Anderson Kristi B1, Hansen Ditte N2, Haals Caroline3, Sinding Marianne2, Petersen Astrid4, Frøkjær Jens B5, Peters David A6, Sørensen Anne2. 1. Department of Pathology, Aalborg University Hospital, Ladegaardsgade 3, 9000, Aalborg, Denmark. Electronic address: ander.krist@gmail.com. 2. Department of Obstetrics and Gynecology, Aalborg University Hospital, Reberbansgade 15, 9000, Aalborg, Denmark; Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, 9000, Aalborg, Denmark. 3. Department of Obstetrics and Gynecology, Aalborg University Hospital, Reberbansgade 15, 9000, Aalborg, Denmark. 4. Department of Pathology, Aalborg University Hospital, Ladegaardsgade 3, 9000, Aalborg, Denmark. 5. Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, 9000, Aalborg, Denmark; Department of Radiology, Aalborg University Hospital, Hobrovej 18-22, 9000, Aalborg, Denmark. 6. Department of Clinical Engineering, Central Denmark Region, Nørrebrogade 44, 8000, Aarhus C, Denmark.
Abstract
INTRODUCTION: Our aim was to assess placental function by diffusion-weighted magnetic resonance imaging (MRI) using intravoxel incoherent motion (IVIM) analysis in uncomplicated pregnancies and pregnancies complicated by placental dysfunction. METHODS: 31 normal pregnancies and 9 pregnancies complicated by placental dysfunction (birthweight ≤ -2SD and histological signs of placental vascular malperfusion) were retrieved from our placental MRI research database. MRI was performed at gestational weeks 20.1-40.6 in a 1.5 T system using 10 b-values (0-1000 s/mm2). Regions of interest were drawn covering the entire placenta in five transverse slices. Diffusion coefficient (D), pseudodiffusion coefficient (D*) and perfusion fraction (f) were estimated by IVIM analysis. RESULTS: In normal pregnancies, placental f decreased linearly with gestational age (r = -0.522, p = 0.002) being 26.2% at week 20 and 18.8% at week 40. D and D* were 1.57 ± 0.03 and 31.7 ± 3.1 mm2/s (mean ± SD), respectively, and they were not correlated with gestational age. In complicated pregnancies, f was significantly reduced (mean Z-score = -1.16; p = 0.02) when compared to the group of normal pregnancies, whereas D and D* did not differ significantly between groups. Subgroup analysis demonstrated that f was predominantly reduced in dysfunctional placentas characterized by fetal vascular malperfusion (mean Z-score = -2.11, p < 0.001) rather than maternal vascular malperfusion (mean Z-score = -0.40, p = 0.42). In addition, f was negatively correlated with uterine artery pulsatility index (r = -0.396, p = 0.01). DISCUSSION: Among parameters obtained by the IVIM analysis, only f revealed significant differences between the normal and the dysfunctional placentas. Subgroup analysis suggests that placental f may be able to discriminate non-invasively between different histological types of vascular malperfusion.
INTRODUCTION: Our aim was to assess placental function by diffusion-weighted magnetic resonance imaging (MRI) using intravoxel incoherent motion (IVIM) analysis in uncomplicated pregnancies and pregnancies complicated by placental dysfunction. METHODS: 31 normal pregnancies and 9 pregnancies complicated by placental dysfunction (birthweight ≤ -2SD and histological signs of placental vascular malperfusion) were retrieved from our placental MRI research database. MRI was performed at gestational weeks 20.1-40.6 in a 1.5 T system using 10 b-values (0-1000 s/mm2). Regions of interest were drawn covering the entire placenta in five transverse slices. Diffusion coefficient (D), pseudodiffusion coefficient (D*) and perfusion fraction (f) were estimated by IVIM analysis. RESULTS: In normal pregnancies, placental f decreased linearly with gestational age (r = -0.522, p = 0.002) being 26.2% at week 20 and 18.8% at week 40. D and D* were 1.57 ± 0.03 and 31.7 ± 3.1 mm2/s (mean ± SD), respectively, and they were not correlated with gestational age. In complicated pregnancies, f was significantly reduced (mean Z-score = -1.16; p = 0.02) when compared to the group of normal pregnancies, whereas D and D* did not differ significantly between groups. Subgroup analysis demonstrated that f was predominantly reduced in dysfunctional placentas characterized by fetal vascular malperfusion (mean Z-score = -2.11, p < 0.001) rather than maternal vascular malperfusion (mean Z-score = -0.40, p = 0.42). In addition, f was negatively correlated with uterine artery pulsatility index (r = -0.396, p = 0.01). DISCUSSION: Among parameters obtained by the IVIM analysis, only f revealed significant differences between the normal and the dysfunctional placentas. Subgroup analysis suggests that placental f may be able to discriminate non-invasively between different histological types of vascular malperfusion.
Authors: Paddy J Slator; Jana Hutter; Razvan V Marinescu; Marco Palombo; Laurence H Jackson; Alison Ho; Lucy C Chappell; Mary Rutherford; Joseph V Hajnal; Daniel C Alexander Journal: Med Image Anal Date: 2021-04-20 Impact factor: 8.545