Comparative Study Of Placental T2*And Intravoxel Incoherent Motion In The Prediction Of Fetal Growth Restriction

Introduction: Both transverse relaxation time (T2*) and intravoxel incoherent motion (IVIM) on magnetic resonance imaging (MRI) are promising for discriminating fetal growth restriction (FGR). We aimed to compare the utility of these two parameters and their combination in the same cohort.Methods: Twenty-seven FGR and 24 control pregnancies after 28 weeks of gestation in which both T2* and IVIM scans were performed on a 3.0 T MRI were recruited. We compared the T2* Z-score, perfusion fraction (f), diffusion coefficient (D) and pseudodiffusion coefficient (D*) between groups. Binary logistic regression analysis and areas under the curve (AUCs) with receiver operating characteristic (ROC) curve were used to evaluate the diagnostic efficacy of these parameters and their combination.Results: Compared with normal pregnancies, T2* Z-score (0.036 +/- 0.95 vs. -2.479 +/- 1.56, p < 0.001), f (0.2753 +/- 0.035 vs. 0.3304 +/- 0.035, p < 0.001), D* (48279.82 +/- 7497.36 mu m(2)/s vs. 56167.92 +/- 8549.87 mu m(2)/s, p = 0.001) and D (1664.32 +/- 288.53 mu m(2)/s vs. 1887.15 +/- 204.08 mu m(2)/s, p = 0.002) were significantly decreased in FGR pregnancies. However, only AUC(T2* Z-score) (0.903) and AUC(f) (0.873) were good predictors of FGR. The AUC(T2* Z-score-IVIM) (0.937), calculated with the combination of T2* Z-score and f, was similar to AUC(T2* Z-score) and ACU(f).Discussion: Both T2* and f were effective in discriminating FGR. However, the combination of the two parameters did not further improve diagnostic efficacy. We suggest that T2* might be more suitable for evaluating placental dysfunction, as it is fast to obtain and easy to measure.