Department of Radiology, Shandong Provincial Hospital, Shandong University, Jinan, China.
Department of Radiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China.
Eur Radiol. 2023 Jan;33(1):606-614. doi: 10.1007/s00330-022-09042-5. Epub 2022 Aug 31.
To evaluate calcium deposition in the fetal spine in vivo during the second and third trimesters using quantitative susceptibility mapping (QSM).
Fifty-four pregnant women in their second and third trimesters underwent a 2D multi-echo STrategically Acquired Gradient Echo (STAGE) MR imaging protocol at 3T covering the fetal spine. The first echo data was used for QSM processing. A linear regression model was used to assess the correlation between magnetic susceptibility and gestational age (GA). A paired sample t-test was used to compare the consistency of QSM measurements from each sequence.
The magnetic susceptibility of the fetal spine decreased linearly with advancing GA, with a slope of -52.3 parts per billion (ppb)/week and a Pearson correlation coefficient (r) of 0.83 (p < 0.001). In 37 subjects for whom the STAGE local QSM data were available from both flip angles, the average magnetic susceptibility values were -1111 ± 278 ppb and -1081 ± 262 ppb for FA = 8° and FA = 40°, respectively. These means were not statistically different according to a paired sample t-test (p = 0.156).
QSM is a reliable technique for evaluating calcium deposition and bone mineral density of fetal vertebrae. Our results demonstrate an increase in fetal calcium levels as a function of GA. These measures might be able to provide reference values for calcium content in the fetal spine during the second and third trimesters.
• Calcium deposition and mineralization in the fetal spine, evaluated by vertebral magnetic susceptibility, increased with advancing gestational age. • Our results provide reference values for calcium content in the fetal spine during the second and third trimesters.
利用定量磁化率映射（QSM）技术在第二和第三孕期体内评估胎儿脊柱的钙沉积。
54 名处于第二和第三孕期的孕妇在 3T 上进行二维多回波 STrategically Acquired Gradient Echo（STAGE）MR 成像扫描，覆盖胎儿脊柱。第一个回波数据用于 QSM 处理。采用线性回归模型评估磁化率与胎龄（GA）之间的相关性。采用配对样本 t 检验比较来自每个序列的 QSM 测量值的一致性。
胎儿脊柱的磁化率随 GA 的增加呈线性下降，斜率为-52.3 每十亿分之一（ppb）/周，皮尔逊相关系数（r）为 0.83（p < 0.001）。在 37 名受试者中，STAGE 局部 QSM 数据可从两个翻转角获得，翻转角分别为 8°和 40°时，平均磁化率值分别为-1111±278 ppb 和-1081±262 ppb。配对样本 t 检验显示这些平均值无统计学差异（p = 0.156）。
QSM 是评估胎儿椎骨钙沉积和骨矿物质密度的可靠技术。我们的结果表明，胎儿钙水平随 GA 增加而增加。这些指标可能能够为第二和第三孕期胎儿脊柱中的钙含量提供参考值。
• 通过椎体磁化率评估，胎儿脊柱中的钙沉积和矿化随着胎龄的增加而增加。
• 我们的结果为第二和第三孕期胎儿脊柱中的钙含量提供了参考值。
