Quantifying calcium changes in the fetal spine using quantitative susceptibility mapping as extracted from STAGE...

Area of Science:

• Biomedical Imaging
• Fetal Development
• Quantitative Susceptibility Mapping

Background:

• Assessing fetal bone mineralization is crucial for monitoring development.
• Current methods for evaluating fetal calcium deposition are limited.
• Quantitative Susceptibility Mapping (QSM) offers a novel approach for in vivo assessment.

Purpose of the Study:

• To evaluate fetal spine calcium deposition during the second and third trimesters using QSM.
• To establish a correlation between magnetic susceptibility and gestational age in the fetal spine.
• To determine the reliability of QSM for assessing fetal bone mineral density.

Main Methods:

• A 2D multi-echo STrategically Acquired Gradient Echo (STAGE) MR imaging protocol was used at 3T.
• Fifty-four pregnant women in their second and third trimesters were included.
• Linear regression and paired sample t-tests were employed to analyze QSM data and gestational age.

Main Results:

• Fetal spine magnetic susceptibility decreased linearly with advancing gestational age (r=0.83, p<0.001).
• The slope of the decrease was -52.3 parts per billion (ppb)/week.
• QSM measurements were consistent across different flip angles, indicating reliability.

Conclusions:

• QSM is a reliable technique for evaluating fetal vertebral calcium deposition and bone mineral density.
• Fetal calcium levels, indicated by magnetic susceptibility, increase with gestational age.
• The study provides potential reference values for fetal spine calcium content during mid-to-late pregnancy.