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Knapp J, Tavares de Sousa M, Schönnagel BP. Fetal Cardiovascular MRI - A Systemic Review of the Literature: Challenges, New Technical Developments, and Perspectives. ROFO-FORTSCHR RONTG 2022; 194:841-851. [PMID: 35905903 DOI: 10.1055/a-1761-3500] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
BACKGROUND Fetal magnetic resonance imaging (MRI) has become a valuable adjunct to ultrasound in the prenatal diagnosis of congenital pathologies of the central nervous system, thorax, and abdomen. Fetal cardiovascular magnetic resonance (CMR) was limited, mainly by the lack of cardiac gating, and has only recently evolved due to technical developments. METHOD A literature search was performed on PubMed, focusing on technical advancements to perform fetal CMR. In total, 20 publications on cardiac gating techniques in the human fetus were analyzed. RESULTS Fetal MRI is a safe imaging method with no developmental impairments found to be associated with in utero exposure to MRI. Fetal CMR is challenging due to general drawbacks (e. g., fetal motion) and specific limitations such as the difficulty to generate a cardiac gating signal to achieve high spatiotemporal resolution. Promising technical advancements include new methods for fetal cardiac gating, based on novel post-processing approaches and an external hardware device, as well as motion compensation and acceleration techniques. CONCLUSION Newly developed direct and indirect gating approaches were successfully applied to achieve high-quality morphologic and functional imaging as well as quantitative assessment of fetal hemodynamics in research settings. In cases when prenatal echocardiography is limited, e. g., by an unfavorable fetal position in utero, or when its results are inconclusive, fetal CMR could potentially serve as a valuable adjunct in the prenatal assessment of congenital cardiovascular malformations. However, sufficient data on the diagnostic performance and clinical benefit of new fetal CMR techniques is still lacking. KEY POINTS · New fetal cardiac gating methods allow high-quality fetal CMR.. · Motion compensation and acceleration techniques allow for improvement of image quality.. · Fetal CMR could potentially serve as an adjunct to fetal echocardiography in the future.. CITATION FORMAT · Knapp J, Tavares de Sousa M, Schönnagel BP. Fetal Cardiovascular MRI - A Systemic Review of the Literature: Challenges, New Technical Developments, and Perspectives. Fortschr Röntgenstr 2022; 194: 841 - 851.
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Affiliation(s)
- Janine Knapp
- Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Björn P Schönnagel
- Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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2
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van Amerom JFP, Goolaub DS, Schrauben EM, Sun L, Macgowan CK, Seed M. Fetal cardiovascular blood flow MRI: techniques and applications. Br J Radiol 2022:20211096. [DOI: 10.1259/bjr.20211096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Fetal cardiac MRI is challenging due to fetal and maternal movements as well as the need for a reliable cardiac gating signal and high spatiotemporal resolution. Ongoing research and recent technical developments to address these challenges show the potential of MRI as an adjunct to ultrasound for the assessment of the fetal heart and great vessels. MRI measurements of blood flow have enabled the assessment of normal fetal circulation as well as conditions with disrupted circulations, such as congenital heart disease, along with associated organ underdevelopment and hemodynamic instability. This review provides details of the techniques used in fetal cardiovascular blood flow MRI, including single slice and volumetric imaging sequences, post-processing and analysis, along with a summary of applications in human studies and animal models.
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Affiliation(s)
- Joshua FP van Amerom
- Division of Translational Medicine, SickKids Research Institute, Toronto, Canada
| | - Datta Singh Goolaub
- Division of Translational Medicine, SickKids Research Institute, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Eric M Schrauben
- Department of Radiology & Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam, Netherlands
| | - Liqun Sun
- Division of Cardiology, Hospital for Sick Children, Toronto, Canada
- Department of Paediatrics, University of Toronto, Toronto, Canada
| | - Christopher K Macgowan
- Division of Translational Medicine, SickKids Research Institute, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Mike Seed
- Division of Translational Medicine, SickKids Research Institute, Toronto, Canada
- Division of Cardiology, Hospital for Sick Children, Toronto, Canada
- Department of Paediatrics, University of Toronto, Toronto, Canada
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
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Schulz A, Lloyd DFA, van Poppel MPM, Roberts TA, Steinweg JK, Pushparajah K, Hajnal JV, Razavi R. Structured analysis of the impact of fetal motion on phase-contrast MRI flow measurements with metric optimized gating. Sci Rep 2022; 12:5395. [PMID: 35354868 PMCID: PMC8967860 DOI: 10.1038/s41598-022-09327-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 03/21/2022] [Indexed: 01/19/2023] Open
Abstract
The impact of fetal motion on phase contrast magnetic resonance imaging (PC-MRI) with metric optimized gating (MOG) remains unknown, despite being a known limitation to prenatal MRI. This study aims to describe the effect of motion on fetal flow-measurements using PC-MRI with MOG and to generate a scoring-system that could be used to predict motion-corrupted datasets at the time of acquisition. Ten adult volunteers underwent PC-MRI with MOG using a motion-device to simulate reproducible in-plane motion encountered in fetuses. PC-MRI data were acquired on ten fetuses. All ungated images were rated on their quality from 0 (no motion) to 2 (severe motion). There was no significant difference in measured flows with in-plane motion during the first and last third of sequence acquisition. Movement in the middle section of acquisition produced a significant difference while all referring ungated images were rated with a score of 2. Intra-Class-Correlation (ICC) for flow-measurements in adult and fetal datasets was lower for datasets with scores of 2. For fetal applications, the use of a simple three-point scoring system reliably identifies motion-corrupted sequences from unprocessed data at the time of acquisition, with a high score corresponding to significant underestimation of flow values and increased interobserver variability.
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Affiliation(s)
- Alexander Schulz
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK. .,Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Charitéplatz 1, Berlin, 10117, Germany.
| | - David F A Lloyd
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK.,Department of Congenital Heart Disease, Evelina London Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Milou P M van Poppel
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK
| | - Thomas A Roberts
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK
| | - Johannes K Steinweg
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK
| | - Kuberan Pushparajah
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK.,Department of Congenital Heart Disease, Evelina London Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Joseph V Hajnal
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK
| | - Reza Razavi
- School of Biomedical Engineering and Imaging Sciences, King's College London, St. Thomas' Hospital, London, UK.,Department of Congenital Heart Disease, Evelina London Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK
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4
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Sun L, Lee FT, van Amerom JFP, Freud L, Jaeggi E, Macgowan CK, Seed M. Update on fetal cardiovascular magnetic resonance and utility in congenital heart disease. JOURNAL OF CONGENITAL CARDIOLOGY 2021. [DOI: 10.1186/s40949-021-00059-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Congenital heart disease (CHD) is the most common birth defect, affecting approximately eight per thousand newborns. Between one and two neonates per thousand have congenital cardiac lesions that require immediate post-natal treatment to stabilize the circulation, and the management of these patients in particular has been greatly enhanced by prenatal detection. The antenatal diagnosis of CHD has been made possible through the development of fetal echocardiography, which provides excellent visualization of cardiac anatomy and physiology and is widely available. However, late gestational fetal echocardiographic imaging can be hampered by suboptimal sonographic windows, particularly in the setting of oligohydramnios or adverse maternal body habitus.
Main body
Recent advances in fetal cardiovascular magnetic resonance (CMR) technology now provide a feasible alternative that could be helpful when echocardiography is inconclusive or limited. Fetal CMR has also been used to study fetal circulatory physiology in human fetuses with CHD, providing new insights into how these common anatomical abnormalities impact the distribution of blood flow and oxygen across the fetal circulation. In combination with conventional fetal and neonatal magnetic resonance imaging (MRI) techniques, fetal CMR can be used to explore the relationship between abnormal cardiovascular physiology and fetal development. Similarly, fetal CMR has been successfully applied in large animal models of the human fetal circulation, aiding in the evaluation of experimental interventions aimed at improving in utero development. With the advent of accelerated image acquisition techniques, post-processing approaches to correcting motion artifacts and commercial MRI compatible cardiotocography units for acquiring gated fetal cardiac imaging, an increasing number of CMR methods including angiography, ventricular volumetry, and the quantification of vessel blood flow and oxygen content are now possible.
Conclusion
Fetal CMR has reached an exciting stage whereby it may now be used to enhance the assessment of cardiac morphology and fetal hemodynamics in the setting of prenatal CHD.
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Sun L, Marini D, Saini B, Schrauben E, Macgowan CK, Seed M. Understanding Fetal Hemodynamics Using Cardiovascular Magnetic Resonance Imaging. Fetal Diagn Ther 2020; 47:354-362. [PMID: 32062652 DOI: 10.1159/000505091] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 11/25/2019] [Indexed: 11/19/2022]
Abstract
Human fetal circulatory physiology has been investigated extensively using grey-scale ultrasound, which provides excellent visualization of cardiac anatomy and function, while velocity profiles in the heart and vessels can be interrogated using Doppler. Measures of cerebral and placental vascular resistance, as well as indirect measures of intracardiac pressure obtained from the velocity waveform in the ductus venosus are routinely used to guide the management of fetal cardiovascular and placental disease. However, the characterization of some key elements of cardiovascular physiology such as vessel blood flow and the oxygen content of blood in the arteries and veins, as well as fetal oxygen delivery and consumption are not readily measured using ultrasound. To study these parameters, we have historically relied on data obtained using invasive measurements made in animal models, which are not equivalent to the human in every respect. Over recent years, a number of technical advances have been made that have allowed us to examine the human fetal circulatory system using cardiovascular magnetic resonance (CMR). The combination of vessel blood flow measurements made using cine phase contrast magnetic resonance imaging and vessel blood oxygen saturation and hematocrit measurements made using T1 and T2 mapping have enabled us to emulate those classic fetal sheep experiments defining the distribution of blood flow and oxygen transport across the fetal circulation in the human fetus. In addition, we have applied these techniques to study the relationship between abnormal fetal cardiovascular physiology and fetal development in the setting of congenital heart disease and placental insufficiency. CMR has become an important diagnostic tool in the assessment of cardiovascular physiology in the setting of postnatal cardiovascular disease, and is now being applied to the fetus to enhance our understanding of normal and abnormal fetal circulatory physiology and its impact on fetal well-being.
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Affiliation(s)
- Liqun Sun
- Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Davide Marini
- Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Brahmdeep Saini
- Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Eric Schrauben
- Division of Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Christopher K Macgowan
- Division of Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Mike Seed
- Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada, .,Department of Paediatrics and Medical Imaging, University of Toronto, Toronto, Ontario, Canada,
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Abstract
Magnetic resonance imaging (MRI) is an appealing technology for fetal cardiovascular assessment. It can be used to visualize fetal cardiac and vascular anatomy, to quantify fetal blood flow, and to quantify fetal blood oxygen saturation and hematocrit. However, there are practical limitations to the use of conventional MRI for fetal cardiovascular assessment, including the small size and high heart rate of the human fetus, the lack of conventional cardiac gating methods to synchronize data acquisition, and the potential corruption of MRI data due to maternal respiration and unpredictable fetal movements. In this review, we discuss recent technical advances in accelerated imaging, image reconstruction, cardiac gating, and motion compensation that have enabled dynamic MRI of the fetal heart.
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Ryd D, Sun L, Steding-Ehrenborg K, Bidhult S, Kording F, Ruprecht C, Macgowan CK, Seed M, Aletras AH, Arheden H, Hedström E. Quantification of blood flow in the fetus with cardiovascular magnetic resonance imaging using Doppler ultrasound gating: validation against metric optimized gating. J Cardiovasc Magn Reson 2019; 21:74. [PMID: 31783877 PMCID: PMC6883707 DOI: 10.1186/s12968-019-0586-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/25/2019] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Fetal cardiovascular magnetic resonance (CMR) imaging is used clinically and for research, but has been previously limited due to lack of direct gating methods. A CMR-compatible Doppler ultrasound (DUS) gating device has resolved this. However, the DUS-gating method is not validated against the current reference method for fetal phase-contrast blood flow measurements, metric optimized gating (MOG). Further, we investigated how different methods for vessel delineation affect flow volumes and observer variability in fetal flow acquisitions. AIMS To 1) validate DUS gating versus MOG for quantifying fetal blood flow; 2) assess repeatability of DUS gating; 3) assess impact of region of interest (ROI) size on flow volume; and 4) compare time-resolved and static delineations for flow volume and observer variability. METHODS Phase-contrast CMR was acquired in the fetal descending aorta (DAo) and umbilical vein by DUS gating and MOG in 22 women with singleton pregnancy in gestational week 360 (265-400) with repeated scans in six fetuses. Impact of ROI size on measured flow was assessed for ROI:s 50-150% of the vessel diameter. Four observers from two centers provided time-resolved and static delineations. Bland-Altman analysis was used to determine agreement between both observers and methods. RESULTS DAo flow was 726 (348-1130) ml/min and umbilical vein flow 366 (150-782) ml/min by DUS gating. Bias±SD for DUS-gating versus MOG were - 45 ± 122 ml/min (-6 ± 15%) for DAo and 19 ± 136 ml/min (2 ± 24%) for umbilical vein flow. Repeated flow measurements in the same fetus showed similar volumes (median CoV = 11% (DAo) and 23% (umbilical vein)). Region of interest 50-150% of vessel diameter yielded flow 35-120%. Bias±SD for time-resolved versus static DUS-gated flow was 33 ± 39 ml/min (4 ± 6%) for DAo and 11 ± 84 ml/min (2 ± 15%) for umbilical vein flow. CONCLUSIONS Quantification of blood flow in the fetal DAo and umbilical vein using DUS-gated phase-contrast CMR is feasible and agrees with the current reference method. Repeatability was generally high for CMR fetal blood flow assessment. An ROI similar to the vessel area or slightly larger is recommended. A static ROI is sufficient for fetal flow quantification using currently available CMR sequences.
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Affiliation(s)
- Daniel Ryd
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
| | - Liqun Sun
- Department of Pediatrics, University of Toronto and Hospital for Sick Children, Toronto, ON Canada
| | - Katarina Steding-Ehrenborg
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
- Department of Health Sciences, Physiotherapy, Lund University, Lund, Sweden
| | - Sebastian Bidhult
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
- Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden
| | - Fabian Kording
- Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Ruprecht
- Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christopher K. Macgowan
- Department of Medical Biophysics, University of Toronto and Hospital for Sick Children, Toronto, ON Canada
| | - Michael Seed
- Department of Pediatrics, University of Toronto and Hospital for Sick Children, Toronto, ON Canada
- Department of Diagnostic Imaging, University of Toronto and Hospital for Sick Children, Toronto, ON Canada
| | - Anthony H. Aletras
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
- School of Medicine, Laboratory of Computing, Medical Informatics and Biomedical, Imaging Technologies, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Håkan Arheden
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
| | - Erik Hedström
- Clinical Physiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
- Diagnostic Radiology, Department of Clinical Sciences Lund, Lund University, Skane University Hospital, Lund, Sweden
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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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Bidhult S, Töger J, Heiberg E, Carlsson M, Arheden H, Aletras AH, Hedström E. Independent validation of metric optimized gating for fetal cardiovascular phase-contrast flow imaging. Magn Reson Med 2019; 81:495-503. [PMID: 30159933 PMCID: PMC6282515 DOI: 10.1002/mrm.27392] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 11/24/2022]
Abstract
PURPOSE To validate metric optimized gating phase-contrast MR (MOG PC-MR) flow measurements for a range of fetal flow velocities in phantom experiments. 2) To investigate intra- and interobserver variability for fetal flow measurements at an imaging center other than the original site. METHODS MOG PC-MR was compared to timer/beaker measurements in a pulsatile flow phantom using a heart rate (∼145 bpm), nozzle diameter (∼6 mm), and flow range (∼130-700 mL/min) similar to fetal imaging. Fifteen healthy fetuses were included for intra- and interobserver variability in the fetal descending aorta and umbilical vein. RESULTS Phantom MOG PC-MR flow bias and variability was 2% ± 23%. Accuracy of MOG PC-MR was degraded for flow profiles with low velocity-to-noise ratio. Intra- and interobserver coefficients of variation were 6% and 19%, respectively, for fetal descending aorta; and 10% and 17%, respectively, for the umbilical vein. CONCLUSION Phantom validation showed good agreement between MOG and conventionally gated PC-MR, except for cases with low velocity-to-noise ratio, which resulted in MOG misgating and underestimated peak velocities and warranted optimization of sequence parameters to individual fetal vessels. Inter- and intraobserver variability for fetal MOG PC-MR imaging were comparable to previously reported values.
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Affiliation(s)
- Sebastian Bidhult
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Clinical PhysiologyLundSweden
- Lund UniversityDepartment of Biomedical Engineering, Faculty of EngineeringLundSweden
| | - Johannes Töger
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Clinical PhysiologyLundSweden
| | - Einar Heiberg
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Clinical PhysiologyLundSweden
- Lund UniversityDepartment of Biomedical Engineering, Faculty of EngineeringLundSweden
| | - Marcus Carlsson
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Clinical PhysiologyLundSweden
| | - Håkan Arheden
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Clinical PhysiologyLundSweden
| | - Anthony H. Aletras
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Clinical PhysiologyLundSweden
- Laboratory of Computing, Medical Informatics and Biomedical–Imaging Technologies, School of MedicineAristotle University of ThessalonikiGreece
| | - Erik Hedström
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Clinical PhysiologyLundSweden
- Lund University, Skane University HospitalDepartment of Clinical Sciences Lund, Diagnostic RadiologyLundSweden
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