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Wang J, Hu S, Liang P, Hu X, Shen Y, Peng Y, Kamel I, Li Z. R2* mapping and reduced field-of-view diffusion-weighted imaging for preoperative assessment of nonenlarged lymph node metastasis in rectal cancer. NMR IN BIOMEDICINE 2024:e5174. [PMID: 38712650 DOI: 10.1002/nbm.5174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 04/18/2024] [Accepted: 04/20/2024] [Indexed: 05/08/2024]
Abstract
The aim of the current study is to investigate the diagnostic value of R2* mapping versus reduced field-of-view diffusion-weighted imaging (rDWI) of the primary lesion of rectal cancer for preoperative prediction of nonenlarged lymph node metastasis (NLNM). Eighty-one patients with pathologically confirmed rectal cancer underwent preoperative R2* mapping and rDWI sequences before total mesorectal excisions and accompanying regional lymph node dissections. Two radiologists independently performed whole-tumor measurements of R2* and apparent diffusion coefficient (ADC) parameters on primary lesions of rectal cancer. Patients were divided into positive (NLNM+) and negative (NLNM-) groups based on their pathological analysis. The tumor location, maximum diameter of the tumor, and maximum short diameter of the lymph node were assessed. R2* and ADC, pT stage, tumor grade, status of mesorectal fascia, and extramural vascular invasion were also studied for their potential relationships with NLNM using multivariate logistic regression analysis. The NLNM+ group had significantly higher R2* (43.56 ± 8.43 vs. 33.87 ± 9.57, p < 0.001) and lower ADC (1.00 ± 0.13 vs. 1.06 ± 0.22, p = 0.036) than the NLNM- group. R2* and ADC were correlated to lymph node metastasis (r = 0.510, p < 0.001 for R2*; r = -0.235, p = 0.035 for ADC). R2* and ADC showed good and moderate diagnostic abilities in the assessment of NLNM status with corresponding area-under-the-curve values of 0.795 and 0.636. R2* provided a significantly better diagnostic performance compared with ADC for the prediction of NLNM status (z = 1.962, p = 0.0498). The multivariate logistic regression analysis demonstrated that R2* was a compelling factor of lymph node metastasis (odds ratio = 56.485, 95% confidence interval: 5.759-554.013; p = 0.001). R2* mapping had significantly higher diagnostic performance than rDWI from the primary tumor of rectal cancer in the prediction of NLNM status.
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Affiliation(s)
- Jing Wang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shan Hu
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Ping Liang
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xuemei Hu
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yaqi Shen
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yang Peng
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ihab Kamel
- Russell H. Morgan Department of Radiology and Radiological Science, the Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
| | - Zhen Li
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Janzen C, Lei MYY, Lee BR, Vangala S, DelRosario I, Meng Q, Ritz B, Liu J, Jerrett M, Chanlaw T, Choi S, Aliabadi A, Fortes PA, Sullivan PS, Murphy A, Vecchio GD, Thamotharan S, Sung K, Devaskar SU. A Description of the Imaging Innovations for Placental Assessment in Response to Environmental Pollution Study. Am J Perinatol 2024; 41:e853-e862. [PMID: 36241211 PMCID: PMC11111287 DOI: 10.1055/a-1961-2059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/22/2022] [Indexed: 11/01/2022]
Abstract
OBJECTIVE The aim of Placental Assessment in Response to Environmental Pollution Study (PARENTs) was to determine whether imaging of the placenta by novel multiparametric magnetic resonance imaging (MRI) techniques in early pregnancy could help predict adverse pregnancy outcomes (APOs) due to ischemic placental disease (IPD). Additionally, we sought to determine maternal characteristics and environmental risk factors that contribute to IPD and secondary APOs. STUDY DESIGN Potential patients in their first trimester of pregnancy, who agreed to MRI of the placenta and measures of assessment of environmental pollution, were recruited into PARENTs, a prospective population-based cohort study. Participants were seen at three study visits during pregnancy and again at their delivery from 2015 to 2019. We collected data from interviews, chart abstractions, and imaging. Maternal biospecimens (serum, plasma, and urine) at antepartum study visits and delivery specimens (placenta, cord, and maternal blood) were collected, processed, and stored. The primary outcome was a composite of IPD, which included any of the following: placental abruption, hypertensive disease of pregnancy, fetal growth restriction, or a newborn of small for gestational age. RESULTS In this pilot cohort, of the 190 patients who completed pregnancy to viable delivery, 50 (26%) developed IPD. Among demographic characteristics, having a history of prior IPD in multiparous women was associated with the development of IPD. In the multiple novel perfusion measurements taken of the in vivo placenta using MRI, decreased high placental blood flow (mL/100 g/min) in early pregnancy (between 14 and 16 weeks) was found to be significantly associated with the later development of IPD. CONCLUSION Successful recruitment of the PARENTs prospective cohort demonstrated the feasibility and acceptability of the use of MRI in human pregnancy to study the placenta in vivo and at the same time collect environmental exposure data. Analysis is ongoing and we hope these methods will assist researchers in the design of prospective imaging studies of pregnancy. KEY POINTS · MRI was acceptable and feasible for the study of the human placenta in vivo.. · Functional imaging of the placenta by MRI showed a significant decrease in high placental blood flow.. · Measures of environmental exposures are further being analyzed to predict IPD..
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Affiliation(s)
- Carla Janzen
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Margarida Y. Y. Lei
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Brian R. Lee
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Sitaram Vangala
- Department of Internal Medicine and Health Services Research, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Irish DelRosario
- Department of Epidemiology, Jonathan Fielding School of Public Health at University of California Los Angeles, Los Angeles, California
| | - Qi Meng
- Department of Epidemiology, Jonathan Fielding School of Public Health at University of California Los Angeles, Los Angeles, California
| | - Beate Ritz
- Department of Epidemiology, Jonathan Fielding School of Public Health at University of California Los Angeles, Los Angeles, California
| | - Jonathan Liu
- Department of Environmental Health Sciences, Jonathan Fielding School of Public Health at University of California Los Angeles, Los Angeles, California
| | - Michael Jerrett
- Department of Environmental Health Sciences, Jonathan Fielding School of Public Health at University of California Los Angeles, Los Angeles, California
| | - Teresa Chanlaw
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Sarah Choi
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Arya Aliabadi
- Department of Internal Medicine and Health Services Research, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Precious Ann Fortes
- Department of Pathology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Peggy S. Sullivan
- Department of Pathology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Aisling Murphy
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Giorgia Del Vecchio
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Shanthie Thamotharan
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - KyungHyun Sung
- Department of Radiology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
| | - Sherin U. Devaskar
- Department of Pediatrics, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
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Bano W, Holmes W, Goodburn R, Golbabaee M, Gupta A, Withey S, Tree A, Oelfke U, Wetscherek A. Joint radial trajectory correction for accelerated T 2 * mapping on an MR-Linac. Med Phys 2023; 50:7027-7038. [PMID: 37245075 PMCID: PMC10946747 DOI: 10.1002/mp.16479] [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: 08/04/2022] [Revised: 04/20/2023] [Accepted: 04/28/2023] [Indexed: 05/29/2023] Open
Abstract
BACKGROUND T2 * mapping can characterize tumor hypoxia, which may be associated with resistance to therapy. Acquiring T2 * maps during MR-guided radiotherapy could inform treatment adaptation by, for example, escalating the dose to resistant sub-volumes. PURPOSE The purpose of this work is to demonstrate the feasibility of the accelerated T2 * mapping technique using model-based image reconstruction with integrated trajectory auto-correction (TrACR) for MR-guided radiotherapy on an MR-Linear accelerator (MR-Linac). MATERIALS AND METHODS The proposed method was validated in a numerical phantom, where two T2 * mapping approaches (sequential and joint) were compared for different noise levels (0,0.1,0.5,1) and gradient delays ([1, -1] and [1, -2] in units of dwell time for x- and y-axis, respectively). Fully sampled k-space was retrospectively undersampled using two different undersampling patterns. Root mean square errors (RMSEs) were calculated between reconstructed T2 * maps and ground truth. In vivo data was acquired twice weekly in one prostate and one head and neck cancer patient undergoing treatment on a 1.5 T MR-Linac. Data were retrospectively undersampled and T2 * maps reconstructed, with and without trajectory corrections were compared. RESULTS Numerical simulations demonstrated that, for all noise levels, T2 * maps reconstructed with a joint approach demonstrated less error compared to an uncorrected and sequential approach. For a noise level of 0.1, uniform undersampling and gradient delay [1, -1] (in units of dwell time for x- and y-axis, respectively), RMSEs for sequential and joint approaches were 13.01 and 9.32 ms, respectively, which reduced to 10.92 and 5.89 ms for a gradient delay of [1, 2]. Similarly, for alternate undersampling and gradient delay [1, -1], RMSEs for sequential and joint approaches were 9.80 and 8.90 ms, respectively, which reduced to 9.10 and 5.40 ms for gradient delay [1, 2]. For in vivo data, T2 * maps reconstructed with our proposed approach resulted in less artifacts and improved visual appearance compared to the uncorrected approach. For both prostate and head and neck cancer patients, T2 * maps reconstructed from different treatment fractions showed changes within the planning target volume (PTV). CONCLUSION Using the proposed approach, a retrospective data-driven gradient delay correction can be performed, which is particularly relevant for hybrid devices, where full information on the machine configuration is not available for image reconstruction. T2 * maps were acquired in under 5 min and can be integrated into MR-guided radiotherapy treatment workflows, which minimizes patient burden and leaves time for additional imaging for online adaptive radiotherapy on an MR-Linac.
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Affiliation(s)
- Wajiha Bano
- Joint Department of PhysicsThe Institute of Cancer Research and The Royal Marsden NHS Foundation TrustLondonUK
| | - Will Holmes
- Joint Department of PhysicsThe Institute of Cancer Research and The Royal Marsden NHS Foundation TrustLondonUK
| | - Rosie Goodburn
- Joint Department of PhysicsThe Institute of Cancer Research and The Royal Marsden NHS Foundation TrustLondonUK
| | | | - Amit Gupta
- The Royal Marsden NHS Foundation Trust and The Institute of Cancer ResearchLondonUK
| | - Sam Withey
- The Royal Marsden NHS Foundation Trust and The Institute of Cancer ResearchLondonUK
| | - Alison Tree
- The Royal Marsden NHS Foundation Trust and The Institute of Cancer ResearchLondonUK
| | - Uwe Oelfke
- Joint Department of PhysicsThe Institute of Cancer Research and The Royal Marsden NHS Foundation TrustLondonUK
| | - Andreas Wetscherek
- Joint Department of PhysicsThe Institute of Cancer Research and The Royal Marsden NHS Foundation TrustLondonUK
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Herrera CL, Kim MJ, Do QN, Owen DM, Fei B, Twickler DM, Spong CY. The human placenta project: Funded studies, imaging technologies, and future directions. Placenta 2023; 142:27-35. [PMID: 37634371 PMCID: PMC11257151 DOI: 10.1016/j.placenta.2023.08.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 08/16/2023] [Accepted: 08/19/2023] [Indexed: 08/29/2023]
Abstract
The placenta plays a critical role in fetal development. It serves as a multi-functional organ that protects and nurtures the fetus during pregnancy. However, despite its importance, the intricacies of placental structure and function in normal and diseased states have remained largely unexplored. Thus, in 2014, the National Institute of Child Health and Human Development launched the Human Placenta Project (HPP). As of May 2023, the HPP has awarded over $101 million in research funds, resulting in 41 funded studies and 459 publications. We conducted a comprehensive review of these studies and publications to identify areas of funded research, advances in those areas, limitations of current research, and continued areas of need. This paper will specifically review the funded studies by the HPP, followed by an in-depth discussion on advances and gaps within placental-focused imaging. We highlight the progress within magnetic reasonance imaging and ultrasound, including development of tools for the assessment of placental function and structure.
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Affiliation(s)
- Christina L Herrera
- Department of Obstetrics and Gynecology, UT Southwestern Medical Center, and Parkland Health Dallas, Texas, USA; Green Center for Reproductive Biology Sciences, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Meredith J Kim
- University of Texas Southwestern Medical School, Dallas, TX, USA
| | - Quyen N Do
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - David M Owen
- Department of Obstetrics and Gynecology, UT Southwestern Medical Center, and Parkland Health Dallas, Texas, USA; Green Center for Reproductive Biology Sciences, UT Southwestern Medical Center, Dallas, TX, USA
| | - Baowei Fei
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA; Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA; Department of Bioengineering, University of Texas at Dallas, Dallas, TX, USA
| | - Diane M Twickler
- Department of Obstetrics and Gynecology, UT Southwestern Medical Center, and Parkland Health Dallas, Texas, USA; Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Catherine Y Spong
- Department of Obstetrics and Gynecology, UT Southwestern Medical Center, and Parkland Health Dallas, Texas, USA
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Lee B, Janzen C, Aliabadi AR, Lei MYY, Wu H, Liu D, Vangala SS, Devaskar SU, Sung K. Early pregnancy imaging predicts ischemic placental disease. Placenta 2023; 140:90-99. [PMID: 37549442 PMCID: PMC11090111 DOI: 10.1016/j.placenta.2023.07.297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 07/13/2023] [Accepted: 07/29/2023] [Indexed: 08/09/2023]
Abstract
INTRODUCTION To characterize early-gestation changes in placental structure, perfusion, and oxygenation in the context of ischemic placental disease (IPD) as a composite outcome and in individual sub-groups. METHODS In a single-center prospective cohort study, 199 women were recruited from antenatal clinics between February 2017 and February 2019. Maternal magnetic resonance imaging (MRI) studies of the placenta were temporally conducted at two timepoints: 14-16 weeks gestational age (GA) and 19-24 weeks GA. The pregnancy was monitored via four additional study visits, including at delivery. Placental volume, perfusion, and oxygenation were assessed at both MRI timepoints. The primary outcome was defined as pregnancy complicated by IPD, with group assignment confirmed after delivery. RESULTS In early gestation, mothers with IPD who subsequently developed fetal growth restriction (FGR) and/or delivered small-for gestational age (SGA) infants showed significantly decreased MRI indices of placental volume, perfusion, and oxygenation compared to controls. The prediction of FGR or SGA by multiple logistic regression using placental volume, perfusion, and oxygenation revealed receiver operator characteristic curves with areas under the curve of 0.81 (Positive predictive value (PPV) = 0.84, negative predictive value (NPV) = 0.75) at 14-16 weeks GA and 0.66 (PPV = 0.78, NPV = 0.60) at 19-24 weeks GA. DISCUSSION MRI indices showing decreased placental volume, perfusion and oxygenation in early pregnancy were associated with subsequent onset of IPD, with the greatest deviation evident in subjects with FGR and/or SGA. These early-gestation MRI changes may be predictive of the subsequent development of FGR and/or SGA.
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Affiliation(s)
- Brian Lee
- Department of Pediatrics, David Geffen School of Medicine, University of California, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.
| | - Carla Janzen
- Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.
| | - Arya R Aliabadi
- Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.
| | - Margarida Y Y Lei
- Department of Obstetrics and Gynecology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.
| | - Holden Wu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, 300 Medical Plaza, B119, Los Angeles, CA 90095, USA.
| | - Dapeng Liu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, 300 Medical Plaza, B119, Los Angeles, CA 90095, USA.
| | - Sitaram S Vangala
- Department of Medicine Statistical Core, David Geffen School of Medicine, University of California, 1100 Glendon Ave Suite 1820, Los Angeles, CA, 90095, USA.
| | - Sherin U Devaskar
- Department of Pediatrics, David Geffen School of Medicine, University of California, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.
| | - Kyunghyun Sung
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, 300 Medical Plaza, B119, Los Angeles, CA 90095, USA.
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Lee B, Janzen C, Wu H, Vangala SS, Devaskar SU, Sung K. Utility of In Vivo Magnetic Resonance Imaging Is Predictive of Gestational Diabetes Mellitus During Early Pregnancy. J Clin Endocrinol Metab 2023; 108:281-294. [PMID: 36251771 PMCID: PMC9844964 DOI: 10.1210/clinem/dgac602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 10/11/2022] [Indexed: 01/22/2023]
Abstract
CONTEXT Gestational diabetes (GDM) imposes long-term adverse health effects on the mother and fetus. The role of magnetic resonance imaging (MRI) during early gestation in GDM has not been well-studied. OBJECTIVE To investigate the role of quantitative MRI measurements of placental volume and perfusion, with distribution of maternal adiposity, during early gestation in GDM. METHODS At UCLA outpatient antenatal obstetrics clinics, ∼200 pregnant women recruited in the first trimester were followed temporally through pregnancy until parturition. Two placental MRI scans were prospectively performed at 14 to 16 weeks and 19 to 24 weeks gestational age (GA). Placental volume and blood flow (PBF) were calculated from placental regions of interest; maternal adiposity distribution was assessed by subcutaneous fat area ratio (SFAR) and visceral fat area ratio (VFAR). Statistical comparisons were performed using the two-tailed t test. Predictive logistic regression modeling was evaluated by area under the curve (AUC). RESULTS Of a total 186 subjects, 21 subjects (11.3%) developed GDM. VFAR was higher in GDM vs the control group, at both time points (P < 0.001 each). Placental volume was greater in GDM vs the control group at 19 to 24 weeks GA (P = 0.01). Combining VFAR, placental volume and perfusion, improved the AUC to 0.83 at 14 to 16 weeks (positive predictive value [PPV] = 0.77, negative predictive value [NPV] = 0.83), and 0.81 at 19 to 24 weeks GA (PPV = 0.73, NPV = 0.86). CONCLUSION A combination of MRI-based placental volume, perfusion, and visceral adiposity during early pregnancy demonstrates significant changes in GDM and provides a proof of concept for predicting the subsequent development of GDM.
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Affiliation(s)
- Brian Lee
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Carla Janzen
- Department of Obstetrics and Gynecology, Division of Perinatology Maternal Fetal Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Holden Wu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Sitaram S Vangala
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Sherin U Devaskar
- Correspondence: Sherin U. Devaskar, MD, Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, 10833, Le Conte Avenue, Los Angeles, CA 90095-1752, USA.
| | - Kyunghyun Sung
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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Strobel KM, Kafali SG, Shih SF, Artura AM, Masamed R, Elashoff D, Wu HH, Calkins KL. Pregnancies complicated by gestational diabetes and fetal growth restriction: an analysis of maternal and fetal body composition using magnetic resonance imaging. J Perinatol 2023; 43:44-51. [PMID: 36319757 PMCID: PMC9840659 DOI: 10.1038/s41372-022-01549-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Maternal body composition may influence fetal body composition. OBJECTIVE The objective of this pilot study was to investigate the relationship between maternal and fetal body composition. METHODS Three pregnant women cohorts were studied: healthy, gestational diabetes (GDM), and fetal growth restriction (FGR). Maternal body composition (visceral adipose tissue volume (VAT), subcutaneous adipose tissue volume (SAT), pancreatic and hepatic proton-density fat fraction (PDFF) and fetal body composition (abdominal SAT and hepatic PDFF) were measured using MRI between 30 to 36 weeks gestation. RESULTS Compared to healthy and FGR fetuses, GDM fetuses had greater hepatic PDFF (5.2 [4.2, 5.5]% vs. 3.2 [3, 3.3]% vs. 1.9 [1.4, 3.7]%, p = 0.004). Fetal hepatic PDFF was associated with maternal SAT (r = 0.47, p = 0.02), VAT (r = 0.62, p = 0.002), and pancreatic PDFF (r = 0.54, p = 0.008). When controlling for maternal SAT, GDM increased fetal hepatic PDFF by 0.9 ([0.51, 1.3], p = 0.001). CONCLUSION In this study, maternal SAT, VAT, and GDM status were positively associated with fetal hepatic PDFF.
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Affiliation(s)
- Katie M. Strobel
- Department of Pediatrics, Division of Neonatology & Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - Sevgi Gokce Kafali
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, USA
| | - Shu-Fu Shih
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, USA
| | | | - Rinat Masamed
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, USA
| | - David Elashoff
- University of California Los Angeles, Los Angeles, CA, USA
| | - Holden H. Wu
- Department of Medicine, Biostatistics and Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Kara L. Calkins
- Department of Pediatrics, Division of Neonatology & Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
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Ho A, Chappell LC, Story L, Al-Adnani M, Egloff A, Routledge E, Rutherford M, Hutter J. Visual assessment of the placenta in antenatal magnetic resonance imaging across gestation in normal and compromised pregnancies: Observations from a large cohort study. Placenta 2022; 117:29-38. [PMID: 34768166 PMCID: PMC8761363 DOI: 10.1016/j.placenta.2021.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 09/12/2021] [Accepted: 10/06/2021] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Visual assessment of the placenta in antenatal magnetic resonance imaging is important to confirm healthy appearances or to identify pathology complicating fetal anomaly or maternal disease. METHODS We assessed the placenta in a large cohort of 228 women with low and high risk pregnancies across gestation. All women gave written informed consent and were imaged using either a 3T Philips Achieva or 1.5T Philips Ingenia scanner. Images were acquired with a T2-weighted single shot turbo spin echo sequence of the whole uterus (thereby including placenta) for anatomical information. RESULTS A structured approach to visual assessment of the placenta on T2-weighted imaging has been provided including determination of key anatomical landmarks to aid orientation, placental shape, signal intensity, lobularity and granularity. Transient factors affecting imaging are shown including the effect of fetal movement, gross fetal motion and contractions. Placental appearances across gestation in low risk pregnancies are shown and compared to pregnancies complicated by preeclampsia and chronic hypertension. The utility of other magnetic resonance techniques (T2* mapping as an indirect marker for quantifying oxygenation) and histological assessment alongside visual assessment of placental T2-weighted imaging are demonstrated. DISCUSSION A systematic approach with qualitative descriptors for placental visual assessment using T2-weighted imaging allows confirmation of normal placental development and can detect placental abnormalities in pregnancy complications. T2-weighted imaging can be visually assessed alongside functional imaging (such as T2* maps) in order to further probe the visual characteristics seen.
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Affiliation(s)
- Alison Ho
- Department of Women and Children’s Health, School of Life Course Sciences, King’s College London, London, United Kingdom
| | - Lucy C. Chappell
- Department of Women and Children’s Health, School of Life Course Sciences, King’s College London, London, United Kingdom
| | - Lisa Story
- Department of Women and Children’s Health, School of Life Course Sciences, King’s College London, London, United Kingdom
| | - Mudher Al-Adnani
- Department of Cellular Pathology, Guy’s and St Thomas’ Hospital, London, United Kingdom
| | - Alexia Egloff
- Centre for the Developing Brain, King’s College London, London, United Kingdom
| | - Emma Routledge
- Centre for the Developing Brain, King’s College London, London, United Kingdom
| | - Mary Rutherford
- Centre for the Developing Brain, King’s College London, London, United Kingdom
| | - Jana Hutter
- Centre for the Developing Brain, King’s College London, London, United Kingdom,Biomedical Engineering Department, King’s College London, London, United Kingdom
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Pietsch M, Ho A, Bardanzellu A, Zeidan AMA, Chappell LC, Hajnal JV, Rutherford M, Hutter J. APPLAUSE: Automatic Prediction of PLAcental health via U-net Segmentation and statistical Evaluation. Med Image Anal 2021; 72:102145. [PMID: 34229190 PMCID: PMC8350147 DOI: 10.1016/j.media.2021.102145] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 04/26/2021] [Accepted: 06/21/2021] [Indexed: 02/04/2023]
Abstract
PURPOSE Artificial-intelligence population-based automated quantification of placental maturation and health from a rapid functional Magnetic Resonance scan. The placenta plays a crucial role for any successful human pregnancy. Deviations from the normal dynamic maturation throughout gestation are closely linked to major pregnancy complications. Antenatal assessment in-vivo using T2* relaxometry has shown great promise to inform management and possible interventions but clinical translation is hampered by time consuming manual segmentation and analysis techniques based on comparison against normative curves over gestation. METHODS This study proposes a fully automatic pipeline to predict the biological age and health of the placenta based on a free-breathing rapid (sub-30 second) T2* scan in two steps: Automatic segmentation using a U-Net and a Gaussian process regression model to characterize placental maturation and health. These are trained and evaluated on 108 3T MRI placental data sets, the evaluation included 20 high-risk pregnancies diagnosed with pre-eclampsia and/or fetal growth restriction. An independent cohort imaged at 1.5 T is used to assess the generalization of the training and evaluation pipeline. RESULTS Across low- and high-risk groups, automatic segmentation performs worse than inter-rater performance (mean Dice coefficients of 0.58 and 0.68, respectively) but is sufficient for estimating placental mean T2* (0.986 Pearson Correlation Coefficient). The placental health prediction achieves an excellent ability to differentiate cases of placental insufficiency between 27 and 33 weeks. High abnormality scores correlate with low birth weight, premature birth and histopathological findings. Retrospective application on a different cohort imaged at 1.5 T illustrates the ability for direct clinical translation. CONCLUSION The presented automatic pipeline facilitates a fast, robust and reliable prediction of placental maturation. It yields human-interpretable and verifiable intermediate results and quantifies uncertainties on the cohort-level and for individual predictions. The proposed machine-learning pipeline runs in close to real-time and, deployed in clinical settings, has the potential to become a cornerstone of diagnosis and intervention of placental insufficiency. APPLAUSE generalizes to an independent cohort imaged at 1.5 T, demonstrating robustness to different operational and clinical environments.
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Affiliation(s)
- Maximilian Pietsch
- Centre for Medical Engineering, King's College London, London, UK; Centre for the Developing Brain, King's College London, London, UK.
| | - Alison Ho
- Department of Women and Children's Health, King's College London, London, UK
| | - Alessia Bardanzellu
- Centre for Medical Engineering, King's College London, London, UK; Centre for the Developing Brain, King's College London, London, UK
| | - Aya Mutaz Ahmad Zeidan
- Centre for Medical Engineering, King's College London, London, UK; Centre for the Developing Brain, King's College London, London, UK
| | - Lucy C Chappell
- Department of Women and Children's Health, King's College London, London, UK
| | - Joseph V Hajnal
- Centre for Medical Engineering, King's College London, London, UK; Centre for the Developing Brain, King's College London, London, UK
| | - Mary Rutherford
- Centre for Medical Engineering, King's College London, London, UK; Centre for the Developing Brain, King's College London, London, UK
| | - Jana Hutter
- Centre for Medical Engineering, King's College London, London, UK; Centre for the Developing Brain, King's College London, London, UK
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10
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Kee Y, Sandino CM, Syed AB, Cheng JY, Shimakawa A, Colgan TJ, Hernando D, Vasanawala SS. Free-breathing R2∗ mapping of hepatic iron overload in children using 3D multi-echo UTE cones MRI. Magn Reson Med 2021; 85:2608-2621. [PMID: 33432613 PMCID: PMC8886621 DOI: 10.1002/mrm.28610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 10/07/2020] [Accepted: 11/01/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE To enable motion-robust, ungated, free-breathing R 2 ∗ mapping of hepatic iron overload in children with 3D multi-echo UTE cones MRI. METHODS A golden-ratio re-ordered 3D multi-echo UTE cones acquisition was developed with chemical-shift encoding (CSE). Multi-echo complex-valued source images were reconstructed via gridding and coil combination, followed by confounder-corrected R 2 ∗ (=1/ T 2 ∗ ) mapping. A phantom containing 15 different concentrations of gadolinium solution (0-300 mM) was imaged at 3T. 3D multi-echo UTE cones with an initial TE of 0.036 ms and Cartesian CSE-MRI (IDEAL-IQ) sequences were performed. With institutional review board approval, 85 subjects (81 pediatric patients with iron overload + 4 healthy volunteers) were imaged at 3T using 3D multi-echo UTE cones with free breathing (FB cones), IDEAL-IQ with breath holding (BH Cartesian), and free breathing (FB Cartesian). Overall image quality of R 2 ∗ maps was scored by 2 blinded experts and compared by a Wilcoxon rank-sum test. For each pediatric subject, the paired R 2 ∗ maps were assessed to determine if a corresponding artifact-free 15 mm region-of-interest (ROI) could be identified at a mid-liver level on both images. Agreement between resulting R 2 ∗ quantification from FB cones and BH/FB Cartesian was assessed with Bland-Altman and linear correlation analyses. RESULTS ROI-based regression analysis showed a linear relationship between gadolinium concentration and R 2 ∗ in IDEAL-IQ (y = 8.83x - 52.10, R2 = 0.995) as well as in cones (y = 9.19x - 64.16, R2 = 0.992). ROI-based Bland-Altman analysis showed that the mean difference (MD) was 0.15% and the SD was 5.78%. However, IDEAL-IQ R 2 ∗ measurements beyond 200 mM substantially deviated from a linear relationship for IDEAL-IQ (y = 5.85x + 127.61, R2 = 0.827), as opposed to cones (y = 10.87x - 166.96, R2 = 0.984). In vivo, FB cones R 2 ∗ had similar image quality with BH and FB Cartesian in 15 and 42 cases, respectively. FB cones R 2 ∗ had better image quality scores than BH and FB Cartesian in 3 and 21 cases, respectively, where BH/FB Cartesian exhibited severe ghosting artifacts. ROI-based Bland-Altman analyses were 2.23% (MD) and 6.59% (SD) between FB cones and BH Cartesian and were 0.21% (MD) and 7.02% (SD) between FB cones and FB Cartesian, suggesting a good agreement between FB cones and BH (FB) Cartesian R 2 ∗ . Strong linear relationships were observed between BH Cartesian and FB cones (y = 1.00x + 1.07, R2 = 0.996) and FB Cartesian and FB cones (y = 0.98x + 1.68, R2 = 0.999). CONCLUSION Golden-ratio re-ordered 3D multi-echo UTE Cones MRI enabled motion-robust, ungated, and free-breathing R 2 ∗ mapping of hepatic iron overload, with comparable R 2 ∗ measurements and image quality to BH Cartesian, and better image quality than FB Cartesian.
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Affiliation(s)
- Youngwook Kee
- Departments of Radiology and Electrical Engineering, Stanford University, Address: Magnetic Resonance Systems Research Lab (MRSRL), 350 Jane Stanford Way, Stanford, CA 94305
| | - Christopher M Sandino
- Departments of Radiology and Electrical Engineering, Stanford University, Address: Magnetic Resonance Systems Research Lab (MRSRL), 350 Jane Stanford Way, Stanford, CA 94305
| | - Ali B Syed
- Departments of Radiology and Electrical Engineering, Stanford University, Address: Magnetic Resonance Systems Research Lab (MRSRL), 350 Jane Stanford Way, Stanford, CA 94305
| | - Joseph Y Cheng
- Departments of Radiology and Electrical Engineering, Stanford University, Address: Magnetic Resonance Systems Research Lab (MRSRL), 350 Jane Stanford Way, Stanford, CA 94305
| | - Ann Shimakawa
- Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, Address: Menlo Park, CA 94025
| | - Timothy J Colgan
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Address: Wisconsin Institutes for Medical Research, 1111 Highland Ave, Madison, WI 53705
| | - Diego Hernando
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Address: Wisconsin Institutes for Medical Research, 1111 Highland Ave, Madison, WI 53705
| | - Shreyas S Vasanawala
- Departments of Radiology and Electrical Engineering, Stanford University, Address: Magnetic Resonance Systems Research Lab (MRSRL), 350 Jane Stanford Way, Stanford, CA 94305
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11
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Bianchi DW, Maron JL. Conversations With the Editors: The Past, Present, and Future of Placental Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Clin Ther 2021; 43:211-217. [PMID: 33526313 DOI: 10.1016/j.clinthera.2020.12.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Diana W Bianchi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA
| | - Jill L Maron
- Mother Infant Research Institute at Tufts Medical Center, Boston, MA, USA.
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12
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Characterization of Uterine Motion in Early Gestation Using MRI-Based Motion Tracking. Diagnostics (Basel) 2020; 10:diagnostics10100840. [PMID: 33086473 PMCID: PMC7603139 DOI: 10.3390/diagnostics10100840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/25/2020] [Accepted: 10/15/2020] [Indexed: 11/17/2022] Open
Abstract
Magnetic resonance imaging (MRI) is a promising non-invasive imaging technique that can be safely used to study placental development and function. However, studies of the human placenta performed by MRI are limited by uterine motion and motion in the uterus during MRI remains one of the major limiting factors. Here, we aimed to investigate the characterization of uterine activity during MRI in the second trimester of pregnancy using MRI-based motion tracking. In total, 46 pregnant women were scanned twice (first scan between 14 and 18 weeks and second scan between 19 and 24 weeks), and 20 pregnant subjects underwent a single MRI between 14 and 18 weeks GA, resulting in 112 MRI scans. An MRI-based algorithm was used to track uterine motion in the superior-inferior and left-right directions. Uterine contraction and maternal motion cases were separated by the experts, and unpaired Wilcoxon tests were performed within the groups of gestational age (GA), fetal sex, and placental location in terms of the overall intensity measures of the uterine activity. In total, 22.3% of cases had uterine contraction during MRI, which increased from 18.6% at 14–18 weeks to 26.4% at 19–24 weeks GA. The dominant direction of the uterine contraction and maternal motion was the superior to the inferior direction during early gestation.
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13
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Zun Z, Kapse K, Quistorff J, Andescavage N, Gimovsky AC, Ahmadzia H, Limperopoulos C. Feasibility of QSM in the human placenta. Magn Reson Med 2020; 85:1272-1281. [PMID: 32936489 DOI: 10.1002/mrm.28502] [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] [Received: 02/12/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE Quantitative susceptibility mapping (QSM) is an emerging tool for the precise characterization of human tissue, including regional oxygenation. A critical function of the human placenta is oxygen transfer to the developing fetus, which remains difficult to study in utero. The purpose of this study is to investigate the feasibility of performing QSM in the human placenta in utero. METHODS In healthy pregnant women, 3D gradient echo data of the placenta were acquired with prospective respiratory gating at 1.5 Tesla and 3 Tesla. A brief period (6-7 min) of maternal hyperoxia was induced to increase placental oxygenation in a subset of women scanned at 3 Tesla, and data were acquired before and during oxygen administration. Susceptibility and T 2 ∗ / R 2 ∗ maps were reconstructed from gradient echo data, and mean and SD of these measures within the whole placenta were calculated. RESULTS A total of 54 women were studied at a mean gestational age of 30.7 ± 4.2 (range: 24 5/7-38 4/7) weeks. Susceptibility and T 2 ∗ maps demonstrated lobular contrast reflecting regional oxygenation difference at both field strengths. SD of susceptibilities, mean R 2 ∗ , and SD of R 2 ∗ of the placenta showed a linear relationship with gestational age (P < .01 for all). These measures were also responsive to maternal hyperoxia, and there was an increasing response with advancing gestational age (P < .01 for all). CONCLUSION This study demonstrates the feasibility of performing placental QSM in pregnant women and supports the potential for placental QSM to provide noninvasive in vivo assessment of placental oxygenation.
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Affiliation(s)
- Zungho Zun
- Developing Brain Institute, Division of Diagnostic Imaging and Radiology, Children's National Hospital, Washington, DC, USA.,Division of Fetal and Transitional Medicine, Children's National Hospital, Washington, DC, USA.,Department of Pediatrics, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA.,Department of Radiology, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
| | - Kushal Kapse
- Developing Brain Institute, Division of Diagnostic Imaging and Radiology, Children's National Hospital, Washington, DC, USA
| | - Jessica Quistorff
- Developing Brain Institute, Division of Diagnostic Imaging and Radiology, Children's National Hospital, Washington, DC, USA
| | - Nickie Andescavage
- Department of Pediatrics, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA.,Division of Neonatology, Children's National Hospital, Washington, DC, USA
| | - Alexis C Gimovsky
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
| | - Homa Ahmadzia
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
| | - Catherine Limperopoulos
- Developing Brain Institute, Division of Diagnostic Imaging and Radiology, Children's National Hospital, Washington, DC, USA.,Division of Fetal and Transitional Medicine, Children's National Hospital, Washington, DC, USA.,Department of Pediatrics, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA.,Department of Radiology, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
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14
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Ho AEP, Hutter J, Jackson LH, Seed PT, Mccabe L, Al-Adnani M, Marnerides A, George S, Story L, Hajnal JV, Rutherford MA, Chappell LC. T2* Placental Magnetic Resonance Imaging in Preterm Preeclampsia: An Observational Cohort Study. HYPERTENSION (DALLAS, TEX. : 1979) 2020; 75:1523-1531. [PMID: 32336233 PMCID: PMC7682790 DOI: 10.1161/hypertensionaha.120.14701] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Placental dysfunction underlies the cause of pregnancies complicated by preeclampsia. The use of placental magnetic resonance imaging to provide an insight into the pathophysiology of preeclampsia and thus assess its potential use to inform prognosis and clinical management was explored. In this prospective observational cohort study, 14 women with preterm preeclampsia and 48 gestation-matched controls using 3-Tesla magnetic resonance imaging at median of 31.6 weeks (interquartile range [IQR], 28.6-34.6) and 32.2 weeks (IQR, 28.6-33.8), respectively, were imaged. The acquired data included T2-weighted images and T2* maps of the placenta, the latter an indicative measure of placental oxygenation. Placentae in women with preeclampsia demonstrated advanced lobulation, varied lobule sizes, high granularity, and substantial areas of low-signal intensity on T2-weighted imaging, with reduced entire placental mean T2* values for gestational age (2 sample t test, t=7.49) correlating with a reduction in maternal PlGF (placental growth factor) concentrations (Spearman rank correlation coefficient 0.76) and increased lacunarity values (t=3.26). Median mean T2* reduced from 67 ms (IQR, 54-73) at 26.0 to 29.8 weeks' gestation to 38 ms (IQR, 28-40) at 34.0 to 37.9 weeks' gestation in the control group. In women with preeclampsia, median T2* was 23 ms (IQR, 20-23) at 26.0 to 29.8 weeks' gestation and remained low (22 ms [IQR, 20-26] at 34.0-37.8 weeks' gestation). Histological features of maternal vascular malperfusion were only found in placentae from women with preeclampsia. Placental volume did not differ between the control group and women with preeclampsia. Placental magnetic resonance imaging allows both objective quantification of placental function in vivo and elucidation of the complex mechanisms underlying preeclampsia development.
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Affiliation(s)
- Alison E P Ho
- From the Department of Women and Children's Health, School of Life Course Sciences (A.E.P.H., P.S., L.S., L.C.C.), King's College London, United Kingdom
| | - Jana Hutter
- Centre for the Developing Brain (J.H., L.H.J., L.M., J.V.H., M.A.R.), King's College London, United Kingdom.,Biomedical Engineering Department (J.H., L.H.J., J.V.H.), King's College London, United Kingdom
| | - Laurence H Jackson
- Centre for the Developing Brain (J.H., L.H.J., L.M., J.V.H., M.A.R.), King's College London, United Kingdom.,Biomedical Engineering Department (J.H., L.H.J., J.V.H.), King's College London, United Kingdom
| | - Paul T Seed
- From the Department of Women and Children's Health, School of Life Course Sciences (A.E.P.H., P.S., L.S., L.C.C.), King's College London, United Kingdom
| | - Laura Mccabe
- Centre for the Developing Brain (J.H., L.H.J., L.M., J.V.H., M.A.R.), King's College London, United Kingdom
| | - Mudher Al-Adnani
- Department of Cellular Pathology, Guy's and St Thomas' Hospital, London, United Kingdom (M.A.-A., A.M., S.G.)
| | - Andreas Marnerides
- Department of Cellular Pathology, Guy's and St Thomas' Hospital, London, United Kingdom (M.A.-A., A.M., S.G.)
| | - Simi George
- Department of Cellular Pathology, Guy's and St Thomas' Hospital, London, United Kingdom (M.A.-A., A.M., S.G.)
| | - Lisa Story
- From the Department of Women and Children's Health, School of Life Course Sciences (A.E.P.H., P.S., L.S., L.C.C.), King's College London, United Kingdom
| | - Joseph V Hajnal
- Centre for the Developing Brain (J.H., L.H.J., L.M., J.V.H., M.A.R.), King's College London, United Kingdom.,Biomedical Engineering Department (J.H., L.H.J., J.V.H.), King's College London, United Kingdom
| | - Mary A Rutherford
- Centre for the Developing Brain (J.H., L.H.J., L.M., J.V.H., M.A.R.), King's College London, United Kingdom
| | - Lucy C Chappell
- From the Department of Women and Children's Health, School of Life Course Sciences (A.E.P.H., P.S., L.S., L.C.C.), King's College London, United Kingdom
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15
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Schneider M, Benkert T, Solomon E, Nickel D, Fenchel M, Kiefer B, Maier A, Chandarana H, Block KT. Free-breathing fat and R 2 * quantification in the liver using a stack-of-stars multi-echo acquisition with respiratory-resolved model-based reconstruction. Magn Reson Med 2020; 84:2592-2605. [PMID: 32301168 PMCID: PMC7396291 DOI: 10.1002/mrm.28280] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 03/22/2020] [Accepted: 03/23/2020] [Indexed: 01/04/2023]
Abstract
Purpose To develop a free‐breathing hepatic fat and
R2∗ quantification method by extending a previously described stack‐of‐stars model‐based fat‐water separation technique with additional modeling of the transverse relaxation rate
R2∗. Methods The proposed technique combines motion‐robust radial sampling using a stack‐of‐stars bipolar multi‐echo 3D GRE acquisition with iterative model‐based fat‐water separation. Parallel‐Imaging and Compressed‐Sensing principles are incorporated through modeling of the coil‐sensitivity profiles and enforcement of total‐variation (TV) sparsity on estimated water, fat, and
R2∗ parameter maps. Water and fat signals are used to estimate the confounder‐corrected proton‐density fat fraction (PDFF). Two strategies for handling respiratory motion are described: motion‐averaged and motion‐resolved reconstruction. Both techniques were evaluated in patients (n = 14) undergoing a hepatobiliary research protocol at 3T. PDFF and
R2∗ parameter maps were compared to a breath‐holding Cartesian reference approach. Results Linear regression analyses demonstrated strong (r > 0.96) and significant (P ≪ .01) correlations between radial and Cartesian PDFF measurements for both the motion‐averaged reconstruction (slope: 0.90; intercept: 0.07%) and the motion‐resolved reconstruction (slope: 0.90; intercept: 0.11%). The motion‐averaged technique overestimated hepatic
R2∗ values (slope: 0.35; intercept: 30.2 1/s) compared to the Cartesian reference. However, performing a respiratory‐resolved reconstruction led to better
R2∗ value consistency (slope: 0.77; intercept: 7.5 1/s). Conclusions The proposed techniques are promising alternatives to conventional Cartesian imaging for fat and
R2∗ quantification in patients with limited breath‐holding capabilities. For accurate
R2∗ estimation, respiratory‐resolved reconstruction should be used.
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Affiliation(s)
- Manuel Schneider
- Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen Nürnberg, Erlangen, Germany.,MR Applications Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | - Thomas Benkert
- MR Applications Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | - Eddy Solomon
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Dominik Nickel
- MR Applications Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | - Matthias Fenchel
- MR R&D Collaborations, Siemens Medical Solutions, New York, NY, USA
| | - Berthold Kiefer
- MR Applications Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | - Andreas Maier
- Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen Nürnberg, Erlangen, Germany
| | - Hersh Chandarana
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Kai Tobias Block
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA
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16
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Sørensen A, Hutter J, Seed M, Grant PE, Gowland P. T2*-weighted placental MRI: basic research tool or emerging clinical test for placental dysfunction? ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2020; 55:293-302. [PMID: 31452271 DOI: 10.1002/uog.20855] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 08/12/2019] [Accepted: 08/19/2019] [Indexed: 06/10/2023]
Affiliation(s)
- A Sørensen
- Department of Obstetrics and Gynecology, Aalborg University Hospital, Aalborg, Denmark
| | - J Hutter
- Center for Medical Engineering, King's College London, London, UK
| | - M Seed
- Department of Cardiology, The Hospital for Sick Children, Toronto, Canada
| | - P E Grant
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, USA
| | - P Gowland
- Sir Peter Mansfield Imaging Centre, Nottingham University, Nottingham, UK
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17
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Hutter J, Jackson L, Ho A, Pietsch M, Story L, Chappell LC, Hajnal JV, Rutherford M. T2* relaxometry to characterize normal placental development over gestation in-vivo at 3T. Wellcome Open Res 2019. [DOI: 10.12688/wellcomeopenres.15451.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Background: T2* relaxometry has been identified as a non-invasive way to study the placenta in-vivo with good potential to identify placental insufficiency. Typical interpretation links T2* values to oxygen concentrations. This study aimed to comprehensively assess T2* maps as a marker of placental oxygenation in-vivo. Methods: A multi-echo gradient echo echo planar imaging sequence is used in a cohort of 84 healthy pregnant women. Special emphasis is put on spatial analysis: histogram measures, Histogram Asymmetry Measure (HAM) and lacunarity. Influences of maternal, fetal and placental factors and experimental parameters on the proposed measures are evaluated. Results: T2* maps were obtained from each placenta in less than 30sec. The previously reported decreasing trend in mean T2* with gestation was confirmed (3.45 ms decline per week). Factors such as maternal age, BMI, fetal sex, parity, mode of delivery and placental location were shown to be uncorrelated with T2* once corrected for gestational age. Robustness of the obtained values with regard to variation in segmentation and voxel-size were established. The proposed spatially resolved measures reveal a change in T2* in late gestation. Conclusions: T2* mapping is a robust and quick technique allowing quantification of both whole volume and spatial quantification largely independent of confounding factors.
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18
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Turk EA, Stout JN, Ha C, Luo J, Gagoski B, Yetisir F, Golland P, Wald LL, Adalsteinsson E, Robinson JN, Roberts DJ, Barth WH, Grant PE. Placental MRI: Developing Accurate Quantitative Measures of Oxygenation. Top Magn Reson Imaging 2019; 28:285-297. [PMID: 31592995 PMCID: PMC7323862 DOI: 10.1097/rmr.0000000000000221] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The Human Placenta Project has focused attention on the need for noninvasive magnetic resonance imaging (MRI)-based techniques to diagnose and monitor placental function throughout pregnancy. The hope is that the management of placenta-related pathologies would be improved if physicians had more direct, real-time measures of placental health to guide clinical decision making. As oxygen alters signal intensity on MRI and oxygen transport is a key function of the placenta, many of the MRI methods under development are focused on quantifying oxygen transport or oxygen content of the placenta. For example, measurements from blood oxygen level-dependent imaging of the placenta during maternal hyperoxia correspond to outcomes in twin pregnancies, suggesting that some aspects of placental oxygen transport can be monitored by MRI. Additional methods are being developed to accurately quantify baseline placental oxygenation by MRI relaxometry. However, direct validation of placental MRI methods is challenging and therefore animal studies and ex vivo studies of human placentas are needed. Here we provide an overview of the current state of the art of oxygen transport and quantification with MRI. We suggest that as these techniques are being developed, increased focus be placed on ensuring they are robust and reliable across individuals and standardized to enable predictive diagnostic models to be generated from the data. The field is still several years away from establishing the clinical benefit of monitoring placental function in real time with MRI, but the promise of individual personalized diagnosis and monitoring of placental disease in real time continues to motivate this effort.
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Affiliation(s)
- Esra Abaci Turk
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children’s Hospital, MA, USA
| | - Jeffrey N. Stout
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children’s Hospital, MA, USA
| | - Christopher Ha
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children’s Hospital, MA, USA
| | - Jie Luo
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Borjan Gagoski
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children’s Hospital, MA, USA
| | - Filiz Yetisir
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children’s Hospital, MA, USA
| | - Polina Golland
- Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Lawrence L. Wald
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Elfar Adalsteinsson
- Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology, Cambridge, MA, United States
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Julian N. Robinson
- Department of Obstetrics and Gynecology, Brigham and Women’s Hospital, Boston, USA
| | | | - William H. Barth
- Maternal-Fetal Medicine, Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, USA
| | - P. Ellen Grant
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children’s Hospital, MA, USA
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Shulman M, Cho E, Aasi B, Cheng J, Nithiyanantham S, Waddell N, Sussman D. Quantitative analysis of fetal magnetic resonance phantoms and recommendations for an anthropomorphic motion phantom. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2019; 33:257-272. [PMID: 31487004 DOI: 10.1007/s10334-019-00775-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/08/2019] [Accepted: 08/27/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To provide a review and quantitative analysis of the available fetal MR imaging phantoms. MATERIALS AND METHODS A literature search was conducted across Pubmed, Google Scholar, and Ryerson University Library databases to identify fetal MR imaging phantoms. Phantoms were graded on a semi-quantitative scale in regards to four evaluation categories: (1) anatomical accuracy in size and shape, (2) dielectric conductivity similar to the simulated tissue, (3) relaxation times similar to simulated tissue, and (4) physiological motion similar to fetal gross body, cardiovascular, and breathing motion. This was followed by statistical analysis to identify significant findings. RESULTS Seventeen fetal phantoms were identified and had an average overall percentage accuracy of 26%, with anatomical accuracy being satisfied the most (56%) and physiological motion the least (7%). Phantoms constructed using 3D printing were significantly more accurate than conventionally constructed phantoms. DISCUSSION Currently available fetal phantoms lack accuracy and motion simulation. 3D printing may lead to higher accuracy compared with traditional manufacturing. Future research needs to focus on properly simulating both fetal anatomy and physiological motion to produce a phantom that is appropriate for fetal MRI sequence development and optimization.
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Affiliation(s)
- Michael Shulman
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada
| | - Eunyoung Cho
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada
| | - Bipin Aasi
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada
| | - Jin Cheng
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada
| | - Saiee Nithiyanantham
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada
| | - Nicole Waddell
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada.,Institute for Biomedical Engineering, Science and Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada
| | - Dafna Sussman
- Department of Electrical, Computer, and Biomedical Engineering, Ryerson University, Toronto, ON, M5B 2K3, Canada. .,Institute for Biomedical Engineering, Science and Technology (iBEST), Ryerson University and St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada. .,The Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, M5B 1T8, Canada. .,Department of Biomedical Physics, Ryerson University, Toronto, ON, M5B 2K3, Canada.
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20
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Zhu A, Reeder SB, Johnson KM, Nguyen SM, Golos TG, Shimakawa A, Muehler MR, Francois CJ, Bird IM, Fain SB, Shah DM, Wieben O, Hernando D. Evaluation of a motion-robust 2D chemical shift-encoded technique for R2* and field map quantification in ferumoxytol-enhanced MRI of the placenta in pregnant rhesus macaques. J Magn Reson Imaging 2019; 51:580-592. [PMID: 31276263 DOI: 10.1002/jmri.26849] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/19/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND 3D chemical shift-encoded (CSE)-MRI techniques enable assessment of ferumoxytol concentration but are unreliable in the presence of motion. PURPOSE To evaluate a motion-robust 2D-sequential CSE-MRI for R2* and B0 mapping in ferumoxytol-enhanced MRI of the placenta. STUDY TYPE Prospective. ANIMAL MODEL Pregnant rhesus macaques. FIELD STRENGTH/SEQUENCE 3.0T/CSE-MRI. ASSESSMENT 2D-sequential CSE-MRI was compared with 3D respiratory-gated CSE-MRI in placental imaging of 11 anesthetized animals at multiple timepoints before and after ferumoxytol administration, and in ferumoxytol phantoms (0 μg/mL-440 μg/mL). Motion artifacts of CSE-MRI in 10 pregnant women without ferumoxytol administration were assessed retrospectively by three blinded readers (4-point Likert scale). The repeatability of CSE-MRI in seven pregnant women was also prospectively studied. STATISTICAL TESTS Placental R2* and boundary B0 field measurements (ΔB0) were compared between 2D-sequential and 3D respiratory-gated CSE-MRI using linear regression and Bland-Altman analysis. RESULTS In phantoms, a slope of 0.94 (r2 = 0.99, concordance correlation coefficient ρ = 0.99), and bias of -4.8 s-1 (limit of agreement [LOA], -41.4 s-1 , +31.8 s-1 ) in R2*, and a slope of 1.07 (r2 = 1.00, ρ = 0.99) and bias of 11.4 Hz (LOA -12.0 Hz, +34.8 Hz) in ΔB0 were obtained in 2D CSE-MRI compared with 3D CSE-MRI for reference R2* ≤390 s-1 . In animals, a slope of 0.92 (r2 = 0.97, ρ = 0.98) and bias of -2.2 s-1 (LOA -55.6 s-1 , +51.3 s-1 ) in R2*, and a slope of 1.05 (r2 = 0.95, ρ = 0.97) and bias of 0.4 Hz (LOA -9.0 Hz, +9.7 Hz) in ΔB0 were obtained. In humans, motion-impaired R2* maps in 3D CSE-MRI (Reader 1: 1.8 ± 0.6, Reader 2: 1.3 ± 0.7, Reader 3: 1.9 ± 0.6), while 2D CSE-MRI was motion-free (Reader 1: 2.9 ± 0.3, Reader 2: 3.0 ± 0, Reader 3: 3.0 ± 0). A mean difference of 0.66 s-1 and coefficient of repeatability of 9.48 s-1 for placental R2* were observed in the repeated 2D CSE-MRI. DATA CONCLUSION 2D-sequential CSE-MRI provides accurate R2* and B0 measurements in ferumoxytol-enhanced placental MRI of animals in the presence of respiratory motion, and motion-robustness in human placental imaging. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:580-592.
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Affiliation(s)
- Ante Zhu
- Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Scott B Reeder
- Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medicine, University of Wisconsin, Madison, Wisconsin, USA.,Department of Emergency Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Kevin M Johnson
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Sydney M Nguyen
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, Wisconsin, USA.,Department of Obstetrics and Gynecology, University of Wisconsin, Madison, Wisconsin, USA
| | - Thaddeus G Golos
- Wisconsin National Primate Research Center, University of Wisconsin, Madison, Wisconsin, USA.,Department of Obstetrics and Gynecology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Comparative Biosciences, University of Wisconsin, Madison, Wisconsin, USA
| | - Ann Shimakawa
- Global MR Applications and Workflow, GE Healthcare, Menlo Park, California, USA
| | - Matthias R Muehler
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | | | - Ian M Bird
- Department of Comparative Biosciences, University of Wisconsin, Madison, Wisconsin, USA
| | - Sean B Fain
- Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Dinesh M Shah
- Department of Obstetrics and Gynecology, University of Wisconsin, Madison, Wisconsin, USA
| | - Oliver Wieben
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Diego Hernando
- Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA.,Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.,Department of Electrical and Computer Engineering, University of Wisconsin, Madison, Wisconsin, USA
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21
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Armstrong T, Liu D, Martin T, Masamed R, Janzen C, Wong C, Chanlaw T, Devaskar SU, Sung K, Wu HH. 3D R 2 * mapping of the placenta during early gestation using free-breathing multiecho stack-of-radial MRI at 3T. J Magn Reson Imaging 2018; 49:291-303. [PMID: 30142239 DOI: 10.1002/jmri.26203] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 05/08/2018] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Multiecho gradient-echo Cartesian MRI characterizes placental oxygenation by quantifying R 2 * . Previous research was performed at 1.5T using breath-held 2D imaging during later gestational age (GA). PURPOSE To evaluate the accuracy and repeatability of a free-breathing (FB) 3D multiecho gradient-echo stack-of-radial technique (radial) for placental R 2 * mapping at 3T and report placental R 2 * during early GA. STUDY TYPE Prospective. POPULATION Thirty subjects with normal pregnancies and three subjects with ischemic placental disease (IPD) were scanned twice: between 14-18 and 19-23 weeks GA. FIELD STRENGTH 3T. SEQUENCE FB radial. ASSESSMENT Linear correlation (concordance coefficient, ρc ) and Bland-Altman analyses (mean difference, MD) were performed to evaluate radial R 2 * mapping accuracy compared to Cartesian in a phantom. Radial R 2 * mapping repeatability was characterized using the coefficient of repeatability (CR) between back-to-back scans. The mean and spatial coefficient of variation (CV) of R 2 * was determined for all subjects, and separately for anterior and posterior placentas, at each GA range. STATISTICAL TESTS ρc was tested for significance. Differences in mean R 2 * and CV were tested using Wilcoxon Signed-Rank and Rank-Sum tests. P < 0.05 was considered significant. Z-scores for the IPD subjects were determined. RESULTS FB radial demonstrated accurate (ρc ≥0.996; P < 0.001; |MD|<0.2s-1 ) and repeatable (CR<4s-1 ) R 2 * mapping in a phantom, and repeatable (CR≤4.6s-1 ) R 2 * mapping in normal subjects. At 3T, placental R 2 * mean ± standard deviation was 12.9s-1 ± 2.7s-1 for 14-18 and 13.2s-1 ± 1.9s-1 for 19-23 weeks GA. The CV was significantly greater (P = 0.043) at 14-18 (0.63 ± 0.12) than 19-23 (0.58 ± 0.13) weeks GA. At 19-23 weeks, the CV was significantly lower (P < 0.001) for anterior (0.49 ± 0.08) than posterior (0.67 ± 0.11) placentas. One IPD subject had a lower mean R 2 * than normal subjects at both GA ranges (Z<-2). DATA CONCLUSION FB radial provides accurate and repeatable 3D R 2 * mapping for the entire placenta at 3T during early GA. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:291-303.
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Affiliation(s)
- Tess Armstrong
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, California, USA.,Department of Physics and Biology in Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Dapeng Liu
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, California, USA
| | - Thomas Martin
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, California, USA.,Department of Physics and Biology in Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Rinat Masamed
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, California, USA
| | - Carla Janzen
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Cass Wong
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, California, USA
| | - Teresa Chanlaw
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Sherin U Devaskar
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Kyunghyun Sung
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, California, USA.,Department of Physics and Biology in Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Holden H Wu
- Department of Radiological Sciences, University of California Los Angeles, Los Angeles, California, USA.,Department of Physics and Biology in Medicine, University of California Los Angeles, Los Angeles, California, USA
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