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Gatehouse PD, Captur G, Nielles-Vallespin S, Pennell DJ. Field camera input to virtual phantom (ViP) scanner acquisitions for quality assurance of derived MRI quantities: first implementation and proof-of-principle. MAGMA (NEW YORK, N.Y.) 2024; 37:199-213. [PMID: 38127221 DOI: 10.1007/s10334-023-01136-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/05/2023] [Accepted: 11/06/2023] [Indexed: 12/23/2023]
Abstract
INTRODUCTION Quality assurance (QA) of measurements derived from MRI can require complicated test phantoms. This work introduces a new QA concept using gradient and transmit RF recordings by a limited field camera (FC) to govern the previous Virtual Phantom (ViP) method. The purpose is to describe the first technical implementation of combined FC+ViP, and illustrate its performance in examples, including quantitative first-pass myocardial perfusion. MATERIALS AND METHODS The new QA concept starts with a synthetic test object (STO) representing some arbitrary test input. Using recordings of the unmodified standard sequence by a gradient and RF waveform camera (FC), ViP calculates by Bloch simulation the continuous RF signal emitted by the STO during this sequence (hence FC+ViP). During nominally identical repetition of the sequence acquisition, ViP transmits the RF signal for scanner reception, reconstruction and any further parametric derivations by the unmodified standard scanner image reconstruction and analysis software. RESULTS The scanner outputs were compared against the input STOs. CONCLUSION First proof-of-principle was discussed and supported by correlation between scanner outputs and the input STO. The work makes no claim that its examples are valid QA methods. It concludes by proposing a new industrial standard for QA without the FC.
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Affiliation(s)
- Peter David Gatehouse
- Royal Brompton Hospital, Sydney Street, Chelsea, London, UK.
- National Heart and Lung Institute of Imperial College London, Cale Street, Chelsea, London, UK.
| | - Gabriella Captur
- University College London Institute of Cardiovascular Science, Torrington Place, Fitzrovia, London, UK
| | - Sonia Nielles-Vallespin
- Royal Brompton Hospital, Sydney Street, Chelsea, London, UK
- National Heart and Lung Institute of Imperial College London, Cale Street, Chelsea, London, UK
| | - Dudley John Pennell
- Royal Brompton Hospital, Sydney Street, Chelsea, London, UK
- National Heart and Lung Institute of Imperial College London, Cale Street, Chelsea, London, UK
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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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Jørgensen LT, Stuart MB, Jensen JA. Transverse oscillation tensor velocity imaging using a row-column addressed array: Experimental validation. ULTRASONICS 2023; 132:106962. [PMID: 36906961 DOI: 10.1016/j.ultras.2023.106962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/02/2023] [Accepted: 02/13/2023] [Indexed: 05/29/2023]
Abstract
Tensor velocity imaging (TVI) performance with a row-column probe was assessed for constant flow in a straight vessel phantom and pulsatile flow in a carotid artery phantom. TVI, i.e., estimating the 3-D velocity vector as a function of time and spatial position, was performed using the transverse oscillation cross-correlation estimator, and the flow was acquired with a Vermon 128+128 row-column array probe connected to a Verasonics 256 research scanner. The emission sequence used 16 emissions per image, and a TVI volume rate of 234 Hz was obtained for a pulse repetition frequency (fprf) of 15 kHz. The TVI was validated by comparing estimates of the flow rate through several cross-sections with the flow rate set by the pump. For the constant 8 mL/s flow in the straight vessel phantom with relative estimator bias (RB) and standards deviation (RSD) was found in the range of -2.18% to 0.55% and 4.58% to 2.48% in measurements performed with an fprf of 15, 10, 8, and 5 kHz. The pulsatile flow in the carotid artery phantom the was set to an average flow rate of 2.44 mL/s, and the flow was acquired with an fprf of 15, 10, and 8 kHz. The pulsatile flow was estimated from two measurement sites: one at a straight section of the artery and one at the bifurcation. In the straight section, the estimator predicted the average flow rate with an RB value ranging from -7.99% to 0.10% and an RSD value ranging from 10.76% to 6.97%. At the bifurcation, RB and RSD values were between -7.47% to 2.02% and 14.46% to 8.89%. This demonstrates that an RCA with 128 receive elements can accurately capture the flow rate through any cross-section at a high sampling rate.
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Affiliation(s)
- Lasse Thurmann Jørgensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, DK-2800 Lyngby, Denmark.
| | - Matthias Bo Stuart
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, DK-2800 Lyngby, Denmark
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Geng R, Zhang Y, Rice J, Muehler MR, Starekova J, Rutkowski DR, Uboha NV, Pirasteh A, Roldán-Alzate A, Guidon A, Hernando D. Motion-robust, blood-suppressed, reduced-distortion diffusion MRI of the liver. Magn Reson Med 2023; 89:908-921. [PMID: 36404637 PMCID: PMC9792444 DOI: 10.1002/mrm.29531] [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: 08/11/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 11/22/2022]
Abstract
PURPOSE To evaluate feasibility and reproducibility of liver diffusion-weighted (DW) MRI using cardiac-motion-robust, blood-suppressed, reduced-distortion techniques. METHODS DW-MRI data were acquired at 3T in an anatomically accurate liver phantom including controlled pulsatile motion, in eight healthy volunteers and four patients with known or suspected liver metastases. Standard monopolar and motion-robust (M1-nulled, and M1-optimized) DW gradient waveforms were each acquired with single-shot echo-planar imaging (ssEPI) and multishot EPI (msEPI). In the motion phantom, apparent diffusion coefficient (ADC) was measured in the motion-affected volume. In healthy volunteers, ADC was measured in the left and right liver lobes separately to evaluate ADC reproducibility between the two lobes. Image distortions were quantified using the normalized cross-correlation coefficient, with an undistorted T2-weighted reference. RESULTS In the motion phantom, ADC mean and SD in motion-affected volumes substantially increased with increasing motion for monopolar waveforms. ADC remained stable in the presence of increasing motion when using motion-robust waveforms. M1-optimized waveforms suppressed slow flow signal present with M1-nulled waveforms. In healthy volunteers, monopolar waveforms generated significantly different ADC measurements between left and right liver lobes ( p = 0 . 0078 $$ p=0.0078 $$ , reproducibility coefficients (RPC) = 470 × 1 0 - 6 $$ 470\times 1{0}^{-6} $$ mm 2 $$ {}^2 $$ /s for monopolar-msEPI), while M1-optimized waveforms showed more reproducible ADC values ( p = 0 . 29 $$ p=0.29 $$ , RPC = 220 × 1 0 - 6 $$ \mathrm{RPC}=220\times 1{0}^{-6} $$ mm 2 $$ {}^2 $$ /s for M1-optimized-msEPI). In phantom and healthy volunteer studies, motion-robust acquisitions with msEPI showed significantly reduced image distortion ( p < 0 . 001 $$ p<0.001 $$ ) compared to ssEPI. Patient scans showed reduction of wormhole artifacts when combining M1-optimized waveforms with msEPI. CONCLUSION Synergistic effects of combined M1-optimized diffusion waveforms and msEPI acquisitions enable reproducible liver DWI with motion robustness, blood signal suppression, and reduced distortion.
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Affiliation(s)
- Ruiqi Geng
- Department of Radiology, University of Wisconsin-Madison, WI, USA,Department of Medical Physics, University of Wisconsin-Madison, WI, USA
| | - Yuxin Zhang
- Department of Radiology, University of Wisconsin-Madison, WI, USA,Department of Medical Physics, University of Wisconsin-Madison, WI, USA
| | - James Rice
- Department of Radiology, University of Wisconsin-Madison, WI, USA,Department of Mechanical Engineering, University of Wisconsin-Madison, WI, USA
| | | | - Jitka Starekova
- Department of Radiology, University of Wisconsin-Madison, WI, USA
| | - David R. Rutkowski
- Department of Radiology, University of Wisconsin-Madison, WI, USA,Department of Mechanical Engineering, University of Wisconsin-Madison, WI, USA
| | - Nataliya V. Uboha
- Division of Hematology and Oncology, Department of Medicine, University of Wisconsin-Madison, WI, USA,UW Carbone Cancer Center, WI, USA
| | - Ali Pirasteh
- Department of Radiology, University of Wisconsin-Madison, WI, USA,Department of Medical Physics, University of Wisconsin-Madison, WI, USA
| | - Alejandro Roldán-Alzate
- Department of Radiology, University of Wisconsin-Madison, WI, USA,Department of Mechanical Engineering, University of Wisconsin-Madison, WI, USA
| | | | - Diego Hernando
- Department of Radiology, University of Wisconsin-Madison, WI, USA,Department of Medical Physics, University of Wisconsin-Madison, WI, USA,Department of Electrical and Computer Engineering, University of Wisconsin-Madison, WI, USA,Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA
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