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McGee KP, Cao M, Das IJ, Yu V, Witte RJ, Kishan AU, Valle LF, Wiesinger F, De-Colle C, Cao Y, Breen WG, Traughber BJ. The Use of Magnetic Resonance Imaging in Radiation Therapy Treatment Simulation and Planning. J Magn Reson Imaging 2024; 60:1786-1805. [PMID: 38265188 DOI: 10.1002/jmri.29246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/25/2024] Open
Abstract
Ever since its introduction as a diagnostic imaging tool the potential of magnetic resonance imaging (MRI) in radiation therapy (RT) treatment simulation and planning has been recognized. Recent technical advances have addressed many of the impediments to use of this technology and as a result have resulted in rapid and growing adoption of MRI in RT. The purpose of this article is to provide a broad review of the multiple uses of MR in the RT treatment simulation and planning process, identify several of the most used clinical scenarios in which MR is integral to the simulation and planning process, highlight existing limitations and provide multiple unmet needs thereby highlighting opportunities for the diagnostic MR imaging community to contribute and collaborate with our oncology colleagues. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 5.
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Affiliation(s)
- Kiaran P McGee
- Department of Radiology, Mayo Clinic & Foundation, Rochester, Minnesota, USA
| | - Minsong Cao
- Department of Radiation Oncology, University of California, Los Angeles, California, USA
| | - Indra J Das
- Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Victoria Yu
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Robert J Witte
- Department of Radiology, Mayo Clinic & Foundation, Rochester, Minnesota, USA
| | - Amar U Kishan
- Department of Radiation Oncology, University of California, Los Angeles, California, USA
| | - Luca F Valle
- Department of Radiation Oncology, University of California, Los Angeles, California, USA
| | | | - Chiara De-Colle
- Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Yue Cao
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA
| | - William G Breen
- Department of Radiation Oncology, Mayo Clinic & Foundation, Rochester, Minnesota, USA
| | - Bryan J Traughber
- Department of Radiation Oncology, Mayo Clinic & Foundation, Rochester, Minnesota, USA
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Riederer SJ, Borisch EA, Du Q, Froemming AT, Hulshizer TC, Kawashima A, McGee KP, Robb F, Rossman PJ, Takahashi N. Application of high-density 2D receiver coil arrays for improved SNR in prostate MRI. Magn Reson Med 2024. [PMID: 39322985 DOI: 10.1002/mrm.30289] [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: 03/20/2024] [Revised: 07/15/2024] [Accepted: 08/22/2024] [Indexed: 09/27/2024]
Abstract
PURPOSE To study if adaptive image receive (AIR) receiver coil elements can be configured into a 2D array with high (>45% by diameter) element-to-element overlap, allowing improved SNR at depth (0.7-1.5× element diameter) versus conventional (20%) overlap. METHODS An anterior array composed of twenty 10-cm diameter elements with 45% overlap arranged into a 4 × 5 grid and a similar 3 × 7 twenty-one-element posterior array were constructed. SNR and g-factor were measured in a pelvic phantom using the new high-density (HD) arrays (41 total elements) and compared to vendor AIR-based arrays (30 total elements) with conventional overlap. T2-weighted fast-spin-echo (T2SE) images acquired using both arrays were compared in 20 subjects. SNR was estimated in vivo. Results were compared blindly by three uroradiologists using a five-point scale. Images using the HD arrays were also compared to a set of images acquired over a range of acceleration factors (R = 2.0, 2.5, 3.0) with the conventional arrays. RESULTS SNR within the phantom was on average 15% higher for R = 1.0, 1.5, and 2.0 using the HD arrays. Across the 20 subjects SNR within the prostate was 11% higher and assessed radiologically as significantly higher (p < 0.001) for the HD versus conventional arrays. At all acceleration factors the new HD arrays outperformed the conventional arrays (p ≤ 0.01), allowing increased R for similar SNR. CONCLUSION AIR elements can be configured into 2D arrays with high (45%) element-to-element overlap, consistently providing increased SNR at depth versus arrays with conventional (20%) overlap. The SNR improvement allows increased acceleration in T2SE prostate MRI.
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Affiliation(s)
| | - Eric A Borisch
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | | | | | - Kiaran P McGee
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | - Naoki Takahashi
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
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Vliem J, Xiao Y, Wenz D, Xin L, Teeuwise W, Ruytenberg T, Webb A, Zivkovic I. Twisted pair transmission line coil - a flexible, self-decoupled and robust element for 7 T MRI. Magn Reson Imaging 2024; 108:146-160. [PMID: 38364973 DOI: 10.1016/j.mri.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/08/2024] [Accepted: 02/08/2024] [Indexed: 02/18/2024]
Abstract
OBJECTIVE This study evaluates the performance of a twisted pair transmission line coil as a transceive element for 7 T MRI in terms of physical flexibility, robustness to shape deformations, and interelement decoupling. METHODS Each coil element was created by shaping a twisted pair of wires into a circle. One wire was interrupted at the top, while the other was interrupted at the bottom, and connected to the matching circuit. Electromagnetic simulations were conducted to determine the optimal number of twists per length (in terms of B₁+ field efficiency, SAR efficiency, sensitivity to elongation, and interelement decoupling properties) and for investigating the fundamental operational principle of the coil through fields streamline visualisation. A comparison between the twisted pair coil and a conventional loop coil in terms of B₁+ fields, maxSAR₁₀g, and stability of S₁₁ when the coil was deformed was performed. Experimentally measured interelement coupling between individual elements of multichannel arrays was also investigated. RESULTS Increasing the number of twists per length resulted in a more physically robust coil. Poynting vector streamline visualisation showed that the twisted pair coil concentrated most of the energy in the near field. The twisted pair coil exhibited comparable B₁+ fields and improved maxSAR₁₀g to the conventional coil but demonstrated exceptional stability with respect to coil deformation and a strong self-decoupling nature when placed in an array configuration. DISCUSSION The findings highlight the robustness of the twisted pair coil, showcasing its stability under shape variations. This coil holds great potential as a flexible RF coil for various imaging applications using multiple-element arrays, benefiting from its inherent decoupling.
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Affiliation(s)
- Jules Vliem
- Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands
| | - Ying Xiao
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland; École Polytechnique Fédérale de Lausanne (EPFL), Animal Imaging and Technology, Lausanne, Switzerland
| | - Daniel Wenz
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland; École Polytechnique Fédérale de Lausanne (EPFL), Animal Imaging and Technology, Lausanne, Switzerland
| | - Lijing Xin
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland; École Polytechnique Fédérale de Lausanne (EPFL), Animal Imaging and Technology, Lausanne, Switzerland
| | - Wouter Teeuwise
- C.J. Gorter MRI Centre, Department of Radiology, Leiden University Medical Center Leiden, the Netherlands
| | - Thomas Ruytenberg
- C.J. Gorter MRI Centre, Department of Radiology, Leiden University Medical Center Leiden, the Netherlands
| | - Andrew Webb
- C.J. Gorter MRI Centre, Department of Radiology, Leiden University Medical Center Leiden, the Netherlands
| | - Irena Zivkovic
- Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands.
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Overson DK, Darnell D, Robb F, Song AW, Truong TK. Flexible multi-purpose integrated RF/shim coil array for MRI and localized B 0 shimming. Magn Reson Med 2024; 91:842-849. [PMID: 37849021 PMCID: PMC10842526 DOI: 10.1002/mrm.29891] [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: 05/02/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/19/2023]
Abstract
PURPOSE To develop a flexible, lightweight, and multi-purpose integrated parallel reception, excitation, and shimming (iPRES) coil array that can conform to the subject's anatomy and perform MR imaging and localized B0 shimming in different anatomical regions with a high SNR, shimming performance, ease of positioning, and subject comfort. METHODS A four-channel flexible iPRES coil array was constructed by enabling RF and direct currents to flow on the same flexible coil elements for imaging and shimming, respectively. Shimming experiments were performed with the coil array wrapped around the knee or neck of healthy subjects to demonstrate its high shimming performance and versatility. Additionally, its SNR and shimming performance in the knee were compared to those obtained with the coil array wrapped around a larger rigid tube designed to fit most knee sizes. RESULTS Shimming with the coil array wrapped around the knee or neck resulted in an average reduction in B0 RMSE of 50.1% and 40.5% relative to first-order and second-order spherical harmonic shimming, respectively, and substantially reduced distortions in DWI images. In contrast, shimming the knee with the coil array wrapped around the rigid tube only provided a 29.6% reduction in B0 RMSE, whereas the SNR was reduced by 58.7%. CONCLUSION The flexible iPRES coil array can conform to different anatomical regions and perform imaging and localized B0 shimming with a higher SNR, shimming performance, ease of positioning, and comfort compared to a rigid iPRES coil array, which should be valuable for many applications throughout the human body.
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Affiliation(s)
- Devon Karl Overson
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
- Medical Physics Graduate Program, Duke University, Durham, North Carolina, USA
| | - Dean Darnell
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
- Medical Physics Graduate Program, Duke University, Durham, North Carolina, USA
| | | | - Allen W Song
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
- Medical Physics Graduate Program, Duke University, Durham, North Carolina, USA
| | - Trong-Kha Truong
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
- Medical Physics Graduate Program, Duke University, Durham, North Carolina, USA
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Li T, Wang J, Yang Y, Glide-Hurst CK, Wen N, Cai J. Multi-parametric MRI for radiotherapy simulation. Med Phys 2023; 50:5273-5293. [PMID: 36710376 PMCID: PMC10382603 DOI: 10.1002/mp.16256] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 09/10/2022] [Accepted: 12/06/2022] [Indexed: 01/31/2023] Open
Abstract
Magnetic resonance imaging (MRI) has become an important imaging modality in the field of radiotherapy (RT) in the past decade, especially with the development of various novel MRI and image-guidance techniques. In this review article, we will describe recent developments and discuss the applications of multi-parametric MRI (mpMRI) in RT simulation. In this review, mpMRI refers to a general and loose definition which includes various multi-contrast MRI techniques. Specifically, we will focus on the implementation, challenges, and future directions of mpMRI techniques for RT simulation.
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Affiliation(s)
- Tian Li
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China
| | - Jihong Wang
- Department of Radiation Physics, Division of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas, USA
| | - Yingli Yang
- Department of Radiology, Ruijin Hospital, Shanghai Jiaotong Univeristy School of Medicine, Shanghai, China
- SJTU-Ruijing-UIH Institute for Medical Imaging Technology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Carri K Glide-Hurst
- Department of Radiation Oncology, University of Wisconsin, Madison, Wisconsin, USA
| | - Ning Wen
- Department of Radiology, Ruijin Hospital, Shanghai Jiaotong Univeristy School of Medicine, Shanghai, China
- SJTU-Ruijing-UIH Institute for Medical Imaging Technology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- The Global Institute of Future Technology, Shanghai Jiaotong University, Shanghai, China
| | - Jing Cai
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, China
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Scherman J, af Wetterstedt S, Persson E, Olsson LE, Jamtheim Gustafsson C. Geometric impact and dose estimation of on-patient placement of a lightweight receiver coil in a clinical magnetic resonance imaging-only radiotherapy workflow for prostate cancer. Phys Imaging Radiat Oncol 2023; 26:100433. [PMID: 37063614 PMCID: PMC10091035 DOI: 10.1016/j.phro.2023.100433] [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: 10/21/2022] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 04/18/2023] Open
Abstract
Background and Purpose For pelvic magnetic resonance imaging (MRI)-only radiotherapy the use of receiver coil bridges (CB) is recommended to avoid deformation of the patient. Development in coil technology has enabled lightweight, flexible coils. In this work we evaluate the effects of a lightweight coil in a pelvic MRI-only radiotherapy workflow. Materials and Methods Twenty-one patients, referred to prostate MRI-only radiotherapy, were included. Images were acquired with and without CB. Anatomical deformation from the on-patient coil placement was measured in the anterior-posterior (AP) and left-right (LR) direction. The change in signal-to-noise ratio (SNR) was measured in phantom and in vivo.The clinical treatment plan, created on the image with CB, was transferred and recalculated on the image without the CB. Dose metrics for the targets (planning- and clinical target volume) and organs at risks (OAR) were analyzed. Results There was a statistically significant increase in SNR in-vivo (median 21 %, p = 0.002) when removing the CB. Anatomical differences after removing the CB in patients were -1.5 mm in AP (median change) and + 2.5 mm in LR direction. Dosimetric differences for the target structures were clinically negligible, but statistically significant. The difference in target mean doses were 0.2 % (both p = 0.004) of the prescribed dose. No dosimetric differences were observed for the OAR, except for the penile bulb. Conclusions We concluded that anatomical change and dosimetric differences, originating from scanning without CB were minor. The CB can thereby be removed from the workflow, enabling easier patient positioning and increased SNR when using lightweight coils.
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Affiliation(s)
- Jonas Scherman
- Department of Hematology, Oncology, and Radiation Physics Skåne University Hospital, Klinikgatan 5, Lund 221 85, Sweden
| | - Sacha af Wetterstedt
- Department of Hematology, Oncology, and Radiation Physics Skåne University Hospital, Klinikgatan 5, Lund 221 85, Sweden
| | - Emilia Persson
- Department of Hematology, Oncology, and Radiation Physics Skåne University Hospital, Klinikgatan 5, Lund 221 85, Sweden
- Department of Translational Medicine, Medical Radiation Physics, Lund University, Carl Bertil Laurells gata 9, Malmö 205 02, Sweden
| | - Lars E. Olsson
- Department of Hematology, Oncology, and Radiation Physics Skåne University Hospital, Klinikgatan 5, Lund 221 85, Sweden
- Department of Translational Medicine, Medical Radiation Physics, Lund University, Carl Bertil Laurells gata 9, Malmö 205 02, Sweden
| | - Christian Jamtheim Gustafsson
- Department of Hematology, Oncology, and Radiation Physics Skåne University Hospital, Klinikgatan 5, Lund 221 85, Sweden
- Department of Translational Medicine, Medical Radiation Physics, Lund University, Carl Bertil Laurells gata 9, Malmö 205 02, Sweden
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McGee KP, Campeau NG, Witte RJ, Rossman PJ, Christopherson JA, Tryggestad EJ, Brinkmann DH, Ma DJ, Park SS, Rettmann DW, Robb FJ. Evaluation of a New, Highly Flexible Radiofrequency Coil for MR Simulation of Patients Undergoing External Beam Radiation Therapy. J Clin Med 2022; 11:5984. [PMID: 36294304 PMCID: PMC9604708 DOI: 10.3390/jcm11205984] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 09/30/2022] [Accepted: 10/08/2022] [Indexed: 04/20/2024] Open
Abstract
PURPOSE To evaluate the performance of a new, highly flexible radiofrequency (RF) coil system for imaging patients undergoing MR simulation. METHODS Volumetric phantom and in vivo images were acquired with a commercially available and prototype RF coil set. Phantom evaluation was performed using a silicone-filled humanoid phantom of the head and shoulders. In vivo assessment was performed in five healthy and six patient subjects. Phantom data included T1-weighted volumetric imaging, while in vivo acquisitions included both T1- and T2-weighted volumetric imaging. Signal to noise ratio (SNR) and uniformity metrics were calculated in the phantom data, while SNR values were calculated in vivo. Statistical significance was tested by means of a non-parametric analysis of variance test. RESULTS At a threshold of p = 0.05, differences in measured SNR distributions within the entire phantom volume were statistically different in two of the three paired coil set comparisons. Differences in per slice average SNR between the two coil sets were all statistically significant, as well as differences in per slice image uniformity. For patients, SNRs within the entire imaging volume were statistically significantly different in four of the nine comparisons and seven of the nine comparisons performed on the per slice average SNR values. For healthy subjects, SNRs within the entire imaging volume were statistically significantly different in seven of the nine comparisons and eight of the nine comparisons when per slice average SNR was tested. CONCLUSIONS Phantom and in vivo results demonstrate that image quality obtained from the novel flexible RF coil set was similar or improved over the conventional coil system. The results also demonstrate that image quality is impacted by the specific coil configurations used for imaging and should be matched appropriately to the anatomic site imaged to ensure optimal and reproducible image quality.
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Affiliation(s)
- Kiaran P. McGee
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | - Norbert G. Campeau
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | - Robert J. Witte
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | - Philip J. Rossman
- Department of Radiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | | | - Erik J. Tryggestad
- Department of Radiation Oncology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | - Debra H. Brinkmann
- Department of Radiation Oncology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | - Daniel J. Ma
- Department of Radiation Oncology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | - Sean S. Park
- Department of Radiation Oncology, Mayo Clinic and Foundation, Rochester, MN 55905, USA
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Cuthbertson JD, Truong TK, Stormont R, Robb F, Song AW, Darnell D. An iPRES-W Coil Array for Simultaneous Imaging and Wireless Localized B 0 Shimming of the Cervical Spinal Cord. Magn Reson Med 2022; 88:1002-1014. [PMID: 35468243 PMCID: PMC10445458 DOI: 10.1002/mrm.29257] [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: 01/07/2022] [Revised: 02/13/2022] [Accepted: 03/11/2022] [Indexed: 11/07/2022]
Abstract
PURPOSE To develop a wireless integrated parallel reception, excitation, and shimming (iPRES-W) coil array for simultaneous imaging and wireless localized B0 shimming, and to demonstrate its ability to correct for distortions in DTI of the spinal cord in vivo. METHODS A 4-channel coil array was modified to allow an RF current at the Larmor frequency and a direct current to flow on each coil element, enabling imaging and localized B0 shimming, respectively. One coil element was further modified to allow additional RF currents within a wireless communication band to flow on it to wirelessly control the direct currents for shimming, which were supplied from a battery pack within the scanner bore. The RF signals for imaging were transferred via conventional wired connections. Experiments were conducted to evaluate the RF, B0 shimming, and wireless performance of this coil design. RESULTS The coil modifications did not degrade the SNR. Wireless localized B0 shimming with the iPRES-W coil array substantially reduced the B0 RMSE (-57.5% on average) and DTI distortions in the spinal cord. The antenna radiation efficiency, antenna gain pattern, and battery power consumption of an iPRES-W coil measured in an anechoic chamber were minimally impacted by the introduction of a saline phantom representing tissue. CONCLUSION The iPRES-W coil array can perform imaging and wireless localized B0 shimming of the spinal cord with no SNR degradation, with minimal change in wireless performance and without any scanner modifications or additional antenna systems within the scanner bore.
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Affiliation(s)
- Jonathan D. Cuthbertson
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina
- Medical Physics Graduate Program, Duke University, Durham, North Carolina
| | - Trong-Kha Truong
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina
- Medical Physics Graduate Program, Duke University, Durham, North Carolina
| | | | | | - Allen W. Song
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina
- Medical Physics Graduate Program, Duke University, Durham, North Carolina
| | - Dean Darnell
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina
- Medical Physics Graduate Program, Duke University, Durham, North Carolina
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Compact pediatric cardiac magnetic resonance imaging protocols. Pediatr Radiol 2022:10.1007/s00247-022-05447-y. [PMID: 35821442 DOI: 10.1007/s00247-022-05447-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/25/2022] [Accepted: 06/30/2022] [Indexed: 10/17/2022]
Abstract
Cardiac MRI is in many respects an ideal modality for pediatric cardiovascular imaging, enabling a complete noninvasive assessment of anatomy, morphology, function and flow in one radiation-free and potentially non-contrast exam. Nonetheless, traditionally lengthy and complex imaging acquisition strategies have often limited its broader use beyond specialized centers. In this review, the author presents practical cardiac MRI imaging protocols to facilitate the performance of succinct yet successful exams that provide the most salient clinical data for the majority of congenital and acquired pediatric cardiac disease. In addition, the author reviews newer and evolving techniques that permit more rapid but similarly diagnostic MRI, including compressed sensing and artificial intelligence/machine learning reconstruction, four-dimensional flow acquisition and blood pool contrast agents. With the modern armamentarium of cardiac MRI methods, the goal of compact yet comprehensive exams in children can now be realized.
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Kwok WE. Basic Principles of and Practical Guide to Clinical MRI Radiofrequency Coils. Radiographics 2022; 42:898-918. [PMID: 35394887 DOI: 10.1148/rg.210110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Radiofrequency (RF) coils are an essential MRI component used for transmission of the RF field to excite nuclear spins and for reception of the MRI signal. They play an important role in image quality in terms of signal-to-noise ratio, signal uniformity, and image resolution. However, they are also associated with potential image artifacts and RF heating that may lead to patient burns. Knowledge of the basic principles of RF coils-including coil designs commonly used in clinical MRI and the anatomy of RF receive coils-facilitates understanding of the use and safety issues of RF coils. Selection of suitable RF coils for individual applications and proper use of RF coils in particular MRI techniques such as parallel imaging are needed to achieve optimal image quality, prevent image artifacts, and reduce the risk of RF burns. The ability to correctly identify RF coil problems and distinguish them from other problems with image artifacts resembling those of RF coil problems allows effective handling of the problems and efficient clinical MRI operation. Quality control of RF coils is required to ensure consistent image quality for clinical MRI and avoid coil problems that may affect image diagnostic evaluation or interrupt patient imaging. There are different phantom test methods for RF coil quality control; the appropriate one to use depends on the coil design and MRI system. An invited commentary by Ohliger is available online. Online supplemental material is available for this article. ©RSNA, 2022.
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Affiliation(s)
- Wingchi E Kwok
- From the Department of Imaging Sciences, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642; and University of Rochester Center for Advanced Brain Imaging and Neurophysiology, Rochester, NY
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11
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Zhang B, Wang B, Ho J, Hodono S, Burke C, Lattanzi R, Vester M, Rehner R, Sodickson D, Brown R, Cloos M. Twenty-four-channel high-impedance glove array for hand and wrist MRI at 3T. Magn Reson Med 2022; 87:2566-2575. [PMID: 34971464 PMCID: PMC8847333 DOI: 10.1002/mrm.29147] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 12/29/2022]
Abstract
PURPOSE To present a novel 3T 24-channel glove array that enables hand and wrist imaging in varying postures. METHODS The glove array consists of an inner glove holding the electronics and an outer glove protecting the components. The inner glove consists of four main structures: palm, fingers, wrist, and a flap that rolls over on top. Each structure was constructed out of three layers: a layer of electrostatic discharge flame-resistant fabric, a layer of scuba neoprene, and a layer of mesh fabric. Lightweight and flexible high impedance coil (HIC) elements were inserted into dedicated tubes sewn into the fabric. Coil elements were deliberately shortened to minimize the matching interface. Siemens Tim 4G technology was used to connect all 24 HIC elements to the scanner with only one plug. RESULTS The 24-channel glove array allows large motion of both wrist and hand while maintaining the SNR needed for high-resolution imaging. CONCLUSION In this work, a purpose-built 3T glove array that embeds 24 HIC elements is demonstrated for both hand and wrist imaging. The 24-channel glove array allows a great range of motion of both the wrist and hand while maintaining a high SNR and providing good theoretical acceleration performance, thus enabling hand and wrist imaging at different postures to extract kinematic information.
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Affiliation(s)
- Bei Zhang
- Center for Advanced Imaging Innovation and Research (CAIR) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Bili Wang
- Center for Advanced Imaging Innovation and Research (CAIR) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Justin Ho
- Center for Advanced Imaging Innovation and Research (CAIR) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Shota Hodono
- Centre for Advanced Imaging, Queensland University, Brisbane, Australia
| | | | - Riccardo Lattanzi
- Center for Advanced Imaging Innovation and Research (CAIR) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
- Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York, NY, USA
| | | | | | - Daniel Sodickson
- Center for Advanced Imaging Innovation and Research (CAIR) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ryan Brown
- Center for Advanced Imaging Innovation and Research (CAIR) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Martijn Cloos
- Center for Advanced Imaging Innovation and Research (CAIR) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
- Centre for Advanced Imaging, Queensland University, Brisbane, Australia
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12
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Darnell D, Truong TK, Song AW. Recent Advances in Radio-Frequency Coil Technologies: Flexible, Wireless, and Integrated Coil Arrays. J Magn Reson Imaging 2022; 55:1026-1042. [PMID: 34324753 PMCID: PMC10494287 DOI: 10.1002/jmri.27865] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/19/2021] [Accepted: 07/19/2021] [Indexed: 12/25/2022] Open
Abstract
Radio-frequency (RF) coils are to magnetic resonance imaging (MRI) scanners what eyes are to the human body. Because of their critical importance, there have been constant innovations driving the rapid development of RF coil technologies. Over the past four decades, the breadth and depth of the RF coil technology evolution have far exceeded the space allowed for this review article. However, these past developments have laid the very foundation on which some of the recent technical breakthroughs are built upon. Here, we narrow our focus on some of the most recent RF coil advances, specifically, on flexible, wireless, and integrated coil arrays. To provide a detailed review, we discuss the theoretical underpinnings, experimental implementations, promising results, as well as future outlooks covering these exciting topics. These recent innovations have greatly improved patient comfort and ease of scan, while also increasing the signal-to-noise ratio, image resolution, temporal throughput, and diagnostic and treatment accuracy. Together with advances in other MRI subfields, they will undoubtedly continue to drive the field forward and lead us to an ever more exciting future. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Dean Darnell
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
| | - Trong-Kha Truong
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
| | - Allen W. Song
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
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Fukui H, Onishi H, Nakamoto A, Wakayama T, Ota T, Tsuboyama T, Yano K, Tarewaki H, Koyama Y, Tatsumi M, Tomiyama N. Impact of Adaptive Image Receive Coil Technology for Liver MR Imaging at 3.0 Tesla: Intraindividual Comparison with use of Conventional Coil. Eur J Radiol 2022; 150:110271. [DOI: 10.1016/j.ejrad.2022.110271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/22/2022] [Accepted: 03/17/2022] [Indexed: 11/03/2022]
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Saniour I, Robb FJL, Taracila V, Mishra V, Vincent J, Voss HU, Kaplitt MG, Chazen JL, Winkler SA. Characterization of a Low-Profile, Flexible, and Acoustically Transparent Receive-Only MRI Coil Array for High Sensitivity MR-Guided Focused Ultrasound. IEEE ACCESS : PRACTICAL INNOVATIONS, OPEN SOLUTIONS 2022; 10:25062-25072. [PMID: 35600672 PMCID: PMC9119199 DOI: 10.1109/access.2022.3154824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Magnetic resonance guided focused ultrasound (MRgFUS) is a non-invasive therapeutic modality for neurodegenerative diseases that employs real-time imaging and thermometry monitoring of targeted regions. MRI is used in guidance of ultrasound treatment; however, the MR image quality in current clinical applications is poor when using the vendor built-in body coil. We present an 8-channel, ultra-thin, flexible, and acoustically transparent receive-only head coil design (FUS-Flex) to improve the signal-to-noise ratio (SNR) and thus the quality of MR images during MRgFUS procedures. Acoustic simulations/experiments exhibit transparency of the FUS-Flex coil as high as 97% at 650 kHz. Electromagnetic simulations show a SNR increase of 13× over the body coil. In vivo results show an increase of the SNR over the body coil by a factor of 7.3 with 2× acceleration (equivalent to 11× without acceleration) in the brain of a healthy volunteer, which agrees well with simulation. These preliminary results show that the use of a FUS-Flex coil in MRgFUS surgery can increase MR image quality, which could yield improved focal precision, real-time intraprocedural anatomical imaging, and real-time 3D thermometry mapping.
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Affiliation(s)
- Isabelle Saniour
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, New York, NY 10065, USA
| | | | | | - Vishwas Mishra
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, New York, NY 10065, USA
| | - Jana Vincent
- MR Engineering, GE Healthcare Coils, Aurora, OH 44202, USA
| | - Henning U Voss
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, New York, NY 10065, USA
| | - Michael G Kaplitt
- Department of Neurological Surgery, Weill Cornell Medicine, NewYork-Presbyterian Hospital, New York, NY 10065, USA
| | - J Levi Chazen
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, New York, NY 10065, USA
| | - Simone Angela Winkler
- Department of Radiology, Weill Cornell Medicine, NewYork-Presbyterian Hospital, New York, NY 10065, USA
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15
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Application of Highly Flexible Adaptive Image Receive Coil for Lung MR Imaging Using Zero TE Sequence: Comparison with Conventional Anterior Array Coil. Diagnostics (Basel) 2022; 12:diagnostics12010148. [PMID: 35054316 PMCID: PMC8774338 DOI: 10.3390/diagnostics12010148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/06/2022] [Accepted: 01/06/2022] [Indexed: 02/06/2023] Open
Abstract
(1) Background: Highly flexible adaptive image receive (AIR) coil has become available for clinical use. The present study aimed to evaluate the performance of AIR anterior array coil in lung MR imaging using a zero echo time (ZTE) sequence compared with conventional anterior array (CAA) coil. (2) Methods: Sixty-six patients who underwent lung MR imaging using both AIR coil (ZTE-AIR) and CAA coil (ZTE-CAA) were enrolled. Image quality of ZTE-AIR and ZTE-CAA was quantified by calculating blur metric value, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of lung parenchyma. Image quality was qualitatively assessed by two independent radiologists. Lesion detection capabilities for lung nodules and emphysema and/or lung cysts were evaluated. Patients' comfort levels during examinations were assessed. (3) Results: SNR and CNR of lung parenchyma were higher (both p < 0.001) in ZTE-AIR than in ZTE-CAA. Image sharpness was superior in ZTE-AIR (p < 0.001). Subjective image quality assessed by two independent readers was superior (all p < 0.05) in ZTE-AIR. AIR coil was preferred by 64 of 66 patients. ZTE-AIR showed higher (all p < 0.05) sensitivity for sub-centimeter nodules than ZTE-CAA by both readers. ZTE-AIR showed higher (all p < 0.05) sensitivity and accuracy for detecting emphysema and/or cysts than ZTE-CAA by both readers. (4) Conclusions: The use of highly flexible AIR coil in ZTE lung MR imaging can improve image quality and patient comfort. Application of AIR coil in parenchymal imaging has potential for improving delineation of low-density parenchymal lesions and tiny nodules.
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Glide-Hurst CK, Paulson ES, McGee K, Tyagi N, Hu Y, Balter J, Bayouth J. Task group 284 report: magnetic resonance imaging simulation in radiotherapy: considerations for clinical implementation, optimization, and quality assurance. Med Phys 2021; 48:e636-e670. [PMID: 33386620 DOI: 10.1002/mp.14695] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 12/12/2020] [Accepted: 12/16/2020] [Indexed: 12/18/2022] Open
Abstract
The use of dedicated magnetic resonance simulation (MR-SIM) platforms in Radiation Oncology has expanded rapidly, introducing new equipment and functionality with the overall goal of improving the accuracy of radiation treatment planning. However, this emerging technology presents a new set of challenges that need to be addressed for safe and effective MR-SIM implementation. The major objectives of this report are to provide recommendations for commercially available MR simulators, including initial equipment selection, siting, acceptance testing, quality assurance, optimization of dedicated radiation therapy specific MR-SIM workflows, patient-specific considerations, safety, and staffing. Major contributions include guidance on motion and distortion management as well as MRI coil configurations to accommodate patients immobilized in the treatment position. Examples of optimized protocols and checklists for QA programs are provided. While the recommendations provided here are minimum requirements, emerging areas and unmet needs are also highlighted for future development.
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Affiliation(s)
- Carri K Glide-Hurst
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, 53792, USA
| | - Eric S Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Kiaran McGee
- Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Neelam Tyagi
- Medical Physics Department, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Yanle Hu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona, 85054, USA
| | - James Balter
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - John Bayouth
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, 53792, USA
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Abstract
Clinical MRI systems have continually improved over the years since their introduction in the 1980s. In MRI technical development, the developments in each MRI system component, including data acquisition, image reconstruction, and hardware systems, have impacted the others. Progress in each component has induced new technology development opportunities in other components. New technologies outside of the MRI field, for example, computer science, data processing, and semiconductors, have been immediately incorporated into MRI development, which resulted in innovative applications. With high performance computing and MR technology innovations, MRI can now provide large volumes of functional and anatomical image datasets, which are important tools in various research fields. MRI systems are now combined with other modalities, such as positron emission tomography (PET) or therapeutic devices. These hybrid systems provide additional capabilities. In this review, MRI advances in the last two decades will be considered. We will discuss the progress of MRI systems, the enabling technology, established applications, current trends, and the future outlook.
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Affiliation(s)
- Hiroyuki Kabasawa
- Department of Radiological Sciences, School of Health Sciences at Narita, International University of Health and Welfare
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18
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Port A, Luechinger R, Brunner DO, Pruessmann KP. Elastomer coils for wearable MR detection. Magn Reson Med 2021; 85:2882-2891. [PMID: 33433044 DOI: 10.1002/mrm.28662] [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: 08/20/2020] [Revised: 11/20/2020] [Accepted: 12/07/2020] [Indexed: 01/06/2023]
Abstract
PURPOSE To explore the use of conductive elastomer for MR signal detection and the utility of this approach for wearable detector arrays. METHODS An elastomer filled with silver microparticles was used to form stretchable radiofrequency coils for MR detection. Their electrical performance in terms of the Qunloaded and Q ratio was assessed in the relaxed state and under repeated strain up to 40%. In a phantom imaging study, the signal-to-noise ratio yield of conductive elastomer coils was compared with that of a reference copper coil. Four elastomer coils were integrated with a stretchable textile substrate to form a wearable array for knee imaging. The array was employed for multiple-angle and kinematic knee imaging in vivo. RESULTS The elastomer coils proved highly stretchable and mechanically robust. Upon repeated stretching by 20%, a medium-sized coil element settled at Qunloaded of 42 in the relaxed state and 32 at full strain, reflecting sample-noise dominance. The signal-to-noise ratio of elastomer coils was found to be 8% to 16% lower than that achieved with a conventional copper coil. Multiple-angle and kinematic knee imaging with the wearable array yielded high-quality results indicating robustness of detection performance against stretching and warping of the array. CONCLUSION Conductive elastomer is a viable material for MR detection. Coils made from this material reconcile high stretchability and adequate electrical performance with ease of manufacturing. Conductive elastomer also offers inherent restoring forces and is readily washable and sanitizable, making it an excellent basis of wearable detector front ends.
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Affiliation(s)
- Andreas Port
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Roger Luechinger
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - David O Brunner
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Klaas P Pruessmann
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
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19
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Otazo R, Lambin P, Pignol JP, Ladd ME, Schlemmer HP, Baumann M, Hricak H. MRI-guided Radiation Therapy: An Emerging Paradigm in Adaptive Radiation Oncology. Radiology 2020; 298:248-260. [PMID: 33350894 DOI: 10.1148/radiol.2020202747] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Radiation therapy (RT) continues to be one of the mainstays of cancer treatment. Considerable efforts have been recently devoted to integrating MRI into clinical RT planning and monitoring. This integration, known as MRI-guided RT, has been motivated by the superior soft-tissue contrast, organ motion visualization, and ability to monitor tumor and tissue physiologic changes provided by MRI compared with CT. Offline MRI is already used for treatment planning at many institutions. Furthermore, MRI-guided linear accelerator systems, allowing use of MRI during treatment, enable improved adaptation to anatomic changes between RT fractions compared with CT guidance. Efforts are underway to develop real-time MRI-guided intrafraction adaptive RT of tumors affected by motion and MRI-derived biomarkers to monitor treatment response and potentially adapt treatment to physiologic changes. These developments in MRI guidance provide the basis for a paradigm change in treatment planning, monitoring, and adaptation. Key challenges to advancing MRI-guided RT include real-time volumetric anatomic imaging, addressing image distortion because of magnetic field inhomogeneities, reproducible quantitative imaging across different MRI systems, and biologic validation of quantitative imaging. This review describes emerging innovations in offline and online MRI-guided RT, exciting opportunities they offer for advancing research and clinical care, hurdles to be overcome, and the need for multidisciplinary collaboration.
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Affiliation(s)
- Ricardo Otazo
- From the Departments of Medical Physics (R.O.) and Radiology (R.O., H.H.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065; The D-Lab, Department of Precision Medicine, Department of Radiology & Nuclear Medicine, GROW-School for Oncology, Maastricht University Medical Centre, Maastricht, the Netherlands (P.L.); Department of Radiation Oncology, Dalhousie University, Halifax, Canada (J.P.P.); Divisions of Medical Physics in Radiology (M.E.L.), Radiology (H.P.S.), and Radiation Oncology/Radiobiology (M.B.), German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy (M.E.L.) and Faculty of Medicine (M.E.L., M.B.), Heidelberg University, Heidelberg, Germany; and OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany (M.B.)
| | - Philippe Lambin
- From the Departments of Medical Physics (R.O.) and Radiology (R.O., H.H.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065; The D-Lab, Department of Precision Medicine, Department of Radiology & Nuclear Medicine, GROW-School for Oncology, Maastricht University Medical Centre, Maastricht, the Netherlands (P.L.); Department of Radiation Oncology, Dalhousie University, Halifax, Canada (J.P.P.); Divisions of Medical Physics in Radiology (M.E.L.), Radiology (H.P.S.), and Radiation Oncology/Radiobiology (M.B.), German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy (M.E.L.) and Faculty of Medicine (M.E.L., M.B.), Heidelberg University, Heidelberg, Germany; and OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany (M.B.)
| | - Jean-Philippe Pignol
- From the Departments of Medical Physics (R.O.) and Radiology (R.O., H.H.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065; The D-Lab, Department of Precision Medicine, Department of Radiology & Nuclear Medicine, GROW-School for Oncology, Maastricht University Medical Centre, Maastricht, the Netherlands (P.L.); Department of Radiation Oncology, Dalhousie University, Halifax, Canada (J.P.P.); Divisions of Medical Physics in Radiology (M.E.L.), Radiology (H.P.S.), and Radiation Oncology/Radiobiology (M.B.), German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy (M.E.L.) and Faculty of Medicine (M.E.L., M.B.), Heidelberg University, Heidelberg, Germany; and OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany (M.B.)
| | - Mark E Ladd
- From the Departments of Medical Physics (R.O.) and Radiology (R.O., H.H.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065; The D-Lab, Department of Precision Medicine, Department of Radiology & Nuclear Medicine, GROW-School for Oncology, Maastricht University Medical Centre, Maastricht, the Netherlands (P.L.); Department of Radiation Oncology, Dalhousie University, Halifax, Canada (J.P.P.); Divisions of Medical Physics in Radiology (M.E.L.), Radiology (H.P.S.), and Radiation Oncology/Radiobiology (M.B.), German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy (M.E.L.) and Faculty of Medicine (M.E.L., M.B.), Heidelberg University, Heidelberg, Germany; and OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany (M.B.)
| | - Heinz-Peter Schlemmer
- From the Departments of Medical Physics (R.O.) and Radiology (R.O., H.H.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065; The D-Lab, Department of Precision Medicine, Department of Radiology & Nuclear Medicine, GROW-School for Oncology, Maastricht University Medical Centre, Maastricht, the Netherlands (P.L.); Department of Radiation Oncology, Dalhousie University, Halifax, Canada (J.P.P.); Divisions of Medical Physics in Radiology (M.E.L.), Radiology (H.P.S.), and Radiation Oncology/Radiobiology (M.B.), German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy (M.E.L.) and Faculty of Medicine (M.E.L., M.B.), Heidelberg University, Heidelberg, Germany; and OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany (M.B.)
| | - Michael Baumann
- From the Departments of Medical Physics (R.O.) and Radiology (R.O., H.H.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065; The D-Lab, Department of Precision Medicine, Department of Radiology & Nuclear Medicine, GROW-School for Oncology, Maastricht University Medical Centre, Maastricht, the Netherlands (P.L.); Department of Radiation Oncology, Dalhousie University, Halifax, Canada (J.P.P.); Divisions of Medical Physics in Radiology (M.E.L.), Radiology (H.P.S.), and Radiation Oncology/Radiobiology (M.B.), German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy (M.E.L.) and Faculty of Medicine (M.E.L., M.B.), Heidelberg University, Heidelberg, Germany; and OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany (M.B.)
| | - Hedvig Hricak
- From the Departments of Medical Physics (R.O.) and Radiology (R.O., H.H.), Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065; The D-Lab, Department of Precision Medicine, Department of Radiology & Nuclear Medicine, GROW-School for Oncology, Maastricht University Medical Centre, Maastricht, the Netherlands (P.L.); Department of Radiation Oncology, Dalhousie University, Halifax, Canada (J.P.P.); Divisions of Medical Physics in Radiology (M.E.L.), Radiology (H.P.S.), and Radiation Oncology/Radiobiology (M.B.), German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy (M.E.L.) and Faculty of Medicine (M.E.L., M.B.), Heidelberg University, Heidelberg, Germany; and OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany (M.B.)
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Abstract
OBJECTIVE. The Adaptive Image Receive (AIR) radiofrequency coil is an emergent technology that is lightweight and flexible and exhibits electrical characteristics that overcome many of the limitations of traditional rigid coil designs. The purpose of this study was to apply the AIR coil for whole-brain imaging and compare the performance of a prototype AIR coil array with the performance of conventional head coils. SUBJECTS AND METHODS. A phantom and 15 healthy adult participants were imaged. A prototype 16-channel head AIR coil was compared with conventional 8-and 32-channel head coils using clinically available MRI sequences. During consensus review, two board-certified neuroradiologists graded the AIR coil compared with an 8-channel coil and a 32-channel coil on a 5-point ordinal scale in multiple categories. One- and two-sided Wilcoxon signed rank tests were performed. Noise covariance matrices and geometry factor (g-factor) maps were calculated. RESULTS. The signal-to-noise ratio, structural sharpness, and overall image quality scores of the prototype 16-channel AIR coil were better than those of the 8-channel coil but were not as good as those of the 32-channel coil. Noise covariance matrices showed stable performance of the AIR coil across participants. The median g-factors for the 16-channel AIR coil were, overall, less than those of the 8-channel coil but were greater than those of the 32-channel coil. CONCLUSION. On average, the prototype 16-channel head AIR coil outperformed a conventional 8-channel head coil but did not perform as well as a conventional 32-channel head coil. This study shows the feasibility of the novel AIR coil technology for imaging the brain and provides insight for future coil design improvements.
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Deller TW, Mathew NK, Hurley SA, Bobb CM, McMillan AB. PET Image Quality Improvement for Simultaneous PET/MRI with a Lightweight MRI Surface Coil. Radiology 2020; 298:166-172. [PMID: 33141004 DOI: 10.1148/radiol.2020200967] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background During simultaneous PET/MRI, flexible MRI surface coils that lay on the patient are often omitted from PET attenuation correction processing, leading to quantification bias in PET images. Purpose To identify potential PET image quality improvement by using a recently developed lightweight MRI coil technology for the anterior array (AA) surface coil in both a phantom and in vivo study. Materials and Methods A phantom study and a prospective in vivo study were performed with a PET/CT scanner under three conditions: (a) no MRI surface coil (standard of reference), (b) traditional AA coil, and (c) lightweight AA coil. AA coils were not used in attenuation correction processing to emulate clinical PET/MRI. For the phantom study, PET images were reconstructed with and without time of flight (TOF) to assess quantification accuracy and uniformity. The in vivo study consisted of 10 participants (mean age, 66 years ± 10 [standard deviation]; six men) referred for a PET/CT oncologic examination who had undergone imaging between October 2019 and February 2020. Assessment of image quantification bias (defined as the standard error of the mean values) was conducted by comparing mean liver region of interest standardized uptake values with the no-coil standard of reference. A Wilcoxon signed-rank test was used to establish significance. Results For TOF and non-TOF, respectively, the phantom study revealed a mean PET quantification bias of -9.0% and -8.6% with the traditional AA coil and a mean PET quantification bias of -4.3% and -4.0% with the lightweight AA coil. The coefficients of variation reduced from 4.3% and 6.2% with the traditional AA coil to 2.1% and 2.7% with the lightweight AA coil, which demonstrated a homogeneity benefit from the lightweight coil that was greater with, versus without, TOF reconstruction. For the in vivo study, the mean liver standardized uptake value error was -5.9% with the traditional AA coil (P = .002 vs no coil) and -2.4% with the lightweight AA coil (P = .004 vs no coil). Conclusion The lightweight anterior array coil reduced PET image quantification bias by more than 50% compared with the traditional coil. Using the lightweight coil and performing time of flight-based reconstruction each reduced the variation of error. © RSNA, 2020 Online supplemental material is available for this article.
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Affiliation(s)
- Timothy W Deller
- From the Departments of PET/MR Engineering (T.W.D.) and Clinical Development (C.M.B.), GE Healthcare, 3200 N Grandview Blvd, Waukesha, WI 53188; and Department of Radiology, University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, Madison, Wis (N.K.M., S.A.H., A.B.M.)
| | - Nicholas K Mathew
- From the Departments of PET/MR Engineering (T.W.D.) and Clinical Development (C.M.B.), GE Healthcare, 3200 N Grandview Blvd, Waukesha, WI 53188; and Department of Radiology, University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, Madison, Wis (N.K.M., S.A.H., A.B.M.)
| | - Samuel A Hurley
- From the Departments of PET/MR Engineering (T.W.D.) and Clinical Development (C.M.B.), GE Healthcare, 3200 N Grandview Blvd, Waukesha, WI 53188; and Department of Radiology, University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, Madison, Wis (N.K.M., S.A.H., A.B.M.)
| | - Chad M Bobb
- From the Departments of PET/MR Engineering (T.W.D.) and Clinical Development (C.M.B.), GE Healthcare, 3200 N Grandview Blvd, Waukesha, WI 53188; and Department of Radiology, University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, Madison, Wis (N.K.M., S.A.H., A.B.M.)
| | - Alan B McMillan
- From the Departments of PET/MR Engineering (T.W.D.) and Clinical Development (C.M.B.), GE Healthcare, 3200 N Grandview Blvd, Waukesha, WI 53188; and Department of Radiology, University of Wisconsin-Madison, Wisconsin Institutes for Medical Research, Madison, Wis (N.K.M., S.A.H., A.B.M.)
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Chaudhari AS, Kogan F, Pedoia V, Majumdar S, Gold GE, Hargreaves BA. Rapid Knee MRI Acquisition and Analysis Techniques for Imaging Osteoarthritis. J Magn Reson Imaging 2020; 52:1321-1339. [PMID: 31755191 PMCID: PMC7925938 DOI: 10.1002/jmri.26991] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 12/16/2022] Open
Abstract
Osteoarthritis (OA) of the knee is a major source of disability that has no known treatment or cure. Morphological and compositional MRI is commonly used for assessing the bone and soft tissues in the knee to enhance the understanding of OA pathophysiology. However, it is challenging to extend these imaging methods and their subsequent analysis techniques to study large population cohorts due to slow and inefficient imaging acquisition and postprocessing tools. This can create a bottleneck in assessing early OA changes and evaluating the responses of novel therapeutics. The purpose of this review article is to highlight recent developments in tools for enhancing the efficiency of knee MRI methods useful to study OA. Advances in efficient MRI data acquisition and reconstruction tools for morphological and compositional imaging, efficient automated image analysis tools, and hardware improvements to further drive efficient imaging are discussed in this review. For each topic, we discuss the current challenges as well as potential future opportunities to alleviate these challenges. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.
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Affiliation(s)
| | - Feliks Kogan
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Valentina Pedoia
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- Center of Digital Health Innovation (CDHI), University of California San Francisco, San Francisco, California, USA
| | - Sharmila Majumdar
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
- Center of Digital Health Innovation (CDHI), University of California San Francisco, San Francisco, California, USA
| | - Garry E. Gold
- Department of Radiology, Stanford University, Stanford, California, USA
- Department of Orthopaedic Surgery, Stanford University, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Brian A. Hargreaves
- Department of Radiology, Stanford University, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
- Department of Electrical Engineering, Stanford University, Stanford, California, USA
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23
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Collick BD, Behzadnezhad B, Hurley SA, Mathew NK, Behdad N, Lindsay SA, Robb F, Stormont RS, McMillan AB. Rapid development of application-specific flexible MRI receive coils. Phys Med Biol 2020; 65:19NT01. [PMID: 32975219 PMCID: PMC8064628 DOI: 10.1088/1361-6560/abaffb] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Over the last 30 years, there have been dramatic changes in phased array coil technology leading to increasing channel density and parallel imaging functionality. Current receiver array coils are rigid and often mismatched to patient's size. Recently there has been a move towards flexible coil technology, which is more conformal to the human anatomy. Despite the advances of so-called flexible surface coil arrays, these coils are still relatively rigid and limited in terms of design conformability, compromising signal-to-noise ratio (SNR) for flexibility, and are not designed for optimum parallel imaging performance. The purpose of this study is to report on the development and characterization of a 15-channel flexible foot and ankle coil, rapidly designed and constructed using highly decoupled radio-frequency (RF) coil elements. Coil performance was evaluated by performing SNR and g-factor measurements. In vivo testing was performed in a healthy volunteer using both the 15-channel coil and a commercially available 8-channel foot coil. The highly decoupled elements used in this design allow for extremely rapid development and prototyping of application-specific coils for different patient sizes (adult vs child) with minimal additional design consideration in terms of coil overlap and geometry. Image quality was comparable to a commercially available RF coil.
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Affiliation(s)
- B D Collick
- Department of Radiology, University of Wisconsin, Madison, WI 53705, United States of America. Author B D Collick and author B Behzadnezhad contributed equally to this work
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24
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Brunnquell CL, Hoff MN, Balu N, Nguyen XV, Oztek MA, Haynor DR. Making Magnets More Attractive: Physics and Engineering Contributions to Patient Comfort in MRI. Top Magn Reson Imaging 2020; 29:167-174. [PMID: 32541257 DOI: 10.1097/rmr.0000000000000246] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Patient comfort is an important factor of a successful magnetic resonance (MR) examination, and improvements in the patient's MR scanning experience can contribute to improved image quality, diagnostic accuracy, and efficiency in the radiology department, and therefore reduced cost. Magnet designs that are more open and accessible, reduced auditory noise of MR examinations, light and flexible radiofrequency (RF) coils, and faster motion-insensitive imaging techniques can all significantly improve the patient experience in MR imaging. In this work, we review the design, development, and implementation of these physics and engineering approaches to improve patient comfort.
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Affiliation(s)
- Christina L Brunnquell
- Department of Radiology, University of Washington, Seattle, WA Department of Radiology, The Ohio State University Wexler Medical Center, Columbus, OH
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25
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Börnert P, Norris DG. A half-century of innovation in technology-preparing MRI for the 21st century. Br J Radiol 2020; 93:20200113. [PMID: 32496816 DOI: 10.1259/bjr.20200113] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
MRI developed during the last half-century from a very basic concept to an indispensable non-ionising medical imaging technique that has found broad application in diagnostics, therapy control and far beyond. Due to its excellent soft-tissue contrast and the huge variety of accessible tissue- and physiological-parameters, MRI is often preferred to other existing modalities. In the course of its development, MRI underwent many substantial transformations. From the beginning, starting as a proof of concept, much effort was expended to develop the appropriate basic scanning technology and methodology, and to establish the many clinical contrasts (e.g., T1, T2, flow, diffusion, water/fat, etc.) that MRI is famous for today. Beyond that, additional prominent innovations to the field have been parallel imaging and compressed sensing, leading to significant scanning time reductions, and the move towards higher static magnetic field strengths, which led to increased sensitivity and improved image quality. Improvements in workflow and the use of artificial intelligence are among many current trends seen in this field, paving the way for a broad use of MRI. The 125th anniversary of the BJR is a good point to reflect on all these changes and developments and to offer some slightly speculative ideas as to what the future may bring.
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Affiliation(s)
- Peter Börnert
- Philips Research, Hamburg, Germany.,Department of Radiology, LUMC, Leiden, the Netherlands
| | - David G Norris
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands.,Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany.,Magnetic Detection and Imaging, Science and Technology Faculty, University of Twente, Enschede, Netherlands
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26
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Detector clothes for MRI: A wearable array receiver based on liquid metal in elastic tubes. Sci Rep 2020; 10:8844. [PMID: 32483259 PMCID: PMC7264329 DOI: 10.1038/s41598-020-65634-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/06/2020] [Indexed: 11/08/2022] Open
Abstract
In modern magnetic resonance imaging, signal detection is performed by dense arrays of radiofrequency resonators. Tight-fitting arrays boost the sensitivity and speed of imaging. However, current devices are rigid and cage-like at the expense of patient comfort. They also constrain posture, limiting the examination of joints. For better ergonomics and versatility, detectors should be flexible, adapt to individual anatomy, and follow posture. Towards this goal, the present work proposes a novel design based on resonators formed by liquid metal in polymer tubes. Textile integration creates lightweight, elastic devices that are worn like pieces of clothing. A liquid-metal array tailored to the human knee is shown to deliver competitive image quality while self-adapting to individual anatomy and adding the ability to image flexion of the joint. Relative to other options for stretchable conductors, liquid metal in elastic tubes stands out by reconciling excellent electrical and mechanical properties with ease of manufacturing.
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27
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Tyagi N, Zakian KL, Italiaander M, Almujayyaz S, Lis E, Yamada J, Topf J, Hunt M, Deasy JO. Technical Note: A custom-designed flexible MR coil array for spine radiotherapy treatment planning. Med Phys 2020; 47:3143-3152. [PMID: 32304237 DOI: 10.1002/mp.14184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 03/20/2020] [Accepted: 03/27/2020] [Indexed: 01/05/2023] Open
Abstract
PURPOSE To assess the performance and optimize the MR image quality when using a custom-built flexible radiofrequency (RF) spine coil array fitted between the immobilization device and the patient for spine radiotherapy treatment planning. METHODS A 32 channel flexible custom-designed receive-only coil array has been developed for spine radiotherapy simulation for a 3 T Philips MR scanner. Coil signal-to-noise performance and interactions with standard vendor hardware were assessed. In four volunteers, immobilization molds were created with a dummy version of the array within the mold, and subjects were scanned using the custom array in the mold. Phantoms and normal volunteers were scanned with both the custom spine coil array and the vendor's FDA-approved in-table posterior coil array to compare performance. RESULTS The superior-inferior field of view for the custom spine array was ~30 cm encompassing at least 10 vertebrae. A noise correlation matrix showed at least 25 dB isolation between all coil elements. Signal-to-noise ratio (SNR) calculated on a phantom scan at the depth of the spinal cord was a factor of 3 higher with the form-fit spine array as compared to the vendor's posterior coil array. The body coil B1 transmit map was equivalent with and without the spine array in place demonstrating that the elements are decoupled from the body coil. Volunteer imaging showed improved SNR as compared to the vendor's posterior coil array. The custom array permitted a high degree of acceleration making possible the acquisition of isotropic high-resolution 1.1 × 1.1 × 1.1 mm3 three-dimensional data set over a 30-cm section of the spine in less than 5 min. CONCLUSION The custom-designed form-fitting flexible spine coil array provided enhanced SNR and increased acceleration compared to the vendor's posterior array. Future studies will assess MR-based spinal cord imaging with the custom coil in comparison to CT myelogram.
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Affiliation(s)
- Neelam Tyagi
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Kristen L Zakian
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA.,Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | | | | | - Eric Lis
- Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Josh Yamada
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Jill Topf
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Margie Hunt
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
| | - Joseph O Deasy
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
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28
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Voskuilen L, de Heer P, van der Molen L, Balm AJM, van der Heijden F, Strijkers GJ, Smeele LE, Nederveen AJ. A 12-channel flexible receiver coil for accelerated tongue imaging. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2020; 33:581-590. [PMID: 31950389 PMCID: PMC7351800 DOI: 10.1007/s10334-019-00824-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/28/2019] [Accepted: 12/23/2019] [Indexed: 12/15/2022]
Abstract
Objective MRI of the tongue requires acceleration to minimise motion artefacts and to facilitate real-time imaging of swallowing. To accelerate tongue MRI, we designed a dedicated flexible receiver coil. Materials and methods We designed a flexible 12-channel receiver coil for tongue MRI at 3T and compared it to a conventional head-and-neck coil regarding SNR and g-factor. Furthermore, two accelerated imaging techniques were evaluated using both coils: multiband (MB) diffusion-tensor imaging (DTI) and real-time MRI of swallowing. Results The flexible coil had significantly higher SNR in the anterior (2.1 times higher, P = 0.002) and posterior (2.0 times higher, P < 0.001) parts of the tongue, while the g-factor was lower at higher acceleration. Unlike for the flexible coil, the apparent diffusion coefficient (P = 0.001) and fractional anisotropy (P = 0.008) deteriorated significantly while using the conventional coil after accelerating DTI with MB. The image quality of real-time MRI of swallowing was significantly better for hyoid elevation (P = 0.029) using the flexible coil. Conclusion Facilitated by higher SNR and lower g-factor values, our flexible tongue coil allows faster imaging, which was successfully demonstrated in MB DTI and real-time MRI of swallowing. Electronic supplementary material The online version of this article (10.1007/s10334-019-00824-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Luuk Voskuilen
- Department of Head and Neck Oncology and Surgery, Netherlands Cancer Institute, Antoni Van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands. .,Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands. .,Department of Oral and Maxillofacial Surgery, Academic Centre for Dentistry Amsterdam and Academic Medical Center, University of Amsterdam and VU University Amsterdam, Amsterdam, Netherlands.
| | - Paul de Heer
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Lisette van der Molen
- Department of Head and Neck Oncology and Surgery, Netherlands Cancer Institute, Antoni Van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Alfons J M Balm
- Department of Head and Neck Oncology and Surgery, Netherlands Cancer Institute, Antoni Van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.,Department of Oral and Maxillofacial Surgery, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.,Department of Robotics and Mechatronics, MIRA Institute, University of Twente, Enschede, Netherlands
| | - Ferdinand van der Heijden
- Department of Head and Neck Oncology and Surgery, Netherlands Cancer Institute, Antoni Van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.,Department of Robotics and Mechatronics, MIRA Institute, University of Twente, Enschede, Netherlands
| | - Gustav J Strijkers
- Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ludi E Smeele
- Department of Head and Neck Oncology and Surgery, Netherlands Cancer Institute, Antoni Van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.,Department of Oral and Maxillofacial Surgery, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Aart J Nederveen
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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29
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Ferrer L, Josset S, Moignier A, Delpon G. [Hybrid radiotherapy machines: Evolution or revolution?]. Cancer Radiother 2019; 23:761-764. [PMID: 31471254 DOI: 10.1016/j.canrad.2019.07.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 07/15/2019] [Indexed: 11/19/2022]
Abstract
The arrival of new hybrid radiotherapy machines with MRI or PET is announced as a milestone in radiotherapy management. Based on recent literature, we will describe the contribution of each of these modalities and the technological challenges that have already been or are still to be addressed.
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Affiliation(s)
- L Ferrer
- Service de physique médicale, institut de cancérologie de l'Ouest, boulevard Jacques-Monod, 44805 Saint-Herblain, France.
| | - S Josset
- Service de physique médicale, institut de cancérologie de l'Ouest, boulevard Jacques-Monod, 44805 Saint-Herblain, France
| | - A Moignier
- Service de physique médicale, institut de cancérologie de l'Ouest, boulevard Jacques-Monod, 44805 Saint-Herblain, France
| | - G Delpon
- Service de physique médicale, institut de cancérologie de l'Ouest, boulevard Jacques-Monod, 44805 Saint-Herblain, France
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30
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Sneag DB, Queler S. Technological Advancements in Magnetic Resonance Neurography. Curr Neurol Neurosci Rep 2019; 19:75. [DOI: 10.1007/s11910-019-0996-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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31
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Stieb S, Elgohari B, Fuller CD. Repetitive MRI of organs at risk in head and neck cancer patients undergoing radiotherapy. Clin Transl Radiat Oncol 2019; 18:131-139. [PMID: 31341989 PMCID: PMC6630152 DOI: 10.1016/j.ctro.2019.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 02/07/2023] Open
Abstract
First review on MRI changes in head and neck organs at risk during radiotherapy. Focus on dynamics in salivary gland, muscle and bone in the head and neck region. Pointing out the limitations in implementing MRI in guiding radiation therapy.
With emerging technical advances like real-time MR imaging during radiotherapy (RT) with an integrated MR linear accelerator, it will soon be possible to analyze changes in the organs at risk (OARs) during radiotherapy without additional effort for the patients. Until then, patients have to undergo additional MR imaging and often without the same immobilization devices as used for radiotherapy. Consequently, studies with repetitive MRI during the course of radiotherapy are rare, with low patient numbers and with the challenge of registration between the different MR sequences and the varying imaging time points. This review focuses on studies with at least two MRIs, one before and another either during or post-RT, in order to report on RT-induced changes in normal tissues and their correlation with toxicity. We therefore included clinical studies published in English until March 2019, with repetitive MRI of OARs in head and neck cancer patients receiving external beam radiotherapy. OARs analyzed were salivary glands, musculoskeletal structures and bones. MR sequences used included T1, T2, dynamic contrast enhanced (DCE) imaging, diffusion-weighted imaging (DWI), DIXON and MR sialography.
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Affiliation(s)
- Sonja Stieb
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Baher Elgohari
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,Department of Clinical Oncology and Nuclear Medicine, Mansoura University, Mansoura, Egypt
| | - Clifton David Fuller
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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32
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Das IJ, McGee KP, Tyagi N, Wang H. Role and future of MRI in radiation oncology. Br J Radiol 2018; 92:20180505. [PMID: 30383454 DOI: 10.1259/bjr.20180505] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Technical innovations and developments in areas such as disease localization, dose calculation algorithms, motion management and dose delivery technologies have revolutionized radiation therapy resulting in improved patient care with superior outcomes. A consequence of the ability to design and accurately deliver complex radiation fields is the need for improved target visualization through imaging. While CT imaging has been the standard of care for more than three decades, the superior soft tissue contrast afforded by MR has resulted in the adoption of this technology in radiation therapy. With the development of real time MR imaging techniques, the problem of real time motion management is enticing. Currently, the integration of an MR imaging and megavoltage radiation therapy treatment delivery system (MR-linac or MRL) is a reality that has the potential to provide improved target localization and real time motion management during treatment. Higher magnetic field strengths provide improved image quality potentially providing the backbone for future work related to image texture analysis-a field known as Radiomics-thereby providing meaningful information on the selection of future patients for radiation dose escalation, motion-managed treatment techniques and ultimately better patient care. On-going advances in MRL technologies promise improved real time soft tissue visualization, treatment margin reductions, beam optimization, inhomogeneity corrected dose calculation, fast multileaf collimators and volumetric arc radiation therapy. This review article provides rationale, advantages and disadvantages as well as ideas for future research in MRI related to radiation therapy mainly in adoption of MRL.
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Affiliation(s)
- Indra J Das
- 1 Department of Radiation Oncology, NYU Langone Medical Center , New York, NY , USA
| | - Kiaran P McGee
- 2 Department of Radiology, Mayo Clinic , Rochester, MN , USA
| | - Neelam Tyagi
- 3 Department of Medical Physics, Memorial Sloan-Kettering Cancer Center , New York, NY , USA
| | - Hesheng Wang
- 1 Department of Radiation Oncology, NYU Langone Medical Center , New York, NY , USA
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