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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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Darby JRT, Flouri D, Cho SKS, Williams GK, Holman SL, Meakin AS, Wiese MD, David AL, Macgowan CK, Seed M, Melbourne A, Morrison JL. Maternal tadalafil treatment does not increase uterine artery blood flow or oxygen delivery in the pregnant ewe. Exp Physiol 2024; 109:980-991. [PMID: 38606906 PMCID: PMC11140180 DOI: 10.1113/ep091593] [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: 10/17/2023] [Accepted: 03/26/2024] [Indexed: 04/13/2024]
Abstract
Increasing placental perfusion (PP) could improve outcomes of growth-restricted fetuses. One way of increasing PP may be by using phosphodiesterase (PDE)-5 inhibitors, which induce vasodilatation of vascular beds. We used a combination of clinically relevant magnetic resonance imaging (MRI) techniques to characterize the impact that tadalafil infusion has on maternal, placental and fetal circulations. At 116-117 days' gestational age (dGA; term, 150 days), pregnant ewes (n = 6) underwent fetal catheterization surgery. At 120-123 dGA ewes were anaesthetized and MRI scans were performed during three acquisition windows: a basal state and then ∼15-75 min (TAD 1) and ∼75-135 min (TAD 2) post maternal administration (24 mg; intravenous bolus) of tadalafil. Phase contrast MRI and T2 oximetry were used to measure blood flow and oxygen delivery. Placental diffusion and PP were assessed using the Diffusion-Relaxation Combined Imaging for Detailed Placental Evaluation-'DECIDE' technique. Uterine artery (UtA) blood flow when normalized to maternal left ventricular cardiac output (LVCO) was reduced in both TAD periods. DECIDE imaging found no impact of tadalafil on placental diffusivity or fetoplacental blood volume fraction. Maternal-placental blood volume fraction was increased in the TAD 2 period. FetalD O 2 ${D_{{{\mathrm{O}}_2}}}$ andV ̇ O 2 ${\dot V_{{{\mathrm{O}}_2}}}$ were not affected by maternal tadalafil administration. Maternal tadalafil administration did not increase UtA blood flow and thus may not be an effective vasodilator at the level of the UtAs. The increased maternal-placental blood volume fraction may indicate local vasodilatation of the maternal intervillous space, which may have compensated for the reduced proportion of UtAD O 2 ${D_{{{\mathrm{O}}_2}}}$ .
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Affiliation(s)
- Jack R. T. Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Dimitra Flouri
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Steven K. S. Cho
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Georgia K. Williams
- Preclinical, Imaging & Research LaboratoriesSouth Australian Health & Medical Research InstituteAdelaideAustralia
| | - Stacey L. Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Ashley S. Meakin
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Michael D. Wiese
- Centre for Pharmaceutical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Anna L. David
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonUK
- National Institute for Health and Care Research (NIHR)University College London, Hospitals Biomedical Research CentreLondonUK
| | | | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
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Cromb D, Slator PJ, De La Fuente M, Price AN, Rutherford M, Egloff A, Counsell SJ, Hutter J. Assessing within-subject rates of change of placental MRI diffusion metrics in normal pregnancy. Magn Reson Med 2023; 90:1137-1150. [PMID: 37183839 PMCID: PMC10962570 DOI: 10.1002/mrm.29665] [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: 11/29/2022] [Revised: 03/14/2023] [Accepted: 03/22/2023] [Indexed: 05/16/2023]
Abstract
PURPOSE Studying placental development informs when development is abnormal. Most placental MRI studies are cross-sectional and do not study the extent of individual variability throughout pregnancy. We aimed to explore how diffusion MRI measures of placental function and microstructure vary in individual healthy pregnancies throughout gestation. METHODS Seventy-nine pregnant, low-risk participants (17 scanned twice and 62 scanned once) were included. T2 -weighted anatomical imaging and a combined multi-echo spin-echo diffusion-weighted sequence were acquired at 3 T. Combined diffusion-relaxometry models were performed using both aT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -ADC and a bicompartmentalT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -intravoxel-incoherent-motion (T 2 * IVIM $$ {\mathrm{T}}_2^{\ast}\;\mathrm{IVIM} $$ ) model fit. RESULTS There was a significant decline in placentalT 2 * $$ {\mathrm{T}}_2^{\ast } $$ and ADC (both P < 0.01) over gestation. These declines are consistent in individuals forT 2 * $$ {\mathrm{T}}_2^{\ast } $$ (covariance = -0.47), but not ADC (covariance = -1.04). TheT 2 * IVIM $$ {\mathrm{T}}_2^{\ast}\;\mathrm{IVIM} $$ model identified a consistent decline in individuals over gestation inT 2 * $$ {\mathrm{T}}_2^{\ast } $$ from both the perfusing and diffusing placental compartments, but not in ADC values from either. The placental perfusing compartment fraction increased over gestation (P = 0.0017), but this increase was not consistent in individuals (covariance = 2.57). CONCLUSION Whole placentalT 2 * $$ {\mathrm{T}}_2^{\ast } $$ and ADC values decrease over gestation, although onlyT 2 * $$ {\mathrm{T}}_2^{\ast } $$ values showed consistent trends within subjects. There was minimal individual variation in rates of change ofT 2 * $$ {\mathrm{T}}_2^{\ast } $$ values from perfusing and diffusing placental compartments, whereas trends in ADC values from these compartments were less consistent. These findings probably relate to the increased complexity of the bicompartmentalT 2 * IVIM $$ {\mathrm{T}}_2^{\ast}\;\mathrm{IVIM} $$ model, and differences in how different placental regions evolve at a microstructural level. These placental MRI metrics from low-risk pregnancies provide a useful benchmark for clinical cohorts.
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Affiliation(s)
- Daniel Cromb
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Paddy J. Slator
- Centre for Medical Image Computing, Department of Computer ScienceUniversity College LondonLondonUK
| | - Miguel De La Fuente
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Anthony N. Price
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
- Centre for Medical EngineeringSchool of Biomedical Engineering and Imaging Sciences, King's College LondonLondonUK
| | - Mary Rutherford
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
- MRC Centre for Neurodevelopmental DisordersKing's College LondonLondonUK
| | - Alexia Egloff
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Serena J. Counsell
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
| | - Jana Hutter
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonUK
- Centre for Medical EngineeringSchool of Biomedical Engineering and Imaging Sciences, King's College LondonLondonUK
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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, Cho SKS, Dimasi CG, Perumal SR, Ourselin S, Aughwane R, Mufti N, Macgowan CK, Seed M, David AL, Melbourne A, Morrison JL. Placental MRI Predicts Fetal Oxygenation and Growth Rates in Sheep and Human Pregnancy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203738. [PMID: 36031385 PMCID: PMC9596844 DOI: 10.1002/advs.202203738] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/05/2022] [Indexed: 06/09/2023]
Abstract
Magnetic resonance imaging (MRI) assessment of fetal blood oxygen saturation (SO2 ) can transform the clinical management of high-risk pregnancies affected by fetal growth restriction (FGR). Here, a novel MRI method assesses the feasibility of identifying normally grown and FGR fetuses in sheep and is then applied to humans. MRI scans are performed in pregnant ewes at 110 and 140 days (term = 150d) gestation and in pregnant women at 28+3 ± 2+5 weeks to measure feto-placental SO2 . Birth weight is collected and, in sheep, fetal blood SO2 is measured with a blood gas analyzer (BGA). Fetal arterial SO2 measured by BGA predicts fetal birth weight in sheep and distinguishes between fetuses that are normally grown, small for gestational age, and FGR. MRI feto-placental SO2 in late gestation is related to fetal blood SO2 measured by BGA and body weight. In sheep, MRI feto-placental SO2 in mid-gestation is related to fetal SO2 later in gestation. MRI feto-placental SO2 distinguishes between normally grown and FGR fetuses, as well as distinguishing FGR fetuses with and without normal Doppler in humans. Thus, a multi-compartment placental MRI model detects low placental SO2 and distinguishes between small hypoxemic fetuses and normally grown fetuses.
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Affiliation(s)
- Dimitra Flouri
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonSE1 7EUUK
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
| | - Jack R. T. Darby
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Stacey L. Holman
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Steven K. S. Cho
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
- Department of PhysiologyThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
| | - Catherine G. Dimasi
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Sunthara R. Perumal
- South Australian Health & Medical Research InstitutePreclinicalImaging & Research LaboratoriesAdelaideSA 5001Australia
| | - Sebastien Ourselin
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonSE1 7EUUK
| | - Rosalind Aughwane
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonWC1E 6AUUK
| | - Nada Mufti
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonWC1E 6AUUK
| | - Christopher K. Macgowan
- Division of Translational MedicineThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
- Department of Medical BiophysicsUniversity of TorontoTorontoON M5S 1A1Canada
| | - Mike Seed
- Department of PaediatricsDivision of CardiologyThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
- Department of Diagnostic ImagingThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
| | - Anna L. David
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonWC1E 6AUUK
- NIHR Biomedical Research CentreUniversity College London HospitalsLondonW1T 7DNUK
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonSE1 7EUUK
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Janna L. Morrison
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
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Malmberg M, Kragsterman E, Sinding M, Hansen DN, Peters DA, Frøkjær JB, Petersen AC, Sørensen A. Perfusion fraction derived from IVIM analysis of diffusion-weighted MRI in the assessment of placental vascular malperfusion antenatally. Placenta 2022; 119:1-7. [DOI: 10.1016/j.placenta.2022.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 12/19/2021] [Accepted: 01/05/2022] [Indexed: 12/16/2022]
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Mizutani T, Kotani T, Kato N, Imai K, Ushida T, Nakano-Kobayashi T, Kinoshita Y, Ito M, Kinoshita F, Yamamuro O, Kajiyama H. Assessment of placental abruption with diffusion-weighted imaging. J Obstet Gynaecol Res 2022; 48:930-937. [PMID: 35194877 DOI: 10.1111/jog.15183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/28/2021] [Accepted: 01/26/2022] [Indexed: 11/30/2022]
Abstract
AIM To investigate whether placental abruption without fetal distress could be assessed by apparent diffusion coefficient (ADC) values in magnetic resonance imaging (MRI). METHODS We conducted a retrospective case-control study at a single center. ADC values at the lesions of placental abruption in the abruption group (n = 8) were compared to those in the control group (n = 32). In the abruption group, ADC values at the sites of abruption were also compared to those at the nonabruption sites within the same placenta. RESULTS The ADC values in the placental area above the abruption site in the abruption group showed lower values than those in the control group when the slice containing the umbilical cord insertion site was set as the reference, and those values were compared in each corresponding slice. Compared with average ADC values, those above the abruption site in the abruption group were also significantly lower than those in the control group (p < 0.001). Furthermore, ADC values at the area above abruption were lower than those at the nonabruption area of all planes in the abruption group. CONCLUSIONS ADC values at the lesions above the placental abruption site were reduced compared to those in the normal placenta and those in the nonabruption area. Thus, it would be helpful to understand the pathophysiology of placental abruption in expectant management, although further investigations would be needed.
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Affiliation(s)
- Teruyuki Mizutani
- Department of Obstetrics and Gynaecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Obstetrics and Gynaecology, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Nagoya, Japan
| | - Tomomi Kotani
- Department of Obstetrics and Gynaecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan
| | - Noriko Kato
- Department of Obstetrics and Gynaecology, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Nagoya, Japan
| | - Kenji Imai
- Department of Obstetrics and Gynaecology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takafumi Ushida
- Department of Obstetrics and Gynaecology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tomoko Nakano-Kobayashi
- Department of Obstetrics and Gynaecology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshimi Kinoshita
- Diagnostic Radiology, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Nagoya, Japan
| | - Masato Ito
- Diagnostic Radiology, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Nagoya, Japan
| | - Fumie Kinoshita
- Data Science Division, Data Coordinating Center, Department of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Osamu Yamamuro
- Department of Obstetrics and Gynaecology, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Nagoya, Japan
| | - Hiroaki Kajiyama
- Department of Obstetrics and Gynaecology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Flouri D, Lesnic D, Chrysochou C, Parikh J, Thelwall P, Sheerin N, Kalra PA, Buckley DL, Sourbron SP. Motion correction of free-breathing magnetic resonance renography using model-driven registration. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2021; 34:805-822. [PMID: 34160718 PMCID: PMC8578117 DOI: 10.1007/s10334-021-00936-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/24/2021] [Accepted: 06/08/2021] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Model-driven registration (MDR) is a general approach to remove patient motion in quantitative imaging. In this study, we investigate whether MDR can effectively correct the motion in free-breathing MR renography (MRR). MATERIALS AND METHODS MDR was generalised to linear tracer-kinetic models and implemented using 2D or 3D free-form deformations (FFD) with multi-resolution and gradient descent optimization. MDR was evaluated using a kidney-mimicking digital reference object (DRO) and free-breathing patient data acquired at high temporal resolution in multi-slice 2D (5 patients) and 3D acquisitions (8 patients). Registration accuracy was assessed using comparison to ground truth DRO, calculating the Hausdorff distance (HD) between ground truth masks with segmentations and visual evaluation of dynamic images, signal-time courses and parametric maps (all data). RESULTS DRO data showed that the bias and precision of parameter maps after MDR are indistinguishable from motion-free data. MDR led to reduction in HD (HDunregistered = 9.98 ± 9.76, HDregistered = 1.63 ± 0.49). Visual inspection showed that MDR effectively removed motion effects in the dynamic data, leading to a clear improvement in anatomical delineation on parametric maps and a reduction in motion-induced oscillations on signal-time courses. DISCUSSION MDR provides effective motion correction of MRR in synthetic and patient data. Future work is needed to compare the performance against other more established methods.
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Affiliation(s)
- Dimitra Flouri
- Department of Applied Mathematics, University of Leeds, Leeds, UK. .,Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK. .,School of Biomedical Engineering and Imaging Sciences, Kings College London, London, UK. .,Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
| | - Daniel Lesnic
- Department of Applied Mathematics, University of Leeds, Leeds, UK
| | - Constantina Chrysochou
- Department of Renal Medicine, Salford Royal National Health Service Foundation Trust, Salford, UK
| | - Jehill Parikh
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.,Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, University of Newcastle, Newcastle upon Tyne, UK
| | - Peter Thelwall
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.,Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, University of Newcastle, Newcastle upon Tyne, UK
| | - Neil Sheerin
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Philip A Kalra
- Department of Renal Medicine, Salford Royal National Health Service Foundation Trust, Salford, UK
| | - David L Buckley
- Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK
| | - Steven P Sourbron
- Department of Biomedical Imaging Sciences, University of Leeds, Leeds, UK.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, 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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10
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Couper S, Clark A, Thompson JMD, Flouri D, Aughwane R, David AL, Melbourne A, Mirjalili A, Stone PR. The effects of maternal position, in late gestation pregnancy, on placental blood flow and oxygenation: an MRI study. J Physiol 2021; 599:1901-1915. [PMID: 33369732 DOI: 10.1113/jp280569] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/10/2020] [Indexed: 01/07/2023] Open
Abstract
KEY POINTS Maternal supine sleep position in late pregnancy is associated with an increased risk of stillbirth. Maternal supine position in late pregnancy reduces maternal cardiac output and uterine blood flow. Using MRI, this study shows that compared to the left lateral position, maternal supine position in late pregnancy is associated with reduced utero-placental blood flow and oxygen transfer across the placenta with an average 6.2% reduction in oxygen delivery to the fetus and an average 11% reduction in fetal umbilical venous blood flow. ABSTRACT Maternal sleep position in late gestation is associated with an increased risk of stillbirth, though the pathophysiological reasons for this are unclear. Studies using magnetic resonance imaging (MRI) have shown that compared with lateral positions, lying supine causes a reduction in cardiac output, reduced abdominal aortic blood flow and reduced vena caval flow which is only partially compensated for by increased flow in the azygos venous system. Using functional MRI techniques, including an acquisition termed diffusion-relaxation combined imaging of the placenta (DECIDE), which combines diffusion weighted imaging and T2 relaxometry, blood flow and oxygen transfer were estimated in the maternal, fetal and placental compartments when subjects were scanned both supine and in left lateral positions. In late gestation pregnancy, lying supine caused a 23.7% (P < 0.0001) reduction in total internal iliac arterial blood flow to the uterus. In addition, lying in the supine position caused a 6.2% (P = 0.038) reduction in oxygen movement across the placenta. The reductions in oxygen transfer to the fetus, termed delivery flux, of 11.2% (P = 0.0597) and in fetal oxygen saturation of 4.4% (P = 0.0793) did not reach statistical significance. It is concluded that even in healthy late gestation pregnancy, maternal position significantly affects oxygen transfer across the placenta and may in part provide an explanation for late stillbirth in vulnerable fetuses.
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Affiliation(s)
- Sophie Couper
- Department of Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand
| | - Alys Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - John M D Thompson
- Department of Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand.,Department of Paediatrics and Child Health, University of Auckland, Auckland, New Zealand
| | - Dimitra Flouri
- School of Biomedical Engineering and Imaging, Kings College London, London, UK
| | - Rosalind Aughwane
- Elizabeth Garrett Anderson Institute for Women's Health, University College, Huntley Street, London, UK
| | - Anna L David
- Elizabeth Garrett Anderson Institute for Women's Health, University College, Huntley Street, London, UK
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging, Kings College London, London, UK
| | - Ali Mirjalili
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Peter R Stone
- Department of Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand
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11
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Saini BS, Darby JRT, Portnoy S, Sun L, van Amerom J, Lock MC, Soo JY, Holman SL, Perumal SR, Kingdom JC, Sled JG, Macgowan CK, Morrison JL, Seed M. Normal human and sheep fetal vessel oxygen saturations by T2 magnetic resonance imaging. J Physiol 2020; 598:3259-3281. [PMID: 32372463 DOI: 10.1113/jp279725] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/30/2020] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Human fetal Doppler ultrasound and invasive blood gas measurements obtained by cordocentesis or at the time of delivery reveal similarities with sheep (an extensively used model for human fetal cardiovascular physiology). Oxygen saturation (SO2 ) measurements in human fetuses have been limited to the umbilical and scalp vessels, providing little information about normal regional SO2 differences in the fetus. Blood T2 MRI relaxometry presents a non-invasive measure of SO2 in the major fetal vessels. This study presents the first in vivo validation of fetal vessel T2 oximetry against the in vitro T2-SO2 relationship using catheterized sheep fetuses and compares the normal SO2 in the major vessels between the human and sheep fetal circulations. Human fetal vessel SO2 by T2 MRI confirms many similarities with the sheep fetal circulation and is able to demonstrate regional differences in SO2 ; in particular the significantly higher SO2 in the left versus right heart. ABSTRACT Blood T2 magnetic resonance imaging (MRI) relaxometry non-invasively measures oxygen saturation (SO2 ) in major vessels but has not been validated in fetuses in vivo. We compared the blood T2-SO2 relationship in vitro (tubes) and in vivo (vessels) in sheep, and measured SO2 across the normal human and sheep fetal circulations by T2. Singleton pregnant ewes underwent surgery to implant vascular catheters. In vitro and in vivo sheep blood T2 measurements were related to corresponding SO2 measured using a blood gas analyser, as well as relating T2 and SO2 of human fetal blood in vitro. MRI oximetry was performed in the major vessels of 30 human fetuses at 36 weeks (term, 40 weeks) and 10 fetal sheep (125 days; term, 150 days). The fidelity of in vivo fetal T2 oximetry was confirmed through comparison of in vitro and in vivo sheep blood T2-SO2 relationships (P = 0.1). SO2 was similar between human and sheep fetuses, as was the fetal oxygen extraction fraction (human, 33 ± 11%; sheep, 34 ± 7%; P = 0.798). The presence of streaming in the human fetal circulation was demonstrated by the SO2 gradient between the ascending aorta (68 ± 10%) and the main pulmonary artery (49 ± 9%; P < 0.001). Human and sheep fetal vessel MRI oximetry based on T2 is a validated approach that confirms the presence of streaming of umbilical venous blood towards the heart and brain. Streaming is important in ensuring oxygen delivery to these organs and its disruption may have important implications for organ development, especially in conditions such as congenital heart disease and fetal growth restriction.
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Affiliation(s)
- Brahmdeep S Saini
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - 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, South Australia, 5000, Australia
| | - Sharon Portnoy
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Liqun Sun
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Joshua van Amerom
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, 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, South Australia, 5000, Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, South Australia, 5086, Australia
| | - John C Kingdom
- Department of Obstetrics and Gynaecology, Maternal-Fetal Medicine, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
| | - John G Sled
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Christopher K Macgowan
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Mike Seed
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
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12
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Can introvoxel incoherent motion MRI be used to differentiate patients with placenta accreta spectrum disorders? BMC Pregnancy Childbirth 2019; 19:531. [PMID: 31888572 PMCID: PMC6937691 DOI: 10.1186/s12884-019-2676-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/12/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The incidence of PAS disorders increased rapidly in recent years, and introvoxel incoherent motion (IVIM) MRI has been applied in the assessment of placenta. The study aims to investigate whether the parameters from IVIM can be used to differentiate patients with PAS disorders complicating placenta previa and secondly to differentiate different categories of PAS disorders. METHODS The study participants were comprised of 99 patients with placenta previa, including 16 patients with placenta accreta, 51 patients with increta, 8 patients with percreta and 24 patients without PAS disorders between 28 + 0 and 39 + 6 weeks. IVIM MRI was performed on a 1.5 T scanner. Perfusion fraction (f), pseudodiffusion coefficient (D*) and diffusion coefficient (D) were calculated. RESULTS Women with PAS disorders had a higher perfusion fraction (p = 0.019) than women without the disease. Multiple comparisons showed perfusion fraction in patients without PAS disorders was significantly lower than in patients with placenta accreta and percreta(P = 0.018 and 0.033 respectively), but was not lower than in patients with increta(p = 1). CONCLUSION Patients with placenta accreta and percreta differed in placental perfusion fraction from women with increta and without PAS disorders.
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13
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Flouri D, Owen D, Aughwane R, Mufti N, Maksym K, Sokolska M, Kendall G, Bainbridge A, Atkinson D, Vercauteren T, Ourselin S, David AL, Melbourne A. Improved fetal blood oxygenation and placental estimated measurements of diffusion-weighted MRI using data-driven Bayesian modeling. Magn Reson Med 2019; 83:2160-2172. [PMID: 31742785 PMCID: PMC7064949 DOI: 10.1002/mrm.28075] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 12/24/2022]
Abstract
PURPOSE Motion correction in placental DW-MRI is challenging due to maternal breathing motion, maternal movements, and rapid intensity changes. Parameter estimates are usually obtained using least-squares methods for voxel-wise fitting; however, they typically give noisy estimates due to low signal-to-noise ratio. We introduce a model-driven registration (MDR) technique which incorporates a placenta-specific signal model into the registration process, and we present a Bayesian approach for Diffusion-rElaxation Combined Imaging for Detailed placental Evaluation model to obtain individual and population trends in estimated parameters. METHODS MDR exploits the fact that a placenta signal model is available and thus we incorporate it into the registration to generate a series of target images. The proposed registration method is compared to a pre-existing method used for DCE-MRI data making use of principal components analysis. The Bayesian shrinkage prior (BSP) method has no user-defined parameters and therefore measures of parameter variation in a region of interest are determined by the data alone. The MDR method and the Bayesian approach were evaluated on 10 control 4D DW-MRI singleton placental data. RESULTS MDR method improves the alignment of placenta data compared to the pre-existing method. It also shows a further reduction of the residual error between the data and the fit. BSP approach showed higher precision leading to more clearly apparent spatial features in the parameter maps. Placental fetal oxygen saturation (FO2 ) showed a negative linear correlation with gestational age. CONCLUSIONS The proposed pipeline provides a robust framework for registering DW-MRI data and analyzing longitudinal changes of placental function.
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Affiliation(s)
- Dimitra Flouri
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - David Owen
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Rosalind Aughwane
- Institute for Women's Health, University College Hospital, London, United Kingdom
| | - Nada Mufti
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Institute for Women's Health, University College Hospital, London, United Kingdom
| | - Kasia Maksym
- Institute for Women's Health, University College Hospital, London, United Kingdom
| | | | - Giles Kendall
- Institute for Women's Health, University College Hospital, London, United Kingdom
| | - Alan Bainbridge
- Medical Physics, University College Hospital, London, United Kingdom
| | - David Atkinson
- Centre for Medical Imaging, University College London, London, United Kingdom
| | - Tom Vercauteren
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Sebastien Ourselin
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Anna L David
- Institute for Women's Health, University College Hospital, London, United Kingdom.,University Hospital KU Leuven, Leuven, Belgium.,NIHR Biomedical Research Centre, University College London Hospitals, London, United Kingdom
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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