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Degenhardt K, Schmidt S, Aigner CS, Kratzer FJ, Seiter DP, Mueller M, Kolbitsch C, Nagel AM, Wieben O, Schaeffter T, Schulz-Menger J, Schmitter S. Toward accurate and fast velocity quantification with 3D ultrashort TE phase-contrast imaging. Magn Reson Med 2024; 91:1994-2009. [PMID: 38174601 DOI: 10.1002/mrm.29978] [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: 08/11/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024]
Abstract
PURPOSE Traditional phase-contrast MRI is affected by displacement artifacts caused by non-synchronized spatial- and velocity-encoding time points. The resulting inaccurate velocity maps can affect the accuracy of derived hemodynamic parameters. This study proposes and characterizes a 3D radial phase-contrast UTE (PC-UTE) sequence to reduce displacement artifacts. Furthermore, it investigates the displacement of a standard Cartesian flow sequence by utilizing a displacement-free synchronized-single-point-imaging MR sequence (SYNC-SPI) that requires clinically prohibitively long acquisition times. METHODS 3D flow data was acquired at 3T at three different constant flow rates and varying spatial resolutions in a stenotic aorta phantom using the proposed PC-UTE, a Cartesian flow sequence, and a SYNC-SPI sequence as reference. Expected displacement artifacts were calculated from gradient timing waveforms and compared to displacement values measured in the in vitro flow experiments. RESULTS The PC-UTE sequence reduces displacement and intravoxel dephasing, leading to decreased geometric distortions and signal cancellations in magnitude images, and more spatially accurate velocity quantification compared to the Cartesian flow acquisitions; errors increase with velocity and higher spatial resolution. CONCLUSION PC-UTE MRI can measure velocity vector fields with greater accuracy than Cartesian acquisitions (although pulsatile fields were not studied) and shorter scan times than SYNC-SPI. As such, this approach is superior to traditional Cartesian 3D and 4D flow MRI when spatial misrepresentations cannot be tolerated, for example, when computational fluid dynamics simulations are compared to or combined with in vitro or in vivo measurements, or regional parameters such as wall shear stress are of interest.
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Affiliation(s)
- Katja Degenhardt
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Berlin, Germany
- Department of Radiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Simon Schmidt
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christoph S Aigner
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Berlin, Germany
| | - Fabian J Kratzer
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Daniel P Seiter
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Max Mueller
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Christoph Kolbitsch
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Berlin, Germany
| | - Armin M Nagel
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Oliver Wieben
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
- Department of Radiology, University of Wisconsin Madison, Madison, Wisconsin, USA
| | - Tobias Schaeffter
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Berlin, Germany
- School of Imaging Science and Biomedical Engineering, King's College London, London, United Kingdom
- Department of Medical Engineering, Technical University of Berlin, Berlin, Germany
| | - Jeanette Schulz-Menger
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Berlin, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
- Department of Cardiology and Nephrology, HELIOS Hospital Berlin-Buch, Berlin, Germany
| | - Sebastian Schmitter
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Berlin, Germany
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Henriques J, Amaro AM, Piedade AP. Biomimicking Atherosclerotic Vessels: A Relevant and (Yet) Sub-Explored Topic. Biomimetics (Basel) 2024; 9:135. [PMID: 38534820 DOI: 10.3390/biomimetics9030135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/28/2024] Open
Abstract
Atherosclerosis represents the etiologic source of several cardiovascular events, including myocardial infarction, cerebrovascular accidents, and peripheral artery disease, which remain the leading cause of mortality in the world. Numerous strategies are being delineated to revert the non-optimal projections of the World Health Organization, by both designing new diagnostic and therapeutic approaches or improving the interventional procedures performed by physicians. Deeply understanding the pathological process of atherosclerosis is, therefore, mandatory to accomplish improved results in these trials. Due to their availability, reproducibility, low expensiveness, and rapid production, biomimicking physical models are preferred over animal experimentation because they can overcome some limitations, mainly related to replicability and ethical issues. Their capability to represent any atherosclerotic stage and/or plaque type makes them valuable tools to investigate hemodynamical, pharmacodynamical, and biomechanical behaviors, as well as to optimize imaging systems and, thus, obtain meaningful prospects to improve the efficacy and effectiveness of treatment on a patient-specific basis. However, the broadness of possible applications in which these biomodels can be used is associated with a wide range of tissue-mimicking materials that are selected depending on the final purpose of the model and, consequently, prioritizing some materials' properties over others. This review aims to summarize the progress in fabricating biomimicking atherosclerotic models, mainly focusing on using materials according to the intended application.
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Affiliation(s)
- Joana Henriques
- University of Coimbra, CEMMPRE, ARISE, Department of Mechanical Engineering, 3030-788 Coimbra, Portugal
| | - Ana M Amaro
- University of Coimbra, CEMMPRE, ARISE, Department of Mechanical Engineering, 3030-788 Coimbra, Portugal
| | - Ana P Piedade
- University of Coimbra, CEMMPRE, ARISE, Department of Mechanical Engineering, 3030-788 Coimbra, Portugal
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Anastasiou V, Daios S, Karamitsos T, Peteinidou E, Didagelos M, Giannakoulas G, Aggeli C, Tsioufis K, Ziakas A, Kamperidis V. Multimodality imaging for the global evaluation of aortic stenosis: The valve, the ventricle, the afterload. Trends Cardiovasc Med 2024:S1050-1738(24)00015-X. [PMID: 38387745 DOI: 10.1016/j.tcm.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 02/03/2024] [Accepted: 02/04/2024] [Indexed: 02/24/2024]
Abstract
Aortic stenosis (AS) is the most common valvular heart disease growing in parallel to the increment of life expectancy. Besides the valve, the degenerative process affects the aorta, impairing its elastic properties and leading to increased systemic resistance. The composite of valvular and systemic afterload mediates ventricular damage. The first step of a thorough evaluation of AS should include a detailed assessment of valvular anatomy and hemodynamics. Subsequently, the ventricle, and the global afterload should be assessed to define disease stage and prognosis. Multimodality imaging is of paramount importance for the comprehensive evaluation of these three elements. Echocardiography is the cornerstone modality whereas Multi-Detector Computed Tomography and Cardiac Magnetic Resonance provide useful complementary information. This review comprehensively examines the merits of these imaging modalities in AS for the evaluation of the valve, the ventricle, and the afterload and ultimately endeavors to integrate them in a holistic assessment of AS.
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Affiliation(s)
- Vasileios Anastasiou
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Stylianos Daios
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Theodoros Karamitsos
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Emmanouela Peteinidou
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Matthaios Didagelos
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - George Giannakoulas
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Constantina Aggeli
- 1st Department of Cardiology, Hippokration Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Konstantinos Tsioufis
- 1st Department of Cardiology, Hippokration Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Antonios Ziakas
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Vasileios Kamperidis
- 1st Department of Cardiology, AHEPA Hospital, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Jacobson NM, Brusilovsky J, Ducey R, Stence NV, Barker AJ, Mitchell MB, Smith L, MacCurdy R, Weaver JC. The Inner Complexities of Multimodal Medical Data: Bitmap-Based 3D Printing for Surgical Planning Using Dynamic Physiology. 3D PRINTING AND ADDITIVE MANUFACTURING 2023; 10:855-868. [PMID: 37886401 PMCID: PMC10599423 DOI: 10.1089/3dp.2022.0265] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Motivated by the need to develop more informative and data-rich patient-specific presurgical planning models, we present a high-resolution method that enables the tangible replication of multimodal medical data. By leveraging voxel-level control of multimaterial three-dimensional (3D) printing, our method allows for the digital integration of disparate medical data types, such as functional magnetic resonance imaging, tractography, and four-dimensional flow, overlaid upon traditional magnetic resonance imaging and computed tomography data. While permitting the explicit translation of multimodal medical data into physical objects, this approach also bypasses the need to process data into mesh-based boundary representations, alleviating the potential loss and remodeling of information. After evaluating the optical characteristics of test specimens generated with our correlative data-driven method, we culminate with multimodal real-world 3D-printed examples, thus highlighting current and potential applications for improved surgical planning, communication, and clinical decision-making through this approach.
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Affiliation(s)
- Nicholas M. Jacobson
- School of Engineering, Design, and Computation—Inworks Innovation Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jane Brusilovsky
- School of Engineering, Design, and Computation—Inworks Innovation Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | | | - Nicholas V. Stence
- School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Children's Hospital Colorado, Heart Institute and Advanced Imaging Lab, Aurora, Colorado
| | - Alex J. Barker
- School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Children's Hospital Colorado, Heart Institute and Advanced Imaging Lab, Aurora, Colorado
| | - Max B. Mitchell
- School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Children's Hospital Colorado, Heart Institute and Advanced Imaging Lab, Aurora, Colorado
| | - Lawrence Smith
- School of Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Robert MacCurdy
- School of Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - James C. Weaver
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, USA
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Illi J, Bernhard B, Nguyen C, Pilgrim T, Praz F, Gloeckler M, Windecker S, Haeberlin A, Gräni C. Translating Imaging Into 3D Printed Cardiovascular Phantoms. JACC Basic Transl Sci 2022; 7:1050-1062. [PMID: 36337920 PMCID: PMC9626905 DOI: 10.1016/j.jacbts.2022.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/03/2021] [Accepted: 01/03/2022] [Indexed: 11/27/2022]
Abstract
3D printed patient specific phantoms can visualize complex cardiovascular anatomy Common imaging modalities for 3D printing are CCT and CMR Material jetting/PolyJet and stereolithography are widely used printing techniques Standardized validation is warranted to compare different 3D printing technologies
Translation of imaging into 3-dimensional (3D) printed patient-specific phantoms (3DPSPs) can help visualize complex cardiovascular anatomy and enable tailoring of therapy. The aim of this paper is to review the entire process of phantom production, including imaging, materials, 3D printing technologies, and the validation of 3DPSPs. A systematic review of published research was conducted using Embase and MEDLINE, including studies that investigated 3DPSPs in cardiovascular medicine. Among 2,534 screened papers, 212 fulfilled inclusion criteria and described 3DPSPs as a valuable adjunct for planning and guiding interventions (n = 108 [51%]), simulation of physiological or pathological conditions (n = 19 [9%]), teaching of health care professionals (n = 23 [11%]), patient education (n = 3 [1.4%]), outcome prediction (n = 6 [2.8%]), or other purposes (n = 53 [25%]). The most common imaging modalities to enable 3D printing were cardiac computed tomography (n = 131 [61.8%]) and cardiac magnetic resonance (n = 26 [12.3%]). The printing process was conducted mostly by material jetting (n = 54 [25.5%]) or stereolithography (n = 43 [20.3%]). The 10 largest studies that evaluated the geometric accuracy of 3DPSPs described a mean bias <±1 mm; however, the validation process was very heterogeneous among the studies. Three-dimensional printed patient-specific phantoms are highly accurate, used for teaching, and applied to guide cardiovascular therapy. Systematic comparison of imaging and printing modalities following a standardized validation process is warranted to allow conclusions on the optimal production process of 3DPSPs in the field of cardiovascular medicine.
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Isoda H, Fukuyama A. Quality Control for 4D Flow MR Imaging. Magn Reson Med Sci 2022; 21:278-292. [PMID: 35197395 PMCID: PMC9680545 DOI: 10.2463/mrms.rev.2021-0165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 01/08/2022] [Indexed: 01/06/2023] Open
Abstract
In recent years, 4D flow MRI has become increasingly important in clinical applications for the blood vessels in the whole body, heart, and cerebrospinal fluid. 4D flow MRI has advantages over 2D cine phase-contrast (PC) MRI in that any targeted area of interest can be analyzed post-hoc, but there are some factors to be considered, such as ensuring measurement accuracy, a long imaging time and post-processing complexity, and interobserver variability.Due to the partial volume phenomenon caused by low spatial and temporal resolutions, the accuracy of flow measurement in 4D flow MRI is reduced. For spatial resolution, it is recommended to include at least four voxels in the vessel of interest, and if possible, six voxels. In large vessels such as the aorta, large voxels can be secured and SNR can be maintained, but in small cerebral vessels, SNR is reduced, resulting in reduced accuracy. A temporal resolution of less than 40 ms is recommended. The velocity-to-noise ratio (VNR) of low-velocity blood flow is low, resulting in poor measurement accuracy. The use of dual velocity encoding (VENC) or multi-VENC is recommended to avoid velocity wrap around and to increase VNR. In order to maintain sufficient spatio-temporal resolution, a longer imaging time is required, leading to potential patient movement during examination and a corresponding decrease in measurement accuracy.For the clinical application of new technologies, including various acceleration techniques, in vitro and in vivo accuracy verification based on existing accuracy-validated 2D cine PC MRI and 4D flow MRI, as well as accuracy verification on the conservation of mass' principle, should be performed, and intraobserver repeatability, interobserver reproducibility, and test-retest reproducibility should be checked.
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Affiliation(s)
- Haruo Isoda
- Brain and Mind Research Center, Nagoya University, Nagoya, Aichi, Japan
- Biomedical Imaging Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Atsushi Fukuyama
- Faculty of Health Sciences, Department of Radiological Sciences, Japan Healthcare University, Sapporo, Hokkaido, Japan
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7
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Abstract
This special issue of Magnetic Resonance in Medical Sciences features the most recent reviews on 4D Flow MRI. These reviews deal with the current status of the emerging technique of 4D Flow MRI facilitated in various areas that are difficult to obtain with conventional flowmetry. MR signals inherently contain flow velocity information. In previous decades, in vivo blood flow measurement was traditionally performed by 2D methods, such as Doppler ultrasonography and 2D phase-contrast MRI, which have long been regarded as mature techniques in hemodynamic flowmetry. Although 2D velocimetries have many advantages over 4D Flow MRI in terms of cost and accessibility, and provide excellent temporal and in-plane spatial resolutions, they also have some disadvantages. The emerging technology of 4D Flow MRI can overcome the shortcomings of conventional 2D imaging. In recent years, hemodynamic analysis has witnessed significant progress that is primarily attributable to advances in 4D Flow MRI.
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Affiliation(s)
- Yasuo Takehara
- Department of Fundamental Development for Low Invasive Diagnostic Imaging, Nagoya University Graduate School of Medicine
| | - Tetsuro Sekine
- Department of Radiology, Nippon Medical School Musashi Kosugi Hospital
| | - Takayuki Obata
- Applied MRI Research, Department of Molecular Imaging and Theranostics, National Institutes for Quantum Science and Technology
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Lim SH, Mohd Adib MAH, Abdullah MS, Mohd Taib NH, Hassan R, Abd Aziz A. Investigate the Velocity Difference Between MRI Measurement and CFD Simulation on Patient-Specific Blood Flow Analysis. 6TH KUALA LUMPUR INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING 2021 2022:453-460. [DOI: 10.1007/978-3-030-90724-2_49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Delaney M, Cleveland V, Mass P, Capuano F, Mandell JG, Loke YH, Olivieri L. Right ventricular afterload in repaired D-TGA is associated with inefficient flow patterns, rather than stenosis alone. Int J Cardiovasc Imaging 2021; 38:653-662. [PMID: 34727253 DOI: 10.1007/s10554-021-02436-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 10/04/2021] [Indexed: 11/24/2022]
Abstract
Treatment of D- transposition of great arteries (DTGA) involves the Arterial Switch Operation (ASO), which can create PA branch stenosis (PABS) and alter PA blood flow energetics. This altered PA flow may contribute to elevated right ventricular (RV) afterload more significantly than stenosis alone. Our aim was to correlate RV afterload and PA flow characteristics using 4D flow cardiac magnetic resonance (CMR) imaging of a mock circulatory system (MCS) incorporating 3D printed replicas. CMR imaging and clinical characteristics were analyzed from 22 ASO patients (age 11.9 ± 8.7 years, 68% male). Segmentation was performed to create 3D printed PA replicas that were mounted in an MRI-compatible MCS. Pressure drop across the PA replica was recorded and 4D flow CMR acquisitions were analyzed for blood flow inefficiency (energy loss, vorticity). In post-ASO patients, there is no difference in RV mass (p = 0.07), nor RV systolic pressure (p = 0.26) in the presence or absence of PABS. 4D flow analysis of MCS shows energy loss is correlated to RV mass (p = 0.01, r = 0.67) and MCS pressure differential (p = 0.02, r = 0.57). Receiver operating characteristic curve shows energy loss detects elevated RV mass above 30 g/m2 (p = 0.02, AUC 0.88) while index of PA dimensions (Nakata) does not (p = 0.09, AUC 0.79). PABS alone does not account for differences in RV mass or afterload in post-ASO patients. In MCS simulations, energy loss is correlated with both RV mass and PA pressure, and can moderately detect elevated RV mass. Inefficient PA flow may be an important predictor of RV afterload in this population.
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Affiliation(s)
- Marc Delaney
- Division of Pediatrics, Children's National Medical Center, 111 Michigan Ave, NW, Washington, DC, 20010, USA.
| | - Vincent Cleveland
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, DC, USA
| | - Paige Mass
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, DC, USA
| | - Francesco Capuano
- Department of Mechanics, Mathematics and Management, Politecnico di Bari, Bari, Italy
| | - Jason G Mandell
- Division of Cardiology, Children's National Medical Center, Washington, DC, USA
| | - Yue-Hin Loke
- Division of Cardiology, Children's National Medical Center, Washington, DC, USA
| | - Laura Olivieri
- Division of Cardiology, Children's National Medical Center, Washington, DC, USA
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Yazdi SG, Docherty PD, Williamson PN, Jermy M, Kabaliuk N, Khanafer A, Geoghegan PH. In vitro pulsatile flow study in compliant and rigid ascending aorta phantoms by stereo particle image velocimetry. Med Eng Phys 2021; 96:81-90. [PMID: 34565556 DOI: 10.1016/j.medengphy.2021.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 08/05/2021] [Accepted: 08/31/2021] [Indexed: 10/20/2022]
Abstract
The aorta is a high risk region for cardiovascular disease (CVD). Haemodynamic patterns leading to CVD are not well established despite numerous experimental and numerical studies. Most overlook effects of arterial compliance and pulsatile flow. However, rigid wall assumptions can lead to overestimation of wall shear stress; a key CVD determinant. This work investigates the effect of compliance on aortic arch haemodynamics experiencing pulsatility. Rigid and compliant phantoms of the arch and brachiocephalic branch (BCA) were manufactured. Stereoscopic particle image velocimetry was used to observe velocity fields. Higher velocity magnitude was observed in the rigid BCA during acceleration. However, during deceleration, the compliant phantom experienced higher velocity. During deceleration, a low velocity region initiated and increased in size in the BCA of both phantoms with irregular shape in the compliant. At mid-deceleration, considerably larger recirculation was observed under compliance compared to rigid. Another recirculation region formed and increased in size on the inner wall of the arch in the compliant during late deceleration, but not rigid. The recirculation regions witnessed identify as high risk areas for atherosclerosis formation by a previous ex-vivo study. The results demonstrate necessity of compliance and pulsatility in haemodynamic studies to obtain highly relevant clinical outcomes.
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Affiliation(s)
- Sina G Yazdi
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Paul D Docherty
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Petra N Williamson
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Mark Jermy
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Natalia Kabaliuk
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Adib Khanafer
- Vascular, Endovascular, & Renal Transplant Unit Christchurch Hospital, Canterbury District Health Board, Riccarton Avenue, Christchurch 8053, New Zealand; Christchurch School of Medicine, University of Otago, New Zealand
| | - Patrick H Geoghegan
- Department of Mechanical, Biomedical and Design, College of Engineering and Physical Sciences Aston University, Birmingham, B4 7ET, England; Department of Mechanical and Industrial Engineering, University of South Africa, Johannesburg, South Africa.
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NO-HYPE: a novel hydrodynamic phantom for the evaluation of MRI flow measurements. Med Biol Eng Comput 2021; 59:1889-1899. [PMID: 34365590 PMCID: PMC8382656 DOI: 10.1007/s11517-021-02390-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 06/07/2021] [Indexed: 10/24/2022]
Abstract
Accurate and reproducible measurement of blood flow profile is very important in many clinical investigations for diagnosing cardiovascular disorders. Given that many factors could affect human circulation, and several parameters must be set to properly evaluate blood flows with phase-contrast techniques, we developed an MRI-compatible hydrodynamic phantom to simulate different physiological blood flows. The phantom included a programmable hydraulic pump connected to a series of pipes immersed in a solution mimicking human soft tissues, with a blood-mimicking fluid flowing in the pipes. The pump is able to shape and control the flow by driving a piston through a dedicated software. Periodic waveforms are used as input to the pump to move the fluid into the pipes, with synchronization of the MRI sequences to the flow waveforms. A dedicated software is used to extract and analyze flow data from magnitude and phase images. The match between the nominal and the measured flows was assessed, and the scope of phantom variables useful for a reliable calibration of an MRI system was accordingly defined. Results showed that the NO-HYPE phantom is a valuable tool for the assessment of MRI scanners and sequence design for the MR evaluation of blood flows. Overview of the NOvel HYdrodynamic Phantom for the Evaluation of MRI flow measurements (NO-HYPE). Left: internal of the CompuFlow 1000 MR pump unit. Right: Setting of the NO-HYPE before a MRI acquisition session. Soft tissue mimicking material is hosted in the central part of the phantom (light blue chamber). Glass pipes pass through the chamber carrying the blood mimicking fluid.
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Annio G, Torii R, Ducci A, Muthurangu V, Tsang V, Burriesci G. Experimental Validation of Enhanced Magnetic Resonance Imaging (EMRI) Using Particle Image Velocimetry (PIV). Ann Biomed Eng 2021; 49:3481-3493. [PMID: 34181130 DOI: 10.1007/s10439-021-02811-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/07/2021] [Indexed: 12/27/2022]
Abstract
Flow-sensitive four-dimensional Cardiovascular Magnetic Resonance Imaging (4D Flow CMR) has increasingly been utilised to characterise patients' blood flow, in association with patiens' state of health and disease, even though spatial and temporal resolutions still constitute a limit. Computational fluid dynamics (CFD) is a powerful tool that could expand these information and, if integrated with experimentally-obtained velocity fields, would enable to derive a large variety of the flow descriptors of interest. However, the accuracy of the flow parameters is highly influenced by the quality of the input data such as the anatomical model and boundary conditions typically derived from medical images including 4D Flow CMR. We previously proposed a novel approach in which 4D Flow CMR and CFD velocity fields are integrated to obtain an Enhanced 4D Flow CMR (EMRI), allowing to overcome the spatial-resolution limitation of 4D Flow CMR, and enable an accurate quantification of flow. In this paper, the proposed approach is validated in a U bend channel, an idealised model of the human aortic arch. The flow patterns were studied with 4D Flow CMR, CFD and EMRI, and compared with high resolution 2D PIV experiments obtained in pulsatile conditions. The main strengths and limitations of 4D Flow CMR and CFD were illustrated by exploiting the accuracy of PIV by comparing against PIV velocity fields. EMRI flow patterns showed a better qualitative and quantitative agreement with PIV results than the other techniques. EMRI enables to overcome the experimental limitations of MRI-based velocity measurements and the modelling simplifications of CFD, allowing an accurate prediction of complex flow patterns observed experimentally, while satisfying mass and momentum balance equations.
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Affiliation(s)
- Giacomo Annio
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
| | - Ryo Torii
- Department of Mechanical Engineering, University College London, London, UK.
| | - Andrea Ducci
- Department of Mechanical Engineering, University College London, London, UK
| | - Vivek Muthurangu
- Centre for Cardiovascular Imaging and Physics, University College London, London, UK
| | - Victor Tsang
- Cardiothoracic Surgery Unit, Great Ormond Street Hospital, London, UK
| | - Gaetano Burriesci
- Department of Mechanical Engineering, University College London, London, UK.
- Ri.MED Foundation, Palermo, Italy.
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Pugalendhi A, Ranganathan R. A review of additive manufacturing applications in ophthalmology. Proc Inst Mech Eng H 2021; 235:1146-1162. [PMID: 34176362 DOI: 10.1177/09544119211028069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.
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Affiliation(s)
- Arivazhagan Pugalendhi
- Department of Mechanical Engineering, Coimbatore Institute of Technology, Coimbatore, Tamil Nadu, India
| | - Rajesh Ranganathan
- Department of Mechanical Engineering, Coimbatore Institute of Technology, Coimbatore, Tamil Nadu, India
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Abstract
An implants' effectiveness depends upon the form of biomaterial used in its manufacture. A suitable material for implants should be biocompatible, sterile, mechanically stable and simple to shape. 3D printing technologies have been breaking new ground in the medical and medical industries in order to build patient-specific devices embedded in bioactive drugs, cells and proteins. Widespread use in medical 3D printing is a broad range of biomaterials including metals, ceramics, polymers and composites. Continuous work and developments in biomaterials used in 3D printing have contributed to significant growth of 3D printing applications in the production of personalised joints, prostheses, medication delivery system and 3D tissue engineering and regenerative medicine scaffolds. The present analysis focuses on the biomaterials used for therapeutic applications in different 3D printing technologies. Many specific forms of medical 3D printing technology are explored in depth, including fused deposition modelling, extrusion-based bioprinting, inkjet and poly-jet printing processes, their therapeutic uses, various types of biomaterial used today and the major shortcoming , are being studied in depth.
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Affiliation(s)
- Abhay Mishra
- Department of Mechanical Engineering, DIT University, Dehradun, India
| | - Vivek Srivastava
- Department of Mechanical Engineering, DIT University, Dehradun, India
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On the impact of vessel wall stiffness on quantitative flow dynamics in a synthetic model of the thoracic aorta. Sci Rep 2021; 11:6703. [PMID: 33758315 PMCID: PMC7988183 DOI: 10.1038/s41598-021-86174-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/09/2021] [Indexed: 12/12/2022] Open
Abstract
Aortic wall stiffening is a predictive marker for morbidity in hypertensive patients. Arterial pulse wave velocity (PWV) correlates with the level of stiffness and can be derived using non-invasive 4D-flow magnetic resonance imaging (MRI). The objectives of this study were twofold: to develop subject-specific thoracic aorta models embedded into an MRI-compatible flow circuit operating under controlled physiological conditions; and to evaluate how a range of aortic wall stiffness impacts 4D-flow-based quantification of hemodynamics, particularly PWV. Three aorta models were 3D-printed using a novel photopolymer material at two compliant and one nearly rigid stiffnesses and characterized via tensile testing. Luminal pressure and 4D-flow MRI data were acquired for each model and cross-sectional net flow, peak velocities, and PWV were measured. In addition, the confounding effect of temporal resolution on all metrics was evaluated. Stiffer models resulted in increased systolic pressures (112, 116, and 133 mmHg), variations in velocity patterns, and increased peak velocities, peak flow rate, and PWV (5.8–7.3 m/s). Lower temporal resolution (20 ms down to 62.5 ms per image frame) impacted estimates of peak velocity and PWV (7.31 down to 4.77 m/s). Using compliant aorta models is essential to produce realistic flow dynamics and conditions that recapitulated in vivo hemodynamics.
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16
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Wüstenhagen C, John K, Langner S, Brede M, Grundmann S, Bruschewski M. CFD validation using in-vitro MRI velocity data - Methods for data matching and CFD error quantification. Comput Biol Med 2021; 131:104230. [PMID: 33545507 DOI: 10.1016/j.compbiomed.2021.104230] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 11/26/2022]
Abstract
Predicting blood flow velocities in patient-specific geometries with Computational Fluid Dynamics (CFD) can provide additional data for diagnosis and treatment planning but the solution can be inaccurate. Therefore, it is crucial to understand the simulation errors and calibrate the numerical model. In-vitro velocity-encoded MRI is a versatile tool to validate CFD. The comparison between CFD and in-vitro MRI velocity data, and the analysis of the simulation error are the objectives of this study. A three-step routine is presented to validate medical CFD data. First, a properly scaled model of the patient-specific geometry is fabricated to achieve high relative resolution in the MRI experiment. Second, the measured flow geometry is matched with the CFD data using one of two algorithms, Coherent Point Drift and Iterative Closest Point. The aligned data sets are then interpolated onto a common grid to enable a point-to-point comparison. Third, the global and local deviations between CFD and MRI velocity data are calculated using different algorithms to reliably estimate the simulation error. The routine is successfully tested with a patient-specific model of a cerebral aneurysm. In conclusion, the methods presented here provide a framework for CFD validation using in-vitro MRI velocity data.
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Affiliation(s)
- Carolin Wüstenhagen
- Institute of Fluid Mechanics, University of Rostock, Justus-von-Liebig-Weg 2, 18059, Rostock, Germany
| | - Kristine John
- Institute of Fluid Mechanics, University of Rostock, Justus-von-Liebig-Weg 2, 18059, Rostock, Germany
| | - Sönke Langner
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, Rostock University Medical Center, 18057, Rostock, Germany
| | - Martin Brede
- Institute of Fluid Mechanics, University of Rostock, Justus-von-Liebig-Weg 2, 18059, Rostock, Germany
| | - Sven Grundmann
- Institute of Fluid Mechanics, University of Rostock, Justus-von-Liebig-Weg 2, 18059, Rostock, Germany
| | - Martin Bruschewski
- Institute of Fluid Mechanics, University of Rostock, Justus-von-Liebig-Weg 2, 18059, Rostock, Germany.
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17
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CMR in Evaluating Valvular Heart Disease: Diagnosis, Severity, and Outcomes. JACC Cardiovasc Imaging 2020; 14:2020-2032. [PMID: 33248967 DOI: 10.1016/j.jcmg.2020.09.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/04/2020] [Accepted: 09/14/2020] [Indexed: 01/20/2023]
Abstract
Cardiac magnetic resonance (CMR) is a versatile imaging tool that brings much to the assessment of valvular heart disease. Although it is best known for myocardial imaging (even in valve disease), it provides excellent assessment of all 4 heart valves, with some distinct advantages, including a free choice of image planes and accurate flow and volumetric quantification. These allow the severity of each valve lesion to be characterized, in addition to optimal visualization of the surrounding outflow tracts and vessels, to deliver a comprehensive package. It can assess each valve lesion separately (in multiple valve disease) and is not affected by hemodynamic status. The accurate quantitation of regurgitant lesions and the ability to characterize myocardial changes also provides an ability to predict future clinical outcomes in asymptomatic patients. This review outlines how CMR can be used in cardiac valve disease to compliment echocardiography and enhance the patient assessment. It covers the main CMR methods used, their strengths and limitations, and the optimal way to apply them to evaluate valve disease.
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18
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Three-Dimensional Bioprinting: Role in Craniomaxillary Surgery Ethics and Future. J Craniofac Surg 2020; 31:1114-1116. [PMID: 32433136 DOI: 10.1097/scs.0000000000006553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Three-dimensional (3D) printing and bioprinting is gaining lot of momentum, especially in surgical specialties. These two technologies have wide array of applications in presurgical, surgical, and in vitro scenarios. Bioprinting can generate customized patient specific tissue engineered from specialized cells. This technology can be a gold standard in reconstructive and regenerative surgeries, if used in regulated and ethical environment. This communication focuses on basics of these technologies, their role in surgical specialties, ethical issues specific to these technologies, and its future.
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Elsayed M, Kadom N, Ghobadi C, Strauss B, Al Dandan O, Aggarwal A, Anzai Y, Griffith B, Lazarow F, Straus CM, Safdar NM. Virtual and augmented reality: potential applications in radiology. Acta Radiol 2020; 61:1258-1265. [PMID: 31928346 DOI: 10.1177/0284185119897362] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The modern-day radiologist must be adept at image interpretation, and the one who most successfully leverages new technologies may provide the highest value to patients, clinicians, and trainees. Applications of virtual reality (VR) and augmented reality (AR) have the potential to revolutionize how imaging information is applied in clinical practice and how radiologists practice. This review provides an overview of VR and AR, highlights current applications, future developments, and limitations hindering adoption.
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Affiliation(s)
- Mohammad Elsayed
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Nadja Kadom
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Comeron Ghobadi
- Department of Radiology, The University of Chicago Pritzker School of Medicine, IL, USA
| | - Benjamin Strauss
- Department of Radiology, The University of Chicago Pritzker School of Medicine, IL, USA
| | - Omran Al Dandan
- Department of Radiology, Imam Abdulrahman Bin Faisal University College of Medicine, Dammam, Eastern Province, Saudi Arabia
| | - Abhimanyu Aggarwal
- Department of Radiology, Eastern Virginia Medical School, Norfolk, VA, USA
| | - Yoshimi Anzai
- Department of Radiology and Imaging Sciences, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Brent Griffith
- Department of Radiology, Henry Ford Health System, Detroit, MI, USA
| | - Frances Lazarow
- Department of Radiology, Eastern Virginia Medical School, Norfolk, VA, USA
| | - Christopher M Straus
- Department of Radiology, The University of Chicago Pritzker School of Medicine, IL, USA
| | - Nabile M Safdar
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
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Vali A, Schmitter S, Ma L, Flassbeck S, Schmidt S, Markl M, Schnell S. Development of a rotation phantom for phase contrast MRI sequence validation and quality control. Magn Reson Med 2020; 84:3333-3341. [DOI: 10.1002/mrm.28343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Alireza Vali
- Department of Radiology Northwestern University Chicago Illinois USA
| | - Sebastian Schmitter
- Physikalisch Technische Bundesanstalt Braunschweig and Berlin Germany
- Medical Physics in Radiology German Cancer Research Center (DKFZ) Heidelberg Germany
| | - Liliana Ma
- Department of Radiology Northwestern University Chicago Illinois USA
- Department of Biomedical Engineering Northwestern University Evanston Illinois USA
| | - Sebastian Flassbeck
- Medical Physics in Radiology German Cancer Research Center (DKFZ) Heidelberg Germany
| | - Simon Schmidt
- Medical Physics in Radiology German Cancer Research Center (DKFZ) Heidelberg Germany
- Faculty of Physics and Astronomy Heidelberg University Heidelberg Germany
| | - Michael Markl
- Department of Radiology Northwestern University Chicago Illinois USA
- Department of Biomedical Engineering Northwestern University Evanston Illinois USA
| | - Susanne Schnell
- Department of Radiology Northwestern University Chicago Illinois USA
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21
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Medical 3D Printing. Is This Just The Beginning? Heart Lung Circ 2019; 28:1457-1458. [PMID: 31495503 DOI: 10.1016/j.hlc.2019.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Steier A, Muñiz A, Neale D, Lahann J. Emerging Trends in Information-Driven Engineering of Complex Biological Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806898. [PMID: 30957921 DOI: 10.1002/adma.201806898] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/03/2018] [Indexed: 06/09/2023]
Abstract
Synthetic biological systems are used for a myriad of applications, including tissue engineered constructs for in vivo use and microengineered devices for in vitro testing. Recent advances in engineering complex biological systems have been fueled by opportunities arising from the combination of bioinspired materials with biological and computational tools. Driven by the availability of large datasets in the "omics" era of biology, the design of the next generation of tissue equivalents will have to integrate information from single-cell behavior to whole organ architecture. Herein, recent trends in combining multiscale processes to enable the design of the next generation of biomaterials are discussed. Any successful microprocessing pipeline must be able to integrate hierarchical sets of information to capture key aspects of functional tissue equivalents. Micro- and biofabrication techniques that facilitate hierarchical control as well as emerging polymer candidates used in these technologies are also reviewed.
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Affiliation(s)
- Anke Steier
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Ayşe Muñiz
- Biointerfaces Institute and Macromolecular Science and Engineering Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Dylan Neale
- Biointerfaces Institute and Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Joerg Lahann
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Biointerfaces Institute, Departments of Chemical Engineering, Materials Science and Engineering, and Biomedical Engineering and the, Macromolecular Science and Engineering Program, University of Michigan, Ann Arbor, MI, 48109, USA
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Abstract
Pierre Robin sequence (PRS) is a congenital malformation characterized by micrognathia, glossocoma, and mechanical obstruction of the upper respiratory tract. These deformities impair respiration, sleep, feeding, and swallowing, and can lead to malnutrition, stunted development, and death. Bilateral mandibular distraction osteogenesis, whereby the mandible and tongue root are extended outward, is the standard treatment to relieve upper airway obstruction in severe PRS. Accurate placement of the distraction device is essential but challenging, especially in infants, and requires the pre-operative fabrication of surgical guides based on CT images. Three-dimensional (3D) printing allows for the accurate recreation of objects from digitized models. We compared surgical efficacy and safety of bilateral mandibular distraction osteogenesis using 3D printed or traditionally fabricated surgery guides for treatment of infants with severe PRS.During the period from 2014 to 2016, 22 patients with severe PRS were treated using either traditional or 3D printed surgery guides. We compared outcome measures of operations, including intraoperative bleeding, operation time, and postoperative complications.The 3D printed surgery guide group demonstrated significantly shorter operation time (P <.05) as well as moderately shorter hospital stay and artificial ventilation time (∼1 day less). Furthermore, despite markedly younger average age of the 3D printed group (1.3 vs 3.5 months), there was no increase in postoperative complications using the 3D printed guides.Three-dimensional printed surgery guides were used successfully for bilateral mandibular traction osteogenesis, and according to several outcome, parameters demonstrated superior efficacy and safety compared to traditional guides. Further research is warranted to extend the applications of 3D printed surgical guides for craniofacial surgery.
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Quiñones DR, Ferragud-Agulló J, Pérez-Feito R, García-Manrique JA, Canals S, Moratal D. A Tangible Educative 3D Printed Atlas of the Rat Brain. MATERIALS 2018; 11:ma11091531. [PMID: 30149609 PMCID: PMC6164676 DOI: 10.3390/ma11091531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 12/17/2022]
Abstract
In biology and neuroscience courses, brain anatomy is usually explained using Magnetic Resonance (MR) images or histological sections of different orientations. These can show the most important macroscopic areas in an animals’ brain. However, this method is neither dynamic nor intuitive. In this work, an anatomical 3D printed rat brain with educative purposes is presented. Hand manipulation of the structure, facilitated by the scale up of its dimensions, and the ability to dismantle the “brain” into some of its constituent parts, facilitates the understanding of the 3D organization of the nervous system. This is an alternative method for teaching students in general and biologists in particular the rat brain anatomy. The 3D printed rat brain has been developed with eight parts, which correspond to the most important divisions of the brain. Each part has been fitted with interconnections, facilitating assembling and disassembling as required. These solid parts were smoothed out, modified and manufactured through 3D printing techniques with poly(lactic acid) (PLA). This work presents a methodology that could be expanded to almost any field of clinical and pre-clinical research, and moreover it avoids the need for dissecting animals to teach brain anatomy.
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Affiliation(s)
- Darío R Quiñones
- Centre for Biomaterials and Tissue Engineering, Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Jorge Ferragud-Agulló
- Centre for Biomaterials and Tissue Engineering, Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Ricardo Pérez-Feito
- Thermodynamics Department, Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Juan A García-Manrique
- Institute of Design for Manufacturing and Automated Production, Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, 03550 Sant Joan d'Alacant, Spain.
| | - David Moratal
- Centre for Biomaterials and Tissue Engineering, Universitat Politècnica de València, 46022 Valencia, Spain.
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Tam CHA, Chan YC, Law Y, Cheng SWK. The Role of Three-Dimensional Printing in Contemporary Vascular and Endovascular Surgery: A Systematic Review. Ann Vasc Surg 2018; 53:243-254. [PMID: 30053547 DOI: 10.1016/j.avsg.2018.04.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 03/16/2018] [Accepted: 04/27/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Three-dimensional (3D) printing, also known as rapid prototyping or additive manufacturing, is a novel adjunct in the medical field. The aim of this systematic review is to evaluate the role of 3D printing technology in the field of contemporary vascular surgery in terms of its technical aspect, practicability, and clinical outcome. METHODS A systematic search of literatures published from January 1, 1980 to July 15, 2017 was identified from the EMBASE, MEDLINE, and Cochrane library database with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The predefined selection inclusion criterion was clinical application of 3D printing technology in vascular surgery of large and small vessel pathology. RESULTS Forty-two articles were included in this systematic review, including 2 retrospective cohorts and 1 prospective case control study. 3D printing was mostly applied to abdominal aortic aneurysm (n = 20) and thoracic aorta pathology (n = 8), other vessels included celiac, splenic, carotid, subclavian, femoral artery, and portal vein (n = 10). The most commonly quoted materials were acrylonitrile-butadiene-styrene (n = 2), polylactic acid (n = 4), polyurethane resin (n = 3) and nylon (n = 3). The cost per replica ranged from USD $4-2,360. Cost for a commercial printer was around USD $2,210-50,000. CONCLUSION 3D printing was recognized and gradually incorporated as a useful adjunct in the field of vascular and endovascular surgery. The production of an accurate anatomic patient-specific replica was shown to bring significant impact in patient management in terms of anatomic understanding, procedural planning, and intraoperative navigation, education, and academic research as well as patient communication. Further analysis on cost-effectiveness was indicated to guide decisions on applicability of such promising technology on a routine basis.
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Affiliation(s)
- Chun Hei Adrian Tam
- Division of Vascular & Endovascular Surgery, Department of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong, China
| | - Yiu Che Chan
- Division of Vascular & Endovascular Surgery, Department of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong, China.
| | - Yuk Law
- Division of Vascular & Endovascular Surgery, Department of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong, China
| | - Stephen Wing Keung Cheng
- Division of Vascular & Endovascular Surgery, Department of Surgery, University of Hong Kong Medical Centre, Queen Mary Hospital, Hong Kong, China
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Zhu Y, Wang F, Deng X. Hemodynamics of cerebral bridging veins connecting the superior sagittal sinus based on numerical simulation. Biomed Eng Online 2018; 17:35. [PMID: 29558949 PMCID: PMC5861626 DOI: 10.1186/s12938-018-0466-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 03/07/2018] [Indexed: 01/23/2023] Open
Abstract
Background The physiological and hemodynamic features of bridging veins involve wall shear stress (WSS) of the cerebral venous system. Based on the data of cadavers and computational fluid dynamics software pack, the hemodynamic physical models of bridging veins (BVs) connecting superior sagittal sinus (SSS) were established. Results A total of 137 BVs formed two clusters along the SSS: anterior group and posterior group. The diameters of the BVs in posterior group were larger than of the anterior group, and the entry angle was smaller. When the diameter of a BV was greater than 1.2 mm, the WSS decreased in the downstream wall of SSS with entry angle less than 105°, and the WSS also decreased in the upstream wall of BVs with entry angle less than 65°. The minimum WSS in BVs was only 63% of that in SSS. Compared with the BVs in anterior group, the minimum WSS in the posterior group was smaller, and the distance from location of the minimum WSS to the dural entrance was longer. Conclusion The cerebral venous thrombosis occurs more easily when the diameter of a BV is greater than 1.2 mm and the entry angle is less than 65°. The embolus maybe form earlier in the upstream wall of BVs in the posterior part of SSS. Electronic supplementary material The online version of this article (10.1186/s12938-018-0466-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Youyu Zhu
- Department of Anatomy, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China
| | - Feng Wang
- Department of Anatomy, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China
| | - Xuefei Deng
- Department of Anatomy, Anhui Medical University, 81 Meishan Road, Hefei, 230032, China.
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27
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Hodgdon T, Danrad R, Patel MJ, Smith SE, Richardson ML, Ballard DH, Ali S, Trace AP, DeBenedectis CM, Zygmont ME, Lenchik L, Decker SJ. Logistics of Three-dimensional Printing: Primer for Radiologists. Acad Radiol 2018; 25:40-51. [PMID: 29030283 DOI: 10.1016/j.acra.2017.08.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 02/07/2023]
Abstract
The Association of University Radiologists Radiology Research Alliance Task Force on three-dimensional (3D) printing presents a review of the logistic considerations for establishing a clinical service using this new technology, specifically focused on implications for radiology. Specific topics include printer selection for 3D printing, software selection, creating a 3D model for printing, providing a 3D printing service, research directions, and opportunities for radiologists to be involved in 3D printing. A thorough understanding of the technology and its capabilities is necessary as the field of 3D printing continues to grow. Radiologists are in the unique position to guide this emerging technology and its use in the clinical arena.
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Quantitative magnetic resonance imaging phantoms: A review and the need for a system phantom. Magn Reson Med 2017; 79:48-61. [DOI: 10.1002/mrm.26982] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 09/01/2017] [Accepted: 10/04/2017] [Indexed: 01/16/2023]
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Elevated Wall Shear Stress in Aortic Type B Dissection May Relate to Retrograde Aortic Type A Dissection: A Computational Fluid Dynamics Pilot Study. Eur J Vasc Endovasc Surg 2017; 54:324-330. [DOI: 10.1016/j.ejvs.2017.06.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 06/13/2017] [Indexed: 11/20/2022]
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Abstract
Objective: The application of 3-D printing has been increasingly used in medicine, with research showing many applications in cardiovascular disease. This systematic review analyzes those studies published about the applications of 3-D printed, patient-specific models in cardiovascular and cerebrovascular diseases. Methods: A search of PubMed/Medline and Scopus databases was performed to identify studies investigating the 3-D printing in cardiovascular and cerebrovascular diseases. Only studies based on patient’s medical images were eligible for review, while reports on in vitro phantom or review articles were excluded. Results: A total of 48 studies met selection criteria for inclusion in the review. A range of patient-specific 3-D printed models of different cardiovascular and cerebrovascular diseases were generated in these studies with most of them being developed using cardiac CT and MRI data, less commonly with 3-D invasive angiographic or echocardiographic images. The review of these studies showed high accuracy of 3-D printed, patient-specific models to represent complex anatomy of the cardiovascular and cerebrovascular system and depict various abnormalities, especially congenital heart diseases and valvular pathologies. Further, 3-D printing can serve as a useful education tool for both parents and clinicians, and a valuable tool for pre-surgical planning and simulation. Conclusion: This systematic review shows that 3-D printed models based on medical imaging modalities can accurately replicate complex anatomical structures and pathologies of the cardiovascular and cerebrovascular system. 3-D printing is a useful tool for both education and surgical planning in these diseases.
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31
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Nardi A, Avrahami I. Approaches for treatment of aortic arch aneurysm, a numerical study. J Biomech 2017; 50:158-165. [DOI: 10.1016/j.jbiomech.2016.11.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
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32
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Heidari Pahlavian S, Bunck AC, Thyagaraj S, Giese D, Loth F, Hedderich DM, Kröger JR, Martin BA. Accuracy of 4D Flow Measurement of Cerebrospinal Fluid Dynamics in the Cervical Spine: An In Vitro Verification Against Numerical Simulation. Ann Biomed Eng 2016; 44:3202-3214. [PMID: 27043214 PMCID: PMC5050060 DOI: 10.1007/s10439-016-1602-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/29/2016] [Indexed: 11/30/2022]
Abstract
Abnormal alterations in cerebrospinal fluid (CSF) flow are thought to play an important role in pathophysiology of various craniospinal disorders such as hydrocephalus and Chiari malformation. Three directional phase contrast MRI (4D Flow) has been proposed as one method for quantification of the CSF dynamics in healthy and disease states, but prior to further implementation of this technique, its accuracy in measuring CSF velocity magnitude and distribution must be evaluated. In this study, an MR-compatible experimental platform was developed based on an anatomically detailed 3D printed model of the cervical subarachnoid space and subject specific flow boundary conditions. Accuracy of 4D Flow measurements was assessed by comparison of CSF velocities obtained within the in vitro model with the numerically predicted velocities calculated from a spatially averaged computational fluid dynamics (CFD) model based on the same geometry and flow boundary conditions. Good agreement was observed between CFD and 4D Flow in terms of spatial distribution and peak magnitude of through-plane velocities with an average difference of 7.5 and 10.6% for peak systolic and diastolic velocities, respectively. Regression analysis showed lower accuracy of 4D Flow measurement at the timeframes corresponding to low CSF flow rate and poor correlation between CFD and 4D Flow in-plane velocities.
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Affiliation(s)
- Soroush Heidari Pahlavian
- Conquer Chiari Research Center, The University of Akron, Akron, OH, USA
- Department of Mechanical Engineering, The University of Akron, Akron, OH, USA
| | - Alexander C Bunck
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
- Department of Radiology, University Hospital of Muenster, Muenster, Germany
| | - Suraj Thyagaraj
- Conquer Chiari Research Center, The University of Akron, Akron, OH, USA
- Department of Mechanical Engineering, The University of Akron, Akron, OH, USA
| | - Daniel Giese
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Francis Loth
- Conquer Chiari Research Center, The University of Akron, Akron, OH, USA
- Department of Mechanical Engineering, The University of Akron, Akron, OH, USA
| | - Dennis M Hedderich
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Jan Robert Kröger
- Department of Radiology, University Hospital of Muenster, Muenster, Germany
| | - Bryn A Martin
- Department of Biological Engineering, The University of Idaho, 875 Perimeter Drive MS 0904, Moscow, ID, 83844-0904, USA.
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Mitsouras D, Liacouras P, Imanzadeh A, Giannopoulos AA, Cai T, Kumamaru KK, George E, Wake N, Caterson EJ, Pomahac B, Ho VB, Grant GT, Rybicki FJ. Medical 3D Printing for the Radiologist. Radiographics 2016; 35:1965-88. [PMID: 26562233 DOI: 10.1148/rg.2015140320] [Citation(s) in RCA: 354] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article.
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Affiliation(s)
- Dimitris Mitsouras
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Peter Liacouras
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Amir Imanzadeh
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Andreas A Giannopoulos
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Tianrun Cai
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Kanako K Kumamaru
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Elizabeth George
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Nicole Wake
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Edward J Caterson
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Bohdan Pomahac
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Vincent B Ho
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Gerald T Grant
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
| | - Frank J Rybicki
- From the Applied Imaging Science Laboratory, Department of Radiology (D.M., A.I., A.A.G., T.C., K.K.K., E.G., F.J.R.), and Division of Plastic Surgery, Department of Surgery (E.J.C., B.P.), Brigham and Women's Hospital, Boston, Mass; 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md (P.L., V.B.H., G.T.G.); Center for Advanced Imaging Innovation and Research, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY (N.W.); and Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY (N.W.)
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Beier S, Ormiston J, Webster M, Cater J, Norris S, Medrano-Gracia P, Young A, Gilbert K, Cowan B. Overcoming spatio-temporal limitations using dynamically scaled in vitro PC-MRI - A flow field comparison to true-scale computer simulations of idealized, stented and patient-specific left main bifurcations. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2016:1220-1223. [PMID: 28324943 DOI: 10.1109/embc.2016.7590925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The majority of patients with angina or heart failure have coronary artery disease. Left main bifurcations are particularly susceptible to pathological narrowing. Flow is a major factor of atheroma development, but limitations in imaging technology such as spatio-temporal resolution, signal-to-noise ratio (SNRv), and imaging artefacts prevent in vivo investigations. Computational fluid dynamics (CFD) modelling is a common numerical approach to study flow, but it requires a cautious and rigorous application for meaningful results. Left main bifurcation angles of 40°, 80° and 110° were found to represent the spread of an atlas based 100 computed tomography angiograms. Three left mains with these bifurcation angles were reconstructed with 1) idealized, 2) stented, and 3) patient-specific geometry. These were then approximately 7× scaled-up and 3D printing as large phantoms. Their flow was reproduced using a blood-analogous, dynamically scaled steady flow circuit, enabling in vitro phase-contrast magnetic resonance (PC-MRI) measurements. After threshold segmentation the image data was registered to true-scale CFD of the same coronary geometry using a coherent point drift algorithm, yielding a small covariance error (σ2 <;5.8×10-4). Natural-neighbour interpolation of the CFD data onto the PC-MRI grid enabled direct flow field comparison, showing very good agreement in magnitude (error 2-12%) and directional changes (r2 0.87-0.91), and stent induced flow alternations were measureable for the first time. PC-MRI over-estimated velocities close to the wall, possibly due to partial voluming. Bifurcation shape determined the development of slow flow regions, which created lower SNRv regions and increased discrepancies. These can likely be minimised in future by testing different similarity parameters to reduce acquisition error and improve correlation further. It was demonstrated that in vitro large phantom acquisition correlates to true-scale coronary flow simulations when dynamically scaled, and thus can overcome current PC-MRI's spatio-temporal limitations. This novel method enables experimental assessment of stent induced flow alternations, and in future may elevate CFD coronary flow simulations by providing sophisticated boundary conditions, and enable investigations of stenosis phantoms.
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Schnell S, Wu C, Ansari SA. Four-dimensional MRI flow examinations in cerebral and extracerebral vessels - ready for clinical routine? Curr Opin Neurol 2016; 29:419-28. [PMID: 27262148 PMCID: PMC4939804 DOI: 10.1097/wco.0000000000000341] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE OF REVIEW To evaluate the feasibility of 4-dimensional (4D) flow MRI for the clinical assessment of cerebral and extracerebral vascular hemodynamics in patients with neurovascular disease. RECENT FINDINGS 4D flow MRI has been applied in multiple studies to qualitatively and quantitatively study intracranial aneurysm blood flow for potential risk stratification and to assess treatment efficacy of various neurovascular lesions, including intraaneurysmal and parent artery blood flow after flow diverter stent placement and staged embolizations of arteriovenous malformations and vein of Galen aneurysmal malformations. Recently, the technique has been utilized to characterize age-related changes of normal cerebral hemodynamics in healthy individuals over a broad age range. SUMMARY 4D flow MRI is a useful tool for the noninvasive, volumetric and quantitative hemodynamic assessment of neurovascular disease without the need for gadolinium contrast agents. Further improvements are warranted to overcome technical limitations before broader clinical implementation. Current developments, such as advanced acceleration techniques (parallel imaging and compressed sensing) for faster data acquisition, dual or multiple velocity encoding strategies for more accurate arterial and venous flow quantification, ultrahigh-field strengths to achieve higher spatial resolution and streamlined postprocessing workflow for more efficient and standardized flow analysis, are promising advancements in 4D flow MRI.
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Affiliation(s)
- Susanne Schnell
- Dept. of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
| | - Can Wu
- Dept. of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
- Dept. of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Sameer A. Ansari
- Dept. of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
- Dept. of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
- Dept. of Neurological Surgery, Northwestern University, Feinberg School of Medicine, Chicago, Illinois
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Whitlock MC, Hundley WG. Noninvasive Imaging of Flow and Vascular Function in Disease of the Aorta. JACC Cardiovasc Imaging 2016; 8:1094-1106. [PMID: 26381770 DOI: 10.1016/j.jcmg.2015.08.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/03/2015] [Accepted: 08/06/2015] [Indexed: 02/06/2023]
Abstract
With advancements in technology and a better understanding of human cardiovascular physiology, research as well as clinical care can go beyond dimensional anatomy offered by traditional imaging and investigate aortic functional properties and the impact disease has on this function. Linking the knowledge of the histopathological changes with the alterations in aortic function observed on noninvasive imaging results in a better understanding of disease pathophysiology. Translating this to clinical medicine, these noninvasive imaging assessments of aortic function are proving to be able to diagnose disease, better predict risk, and assess response to therapies. This review is designed to summarize the various hemodynamic measures that can characterize the aorta, the various noninvasive techniques, and applications for various disease states.
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Affiliation(s)
- Matthew C Whitlock
- Department of Internal Medicine, Section on Cardiovascular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - W Gregory Hundley
- Department of Internal Medicine, Section on Cardiovascular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina; Department of Radiological Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina.
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Klotz S, Meyer-Saraei R, Frydrychowicz A, Scharfschwerdt M, Putman LM, Halder S, Sievers HH. Proposing a novel technique to exclude the left ventricle with an assist device: insights from 4-dimensional flow magnetic resonance imaging. Eur J Cardiothorac Surg 2016; 50:439-45. [DOI: 10.1093/ejcts/ezw092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 02/10/2016] [Indexed: 11/13/2022] Open
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Beier S, Ormiston JA, Webster MW, Cater JE, Norris SE, Medrano-Gracia P, Young AA, Cowan BR. Dynamically scaled phantom phase contrast MRI compared to true-scale computational modeling of coronary artery flow. J Magn Reson Imaging 2016; 44:983-92. [PMID: 27042817 DOI: 10.1002/jmri.25240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 02/24/2016] [Accepted: 02/28/2016] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To examine the feasibility of combining computational fluid dynamics (CFD) and dynamically scaled phantom phase-contrast magnetic resonance imaging (PC-MRI) for coronary flow assessment. MATERIALS AND METHODS Left main coronary bifurcations segmented from computed tomography with bifurcation angles of 33°, 68°, and 117° were scaled-up ∼7× and 3D printed. Steady coronary flow was reproduced in these phantoms using the principle of dynamic similarity to preserve the true-scale Reynolds number, using blood analog fluid and a pump circuit in a 3T MRI scanner. After PC-MRI acquisition, the data were segmented and coregistered to CFD simulations of identical, but true-scale geometries. Velocities at the inlet region were extracted from the PC-MRI to define the CFD inlet boundary condition. RESULTS The PC-MRI and CFD flow data agreed well, and comparison showed: 1) small velocity magnitude discrepancies (2-8%); 2) with a Spearman's rank correlation ≥0.72; and 3) a velocity vector correlation (including direction) of r(2) ≥ 0.82. The highest agreement was achieved for high velocity regions with discrepancies being located in slow or recirculating zones with low MRI signal-to-noise ratio (SNRv ) in tortuous segments and large bifurcating vessels. CONCLUSION Characterization of coronary flow using a dynamically scaled PC-MRI phantom flow is feasible and provides higher resolution than current in vivo or true-scale in vitro methods, and may be used to provide boundary conditions for true-scale CFD simulations. J. MAGN. RESON. IMAGING 2016;44:983-992.
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Urbina J, Sotelo JA, Springmüller D, Montalba C, Letelier K, Tejos C, Irarrázaval P, Andia ME, Razavi R, Valverde I, Uribe SA. Realistic aortic phantom to study hemodynamics using MRI and cardiac catheterization in normal and aortic coarctation conditions. J Magn Reson Imaging 2016; 44:683-97. [DOI: 10.1002/jmri.25208] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/09/2016] [Indexed: 11/06/2022] Open
Affiliation(s)
- Jesús Urbina
- School of Medicine; Pontificia Universidad Católica de Chile; Santiago Chile
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Julio A. Sotelo
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
- Electrical Engineering Department; Pontificia Universidad Católica de Chile; Santiago Chile
- Structural and Geotechnical Engineering Department; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Daniel Springmüller
- Pediatric Cardiology Unit, School of Medicine; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Cristian Montalba
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Karis Letelier
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Cristián Tejos
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
- Electrical Engineering Department; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Pablo Irarrázaval
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
- Electrical Engineering Department; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Marcelo E. Andia
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
- Radiology Department, School of Medicine; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Reza Razavi
- Division of Imaging Sciences; King's College London; London UK
| | - Israel Valverde
- Division of Imaging Sciences; King's College London; London UK
- Pediatric Cardiology Unit, Hospital Virgen del Rocio; Universidad de Sevilla; Seville Spain
- Institute of Biomedicine of Seville; Universidad de Sevilla; Seville Spain
| | - Sergio A. Uribe
- Biomedical Imaging Center; Pontificia Universidad Católica de Chile; Santiago Chile
- Radiology Department, School of Medicine; Pontificia Universidad Católica de Chile; Santiago Chile
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Kim GB, Lee S, Kim H, Yang DH, Kim YH, Kyung YS, Kim CS, Choi SH, Kim BJ, Ha H, Kwon SU, Kim N. Three-Dimensional Printing: Basic Principles and Applications in Medicine and Radiology. Korean J Radiol 2016; 17:182-97. [PMID: 26957903 PMCID: PMC4781757 DOI: 10.3348/kjr.2016.17.2.182] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 11/28/2015] [Indexed: 01/01/2023] Open
Abstract
The advent of three-dimensional printing (3DP) technology has enabled the creation of a tangible and complex 3D object that goes beyond a simple 3D-shaded visualization on a flat monitor. Since the early 2000s, 3DP machines have been used only in hard tissue applications. Recently developed multi-materials for 3DP have been used extensively for a variety of medical applications, such as personalized surgical planning and guidance, customized implants, biomedical research, and preclinical education. In this review article, we discuss the 3D reconstruction process, touching on medical imaging, and various 3DP systems applicable to medicine. In addition, the 3DP medical applications using multi-materials are introduced, as well as our recent results.
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Affiliation(s)
- Guk Bae Kim
- Biomedical Engineering Research Center, Asan Institute of Life Science, Asan Medical Center, Seoul 05505, Korea
| | - Sangwook Lee
- Biomedical Engineering Research Center, Asan Institute of Life Science, Asan Medical Center, Seoul 05505, Korea
| | - Haekang Kim
- Biomedical Engineering Research Center, Asan Institute of Life Science, Asan Medical Center, Seoul 05505, Korea
| | - Dong Hyun Yang
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Young-Hak Kim
- Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Yoon Soo Kyung
- Department of Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Choung-Soo Kim
- Department of Urology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Se Hoon Choi
- Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Bum Joon Kim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Hojin Ha
- POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Sun U Kwon
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Namkug Kim
- Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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Buchoux A, Valluri P, Smith S, Stokes AA, Hoskins PR, Sboros V. Manufacturing of microcirculation phantoms using rapid prototyping technologies. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:5908-11. [PMID: 26737636 DOI: 10.1109/embc.2015.7319736] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this paper, we describe a method for the manufacturing of a microcirculation phantom that may be used to investigate hemodynamics using optics based methods. We made an Acrylonitrile Butadiene Styrene (ABS) negative mold, manufactured in a Fused Deposition Modelling (FDM) printer, embedded it in Polydimethysilioxane (PDMS) and dissolved it from within using acetone. We successfully made an enlarged three-dimensional (3D) network of microcirculation, and tested it using red blood cell (RBC) analogues. This phantom may be used for testing medical imaging technology.
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Rispoli VC, Nielsen JF, Nayak KS, Carvalho JLA. Computational fluid dynamics simulations of blood flow regularized by 3D phase contrast MRI. Biomed Eng Online 2015; 14:110. [PMID: 26611470 PMCID: PMC4661988 DOI: 10.1186/s12938-015-0104-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/16/2015] [Indexed: 11/23/2022] Open
Abstract
Background Phase contrast magnetic resonance imaging (PC-MRI) is used clinically for quantitative assessment of cardiovascular flow and function, as it is capable of providing directly-measured 3D velocity maps. Alternatively, vascular flow can be estimated from model-based computation fluid dynamics (CFD) calculations. CFD provides arbitrarily high resolution, but its accuracy hinges on model assumptions, while velocity fields measured with PC-MRI generally do not satisfy the equations of fluid dynamics, provide limited resolution, and suffer from partial volume effects. The purpose of this study is to develop a proof-of-concept numerical procedure for constructing a simulated flow field that is influenced by both direct PC-MRI measurements and a fluid physics model, thereby taking advantage of both the accuracy of PC-MRI and the high spatial resolution of CFD. The use of the proposed approach in regularizing 3D flow fields is evaluated. Methods The proposed algorithm incorporates both a Newtonian fluid physics model and a linear PC-MRI signal model. The model equations are solved numerically using a modified CFD algorithm. The numerical solution corresponds to the optimal solution of a generalized Tikhonov regularization, which provides a flow field that satisfies the flow physics equations, while being close enough to the measured PC-MRI velocity profile. The feasibility of the proposed approach is demonstrated on data from the carotid bifurcation of one healthy volunteer, and also from a pulsatile carotid flow phantom. Results The proposed solver produces flow fields that are in better agreement with direct PC-MRI measurements than CFD alone, and converges faster, while closely satisfying the fluid dynamics equations. For the implementation that provided the best results, the signal-to-error ratio (with respect to the PC-MRI measurements) in the phantom experiment was 6.56 dB higher than that of conventional CFD; in the in vivo experiment, it was 2.15 dB higher. Conclusions The proposed approach allows partial or complete measurements to be incorporated into a modified CFD solver, for improving the accuracy of the resulting flow fields estimates. This can be used for reducing scan time, increasing the spatial resolution, and/or denoising the PC-MRI measurements.
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Affiliation(s)
- Vinicius C Rispoli
- Department of Electrical Engineering, University of Brasilia, Brasília, Brazil. .,UnB Gama College, University of Brasilia, Brasília, Brazil.
| | - Jon F Nielsen
- fMRI Laboratory, Biomedical Engineering Department, University of Michigan, Ann Arbor, USA.
| | - Krishna S Nayak
- Magnetic Resonance Engineering Laboratory, Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, USA.
| | - Joao L A Carvalho
- Department of Electrical Engineering, University of Brasilia, Brasília, Brazil.
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Viceconti M, Hunter P, Hose R. Big Data, Big Knowledge: Big Data for Personalized Healthcare. IEEE J Biomed Health Inform 2015. [DOI: 10.1109/jbhi.2015.2406883] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ibrahim AMS, Jose RR, Rabie AN, Gerstle TL, Lee BT, Lin SJ. Three-dimensional Printing in Developing Countries. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2015; 3:e443. [PMID: 26301132 PMCID: PMC4527617 DOI: 10.1097/gox.0000000000000298] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/30/2015] [Indexed: 01/24/2023]
Abstract
The advent of 3-dimensional (3D) printing technology has facilitated the creation of customized objects. The lack of regulation in developing countries renders conventional means of addressing various healthcare issues challenging. 3D printing may provide a venue for addressing many of these concerns in an inexpensive and easily accessible fashion. These may potentially include the production of basic medical supplies, vaccination beads, laboratory equipment, and prosthetic limbs. As this technology continues to improve and prices are reduced, 3D printing has the potential ability to promote initiatives across the entire developing world, resulting in improved surgical care and providing a higher quality of healthcare to its residents.
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Affiliation(s)
- Ahmed M. S. Ibrahim
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass.; Department of Biomedical Engineering, Tufts University, Medford, Mass.; and Department of Otolaryngology, Ain Shams University, Faculty of Medicine, Cairo, Egypt
| | - Rod R. Jose
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass.; Department of Biomedical Engineering, Tufts University, Medford, Mass.; and Department of Otolaryngology, Ain Shams University, Faculty of Medicine, Cairo, Egypt
| | - Amr N. Rabie
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass.; Department of Biomedical Engineering, Tufts University, Medford, Mass.; and Department of Otolaryngology, Ain Shams University, Faculty of Medicine, Cairo, Egypt
| | - Theodore L. Gerstle
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass.; Department of Biomedical Engineering, Tufts University, Medford, Mass.; and Department of Otolaryngology, Ain Shams University, Faculty of Medicine, Cairo, Egypt
| | - Bernard T. Lee
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass.; Department of Biomedical Engineering, Tufts University, Medford, Mass.; and Department of Otolaryngology, Ain Shams University, Faculty of Medicine, Cairo, Egypt
| | - Samuel J. Lin
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass.; Department of Biomedical Engineering, Tufts University, Medford, Mass.; and Department of Otolaryngology, Ain Shams University, Faculty of Medicine, Cairo, Egypt
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In vivo analysis of physiological 3D blood flow of cerebral veins. Eur Radiol 2015; 25:2371-80. [PMID: 25638218 DOI: 10.1007/s00330-014-3587-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 12/16/2014] [Accepted: 12/24/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES To visualize and quantify physiological blood flow of intracranial veins in vivo using time-resolved, 3D phase-contrast MRI (4D flow MRI), and to test measurement accuracy. METHODS Fifteen healthy volunteers underwent repeated ECG-triggered 4D flow MRI (3 Tesla, 32-channel head coil). Intracranial venous blood flow was analysed using dedicated software allowing for blood flow visualization and quantification in analysis planes at the superior sagittal, straight, and transverse sinuses. MRI was evaluated for intra- and inter-observer agreement and scan-rescan reproducibility. Measurements of the transverse sinuses were compared with transcranial two-dimensional duplex ultrasound. RESULTS Visualization of 3D blood flow within cerebral sinuses was feasible in 100 % and within at least one deep cerebral vein in 87 % of the volunteers. Blood flow velocity/volume increased along the superior sagittal sinus and was lower in the left compared to the right transverse sinus. Intra- and inter-observer reliability and reproducibility of blood flow velocity (mean difference 0.01/0.02/0.02 m/s) and volume (mean difference 0.0002/-0.0003/0.00003 l/s) were good to excellent. High/low velocities were more pronounced (8 % overestimation/9 % underestimation) in MRI compared to ultrasound. CONCLUSIONS Four-dimensional flow MRI reliably visualizes and quantifies three-dimensional cerebral venous blood flow in vivo and is promising for studies in patients with sinus thrombosis and related diseases. KEY POINTS • 4D flow MRI can be used to visualize and quantify physiological cerebral venous haemodynamics • Flow quantification within cerebral sinuses reveals high reliability and accuracy of 4D flow MRI • Blood flow volume and velocity increase along the superior sagittal sinus • Limited spatial resolution currently precludes flow quantification in small cerebral veins.
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Ziganshin BA, Elefteriades JA. Treatment of Thoracic Aortic Aneurysm: Role of Earlier Intervention. Semin Thorac Cardiovasc Surg 2015; 27:135-43. [DOI: 10.1053/j.semtcvs.2015.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2015] [Indexed: 12/12/2022]
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Schnell S, Ansari SA, Vakil P, Wasielewski M, Carr ML, Hurley MC, Bendok BR, Batjer H, Carroll TJ, Carr J, Markl M. Three-dimensional hemodynamics in intracranial aneurysms: influence of size and morphology. J Magn Reson Imaging 2013; 39:120-31. [PMID: 24151067 DOI: 10.1002/jmri.24110] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 02/12/2013] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To use four-dimensional (4D)-flow MRI for the comprehensive in vivo analysis of hemodynamics and its relationship to size and morphology of different intracranial aneurysms (IA). We hypothesize that different IA groups, defined by size and morphology, exhibit different velocity fields, wall shear stress, and vorticity. MATERIALS AND METHODS The 4D-flow MRI (spatial resolution = 0.99-1.8 × 0.78-1.46 × 1.2-1.4 mm(3) , temporal resolution = 44-48 ms) was performed in 19 IAs (18 patients, age = 55.4 ± 13.8 years) with saccular (n = 16) and fusiform (n = 3) morphology and different sizes ranging from small (n = 8; largest dimension = 6.2 ± 0.4 mm) to large and giant (n = 11; 25 ± 7 mm). Analysis included quantification of volumetric spatial-temporal velocity distribution, vorticity, and wall shear stress (WSS) along the aneurysm's 3D surface. RESULTS The 4D-flow MRI revealed distinct hemodynamic patterns for large/giant saccular aneurysms (Group 1), small saccular aneurysms (Group 2), and large/giant fusiform aneurysms (Group 3). Saccular IA (Groups 1, 2) demonstrated significantly higher peak velocities (P < 0.002) and WSS (P < 0.001) compared with fusiform aneurysms. Although intra-aneurysmal 3D velocity distributions were similar for Group 1 and 2, vorticity and WSS was significantly (P < 0.001) different (increased in Group 1 by 54%) indicating a relationship between IA size and hemodynamics. Group 3 showed reduced velocities (P < 0.001) and WSS (P < 0.001). CONCLUSION The 4D-flow MRI demonstrated the influence of lesion size and morphology on aneurysm hemodynamics suggesting the potential of 4D-flow MRI to assist in the classification of individual aneurysms.
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Affiliation(s)
- Susanne Schnell
- Department of Radiology, Northwestern University, Chicago, Illinois, USA
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Onishi Y, Aoki K, Amaya K, Shimizu T, Isoda H, Takehara Y, Sakahara H, Kosugi T. Accurate determination of patient-specific boundary conditions in computational vascular hemodynamics using 3D cine phase-contrast MRI. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2013; 29:1089-1103. [PMID: 23733738 DOI: 10.1002/cnm.2562] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Revised: 04/04/2013] [Accepted: 04/25/2013] [Indexed: 06/02/2023]
Abstract
In the patient-specific vascular CFD, determination of the inlet and outlet boundary conditions (BCs) is an important issue for a valid diagnosis. The 3D cine phase-contrast MRI (4D Flow) velocimetry is promising for this issue; yet, its measured velocities contain relatively large error and are not admissible as the BCs without any correction. This paper proposes a novel correction method for determining the BCs accurately using the 4D Flow velocimetry. First, we reveal that the error of the velocity measured by the 4D Flow at each measurement voxel is large but is distributed symmetrically. Secondly, our method pays attention to the incompressibility of the blood and the fact that the volume flow rate (VFR) in each vessel is constant on any cross sections. We reveal that the average of the cross-sectional VFRs integrated from many measurement voxel in each vessel is accurate despite the large error. Finally, we propose the novel correction method, which applies a smoothing to the measured velocities on each inlet or outlet boundary with a low-pass filter and then corrects them with the VFR. The results of the several phantom studies are presented to validate the accuracy of our method. A demonstrative analysis for an actual aneurysm is also presented to show the feasibility and effectiveness of our method.
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Affiliation(s)
- Y Onishi
- Department of Mechanical and Environmental Informatics, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8552, Japan
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Knobloch V, Binter C, Gülan U, Sigfridsson A, Holzner M, Lüthi B, Kozerke S. Mapping mean and fluctuating velocities by Bayesian multipoint MR velocity encoding-validation against 3D particle tracking velocimetry. Magn Reson Med 2013; 71:1405-15. [PMID: 23670993 DOI: 10.1002/mrm.24785] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 03/01/2013] [Accepted: 04/04/2013] [Indexed: 11/06/2022]
Abstract
PURPOSE To validate Bayesian multipoint MR velocity encoding against particle tracking velocimetry for measuring velocity vector fields and fluctuating velocities in a realistic aortic model. METHODS An elastic cast of a human aortic arch equipped with an 80 or 64% stenotic section was driven by a pulsatile pump. Peak velocities and peak turbulent kinetic energies of more than 3 m/s and 1000 J/m(3) could be generated. Velocity vector fields and fluctuating velocities were assessed using Bayesian multipoint MR velocity encoding with varying numbers of velocity encoding points and particle tracking velocimetry in the ascending aorta. RESULTS Velocities and turbulent kinetic energies measured with 5-fold k-t undersampled 10-point MR velocity encoding and particle tracking velocimetry were found to reveal good correlation with mean differences of -4.8 ± 13.3 cm/s and r(2) = 0.98 for velocities and -21.8 ± 53.9 J/m(3) and r(2) = 0.98 for turbulent kinetic energies, respectively. Three-dimensional velocity patterns of fast flow downstream of the stenoses and regions of elevated velocity fluctuations were found to agree well. CONCLUSION Accelerated Bayesian multipoint MR velocity encoding has been demonstrated to be accurate for assessing mean and fluctuating velocities against the reference standard particle tracking velocimetry. The MR method holds considerable potential to map velocity vector fields and turbulent kinetic energies in clinically feasible exam times of <15 min.
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Affiliation(s)
- Verena Knobloch
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
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Jung SY, Park HW, Kim BH, Lee SJ. Time-resolved X-ray PIV technique for diagnosing opaque biofluid flow with insufficient X-ray fluxes. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:498-503. [PMID: 23592630 DOI: 10.1107/s0909049513001933] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 01/19/2013] [Indexed: 06/02/2023]
Abstract
X-ray imaging is used to visualize the biofluid flow phenomena in a nondestructive manner. A technique currently used for quantitative visualization is X-ray particle image velocimetry (PIV). Although this technique provides a high spatial resolution (less than 10 µm), significant hemodynamic parameters are difficult to obtain under actual physiological conditions because of the limited temporal resolution of the technique, which in turn is due to the relatively long exposure time (~10 ms) involved in X-ray imaging. This study combines an image intensifier with a high-speed camera to reduce exposure time, thereby improving temporal resolution. The image intensifier amplifies light flux by emitting secondary electrons in the micro-channel plate. The increased incident light flux greatly reduces the exposure time (below 200 µs). The proposed X-ray PIV system was applied to high-speed blood flows in a tube, and the velocity field information was successfully obtained. The time-resolved X-ray PIV system can be employed to investigate blood flows at beamlines with insufficient X-ray fluxes under specific physiological conditions. This method facilitates understanding of the basic hemodynamic characteristics and pathological mechanism of cardiovascular diseases.
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Affiliation(s)
- Sung Yong Jung
- Department of Mechanical Engineering, Pohang University of Science and Technology, San 31, Hyojadong, Pohang, Republic of Korea
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