Low-Field Combined Diffusion-Relaxation MRI for Mapping Placenta Structure and Function

PURPOSE: Demonstrating quantitative multi-parametric mapping in the placenta with combined [Formula: see text]-diffusion MRI at low-field (0.55T). METHODS: We present 57 placental MRI scans performed on a commercially available 0.55T scanner. We acquired the images using a combined [Formula: see text]-diffusion technique scan that simultaneously acquires multiple diffusion preparations and echo times. We processed the data to produce quantitative [Formula: see text] and diffusivity maps using a combined [Formula: see text]-ADC model. We compared the derived quantitative parameters across gestation in healthy controls and a cohort of clinical cases. RESULTS: Quantitative parameter maps closely resemble those from previous experiments at higher field strength, with similar trends in [Formula: see text] and ADC against gestational age observed. CONCLUSION: Combined [Formula: see text]-diffusion placental MRI is reliably achievable at 0.55T. The advantages of lower field strength - such as cost, ease of deployment, increased accessibility and patient comfort due to the wider bore, and increased [Formula: see text] for larger dynamic ranges - can support the widespread roll out of placental MRI as an adjunct to ultrasound during pregnancy.