Improved T2* mapping in fetal brain and placenta using fast multiple overlapping-echo acquisition

Motivation: T2* mapping provides valuable information on blood oxygenation and function in the fetal brain and placenta. However, the widely used multi-echo EPI method suffers from low spatial resolution and geometric distortion. Goal(s): To improve the spatial resolution and reduce distortion of fetal or placental T2* mapping. Approach: The gradient-echo-based multi-overlapping-echo acquisition (GRE-MOLED) was developed in fetal and placental MRI, and was validated on agar-based phantom and six pregnant women. Results: Phantom experiments demonstrated the distortion correction capability and accurate T2* mapping performance of GRE-MOLED. Preliminary fetal and placental T2* maps showed reasonable T2* values and improved spatial resolution. Impact: The proposed GRE-MOLED method achieves improved T2* mapping for the fetal brain and placenta within the same acquisition time as conventional EPI method, offering a promising solution to the limitations of low spatial resolution and distortion artifacts.