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Melbourne A, Schabel MC, David AL, Roberts VHJ. Magnetic resonance imaging of placental intralobule structure and function in a preclinical nonhuman primate model†. Biol Reprod 2024; 110:1065-1076. [PMID: 38442734 PMCID: PMC11180614 DOI: 10.1093/biolre/ioae035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/25/2024] [Accepted: 03/04/2024] [Indexed: 03/07/2024] Open
Abstract
Although the central role of adequate blood flow and oxygen delivery is known, the lack of optimized imaging modalities to study placental structure has impeded our understanding of its vascular function. Magnetic resonance imaging is increasingly being applied in this field, but gaps in knowledge remain, and further methodological developments are needed. In particular, the ability to distinguish maternal from fetal placental perfusion and the understanding of how individual placental lobules are functioning are lacking. The potential clinical benefits of developing noninvasive tools for the in vivo assessment of blood flow and oxygenation, two key determinants of placental function, are tremendous. Here, we summarize a number of structural and functional magnetic resonance imaging techniques that have been developed and applied in animal models and studies of human pregnancy over the past decade. We discuss the potential applications and limitations of these approaches. Their combination provides a novel source of contrast to allow analysis of placental structure and function at the level of the lobule. We outline the physiological mechanisms of placental T2 and T2* decay and devise a model of how tissue composition affects the observed relaxation properties. We apply this modeling to longitudinal magnetic resonance imaging data obtained from a preclinical pregnant nonhuman primate model to provide initial proof-of-concept data for this methodology, which quantifies oxygen transfer and placental structure across and between lobules. This method has the potential to improve our understanding and clinical management of placental insufficiency once validation in a larger nonhuman primate cohort is complete.
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Affiliation(s)
- Andrew Melbourne
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department of Obstetrics and Maternal Fetal Medicine, Elizabeth Garrett Anderson Institute for Women’s Health, University College London, London, UK
| | - Matthias C Schabel
- Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, USA
- Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, Utah, USA
| | - Anna L David
- Department of Obstetrics and Maternal Fetal Medicine, Elizabeth Garrett Anderson Institute for Women’s Health, University College London, London, UK
| | - Victoria H J Roberts
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health and Science University, Portland, OR, USA
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Clark A, Flouri D, Mufti N, James J, Clements E, Aughwane R, Aertsen M, David A, Melbourne A. Developments in functional imaging of the placenta. Br J Radiol 2023; 96:20211010. [PMID: 35234516 PMCID: PMC10321248 DOI: 10.1259/bjr.20211010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/26/2022] [Accepted: 02/22/2022] [Indexed: 12/21/2022] Open
Abstract
The placenta is both the literal and metaphorical black box of pregnancy. Measurement of the function of the placenta has the potential to enhance our understanding of this enigmatic organ and serve to support obstetric decision making. Advanced imaging techniques are key to support these measurements. This review summarises emerging imaging technology being used to measure the function of the placenta and new developments in the computational analysis of these data. We address three important examples where functional imaging is supporting our understanding of these conditions: fetal growth restriction, placenta accreta, and twin-twin transfusion syndrome.
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Affiliation(s)
- Alys Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | | | | | - Joanna James
- Department of Obstetrics and Gynaecology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Eleanor Clements
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Rosalind Aughwane
- Elizabeth Garrett Anderson Institute for Women’s Health, University College London, London, UK
| | - Michael Aertsen
- Department of Radiology, University Hospitals KU Leuven, Leuven, Belgium
| | - Anna David
- Elizabeth Garrett Anderson Institute for Women’s Health, University College London, London, UK
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Flouri D, Darby JRT, Holman SL, Perumal SR, David AL, Morrison JL, Melbourne A. Magnetic resonance imaging of placentome development in the pregnant Ewe. Placenta 2021; 105:61-69. [PMID: 33549925 PMCID: PMC7611430 DOI: 10.1016/j.placenta.2021.01.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/08/2021] [Accepted: 01/15/2021] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Novel imaging measurements of placental development are difficult to validate due to the invasive nature of gold-standard procedures. Animal studies have been important in validation of magnetic resonance imaging (MRI) measurements in invasive preclinical studies, as they allow for controlled experiments and analysis of multiple time-points during pregnancy. This study characterises the longitudinal diffusion and perfusion properties of sheep placentomes using MRI, measurements that are required for future validation studies. METHODS Pregnant ewes were anaesthetised for a MRI session on a 3T scanner. Placental MRI was used to classify placentomes morphologically into three types based on their shape and size at two gestational ages. To validate classification accuracy, placentome type derived from MRI data were compared with placentome categorisation results after delivery. Diffusion-Weighted MRI and T2-relaxometry were used to measure a broad range of biophysical properties of the placentomes. RESULTS MRI morphological classification results showed consistent gestational age changes in placentome shape, as supported by post-delivery gold standard data. The mean apparent diffusion coefficient was significantly higher at 110 days gestation than at late gestation (~140 days; term, 150 days). Mean T2 was higher at mid gestation (152.2 ± 58.1 ms) compared to late gestation (127.8 ms ± 52.0). Significantly higher perfusion fraction was measured in late gestation placentomes that also had a significantly higher fractional anisotropy when compared to the earlier gestational age. DISCUSSION We report baseline measurements of techniques common in placental MRI for the sheep placenta. These measurements are essential to support future validation measurements of placental MRI techniques.
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Affiliation(s)
- Dimitra Flouri
- School of Biomedical Engineering and Imaging Sciences, Kings College London, London, United Kingdom; Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom.
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
| | - Sunthara R Perumal
- South Australian Health & Medical Research Institute, Preclinical, Imaging & Research Laboratories, Adelaide, Australia
| | - Anna L David
- Elizabeth Garrett Anderson Institute for Women's Health, University College London, London, London, United Kingdom; NIHR Biomedical Research Centre, University College London Hospitals, London, United Kingdom
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging Sciences, Kings College London, London, United Kingdom; Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom; Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, Australia
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Anderson KB, Andersen AS, Hansen DN, Sinding M, Peters DA, Frøkjaer JB, Sørensen A. Placental transverse relaxation time (T2) estimated by MRI: Normal values and the correlation with birthweight. Acta Obstet Gynecol Scand 2020; 100:934-940. [PMID: 33258106 DOI: 10.1111/aogs.14057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Placental transverse relaxation time (T2) assessed by MRI may have the potential to improve the antenatal identification of small for gestational age. The aims of this study were to provide normal values of placental T2 in relation to gestational age at the time of MRI and to explore the correlation between placental T2 and birthweight. MATERIAL AND METHODS A mixed cohort of 112 singleton pregnancies was retrieved from our placental MRI research database. MRI was performed at 23.6-41.3 weeks of gestation in a 1.5T system (TE (8): 50-440 ms, TR: 4000 ms). Normal pregnancies were defined by uncomplicated pregnancies with normal obstetric outcome and birthweight deviation within ±1 SD of the expected for gestational age. The correlation between placental T2 and birthweight was investigated using the following outcomes; small for gestational age (birthweight ≤-2 SD of the expected for gestational age) and birthweight deviation (birthweight Z-scores). RESULTS In normal pregnancies (n = 27), placenta T2 showed a significant negative linear correlation with gestational age (r = -.91, P = .0001) being 184 ms ± 15.94 ms (mean ± SD) at 20 weeks of gestation and 89 ms ± 15.94 ms at 40 weeks of gestation. Placental T2 was significantly reduced among small-for-gestational-age pregnancies (mean Z-score -1.95, P < .001). Moreover, we found a significant positive correlation between placenta T2 deviation (Z-score) and birthweight deviation (Z-score) (R2 = .26, P = .0001). CONCLUSIONS This study provides normal values of placental T2 to be used in future studies on placental MRI. Placental T2 is closely related to birthweight and may improve the antenatal identification of small-for-gestational-age pregnancies.
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Affiliation(s)
- Kristi B Anderson
- Department of Pathology, Aalborg University Hospital, Aalborg, Denmark
| | - Anna S Andersen
- Department of Obstetrics and Gynecology, Aalborg University Hospital, Aalborg, Denmark
| | - Ditte N Hansen
- Department of Obstetrics and Gynecology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Marianne Sinding
- Department of Obstetrics and Gynecology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - David A Peters
- Department of Clinical Engineering, Central Denmark Region, Aarhus, Denmark
| | - Jens B Frøkjaer
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.,Department of Radiology, Aalborg University Hospital, Aalborg, Denmark
| | - Anne Sørensen
- Department of Obstetrics and Gynecology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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The application of in utero magnetic resonance imaging in the study of the metabolic and cardiovascular consequences of the developmental origins of health and disease. J Dev Orig Health Dis 2020; 12:193-202. [PMID: 33308364 PMCID: PMC8162788 DOI: 10.1017/s2040174420001154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Observing fetal development in utero is vital to further the understanding of later-life diseases. Magnetic resonance imaging (MRI) offers a tool for obtaining a wealth of information about fetal growth, development, and programming not previously available using other methods. This review provides an overview of MRI techniques used to investigate the metabolic and cardiovascular consequences of the developmental origins of health and disease (DOHaD) hypothesis. These methods add to the understanding of the developing fetus by examining fetal growth and organ development, adipose tissue and body composition, fetal oximetry, placental microstructure, diffusion, perfusion, flow, and metabolism. MRI assessment of fetal growth, organ development, metabolism, and the amount of fetal adipose tissue could give early indicators of abnormal fetal development. Noninvasive fetal oximetry can accurately measure placental and fetal oxygenation, which improves current knowledge on placental function. Additionally, measuring deficiencies in the placenta’s transport of nutrients and oxygen is critical for optimizing treatment. Overall, the detailed structural and functional information provided by MRI is valuable in guiding future investigations of DOHaD.
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Sørensen A, Sinding M. Placental Magnetic Resonance Imaging: A Method to Evaluate Placental Function In Vivo. Obstet Gynecol Clin North Am 2020; 47:197-213. [PMID: 32008669 DOI: 10.1016/j.ogc.2019.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This article describes the use of placental magnetic resonance imaging (MRI) relaxation times in the in vivo assessment of placental function. It focuses on T2*-weighted placental MRI, the main area of the authors' research over the past decade. The rationale behind T2*-weighted placental MRI, the main findings reported in the literature, and directions for future research and clinical applications of this method are discussed. The article concludes that placental T2* relaxation time is an easily obtained and robust measurement, which can discriminate between normal and dysfunctional placenta. Placenta T2* is a promising tool for in vivo assessment of placental function.
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Affiliation(s)
- Anne Sørensen
- Department of Obstetrics and Gynecology, Aalborg University Hospital, Reberbansgade 15, Aalborg 9000, Denmark; Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, Aalborg 9000, Denmark.
| | - Marianne Sinding
- Department of Obstetrics and Gynecology, Aalborg University Hospital, Reberbansgade 15, Aalborg 9000, Denmark; Department of Clinical Medicine, Aalborg University, Sdr. Skovvej 15, Aalborg 9000, Denmark
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Thomason ME. Development of Brain Networks In Utero: Relevance for Common Neural Disorders. Biol Psychiatry 2020; 88:40-50. [PMID: 32305217 PMCID: PMC7808399 DOI: 10.1016/j.biopsych.2020.02.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 01/05/2020] [Accepted: 02/05/2020] [Indexed: 01/27/2023]
Abstract
Magnetic resonance imaging, histological, and gene analysis approaches in living and nonliving human fetuses and in prematurely born neonates have provided insight into the staged processes of prenatal brain development. Increased understanding of micro- and macroscale brain network development before birth has spurred interest in understanding the relevance of prenatal brain development to common neurological diseases. Questions abound as to the sensitivity of the intrauterine brain to environmental programming, to windows of plasticity, and to the prenatal origin of disorders of childhood that involve disruptions in large-scale network connectivity. Much of the available literature on human prenatal neural development comes from cross-sectional or case studies that are not able to resolve the longitudinal consequences of individual variation in brain development before birth. This review will 1) detail specific methodologies for studying the human prenatal brain, 2) summarize large-scale human prenatal neural network development, integrating findings from across a variety of experimental approaches, 3) explore the plasticity of the early developing brain as well as potential sex differences in prenatal susceptibility, and 4) evaluate opportunities to link specific prenatal brain developmental processes to the forms of aberrant neural connectivity that underlie common neurological disorders of childhood.
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Affiliation(s)
- Moriah E Thomason
- Department of Child and Adolescent Psychiatry, Department of Population Health, and Neuroscience Institute, New York University Langone Health, New York, New York.
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Tun WM, Yap CH, Saw SN, James JL, Clark AR. Differences in placental capillary shear stress in fetal growth restriction may affect endothelial cell function and vascular network formation. Sci Rep 2019; 9:9876. [PMID: 31285454 PMCID: PMC6614400 DOI: 10.1038/s41598-019-46151-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 06/19/2019] [Indexed: 11/09/2022] Open
Abstract
Fetal growth restriction (FGR) affects 5-10% of pregnancies, leading to clinically significant fetal morbidity and mortality. FGR placentae frequently exhibit poor vascular branching, but the mechanisms driving this are poorly understood. We hypothesize that vascular structural malformation at the organ level alters microvascular shear stress, impairing angiogenesis. A computational model of placental vasculature predicted elevated placental micro-vascular shear stress in FGR placentae (0.2 Pa in severe FGR vs 0.05 Pa in normal placentae). Endothelial cells cultured under predicted FGR shear stresses migrated significantly slower and with greater persistence than in shear stresses predicted in normal placentae. These cell behaviors suggest a dominance of vessel elongation over branching. Taken together, these results suggest (1) poor vascular development increases vessel shear stress, (2) increased shear stress induces cell behaviors that impair capillary branching angiogenesis, and (3) impaired branching angiogenesis continues to drive elevated shear stress, jeopardizing further vascular formation. Inadequate vascular branching early in gestation could kick off this cyclic loop and continue to negatively impact placental angiogenesis throughout gestation.
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Affiliation(s)
- Win M Tun
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Choon Hwai Yap
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Shier Nee Saw
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Joanna L James
- Department of Obstetrics and Gynaecology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Alys R Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
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Hutter J, Slator PJ, Jackson L, Gomes ADS, Ho A, Story L, O’Muircheartaigh J, Teixeira RPAG, Chappell LC, Alexander DC, Rutherford MA, Hajnal JV. Multi-modal functional MRI to explore placental function over gestation. Magn Reson Med 2019; 81:1191-1204. [PMID: 30242899 PMCID: PMC6585747 DOI: 10.1002/mrm.27447] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/08/2018] [Accepted: 06/12/2018] [Indexed: 01/16/2023]
Abstract
PURPOSE To investigate, visualize and quantify the physiology of the human placenta in several dimensions - functional, temporal over gestation, and spatial over the whole organ. METHODS Bespoke MRI techniques, combining a rich diffusion protocol, anatomical data and T2* mapping together with a multi-modal pipeline including motion correction and extracted quantitative features were developed and employed on pregnant women between 22 and 38 weeks gestational age including two pregnancies diagnosed with pre-eclampsia. RESULTS A multi-faceted assessment was demonstrated showing trends of increasing lacunarity, and decreasing T2* and diffusivity over gestation. CONCLUSIONS The obtained multi-modal acquisition and quantification shows promising opportunities for studying evolution, adaptation and compensation processes.
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Affiliation(s)
- Jana Hutter
- Centre for the Developing BrainKing's College LondonUnited Kingdom
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
| | - Paddy J. Slator
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
| | - Laurence Jackson
- Centre for the Developing BrainKing's College LondonUnited Kingdom
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
| | - Ana Dos Santos Gomes
- Centre for the Developing BrainKing's College LondonUnited Kingdom
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
| | - Alison Ho
- Women's Health Academic CentreKing's College LondonLondonUnited Kingdom
| | - Lisa Story
- Centre for the Developing BrainKing's College LondonUnited Kingdom
- Women's Health Academic CentreKing's College LondonLondonUnited Kingdom
| | | | - Rui P. A. G. Teixeira
- Centre for the Developing BrainKing's College LondonUnited Kingdom
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
| | - Lucy C. Chappell
- Women's Health Academic CentreKing's College LondonLondonUnited Kingdom
| | - Daniel C. Alexander
- Centre for Medical Image Computing and Department of Computer ScienceUniversity College LondonUnited Kingdom
| | | | - Joseph V. Hajnal
- Centre for the Developing BrainKing's College LondonUnited Kingdom
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
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Shi H, Quan X, Liang W, Li X, Ai B, Liu H. Evaluation of Placental Perfusion Based on Intravoxel Incoherent Motion Diffusion Weighted Imaging (IVIM-DWI) and Its Predictive Value for Late-Onset Fetal Growth Restriction. Geburtshilfe Frauenheilkd 2018; 79:396-401. [PMID: 31000885 PMCID: PMC6461467 DOI: 10.1055/a-0717-5275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/22/2018] [Accepted: 08/26/2018] [Indexed: 01/21/2023] Open
Abstract
Objective
The aim of this study was to investigate placental blood perfusion in middle and late pregnancy and explore its predictive value for fetal growth restriction (FGR).
Methods
All pregnant women included in the study were examined using placental intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI). Three IVIM parameters (D, f, D*) were obtained for each pregnant woman and analyzed using Image J software. Perfusion fraction f is a radiological marker of placental perfusion. The pulsatility index (PI) of the uterine artery is used to indirectly evaluate placental function.
Results
f-values were significantly lower in the late-onset FGR group compared to the normal late pregnancy group (19.07 vs. 27.78%). In addition, uterine artery PI values were markedly increased in the late-onset FGR group compared to the normal late pregnancy group (1.96 vs. 1.03), and neonatal weight was significantly lower in the late-onset FGR group (2.75 vs. 3.18 kg). There was a significant positive correlation between f-value, uterine artery PI and neonatal weight (r = 0.968, p < 0.01; r = 0.959, p < 0.01). There was a significant negative correlation between f-value and age of gestation (r = − 0.534, p < 0.01).
Conclusion
Perfusion fraction f was strongly correlated with uterine artery blood flow resistance as measured by color Doppler and had a certain predictive value for late-onset FGR.
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Affiliation(s)
- Hui Shi
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Xianyue Quan
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Wen Liang
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Xinming Li
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Bin Ai
- Department of Medical Image, Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Hongsheng Liu
- Department of Medical Image, Guangzhou Women and Children's Medical Center, Guangzhou, China
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Dallmann A, Ince I, Meyer M, Willmann S, Eissing T, Hempel G. Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy. Clin Pharmacokinet 2018; 56:1303-1330. [PMID: 28401479 DOI: 10.1007/s40262-017-0539-z] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues. OBJECTIVES The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues. METHODS A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility. RESULTS The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions. CONCLUSION The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding optimal dosing regimens in this vulnerable special population.
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Affiliation(s)
- André Dallmann
- Department of Pharmaceutical and Medical Chemistry, Clinical Pharmacy, Westfälische Wilhelm-University Münster, Münster, Germany
| | - Ibrahim Ince
- ET-TD-ET Systems Pharmacology CV, Bayer AG, Leverkusen, Germany.
| | - Michaela Meyer
- DD-CS Clinical Pharmacometrics, Bayer AG, Wuppertal, Germany
| | - Stefan Willmann
- DD-CS Clinical Pharmacometrics, Bayer AG, Wuppertal, Germany
| | - Thomas Eissing
- ET-TD-ET Systems Pharmacology CV, Bayer AG, Leverkusen, Germany
| | - Georg Hempel
- Department of Pharmaceutical and Medical Chemistry, Clinical Pharmacy, Westfälische Wilhelm-University Münster, Münster, Germany
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Grigsby PL. Animal Models to Study Placental Development and Function throughout Normal and Dysfunctional Human Pregnancy. Semin Reprod Med 2016; 34:11-6. [PMID: 26752715 DOI: 10.1055/s-0035-1570031] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Abnormalities of placental development and function are known to underlie many pathologies of pregnancy, including spontaneous preterm birth, fetal growth restriction, and preeclampsia. A growing body of evidence also underscores the importance of placental dysfunction in the lifelong health of both mother and offspring. However, our knowledge regarding placental structure and function throughout pregnancy remains limited. Understanding the temporal growth and functionality of the human placenta throughout the entirety of gestation is important if we are to gain a better understanding of placental dysfunction. The utilization of new technologies and imaging techniques that could enable safe monitoring of placental growth and function in vivo has become a major focus area for the National Institutes of Child Health and Human Development, as evident by the establishment of the "Human Placenta Project." Many of the objectives of the Human Placenta Project will necessitate preclinical studies and testing in appropriately designed animal models that can be readily translated to the clinical setting. This review will describe the advantages and limitations of relevant animals such as the guinea pig, sheep, and nonhuman primate models that have been used to study the role of the placenta in fetal growth disorders, preeclampsia, or other maternal diseases during pregnancy.
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Affiliation(s)
- Peta L Grigsby
- Division of Reproductive and Developmental Sciences, Department of Obstetrics and Gynecology, Oregon Health and Science University, Beaverton, Oregon
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Mayhew T. Morphomics: An integral part of systems biology of the human placenta. Placenta 2015; 36:329-40. [DOI: 10.1016/j.placenta.2015.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/05/2015] [Accepted: 01/07/2015] [Indexed: 01/03/2023]
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Frias AE, Schabel MC, Roberts VHJ, Tudorica A, Grigsby PL, Oh KY, Kroenke CD. Using dynamic contrast-enhanced MRI to quantitatively characterize maternal vascular organization in the primate placenta. Magn Reson Med 2014; 73:1570-8. [PMID: 24753177 DOI: 10.1002/mrm.25264] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 11/09/2022]
Abstract
PURPOSE The maternal microvasculature of the primate placenta is organized into 10-20 perfusion domains that are functionally optimized to facilitate nutrient exchange to support fetal growth. This study describes a dynamic contrast-enhanced magnetic resonance imaging method for identifying vascular domains and quantifying maternal blood flow in them. METHODS A rhesus macaque on the 133rd day of pregnancy (G133, term = 165 days) underwent Doppler ultrasound procedures, dynamic contrast-enhanced magnetic resonance imaging and Cesarean-section delivery. Serial T1 -weighted images acquired throughout intravenous injection of a contrast reagent bolus were analyzed to obtain contrast reagent arrival time maps of the placenta. RESULTS Watershed segmentation of the arrival time map identified 16 perfusion domains. The number and location of these domains corresponded to anatomical cotyledonary units observed following delivery. Analysis of the contrast reagent wave front through each perfusion domain enabled determination of volumetric flow, which ranged from 9.03 to 44.9 mL/s (25.2 ± 10.3 mL/s). These estimates are supported by Doppler ultrasound results. CONCLUSIONS The dynamic contrast-enhanced magnetic resonance imaging analysis described here provides quantitative estimates of the number of maternal perfusion domains in a primate placenta and estimates flow within each domain. Anticipated extensions of this technique are to the study placental function in non-human primate models of obstetric complications.
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Affiliation(s)
- Antonio E Frias
- Division of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Beaverton, Oregon, USA; Division of Developmental and Reproductive Sciences, Oregon National Primate Research Center, Beaverton, Oregon, USA; Department of Obstetrics and Gynecology, Oregon National Primate Research Center, Beaverton, Oregon, USA
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Wareing M. Effects of oxygenation and luminal flow on human placenta chorionic plate blood vessel function. J Obstet Gynaecol Res 2011; 38:185-91. [DOI: 10.1111/j.1447-0756.2011.01666.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Magnetic resonance imaging relaxation time measurements of the placenta at 1.5 T. Placenta 2011; 32:1010-5. [PMID: 21978937 DOI: 10.1016/j.placenta.2011.07.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 07/06/2011] [Accepted: 07/08/2011] [Indexed: 11/20/2022]
Abstract
UNLABELLED Placental insufficiency is a major cause of fetal growth restriction (FGR) and accumulating evidence indicates several aspects of placental morphology are altered in this condition. MRI provides quantitative indices that may be used in non-invasive assessment of the human placenta, such as relaxation time measurements, T1 and T2. We hypothesised that placental relaxation times relate to alterations in placental tissue morphology and hence may be useful in identifying the changes associated with FGR. We report on the first phase of testing this hypothesis, in a study of women in normal pregnancy. AIMS To assess relaxation time measurements in the placenta in normal pregnancy and correlate these with gestational age and stereological analyses of placental morphology following delivery. METHODS 30 women underwent MRI examination (1.5 T) between 20 and 41 weeks gestation. Placental T1 and T2 measurements were acquired from a mid-depth placental region, co-localised to a structural scan. Fixed, wax-embedded sections of these placentas collected at delivery were stained with hematoxylin/eosin and subjected to stereological analysis. RESULTS Placental T1 and T2 show a significant negative correlation with gestation, (Pearson correlation p=0.01, 0.03 respectively). 17 placentas were analysed stereologically. In the group as a whole there was no significant correlation between T1 and T2 and morphological features. However, in a subset of 7 pregnancies scanned within a week of delivery, a significant positive correlation was observed between the fibrin volume density and the ratio of fibrin: villous volume densities and T2 (Spearman correlation p=0.02, 0.03 respectively). DISCUSSION The correlations between placental T1 and T2 and gestation show that these variables are clearly influenced by changes in placental structure. Fibrin might be a key component but further work is needed to fully elucidate the major structural influences on placental T1 and T2.
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Victoria T, Johnson AM, Kramer SS, Coleman B, Bebbington M, Epelman M. Extrafetal findings at fetal MR: evaluation of the normal placenta and correlation with ultrasound. Clin Imaging 2011; 35:371-7. [DOI: 10.1016/j.clinimag.2010.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 08/24/2010] [Indexed: 11/29/2022]
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Chalouhi GE, Deloison B, Siauve N, Aimot S, Balvay D, Cuenod CA, Ville Y, Clément O, Salomon LJ. Dynamic contrast-enhanced magnetic resonance imaging: definitive imaging of placental function? Semin Fetal Neonatal Med 2011; 16:22-8. [PMID: 20851065 DOI: 10.1016/j.siny.2010.09.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The placenta constitutes a complex circulatory interface between the mother and fetus, but the relationship between the maternal and fetal circulation is still very difficult to study in vivo. There is growing evidence that magnetic resonance imaging (MRI) is useful and safe during pregnancy, and MRI is increasingly used for fetal and placental anatomical imaging. MRI functional imaging is now a modern obstetric tool and has the potential to provide new insights into the physiology of the human placenta. Placental perfusion has been studied during the first pass of an MR contrast agent, by arterial spin labeling, diffusion imaging, T1 and T2 relaxation time measurement using echo-planar imaging, and by a combination of magnetization transfer with established stereological methods. The BOLD (blood oxygen level-dependent) effect offers new perspectives for functional MRI evaluation of the placenta.
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Affiliation(s)
- G E Chalouhi
- Laboratoire de Recherche en Imagerie (LRI), INSERM U970, Equipe N°2, Paris Cardiovascular Research Center - PARCC, 56 rue Leblanc, 75015 Paris, France
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19
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Damodaram M, Story L, Eixarch E, Patel A, McGuinness A, Allsop J, Wyatt-Ashmead J, Kumar S, Rutherford M. Placental MRI in intrauterine fetal growth restriction. Placenta 2010; 31:491-8. [PMID: 20347139 DOI: 10.1016/j.placenta.2010.03.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 02/11/2010] [Accepted: 03/01/2010] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Our objectives were to determine if MR imaging of the placenta could demonstrate a specific placental phenotype in small for gestational age fetuses with increasing severity of fetal growth restriction, and if MRI findings at the time of scan could be used to predict fetal or neonatal mortality. METHOD We included singleton growth restricted fetuses with increasing severity of fetal growth restriction secondary to placental insufficiency. 20 growth restricted fetuses and 28 normal fetuses were scanned once during pregnancy at varying gestations. MRI scans were performed on a 1.5T system using ssFSE sequences through the uterus. Data was collected on the severity of fetal growth restriction and pregnancy outcome, including clinical neonatal details, perinatal mortality, and birthweight and centile. Placental volume, maximal placental thickness, the placental thickness to volume ratio, the placenta to amniotic fluid signal intensity ratio, and the presence of abnormal signal intensity consistent with placental pathology were noted. In a subset of patients, histopathological diagnosis was compared with the MRI appearance of the placenta. RESULTS There was a significant increase in the placental volume affected by pathology in growth restricted fetuses (p < 0.001). The placental appearance was also thickened and globular, with an increase in the placental thickness to volume ratio (p < 0.001). Although placental volume increased with increasing gestation, it remained reduced in the growth restricted fetuses (p = 0.003). There was a significant correlation between the severity of fetal growth restriction and the placental volume affected by pathology, the placental thickness to volume ratio, and the placental volume. ROC analysis showed that fetal or neonatal death was predicted by the percentage of abnormal signal intensity consistent with placental pathology (p = 0.002). The presence of a thickened, globular placenta and a maximal placental thickness to volume ratio above the 95% confidence limit for gestation was significantly associated with an increased incidence of fetal or neonatal mortality (relative risk = 1.615, p = 0.001 and relative risk = 7, p < 0.001). CONCLUSIONS The MRI appearance of the placenta provides an indication of the severity and underlying disease process in fetal growth restriction. In units where MRI imaging of the growth restricted fetus occurs, we suggest that the assessment of the placenta should also occur as it may contribute to management decisions in cases at the threshold of viability. It may have a role to play in monitoring disease severity, and the effect of future interventions designed to improve placental function.
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Affiliation(s)
- M Damodaram
- Imperial College London, Hammersmith Campus, London, UK.
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20
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Tomlinson TM, Garbow JR, Anderson JR, Engelbach JA, Nelson DM, Sadovsky Y. Magnetic resonance imaging of hypoxic injury to the murine placenta. Am J Physiol Regul Integr Comp Physiol 2009; 298:R312-9. [PMID: 19923363 DOI: 10.1152/ajpregu.00425.2009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We assessed the use of magnetic resonance imaging (MRI) to define placental hypoxic injury associated with fetal growth restriction. On embryonic day 18.5 (E18.5) we utilized dynamic contrast-enhanced (DCE)-MRI on a 4.7-tesla small animal scanner to examine the uptake and distribution of gadolinium-based contrast agent. Quantitative DCE parameter analysis was performed for the placenta and fetal kidneys of three groups of pregnant C57BL/6 mice: 1) mice that were exposed to Fi(O(2)) = 12% between E15.5 and E18.5, 2) mice in normoxia with food restriction similar to the intake of hypoxic mice between E15.5 and E18.5, and 3) mice in normoxia that were fed ad libitum. After imaging, we assessed fetoplacental weight, placental histology, and gene expression. We found that dams exposed to hypoxia exhibited fetal growth restriction (weight reduction by 28% and 14%, respectively, P < 0.05) with an increased placental-to-fetal ratio. By using MRI-based assessment of placental contrast agent kinetics, referenced to maternal paraspinous muscle, we found decreased placental clearance of contrast media in hypoxic mice, compared with either control group (61%, P < 0.05). This was accompanied by diminished contrast accumulation in the hypoxic fetal kidneys (23%, P < 0.05), reflecting reduced transplacental gadolinium transport. These changes were associated with increased expression of placental Phlda2 and Gcm1 transcripts. Exposure to hypoxia near the end of mouse pregnancy reduces placental perfusion and clearance of contrast. MRI-based DCE imaging provides a novel tool for dynamic, in vivo assessment of placental function.
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Affiliation(s)
- Tracy M Tomlinson
- Department of Obstetrics and Gynecology, Washington University, St. Louis, Missouri, USA
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Grisaru-Granovsky S, Halevy T, Eidelman A, Elstein D, Samueloff A. Hypertensive disorders of pregnancy and the small for gestational age neonate: not a simple relationship. Am J Obstet Gynecol 2007; 196:335.e1-5. [PMID: 17403411 DOI: 10.1016/j.ajog.2006.11.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2006] [Revised: 09/25/2006] [Accepted: 11/15/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Intrauterine growth restriction (IUGR) reflected by small for gestational age (SGA) status is considered a measure of severity of hypertensive disorders of pregnancy. The purpose of this study was to ascertain whether hypertensive disorders of pregnancy and SGA correlate with severity of hypertension, suggestive of common pathophysiological pathways. STUDY DESIGN Perinatal and hospital data from 1998-2002 were reviewed. The study identified women with singletons and hypertensive disorders of pregnancy, including those with SGA babies and those with appropriate for gestational age babies. RESULTS Severity characteristics of hypertensive disorders did not significantly differ between groups (r < .6); however, hypertensive mothers with SGA babies had a higher incidence of a previous SGA baby (but no difference in previous hypertension). CONCLUSION IUGR in hypertensive disorders of pregnancy is not a measure of severity of hypertension, but reflects underlying fetal susceptibility to growth factors and/or unique (familial) growth patterns. IUGR as a gauge of severity of hypertensive disorders of pregnancy should be reassessed.
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Abramowicz JS, Sheiner E. In utero imaging of the placenta: importance for diseases of pregnancy. Placenta 2007; 28 Suppl A:S14-22. [PMID: 17383721 DOI: 10.1016/j.placenta.2007.02.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 02/08/2007] [Accepted: 02/09/2007] [Indexed: 11/15/2022]
Abstract
Maurice Panigel demonstrated by X-rays, almost 40 years ago, placental maternal blood jets in non-human primates. Although to researchers the importance of the placenta is evident, in clinical obstetrical imaging, the fetus takes precedence. The placenta is imaged almost as an after thought and mostly to determine its location in the uterus. In animal species, the placenta was imaged with techniques which would be considered too invasive (or too costly for routine use) in humans, many pioneered by Panigel: radioangiography, radioisotopes scintigraphy, thermography, magnetic resonance imaging (MRI) and spectroscopy, positive emission tomography (PET) and single photon emission computed tomography (SPECT). Ultrasound allows for detailed, and, as far as is known, safe analyses of not only placental structure in the human but also its function. Earlier, only 2-dimensional grey-scale was available and more than 20 years ago, placental grading was popular. Later, colour imaging and spectral Doppler analysis of blood velocity both in the umbilical artery and within the placenta as well as the uterus and fetal vessels became essential and, more recently, the use of ultrasound contrast agents has been described, albeit not yet in a clinical setting. Three-dimensional ultrasound permits evaluation of the placenta in several planes, more precise depiction of internal vasculature as well as more accurate volume assessment. Several medical disorders of the pregnant woman or her fetus begin or end in the placenta, and ultrasound is the optimal investigation method. Obvious examples include pre-eclampsia and other forms of hypertension in pregnancy, less than optimal fetal growth (i.e. intrauterine growth restriction), triploidy (and its placental manifestation: partial mole), non-immune hydrops as well as several infectious processes. Ultrasound is also particularly suited to evaluate specific placental conditions, such as abnormal placentation (placenta previa and accrete for instance), gestational trophoblastic disease and placental tumors (e.g. chorioangioma).
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Affiliation(s)
- J S Abramowicz
- Department of Obstetrics and Gynecology, Rush University, 1653 West Congress Parkway, Chicago, IL 60612, USA.
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Abstract
Placental function is of fundamental importance for normal fetal growth and development. The movement of blood within the placenta ensures adequate transfer of nutrients and waste products across the feto-maternal barrier. The placenta is a relatively easy organ to study with magnetic resonance imaging (MRI) as it has a very high blood volume. MRI can be used to assess both the growth and function of the normal placenta and can distinguish differences from normal in placentas from pregnancies compromised by fetal growth restriction and pre-eclampsia.
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Affiliation(s)
- Penny Gowland
- Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, UK.
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Current awareness in prenatal diagnosis. Prenat Diagn 2004. [DOI: 10.1002/pd.782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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