Evaluating T1-weighted MRI techniques for fetal gastrointestinal diagnostics: A comparative study

In clinical practice, fetal gastrointestinal magnetic resonance imaging (MRI) encounters significant challenges. T1-weighted images are particularly susceptible to the effects of fetal and maternal movements compared to other weighted images, complicating the acquisition of satisfactory results. This study aimed to compare three fast 3D-T1 weighted gradient echo (GRE) sequences-free-breathing stack-of-stars VIBE (STAR-VIBE), breath-hold VIBE (BH-VIBE), and free-breathing multi-average VIBE (MA-VIBE)-for fetal gastrointestinal MRI in fetuses with both normal and abnormal gastrointestinal tracts between 21 and 36 weeks of gestation.

This study enrolled 67 pregnant women who underwent fetal abdominal MRI at our hospital between October 2022 and October 2023, during their gestational period of 21-36 weeks. Among these participants, 22 were suspected of having fetal gastrointestinal anomalies based on ultrasound findings, while the remaining 45 were considered to have normal fetal gastrointestinal development. All subjects underwent True fast imaging with steady-state precession sequence scanning along with three T1-weighted imaging techniques on a Siemens 1.5-T Aera scanner: STAR-VIBE, BH-VIBE, and MA-VIBE. Two radiologists evaluated image quality, intestinal clarity, and lesion conspicuity using a five-point scale where higher scores indicated superior performance for each technique; they were blinded to the acquisition schemes used. Interobserver variability assessments were also conducted.

The free-breathing MA-VIBE sequence demonstrated significantly better performance than both STAR-VIBE and BH-VIBE in terms of fetal gastrointestinal MRI quality (3.81 ± 0.40 vs. 3.35 ± 0.70 vs. 2.90 ± 0.64; p < .05). The STAR-VIBE and BH-VIBE sequences exhibited moderate consistency (kappa = 0.586 and kappa = 0.527 respectively; P < .05), whereas the MA-VIBE sequence showed higher consistency (kappa = 0.712; P < .05).

The free-breathing MA-VIBE sequence provided superior visualization for assessing fetal intestinal conditions compared to other methods employed in this study. On a 1.5 T MRI device, T1-weighted images based on the free-breathing MA-VIBE sequence can effectively overcome motion artifacts and compensate for the reduced signal-to-noise ratio caused by the application of acceleration techniques, thus significantly improving the quality of T1-weighted images.