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

PurposeDemonstrating quantitative multi-parametric mapping in the placenta with combined T2*-diffusion MRI at low-field (0.55T). MethodsWe present 57 placental MRI scans performed on a commercially available 0.55T scanner. We acquired the images using a combined T2*-diffusion technique scan that simultaneously acquires multiple diffusion preparations and echo times. We processed the data to produce quantitative T2* and diffusivity maps using a combined T2*-ADC model. We compared the derived quantitative parameters across gestation in healthy controls and a cohort of clinical cases. ResultsQuantitative parameter maps closely resemble those from previous experiments at higher field strength, with similar trends in T2* and ADC against gestational age observed. ConclusionCombined T2*-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 T2* for larger dynamic ranges - can support the widespread roll out of placental MRI as an adjunct to ultrasound during pregnancy.