 10.3174/ajnr.A7472. Epub 2022 Mar 24.
Former preterm born males are at higher risk for neurodevelopmental disabilities compared with female infants born at the same gestational age. This retrospective study investigated sex-related differences in the maturity of early myelinating brain regions in infants born <28 weeks' gestational age using diffusion tensor- and relaxometry-based MR imaging.
Quantitative MR imaging sequence acquisitions were analyzed in a sample of 35 extremely preterm neonates imaged at term-equivalent ages. Quantitative MR imaging metrics (fractional anisotropy; ADC [10mm/s]; and T1-/T2-relaxation times [ms]) of the medulla oblongata, pontine tegmentum, midbrain, and the right/left posterior limbs of the internal capsule were determined on diffusion tensor- and multidynamic, multiecho sequence-based imaging data. ANCOVA and a paired test were used to compare female and male infants and to detect hemispheric developmental asymmetries.
Seventeen female (mean gestational age at birth: 26 + 0 [SD, 1 + 4] weeks+days) and 18 male (mean gestational age at birth: 26 + 1 [SD, 1 + 3] weeks+days) infants were enrolled in this study. Significant differences were observed in the T2-relaxation time ( = .014) of the pontine tegmentum, T1-relaxation time ( = .011)/T2-relaxation time ( = .024) of the midbrain, and T1-relaxation time ( = .032) of the left posterior limb of the internal capsule. In both sexes, fractional anisotropy ( [♀] < .001/ [♂] < .001) and ADC ( [♀] = .017/ [♂] = .028) differed significantly between the right and left posterior limbs of the internal capsule.
The combined use of various quantitative MR imaging metrics detects sex-related and interhemispheric differences of WM maturity. The brainstem and the left posterior limb of the internal capsule of male preterm neonates are more immature compared with those of female infants at term-equivalent ages. Sex differences in WM maturation need further attention for the personalization of neonatal brain imaging.
与同一胎龄出生的女性婴儿相比，先前早产的男性婴儿患神经发育障碍的风险更高。本回顾性研究使用基于弥散张量和弛豫率的磁共振成像（MR 成像），调查了胎龄小于 28 周的早产儿早期髓鞘化脑区成熟度的性别差异。
对 35 名极早产儿在足月龄时进行的定量 MR 成像序列采集进行了分析。在弥散张量和多动态、多回波序列成像数据上确定了延髓、脑桥被盖部、中脑以及右侧/左侧内囊后肢的定量 MR 成像指标（各向异性分数；ADC[10mm/s]；以及 T1-/T2 弛豫时间[ms]）。采用方差分析和配对 t 检验比较女性和男性婴儿，并检测半球发育不对称性。
本研究纳入了 17 名女性（出生时平均胎龄：26+0[标准差，1+4]周+天）和 18 名男性（出生时平均胎龄：26+1[标准差，1+3]周+天）婴儿。在脑桥被盖部的 T2 弛豫时间（ =.014）、中脑的 T1 弛豫时间（ =.011）/T2 弛豫时间（ =.024）和左侧内囊后肢的 T1 弛豫时间（ =.032）方面，观察到了显著差异。在两性中，内囊后肢的各向异性分数（ [♀] <.001/ [♂] <.001）和 ADC（ [♀] =.017/ [♂] =.028）在右侧和左侧之间存在显著差异。
各种定量 MR 成像指标的联合使用检测到了与性别相关的和半球间的 WM 成熟度差异。与足月龄的女性婴儿相比，男性早产儿的脑桥和内囊后肢更不成熟。WM 成熟度的性别差异需要进一步关注，以实现新生儿脑成像的个体化。
