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

Area of Science:

• Medical Imaging
• Radiology
• Fetal Medicine

Background:

• Fetal gastrointestinal magnetic resonance imaging (MRI) is challenged by fetal and maternal motion, particularly affecting T1-weighted images.
• Existing fast 3D-T1 weighted gradient echo (GRE) sequences struggle with motion artifacts, complicating the assessment of fetal gastrointestinal tracts.
• Accurate visualization of fetal anatomy is crucial for diagnosing congenital gastrointestinal anomalies.

Purpose of the Study:

• To compare the efficacy of three fast 3D-T1 weighted gradient echo (GRE) sequences for fetal gastrointestinal MRI.
• Sequences evaluated: free-breathing stack-of-stars VIBE (STAR-VIBE), breath-hold VIBE (BH-VIBE), and free-breathing multi-average VIBE (MA-VIBE).
• Assessment focused on fetuses between 21 and 36 weeks of gestation with normal and abnormal gastrointestinal tracts.

Main Methods:

• 67 pregnant women (21-36 weeks gestation) underwent fetal abdominal MRI on a 1.5-T scanner.
• Participants included 22 with suspected fetal gastrointestinal anomalies and 45 with normal development.
• Two blinded radiologists assessed image quality, intestinal clarity, and lesion conspicuity using a 5-point scale for STAR-VIBE, BH-VIBE, and MA-VIBE sequences.

Main Results:

• Free-breathing MA-VIBE demonstrated significantly superior image quality (3.81 ± 0.40) compared to STAR-VIBE (3.35 ± 0.70) and BH-VIBE (2.90 ± 0.64) (p < .05).
• MA-VIBE showed higher interobserver consistency (kappa = 0.712) than STAR-VIBE (kappa = 0.586) and BH-VIBE (kappa = 0.527) (p < .05).
• MA-VIBE provided better visualization of fetal intestinal conditions.

Conclusions:

• The free-breathing MA-VIBE sequence is superior for fetal gastrointestinal MRI, offering enhanced visualization of intestinal conditions.
• MA-VIBE effectively overcomes motion artifacts and compensates for signal loss from acceleration techniques on 1.5 T MRI.
• This sequence significantly improves T1-weighted image quality for fetal gastrointestinal assessment.