Fetal cerebral blood perfusion could be a more sensitive biomarker of fetal “brain sparing” at early stages of growth restriction. Fractional moving blood volume (FMBV) provides an indirect but reliable estimate of tissue blood perfusion, and is more sensitive in detecting cerebral blood flow redistribution compared to Doppler indices in fetuses with growth restriction. Quantitative MRI can measure blood oxygenation status in the human fetus using MR-susceptometry. By having both blood oxygenation and perfusion information available, this provides a comprehensive understanding of the fetal cerebral metabolic status in growth restricted fetuses, and might contribute to the clinical management of such pregnancies.
PRB researchers evaluated a dual-modal imaging modality approach to obtain a combined estimation of venous blood oxygenation (using susceptibility-weighted MRI) and blood perfusion (using power Doppler ultrasound and FMBV) in the brain of 33 normally grown and 10 growth-restricted fetuses. Using such combined MRI and ultrasound techniques showed a significant association between cerebral blood oxygenation and blood perfusion in normally grown and growth-restricted fetuses. Thus, this dual-imaging approach could contribute to the early detection of fetal “brain sparing” and brain oxygen saturation changes in high-risk pregnancies.