OBJECTIVES: The objectives of this study were to evaluate the potential of intravoxel incoherent motion (IVIM) magnetic resonance imaging at 4.7 T to distinguish decreased placental perfusion from normal perfusion in a controlled murine model and to determine the effect of transient maternal hyperoxygenation on placental microvascularization. MATERIALS AND METHODS: The study was approved by our animal care committee. Ten pregnant rats underwent ligation of the left uterine vascular pedicle on the 17th embryonic day (E17). A multishot diffusion-weighted spin-echo echo-planar imaging sequence, using 14 b values (b10 to b800), was performed on the 19th embryonic day (E19) under room air and during maternal hyperoxygenation. For each placenta and its 2 layers, the signal intensity decay curve according to the b values was obtained. The following IVIM parameters were calculated using biexponential fitting: the diffusion coefficient (D), the pseudodiffusion coefficient (D*), and the perfusion fraction (f). Mixed regression modeling was used to analyze the effect of ligation status, oxygenation, and the placental layer on IVIM parameters. RESULTS: Seventy-three placentas were examined: 23 in the ligated horn and 50 in the nonligated control horn. The IVIM parameters were obtained for 67% of the placentas. In the control horn, the mean (SD) values on room air were 28% (13%), 9.6 (9) ×10(-3) mm(2)/s, and 0.88 (0.36) ×10(-3) mm(2)/s for the perfusion fraction, the pseudodiffusion coefficient, and the diffusion coefficient, respectively. The perfusion fraction was significantly decreased in the ligated horn (-6.7% [1.9%]; P = 0.001) and during maternal hyperoxygenation (-3.3 [1.64%]; P = 0.047). The diffusion coefficient increased significantly during the hyperoxygenation (0.26 [0.04] × 10(-3) mm(2)/s; P = 0.0001) and in the inner placental layer (0.21 [0.05] ×10(-3) mm(2)/s; P = 0.0001). CONCLUSIONS: The perfusion fraction is a sensitive marker of decreased placental perfusion. The perfusion fraction and the diffusion coefficient are modified during the hyperoxygenation. Our IVIM-based approach may help in the investigation and early diagnosis of vascular diseases during pregnancy.
OBJECTIVES: The objectives of this study were to evaluate the potential of intravoxel incoherent motion (IVIM) magnetic resonance imaging at 4.7 T to distinguish decreased placental perfusion from normal perfusion in a controlled murine model and to determine the effect of transient maternal hyperoxygenation on placental microvascularization. MATERIALS AND METHODS: The study was approved by our animal care committee. Ten pregnant rats underwent ligation of the left uterine vascular pedicle on the 17th embryonic day (E17). A multishot diffusion-weighted spin-echo echo-planar imaging sequence, using 14 b values (b10 to b800), was performed on the 19th embryonic day (E19) under room air and during maternal hyperoxygenation. For each placenta and its 2 layers, the signal intensity decay curve according to the b values was obtained. The following IVIM parameters were calculated using biexponential fitting: the diffusion coefficient (D), the pseudodiffusion coefficient (D*), and the perfusion fraction (f). Mixed regression modeling was used to analyze the effect of ligation status, oxygenation, and the placental layer on IVIM parameters. RESULTS: Seventy-three placentas were examined: 23 in the ligated horn and 50 in the nonligated control horn. The IVIM parameters were obtained for 67% of the placentas. In the control horn, the mean (SD) values on room air were 28% (13%), 9.6 (9) ×10(-3) mm(2)/s, and 0.88 (0.36) ×10(-3) mm(2)/s for the perfusion fraction, the pseudodiffusion coefficient, and the diffusion coefficient, respectively. The perfusion fraction was significantly decreased in the ligated horn (-6.7% [1.9%]; P = 0.001) and during maternal hyperoxygenation (-3.3 [1.64%]; P = 0.047). The diffusion coefficient increased significantly during the hyperoxygenation (0.26 [0.04] × 10(-3) mm(2)/s; P = 0.0001) and in the inner placental layer (0.21 [0.05] ×10(-3) mm(2)/s; P = 0.0001). CONCLUSIONS: The perfusion fraction is a sensitive marker of decreased placental perfusion. The perfusion fraction and the diffusion coefficient are modified during the hyperoxygenation. Our IVIM-based approach may help in the investigation and early diagnosis of vascular diseases during pregnancy.
Authors: Christian Eberhardt; Moritz C Wurnig; Andrea Wirsching; Cristina Rossi; Markus Rottmar; Pinar S Özbay; Lukas Filli; Mickael Lesurtel; Andreas Boss Journal: MAGMA Date: 2016-04-19 Impact factor: 2.310
Authors: Anton S Becker; Jose A Perucho; Moritz C Wurnig; Andreas Boss; Soleen Ghafoor; Pek-Lan Khong; Elaine Y P Lee Journal: Korean J Radiol Date: 2017-04-03 Impact factor: 3.500
Authors: Eddy Solomon; Reut Avni; Ron Hadas; Tal Raz; Joel Richard Garbow; Peter Bendel; Lucio Frydman; Michal Neeman Journal: Proc Natl Acad Sci U S A Date: 2014-06-26 Impact factor: 11.205