Detecting abnormal placental microvascular flow in maternal and fetal diseases based on flow-compensated and non-compensated intravoxel incoherent motion imaging. (4th March 2022) - Liao, Yuhao
Abstract: Introduction: Intravoxel Incoherent Motion (IVIM) imaging has been used to assess placental microcirculatory flows. We proposed a joint analysis of flow-compensated (FC) and non-compensated (NC) diffusion MRI to estimate the fraction and velocity of ballistic microcirculatory flow ( f b and v b ), and evaluated the diagnostic performance of the new markers in maternal and fetal disorders. Methods: Gestational diabetes mellitus (GDM, n = 15) pregnancies and fetal growth restriction (FGR, n = 12), along with gestational age matched normal controls ( n = 19 for GDM and 15 for FGR) underwent FC and NC-encoded IVIM scans at 1.5 T. f b and v b obtained from a FC-NC joint model, along with the conventional IVIM indices, were compared between patient groups for whole-placenta and maternal/fetal sides of the placenta. A linear support vector machine (SVM) was used to classify the GDM, FGR and controls. Results: v b of whole-placenta were significantly lower in both GDM ( p = 0.017) and FGR ( p = 0.043), compared with their controls, and the differences were more evident in the fetal side ( p = 0.010 for GDM and p = 0.042 for FGR). f b and f FC showed group differences in the fetal side and D FC showed differences in whole-placenta for GDM patients. In the classification task, v b showed the highest diagnostic accuracy of 70.6% for GDM and 63.0% for FGR, and the combination of f b and v b further improved the detection accuracy to 73.5% and 66.7% for GDM and FGR, respectively. Discussion : v b showed superior performance in the diagnosis of GDM and FGR, indicating the potential of the joint FC-NC IVIM method for placenta examinations. Highlights: We performed joint analysis of flow-compensated and non-compensated diffusion MRI. Fraction and velocity of ballistic microcirculatory flow were estimated from joint analysis. Ballistic flow markers showed superior diagnosis performance in placental disorders. The combination of the flow markers further improved the diagnostic accuracy.