1
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Liu Q, Yuan K, Zhang Q, Du H, Song X, Zhou Y, Qiu B. Breast intervention device for low-field MRI with a customized unilateral coil. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 357:107579. [PMID: 37949007 DOI: 10.1016/j.jmr.2023.107579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 10/07/2023] [Accepted: 10/25/2023] [Indexed: 11/12/2023]
Abstract
With the incidence of breast cancer rising to the top among female malignant tumors, magnetic resonance images guided breast biopsy intervention and minimally invasive treatment have developed as a clinically practical research issue. High field studies have shown the diagnostic value of breast MRI, but the examination costs greatly exceed those of competing conventional mammography. In this case, low-field MRI cannot merely provide typical MRI contrast, but also significantly reduce the cost of diagnosis and treatment for breast cancer patients. This work describes a unilateral breast coil and prototype intervention device, which provides a customized solution for low-field MRI-guided breast intervention. Results demonstrate that the low-field MRI breast intervention device facilitates medical intervention procedures. And the designed positioning device can locate the target lesion within 2-3 mm accuracy. Phantom tests with the customized unilateral coil indicate that the open loops perform as well as the 4-channel commercial closed breast coil, presenting a relatively good SNR (signal-to-noise ratio) and uniformity characteristics. MR scanning images of the volunteer breast using the breast intervention coil also show high SNR, which lays a foundation for further implementation of image-guided breast interventional minimally invasive surgery with the low-field MRI system.
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Affiliation(s)
- Qingyun Liu
- Medical Imaging Center, Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Kecheng Yuan
- Medical Imaging Center, Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Qing Zhang
- Medical Imaging Center, Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Huiyu Du
- Medical Imaging Center, Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xueyan Song
- Medical Imaging Center, Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yufu Zhou
- Anhui Fuqing Medical Equipment Co., Ltd, Hefei, Anhui 230031, China
| | - Bensheng Qiu
- Medical Imaging Center, Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China.
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2
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Del Bosque R, Cui J, Ogier S, Cheshkov S, Dimitrov IE, Malloy C, Wright SM, McDougall M. A 32-channel receive array coil for bilateral breast imaging and spectroscopy at 7T. Magn Reson Med 2020; 85:551-559. [PMID: 32820540 DOI: 10.1002/mrm.28425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 11/09/2022]
Abstract
PURPOSE This work describes the construction and evaluation of a bilateral 32-channel receive array for breast imaging at 7T. METHODS The receive array consisted of 32 receive coils, placed on two 3D-printed hemispherical formers. Each side of the receive array consisted of 16 receive loops, each loop having a corresponding detachable board with match/tune capacitors, active detuning circuitry, and a balun. Coil performance was evaluated on homogeneous canola oil phantoms using a Philips Achieva 7T system. Array coil performance was compared with a bilateral forced current excitation volume coil in transmit/receive mode and with a previously reported 16-channel unilateral coil with a similar design. RESULTS The 32-channel array had an increase in average SNR throughout both phantoms by a factor of five as compared with the volume coil, with SNR increases up to 10 times along the periphery and three times in the center. Noise measurements showed low interelement noise correlation (average: 5.4%; maximum: 16.8%). Geometry factor maps were acquired for various acceleration factors and showed mean geometry factors <1.2, for combined acceleration factors of up to six. CONCLUSIONS The improvements achieved demonstrate the clear potential for use in dynamic contrast-enhanced or diffusion-weighted MR studies, while maintaining diagnostically relevant spatial and temporal resolutions.
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Affiliation(s)
- Romina Del Bosque
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
| | - Jiaming Cui
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Stephen Ogier
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Sergey Cheshkov
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Center for Brain Health, University of Texas at Dallas, Dallas, Texas, USA
| | - Ivan E Dimitrov
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Philips Healthcare, Gainesville, Florida, USA
| | - Craig Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Steven M Wright
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA.,Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Mary McDougall
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA.,Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
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3
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Chhetri A, Li X, Rispoli JV. Current and Emerging Magnetic Resonance-Based Techniques for Breast Cancer. Front Med (Lausanne) 2020; 7:175. [PMID: 32478083 PMCID: PMC7235971 DOI: 10.3389/fmed.2020.00175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 04/15/2020] [Indexed: 01/10/2023] Open
Abstract
Breast cancer is the most commonly diagnosed cancer among women worldwide, and early detection remains a principal factor for improved patient outcomes and reduced mortality. Clinically, magnetic resonance imaging (MRI) techniques are routinely used in determining benign and malignant tumor phenotypes and for monitoring treatment outcomes. Static MRI techniques enable superior structural contrast between adipose and fibroglandular tissues, while dynamic MRI techniques can elucidate functional characteristics of malignant tumors. The preferred clinical procedure-dynamic contrast-enhanced MRI-illuminates the hypervascularity of breast tumors through a gadolinium-based contrast agent; however, accumulation of the potentially toxic contrast agent remains a major limitation of the technique, propelling MRI research toward finding an alternative, noninvasive method. Three such techniques are magnetic resonance spectroscopy, chemical exchange saturation transfer, and non-contrast diffusion weighted imaging. These methods shed light on underlying chemical composition, provide snapshots of tissue metabolism, and more pronouncedly characterize microstructural heterogeneity. This review article outlines the present state of clinical MRI for breast cancer and examines several research techniques that demonstrate capacity for clinical translation. Ultimately, multi-parametric MRI-incorporating one or more of these emerging methods-presently holds the best potential to afford improved specificity and deliver excellent accuracy to clinics for the prediction, detection, and monitoring of breast cancer.
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Affiliation(s)
- Apekshya Chhetri
- Magnetic Resonance Biomedical Engineering Laboratory, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
- Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States
| | - Xin Li
- Magnetic Resonance Biomedical Engineering Laboratory, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Joseph V. Rispoli
- Magnetic Resonance Biomedical Engineering Laboratory, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
- Center for Cancer Research, Purdue University, West Lafayette, IN, United States
- School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, United States
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4
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Orzada S, Solbach K, Gratz M, Brunheim S, Fiedler TM, Johst S, Bitz AK, Shooshtary S, Abuelhaija A, Voelker MN, Rietsch SHG, Kraff O, Maderwald S, Flöser M, Oehmigen M, Quick HH, Ladd ME. A 32-channel parallel transmit system add-on for 7T MRI. PLoS One 2019; 14:e0222452. [PMID: 31513637 PMCID: PMC6742215 DOI: 10.1371/journal.pone.0222452] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/29/2019] [Indexed: 02/07/2023] Open
Abstract
PURPOSE A 32-channel parallel transmit (pTx) add-on for 7 Tesla whole-body imaging is presented. First results are shown for phantom and in-vivo imaging. METHODS The add-on system consists of a large number of hardware components, including modulators, amplifiers, SAR supervision, peripheral devices, a control computer, and an integrated 32-channel transmit/receive body array. B1+ maps in a phantom as well as B1+ maps and structural images in large volunteers are acquired to demonstrate the functionality of the system. EM simulations are used to ensure safe operation. RESULTS Good agreement between simulation and experiment is shown. Phantom and in-vivo acquisitions show a field of view of up to 50 cm in z-direction. Selective excitation with 100 kHz sampling rate is possible. The add-on system does not affect the quality of the original single-channel system. CONCLUSION The presented 32-channel parallel transmit system shows promising performance for ultra-high field whole-body imaging.
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Affiliation(s)
- Stephan Orzada
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
- * E-mail:
| | - Klaus Solbach
- RF & Microwave Technology, University of Duisburg-Essen, Duisburg, Germany
| | - Marcel Gratz
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
- High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Sascha Brunheim
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
- High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Thomas M. Fiedler
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sören Johst
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
| | - Andreas K. Bitz
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Electromagnetic Theory and Applied Mathematics, Faculty of Electrical Engineering and Information Technology, FH Aachen – University of Applied Sciences, Aachen, Germany
| | - Samaneh Shooshtary
- RF & Microwave Technology, University of Duisburg-Essen, Duisburg, Germany
| | - Ashraf Abuelhaija
- RF & Microwave Technology, University of Duisburg-Essen, Duisburg, Germany
| | - Maximilian N. Voelker
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
- High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Stefan H. G. Rietsch
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
- High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Oliver Kraff
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
| | - Stefan Maderwald
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
| | - Martina Flöser
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mark Oehmigen
- High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Harald H. Quick
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
- High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Mark E. Ladd
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen, Germany
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
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5
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Ianniello C, Madelin G, Moy L, Brown R. A dual-tuned multichannel bilateral RF coil for 1 H/ 23 Na breast MRI at 7 T. Magn Reson Med 2019; 82:1566-1575. [PMID: 31148249 DOI: 10.1002/mrm.27829] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 12/25/2022]
Abstract
PURPOSE Sodium MRI has shown promise for monitoring neoadjuvant chemotherapy response in breast cancer. The purpose of this work was to build a dual-tuned bilateral proton/sodium breast coil for 7T MRI that provides sufficient SNR to enable sodium breast imaging in less than 10 minutes. METHODS The proton/sodium coil consists of 2 shielded unilateral units: 1 for each breast. Each unit consists of 3 nested layers: (1) a 3-loop solenoid for sodium excitation, (2) a 3-loop solenoid for proton excitation and signal reception, and (3) a 4-channel receive array for sodium signal reception. Benchmark measurements were performed in phantoms with and without the sodium receive array insert. In vivo images were acquired on a healthy volunteer. RESULTS The sodium receive array boosted 1.5 to 3 times the SNR compared with the solenoid. Proton SNR loss due to residual interaction with the sodium array was less than 10%. The coil enabled sodium imaging in vivo with 2.8-mm isotropic nominal resolution (~5-mm real resolution) in 9:36 minutes. CONCLUSION The coil design that we propose addresses challenges associated with sodium's low SNR from a hardware perspective and offers the opportunity to investigate noninvasively breast tumor metabolism as a function of sodium concentration in patients undergoing neoadjuvant chemotherapy.
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Affiliation(s)
- Carlotta Ianniello
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York.,The Sackler Institute of Graduate Biomedical Science, New York University School of Medicine, New York, New York
| | - Guillaume Madelin
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York.,The Sackler Institute of Graduate Biomedical Science, New York University School of Medicine, New York, New York
| | - Linda Moy
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York.,The Sackler Institute of Graduate Biomedical Science, New York University School of Medicine, New York, New York
| | - Ryan Brown
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York.,The Sackler Institute of Graduate Biomedical Science, New York University School of Medicine, New York, New York
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6
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Rietsch SHG, Brunheim S, Orzada S, Voelker MN, Maderwald S, Bitz AK, Gratz M, Ladd ME, Quick HH. Development and evaluation of a 16-channel receive-only RF coil to improve 7T ultra-high field body MRI with focus on the spine. Magn Reson Med 2019; 82:796-810. [PMID: 30924181 DOI: 10.1002/mrm.27731] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/02/2019] [Accepted: 01/27/2019] [Indexed: 12/21/2022]
Abstract
PURPOSE A 16-channel receive (16Rx) radiofrequency (RF) array for 7T ultra-high field body MR imaging is presented. The coil is evaluated in conjunction with a 16-channel transmit/receive (16TxRx) coil and additionally with a 32-channel transmit/receive (32TxRx) remote body coil for RF transmit and serving as receive references. METHODS The 16Rx array consists of 16 octagonal overlapping loops connected to custom-built detuning boards with preamplifiers. Performance metrics like noise correlation, g-factors, and signal-to-noise ratio gain were compared between 4 different RF coil configurations. In vivo body imaging was performed in volunteers using radiofrequency shimming, time interleaved acquisition of modes (TIAMO), and 2D spatially selective excitation using parallel transmit (pTx) in the spine. RESULTS Lower g-factors were obtained when using the 16Rx coil in addition to the 16TxRx array coil configuration versus the 16TxRx array alone. Distinct signal-to-noise ratio gain using the 16Rx coil could be demonstrated in the spine region both for a comparison with the 16TxRx coil (>50% gain) in vivo and the 32TxRx coil (>240% gain) in a phantom. The 16Rx coil was successfully applied to improve anatomical imaging in the abdomen and 2D spatially selective excitation in the spine of volunteers. CONCLUSION The novel 16-channel Rx-array as an add-on to multichannel TxRx RF coil configurations provides increased signal-to-noise ratio, lower g-factors, and thus improves 7T ultra-high field body MR imaging.
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Affiliation(s)
- Stefan H G Rietsch
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany.,High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Sascha Brunheim
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany.,High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Stephan Orzada
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany
| | - Maximilian N Voelker
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany.,High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Stefan Maderwald
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany
| | - Andreas K Bitz
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Electromagnetic Theory and Applied Mathematics, Faculty of Electrical Engineering and Information Technology, University of Applied Sciences Aachen, Aachen, Germany
| | - Marcel Gratz
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany.,High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
| | - Mark E Ladd
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany.,Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy and Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Harald H Quick
- Erwin L. Hahn Institute for MR Imaging, University of Duisburg-Essen, Essen, Germany.,High-Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany
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7
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Krikken E, Steensma BR, Voogt IJ, Luijten PR, Klomp DW, Raaijmakers AJ, Wijnen JP. Homogeneous B 1+ for bilateral breast imaging at 7 T using a five dipole transmit array merged with a high density receive loop array. NMR IN BIOMEDICINE 2019; 32:e4039. [PMID: 30489661 PMCID: PMC6587506 DOI: 10.1002/nbm.4039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/24/2018] [Accepted: 10/12/2018] [Indexed: 06/09/2023]
Abstract
To explore the use of five meandering dipole antennas in a multi-transmit setup, combined with a high density receive array for breast imaging at 7 T for improved penetration depth and more homogeneous B1 field. Five meandering dipole antennas and 30 receiver loops were positioned on two cups around the breasts. Finite difference time domain simulations were performed to evaluate RF safety limits of the transmit setup. Scattering parameters of the transmit setup and coupling between the antennas and the detuned loops were measured. In vivo parallel imaging performance was investigated for various acceleration factors. After RF shimming, a B1 map, a T1 -weighted image, and a T2 -weighted image were acquired to assess B1 efficiency, uniformity in contrast weighting, and imaging performance in clinical applications. The maximum achievable local SAR10g value was 7.0 W/kg for 5 × 1 W accepted power. The dipoles were tuned and matched to a maximum reflection of -11.8 dB, and a maximum inter-element coupling of -14.2 dB. The maximum coupling between the antennas and the receive loops was -18.2 dB and the mean noise correlation for the 30 receive loops 7.83 ± 8.69%. In vivo measurements showed an increased field of view, which reached to the axilla, and a high transmit efficiency. This coil enabled the acquisition of T1 -weighted images with a high spatial resolution of 0.7 mm3 isotropic and T2 -weighted spin echo images with uniformly weighted contrast.
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Affiliation(s)
- Erwin Krikken
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Bart R. Steensma
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Ingmar J. Voogt
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Peter R. Luijten
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Dennis W.J. Klomp
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
| | - Alexander J.E. Raaijmakers
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
- Department of Biomedical EngineeringEindhoven University of TechnologyEindhovenThe Netherlands
| | - Jannie P. Wijnen
- Department of RadiologyUniversity Medical Center UtrechtUtrechtThe Netherlands
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8
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Alon L, Lattanzi R, Lakshmanan K, Brown R, Deniz CM, Sodickson DK, Collins CM. Transverse slot antennas for high field MRI. Magn Reson Med 2018; 80:1233-1242. [PMID: 29388250 PMCID: PMC5985532 DOI: 10.1002/mrm.27095] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 12/28/2017] [Accepted: 12/28/2017] [Indexed: 11/23/2022]
Abstract
Purpose Introduce a novel coil design using an electrically long transversely oriented slot in a conductive sheet. Theory and Methods Theoretical considerations, numerical simulations, and experimental measurements are presented for transverse slot antennas as compared with electric dipole antennas. Results Simulations show improved central and average transmit and receive efficiency, as well as larger coverage in the transverse plane, for a single slot as compared to a single dipole element. Experiments on a body phantom confirm the simulation results for a slot antenna relative to a dipole, demonstrating a large region of relatively high sensitivity and homogeneity. Images in a human subject also show a large imaging volume for a single slot and six slot antenna array. High central transmit efficiency was observed for slot arrays relative to dipole arrays. Conclusion Transverse slots can exhibit improved sensitivity and larger field of view compared with traditional conductive dipoles. Simulations and experiments indicate high potential for slot antennas in high field MRI. Magn Reson Med 80:1233–1242, 2018. © 2018 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
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Affiliation(s)
- Leeor Alon
- Center for Advanced Imaging Innovation and Research (CAI2R), and the Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, USA.,NYU WIRELESS, New York University Tandon School of Engineering, Brooklyn, New York, USA.,RF Test Labs, Inc., New York, New York, USA
| | - Riccardo Lattanzi
- Center for Advanced Imaging Innovation and Research (CAI2R), and the Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, USA.,NYU WIRELESS, New York University Tandon School of Engineering, Brooklyn, New York, USA
| | - Karthik Lakshmanan
- Center for Advanced Imaging Innovation and Research (CAI2R), and the Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, USA.,NYU WIRELESS, New York University Tandon School of Engineering, Brooklyn, New York, USA
| | - Ryan Brown
- Center for Advanced Imaging Innovation and Research (CAI2R), and the Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, USA.,NYU WIRELESS, New York University Tandon School of Engineering, Brooklyn, New York, USA
| | - Cem M Deniz
- Center for Advanced Imaging Innovation and Research (CAI2R), and the Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, USA.,NYU WIRELESS, New York University Tandon School of Engineering, Brooklyn, New York, USA.,RF Test Labs, Inc., New York, New York, USA
| | - Daniel K Sodickson
- Center for Advanced Imaging Innovation and Research (CAI2R), and the Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, USA.,NYU WIRELESS, New York University Tandon School of Engineering, Brooklyn, New York, USA
| | - Christopher M Collins
- Center for Advanced Imaging Innovation and Research (CAI2R), and the Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, New York, USA.,NYU WIRELESS, New York University Tandon School of Engineering, Brooklyn, New York, USA
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9
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van der Velden TA, Luijten PR, Klomp DW. Improved fat suppression of the breast using discretized frequency shimming. Magn Reson Med 2017; 79:593-599. [DOI: 10.1002/mrm.26651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 01/24/2017] [Accepted: 01/27/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Tijl A. van der Velden
- Department of Radiology; University Medical Centre Utrecht; 3584CX Utrecht the Netherlands
| | - Peter R. Luijten
- Department of Radiology; University Medical Centre Utrecht; 3584CX Utrecht the Netherlands
| | - Dennis W.J. Klomp
- Department of Radiology; University Medical Centre Utrecht; 3584CX Utrecht the Netherlands
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10
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Kim J, Santini T, Bae KT, Krishnamurthy N, Zhao Y, Zhao T, Ibrahim TS. Development of a 7 T RF coil system for breast imaging. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3664. [PMID: 27859861 PMCID: PMC5943082 DOI: 10.1002/nbm.3664] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 09/23/2016] [Accepted: 10/06/2016] [Indexed: 06/06/2023]
Abstract
In ultrahigh-field MRI, such as 7 T, the signal-to-noise ratio (SNR) increases while transmit (Tx) field (B1+ ) can be degraded due to inhomogeneity and elevated specific absorption rate (SAR). By applying new array coil concepts to both Tx and receive (Rx) coils, the B1+ homogeneity and SNR can be improved. In this study, we developed and tested in vivo a new RF coil system for 7 T breast MRI. An RF coil system composed of an eight-channel Tx-only array based on a tic-tac-toe design (can be combined to operate in single-Tx mode) in conjunction with an eight-channel Rx-only insert was developed. Characterizations of the B1+ field and associated SAR generated by the developed RF coil system were numerically calculated and empirically measured using an anatomically detailed breast model, phantom and human breasts. In vivo comparisons between 3 T (using standard commercial solutions) and 7 T (using the newly developed coil system) breast imaging were made. At 7 T, about 20% B1+ inhomogeneity (standard deviation over the mean) was measured within the breast tissue for both the RF simulations and 7 T experiments. The addition of the Rx-only array enhances the SNR by a factor of about three. High-quality MR images of human breast were acquired in vivo at 7 T. For the in vivo comparisons between 3 T and 7 T, an approximately fourfold increase of SNR was measured with 7 T imaging. The B1+ field distributions in the breast model, phantom and in vivo were in reasonable agreement. High-quality 7 T in vivo breast MRI was successfully acquired at 0.6 mm isotropic resolution using the newly developed RF coil system.
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Affiliation(s)
- Junghwan Kim
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tales Santini
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kyongtae Ty Bae
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Yujuan Zhao
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tiejun Zhao
- MR Research Support, Siemens Healthcare, Pittsburgh, PA, USA
| | - Tamer S. Ibrahim
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
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11
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Pinker K, Helbich TH, Morris EA. The potential of multiparametric MRI of the breast. Br J Radiol 2016; 90:20160715. [PMID: 27805423 DOI: 10.1259/bjr.20160715] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
MRI is an essential tool in breast imaging, with multiple established indications. Dynamic contrast-enhanced MRI (DCE-MRI) is the backbone of any breast MRI protocol and has an excellent sensitivity and good specificity for breast cancer diagnosis. DCE-MRI provides high-resolution morphological information, as well as some functional information about neoangiogenesis as a tumour-specific feature. To overcome limitations in specificity, several other functional MRI parameters have been investigated and the application of these combined parameters is defined as multiparametric MRI (mpMRI) of the breast. MpMRI of the breast can be performed at different field strengths (1.5-7 T) and includes both established (diffusion-weighted imaging, MR spectroscopic imaging) and novel MRI parameters (sodium imaging, chemical exchange saturation transfer imaging, blood oxygen level-dependent MRI), as well as hybrid imaging with positron emission tomography (PET)/MRI and different radiotracers. Available data suggest that multiparametric imaging using different functional MRI and PET parameters can provide detailed information about the underlying oncogenic processes of cancer development and progression and can provide additional specificity. This article will review the current and emerging functional parameters for mpMRI of the breast for improved diagnostic accuracy in breast cancer.
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Affiliation(s)
- Katja Pinker
- 1 Department of Radiology, Molecular Imaging and Therapy Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA.,2 Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna, Vienna, Austria.,3 Department of Radiology, Breast Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Thomas H Helbich
- 2 Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna, Vienna, Austria
| | - Elizabeth A Morris
- 3 Department of Radiology, Breast Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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Kim J, Krishnamurthy N, Santini T, Zhao Y, Zhao T, Bae KT, Ibrahim TS. Experimental and numerical analysis of B1(+) field and SAR with a new transmit array design for 7T breast MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 269:55-64. [PMID: 27240143 PMCID: PMC4979605 DOI: 10.1016/j.jmr.2016.04.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 05/15/2023]
Abstract
Developing a radiofrequency (RF) coil system that produces a uniform B1(+) field (circularly polarized component of the transverse magnetic field responsible for excitation) and low specific absorption rate (SAR) is critical for high performance ultrahigh field human imaging. In this study, we provide the design of a new eight channel radiofrequency (RF) transmit (Tx) array for breast MRI at 7T. A numerical analysis utilizing an in-house finite difference time domain (FDTD) package was carried out in (1) four breast models, (2) homogeneous spherical model and (3) full body model to calculate the B1(+) intensity (μT) and homogeneity represented by coefficient of variation (CoV=standard deviation/mean) in the proposed RF array design. The numerical results were compared with that measured in breast phantom (Bphantom) and homogeneous spherical phantom at 7T MRI and showed very good agreement. Average and peak SARs were also calculated in the four breast models and the temperature rises due to the operation of the RF array were also measured in the Bphantom. The proposed RF array; which can operate in a single or multi transmit modes, demonstrates homogeneous RF field excitation with acceptable local/average SAR levels for breast MRI at 7T.
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Affiliation(s)
- Junghwan Kim
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | | | - Tales Santini
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Yujuan Zhao
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Tiejun Zhao
- MR Research Support, Siemens Healthcare, Pittsburgh, PA 15213, USA
| | - Kyongtae Ty Bae
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Tamer S Ibrahim
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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13
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Menezes GLG, Stehouwer BL, Klomp DWJ, van der Velden TA, van den Bosch MAAJ, Knuttel FM, Boer VO, van der Kemp WJM, Luijten PR, Veldhuis WB. Dynamic contrast-enhanced breast MRI at 7T and 3T: an intra-individual comparison study. SPRINGERPLUS 2016; 5:13. [PMID: 26759752 PMCID: PMC4700043 DOI: 10.1186/s40064-015-1654-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 12/21/2015] [Indexed: 01/01/2023]
Abstract
The aim of this study is to compare the current state of lesion identification, the BI-RADS classification and the contrast-enhancement behavior at 7T and 3T breast MRI in the same patient group. Twenty-seven patients with thirty suspicious lesions were selected for this prospective study and underwent both 7T and 3T MRI. All examinations were rated by two radiologists (R1 and R2) independently on image quality, lesion identification and BI-RADS classification. We assessed sensitivity, specificity, NPV and PPV, observer agreement, lesion sizes, and contrast-enhancement-to-noise ratios (CENRs) of mass lesions. Fifteen of seventeen histopathological proven malignant lesions were detected at both field strengths. Image quality of the dynamic series was good at 7T, and excellent at 3T (P = 0.001 for R1 and P = 0.88 for R2). R1 found higher rates of specificity, NPV and PPV at 7T when compared to 3T, while R2 found the same results for sensitivity, specificity, NPV and PPV for both field strengths. The observers showed excellent agreement for BI-RADS categories at 7T (κ = 0.86) and 3T (κ = 0.93). CENRs were higher at 7T (P = 0.015). Lesion sizes were bigger at 7T according to R2 (P = 0.039). Our comparison study shows that 7T MRI allows BI-RADS conform analysis. Technical improvements, such as acquisition of T2w sequences and adjustment of B1+ field inhomogeneity, are still necessary to allow clinical use of 7T breast MRI.
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Affiliation(s)
- Gisela L G Menezes
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Bertine L Stehouwer
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Dennis W J Klomp
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Tijl A van der Velden
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Maurice A A J van den Bosch
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Floortje M Knuttel
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Vincent O Boer
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Wybe J M van der Kemp
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Peter R Luijten
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
| | - Wouter B Veldhuis
- Department of Radiology and Nuclear Medicine, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
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van der Velden TA, Schmitz AMT, Gilhuijs KGA, Veldhuis WB, Luijten PR, Boer VO, Klomp DWJ. Fat suppression techniques for obtaining high resolution dynamic contrast enhanced bilateral breast MR images at 7T. Magn Reson Imaging 2015; 34:462-8. [PMID: 26708033 DOI: 10.1016/j.mri.2015.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 12/13/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES To compare water selective excitation (WSE) and Dixon fat suppression in the context of high-resolution dynamic contrast enhanced MRI of the breast at 7T. METHODS Ten healthy volunteers and one patient with a malignant breast lesion were scanned at 7T. The MRI protocol contained 3D T1-weighted gradient echo images obtained with both WSE fat suppression, multi echo Dixon fat suppression, and without fat suppression. Images were acquired at a (0.8mm)(3) or (0.7mm)(3) isotropic resolution with equal field of view and optimized such to obtain a maximal SNR. Image quality was scored qualitatively on overall image quality, sharpness of anatomical details, presence of artifacts, inhomogeneous fat suppression and the presence of water-fat shift. A quantitative scoring was obtained from the signal to noise ratio and contrast to noise ratio. RESULTS WSE scored significantly better in terms of overall image quality and the absence of artifacts. No significant difference in contrast to noise ratio was found between the two fat suppression methods. CONCLUSION When maximizing temporal and spatial resolution of high resolution DCE MRI of the breast, water selective excitation provides better image quality than multi echo Dixon at 7T.
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Affiliation(s)
- Tijl A van der Velden
- University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands.
| | - Alexander M Th Schmitz
- University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands; University Medical Center Utrecht, Image Sciences Institute, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands
| | - Kenneth G A Gilhuijs
- University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands; University Medical Center Utrecht, Image Sciences Institute, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands
| | - Wouter B Veldhuis
- University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands
| | - Peter R Luijten
- University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands
| | - Vincent O Boer
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Kettegaard Allé 30, DK-2650, Hvidovre, Denmark
| | - Dennis W J Klomp
- University Medical Center Utrecht, Department of Radiology, Heidelberglaan 100, 3584CX, Utrecht, the Netherlands
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The Potential of High Resolution Magnetic Resonance Microscopy in the Pathologic Analysis of Resected Breast and Lymph Tissue. Sci Rep 2015; 5:17435. [PMID: 26639673 PMCID: PMC4671009 DOI: 10.1038/srep17435] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 10/29/2015] [Indexed: 11/25/2022] Open
Abstract
Pathologic evaluation of breast specimens requires a fixation and staining procedure of at least 12 hours duration, delaying diagnosis and post-operative planning. Here we introduce an MRI technique with a custom-designed radiofrequency resonator for imaging breast and lymph tissue with sufficient spatial resolution and speed to guide pathologic interpretation and offer value in clinical decision making. In this study, we demonstrate the ability to image breast and lymphatic tissue using 7.0 Tesla MRI, achieving a spatial resolution of 59 × 59 × 94 μm3 with a signal-to-noise ratio of 15–20, in an imaging time of 56 to 70 minutes. These are the first MR images to reveal characteristic pathologic features of both benign and malignant breast and lymph tissue, some of which were discernible by blinded pathologists who had no prior training in high resolution MRI interpretation.
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Pinker K, Baltzer P, Bogner W, Leithner D, Trattnig S, Zaric O, Dubsky P, Bago-Horvath Z, Rudas M, Gruber S, Weber M, Helbich TH. Multiparametric MR Imaging with High-Resolution Dynamic Contrast-enhanced and Diffusion-weighted Imaging at 7 T Improves the Assessment of Breast Tumors: A Feasibility Study. Radiology 2015; 276:360-70. [DOI: 10.1148/radiol.15141905] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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