Diffusion and perfusion quantified by Magnetic Resonance Imaging are markers of human placenta development in normal pregnancy

Abstract

PurposeTo investigate the potential of bi-exponential model of diffusion-weighted (DW) signal decay to quantify diffusion and perfusion changes in human placenta of normal pregnancies due to its development. Methods26 normal pregnancies at 19–37 weeks of gestation underwent Magnetic Resonance Imaging (MRI) examination at 1.5 T. DW Spin-Echo Echo Planar Imaging with diffusion gradients applied along 3 no-coplanar directions at seven different b-values (0,50,100,150,400,700,1000 s/mm2) was used.Apparent diffusion coefficient (ADC), pseudodiffusion (D*) and perfusion fraction (f) were extracted in selected placenta regions: umbilical (U-ROI), central (C-ROI) and peripheral (P-ROI). The relation between ADC, D*, f and mother age, gestational age (GA), Body-Mass Index (BMI), basal Glycaemia (bG), were evaluated. Pearson correlation with Bonferroni correction was used. ResultsA significant negative correlation was found between ADC and GA, for GA≥30w in P-ROI, while no-dependence of ADC on GA was observed in GA range 19–29 weeks. A positive linear correlation was found between f and GA in the C-ROI and between f and GA in P-ROI for GA≥30 week. No significant correlations were found between ADC, D*, f and age, BMI, bG. ConclusionADC measurements in P-ROI of normal placenta reflects tissue changes occurring in the third trimester of gestation. Specifically, ADC decreases with GA increase. Besides, f increases with the GA increase in the C-ROI and during the third trimester of pregnancy in the P-ROI.These results suggest the potential of diffusion and perfusion parameters extracted by using a biexponential model to provide information about placenta changes during its development.