Capuani S, et al. – The potential of bi–exponential model of diffusion–weighted (DW) signal decay to measure diffusion and perfusion changes in human placenta of normal pregnancies because of its development is examined in this study. Apparent diffusion coefficient (ADC) measurements in peripheral (P–ROI) of normal placenta reflects tissue changes occurring in the third trimester of gestation. In particular, ADC decreases with gestational age (GA) increase. Besides, f increases with the GA increase in the C–ROI and amid the third trimester of pregnancy in the P–ROI. These outcomes recommend the potential of diffusion and perfusion parameters extracted by utilizing a biexponential model to provide information about placenta changes amid its development.

Methods

• Total 26 normal pregnancies at 19–37 weeks of gestation underwent Magnetic Resonance Imaging (MRI) examination at 1.5 T were enrolled in this study.
• 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 utilized in this study.
• 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).
• In this study, they assessed the connection between ADC, D*, f and mother age, gestational age (GA), Body–Mass Index (BMI), basal Glycaemia (bG). Pearson correlation with Bonferroni correction was utilized.

Results

• In this study, an important negative correlation was seen between ADC and GA, for GA≥30w in P–ROI, while no–dependence of ADC on GA was found in GA range 19–29 weeks.
• A positive linear correlation was observed between f and GA in the C–ROI and between f and GA in P–ROI for GA≥30 week.
• No important correlations were seen between ADC, D*, f and age, BMI, bG.