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Boss A, Heeb L, Vats D, Starsich FHL, Balfourier A, Herrmann IK, Gupta A. Assessment of iron nanoparticle distribution in mouse models using ultrashort-echo-time MRI. NMR IN BIOMEDICINE 2022; 35:e4690. [PMID: 34994020 PMCID: PMC9286043 DOI: 10.1002/nbm.4690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 06/14/2023]
Abstract
Microscopic magnetic field inhomogeneities caused by iron deposition or tissue-air interfaces may result in rapid decay of transverse magnetization in MRI. The aim of this study is to detect and quantify the distribution of iron-based nanoparticles in mouse models by applying ultrashort-echo-time (UTE) sequences in tissues exhibiting extremely fast transverse relaxation. In 24 C57BL/6 mice (two controls), suspensions containing either non-oxidic Fe or AuFeOx nanoparticles were injected into the tail vein at two doses (200 μg and 600 μg per mouse). Mice underwent MRI using a UTE sequence at 4.7 T field strength with five different echo times between 100 μs and 5000 μs. Transverse relaxation times T2 * were computed for the lung, liver, and spleen by mono-exponential fitting. In UTE imaging, the MRI signal could reliably be detected even in liver parenchyma exhibiting the highest deposition of nanoparticles. In animals treated with Fe nanoparticles (600 μg per mouse), the relaxation time substantially decreased in the liver (3418 ± 1534 μs (control) versus 228 ± 67 μs), the spleen (2170 ± 728 μs versus 299 ± 97 μs), and the lungs (663 ± 101 μs versus 413 ± 99 μs). The change in transverse relaxation was dependent on the number and composition of the nanoparticles. By pixel-wise curve fitting, T2 * maps were calculated showing nanoparticle distribution. In conclusion, UTE sequences may be used to assess and quantify nanoparticle distribution in tissues exhibiting ultrafast signal decay in MRI.
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Affiliation(s)
- Andreas Boss
- Institute of Diagnostic and Interventional RadiologyUniversity Hospital ZurichZurichSwitzerland
| | - Laura Heeb
- Division of Visceral SurgeryUniversity Hospital ZurichZurichSwitzerland
| | | | - Fabian H. L. Starsich
- Laboratory for Particles‐Biology InteractionsSwiss Federal Laboratories for Materials Science and Technology (Empa)St. GallenSwitzerland
- Department of Mechanical and Process Engineering, ETH ZurichNanoparticle Systems Engineering LaboratoryZurichSwitzerland
| | - Alice Balfourier
- Laboratory for Particles‐Biology InteractionsSwiss Federal Laboratories for Materials Science and Technology (Empa)St. GallenSwitzerland
- Department of Mechanical and Process Engineering, ETH ZurichNanoparticle Systems Engineering LaboratoryZurichSwitzerland
| | - Inge K. Herrmann
- Laboratory for Particles‐Biology InteractionsSwiss Federal Laboratories for Materials Science and Technology (Empa)St. GallenSwitzerland
- Department of Mechanical and Process Engineering, ETH ZurichNanoparticle Systems Engineering LaboratoryZurichSwitzerland
| | - Anurag Gupta
- Division of Visceral SurgeryUniversity Hospital ZurichZurichSwitzerland
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Stumpf K, Kaye E, Paul J, Wundrak S, Pauly JM, Rasche V. Two‐dimensional UTE overview imaging for dental application. Magn Reson Med 2020; 84:2616-2624. [DOI: 10.1002/mrm.28312] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/10/2020] [Accepted: 04/16/2020] [Indexed: 12/22/2022]
Affiliation(s)
- Kilian Stumpf
- Department of Internal Medicine II Ulm University Medical Center Ulm Germany
| | - Elena Kaye
- Department of Medical Physics Memorial Sloan Kettering Cancer Center New York New York USA
| | - Jan Paul
- Department of Internal Medicine II Ulm University Medical Center Ulm Germany
- Dental Imaging Dentsply Sirona Bensheim Germany
| | - Stefan Wundrak
- Department of Internal Medicine II Ulm University Medical Center Ulm Germany
- Dental Imaging Dentsply Sirona Bensheim Germany
| | - John M. Pauly
- Department of Electrical Engineering Stanford University Stanford California USA
| | - Volker Rasche
- Department of Internal Medicine II Ulm University Medical Center Ulm Germany
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Latta P, Starčuk Z, Kojan M, Gruwel MLH, Tomanek B, Trattnig S, Juras V. Simple compensation method for improved half-pulse excitation profile with rephasing gradient. Magn Reson Med 2020; 84:1796-1805. [PMID: 32129544 DOI: 10.1002/mrm.28233] [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: 11/04/2019] [Revised: 01/14/2020] [Accepted: 02/07/2020] [Indexed: 12/21/2022]
Abstract
PURPOSE To improve the slice profile quality obtained by RF half-pulse excitation for 2D-UTE applications. METHODS The overall first-order and zero-order phase errors along the slice-selection direction were obtained with the help of an optimization task to minimize the out-of-slice signal contamination from the calibration 1-dimenisonal (1D) profile data. The time-phase-error evolution was approximated from the k-space readout data, which were acquired primarily for correction of the readout trajectories during data regridding to the rectilinear grids. The correction of the slice profile was achieved by rephasing gradient pulses applied immediately after the end of excitation. The total prescan calibration typically took less than 2 minutes. RESULTS The improved image quality using the proposed calibration method was demonstrated both on phantoms and on ankle images obtained from healthy volunteers. It was demonstrated that calibration can be performed either as a separate water phantom measurement or directly as a prescan procedure. CONCLUSION The slice-profile distortion from the half-pulse excitation could substantially affect the overall fidelity of 2D-UTE images. The presented experiments proved that the image quality could be substantially increased by application of the proposed slice-correction method.
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Affiliation(s)
- Peter Latta
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Zenon Starčuk
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Martin Kojan
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Marco L H Gruwel
- Biological Resources Imaging Laboratory, Mark Wainwright Analytical Centre, Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Boguslaw Tomanek
- Department of Oncology, Division of Medical Physics, University of Alberta, Edmonton, AB, Canada
| | - Siegfried Trattnig
- High-Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Vladimir Juras
- High-Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
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Fan SJ, Ma Y, Chang EY, Bydder GM, Du J. Inversion recovery ultrashort echo time imaging of ultrashort T 2 tissue components in ovine brain at 3 T: a sequential D 2 O exchange study. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3767. [PMID: 28731616 PMCID: PMC5617132 DOI: 10.1002/nbm.3767] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/22/2017] [Accepted: 05/31/2017] [Indexed: 05/16/2023]
Abstract
Inversion recovery ultrashort echo time (IR-UTE) imaging holds the potential to directly characterize MR signals from ultrashort T2 tissue components (STCs), such as collagen in cartilage and myelin in brain. The application of IR-UTE for myelin imaging has been challenging because of the high water content in brain and the possibility that the ultrashort T2 * signals are contaminated by water protons, including those associated with myelin sheaths. This study investigated such a possibility in an ovine brain D2 O exchange model and explored the potential of IR-UTE imaging for the quantification of ultrashort T2 * signals in both white and gray matter at 3 T. Six specimens were examined before and after sequential immersion in 99.9% D2 O. Long T2 MR signals were measured using a clinical proton density-weighted fast spin echo (PD-FSE) sequence. IR-UTE images were first acquired with different inversion times to determine the optimal inversion time to null the long T2 signals (TInull ). Then, at this TInull , images with echo times (TEs) of 0.01-4 ms were acquired to measure the T2 * values of STCs. The PD-FSE signal dropped to near zero after 24 h of immersion in D2 O. A wide range of TInull values were used at different time points (240-330 ms for white matter and 320-350 ms for gray matter at TR = 1000 ms) because the T1 values of the long T2 tissue components changed significantly. The T2 * values of STCs were 200-300 μs in both white and gray matter (comparable with the values obtained from myelin powder and its mixture with D2 O or H2 O), and showed minimal changes after sequential immersion. The ultrashort T2 * signals seen on IR-UTE images are unlikely to be from water protons as they are exchangeable with deuterons in D2 O. The source is more likely to be myelin itself in white matter, and might also be associated with other membranous structures in gray matter.
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Affiliation(s)
- Shu-Juan Fan
- Department of Radiology, University of California, San Diego
| | - Yajun Ma
- Department of Radiology, University of California, San Diego
| | - Eric Y. Chang
- Department of Radiology, University of California, San Diego
- Department of Radiology, VA San Diego, Healthcare System, San Diego, CA, United States
| | | | - Jiang Du
- Department of Radiology, University of California, San Diego
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Manhard MK, Harkins KD, Gochberg DF, Nyman JS, Does MD. 30-Second bound and pore water concentration mapping of cortical bone using 2D UTE with optimized half-pulses. Magn Reson Med 2017; 77:945-950. [PMID: 28090655 DOI: 10.1002/mrm.26605] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Revised: 11/18/2016] [Accepted: 12/21/2016] [Indexed: 11/09/2022]
Abstract
PURPOSE MRI of cortical bone has the potential to offer new information about fracture risk. Current methods are typically performed with 3D acquisitions, which suffer from long scan times and are generally limited to extremities. This work proposes using 2D UTE with half pulses for quantitatively mapping bound and pore water in cortical bone. METHODS Half-pulse 2D UTE methods were implemented on a 3T Philips Achieva scanner using an optimized slice-select gradient waveform, with preparation pulses to selectively image bound or pore water. The 2D methods were quantitatively compared with previously implemented 3D methods in the tibia in five volunteers. RESULTS The mean difference between bound and pore water concentration acquired from 3D and 2D sequences was 0.6 and 0.9 mol 1 H/Lbone (3 and 12%, respectively). While 2D pore water methods tended to slightly overestimate concentrations relative to 3D methods, differences were less than scan-rescan uncertainty and expected differences between healthy and fracture-prone bones. CONCLUSION Quantitative bound and pore water concentration mapping in cortical bone can be accelerated by 2 orders of magnitude using 2D protocols with optimized half-pulse excitation. Magn Reson Med 77:945-950, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Mary Kate Manhard
- Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA
| | - Kevin D Harkins
- Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA
| | - Daniel F Gochberg
- Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.,Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA
| | - Jeffry S Nyman
- Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.,Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.,Orthopaedic Surgery and Rehabilitation, Vanderbilt University, Nashville, Tennessee, USA.,Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mark D Does
- Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.,Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.,Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Electrical Engineering, Vanderbilt University, Nashville, Tennessee, USA
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Herrmann KH, Krämer M, Reichenbach JR. Time Efficient 3D Radial UTE Sampling with Fully Automatic Delay Compensation on a Clinical 3T MR Scanner. PLoS One 2016; 11:e0150371. [PMID: 26975051 PMCID: PMC4790903 DOI: 10.1371/journal.pone.0150371] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 02/12/2016] [Indexed: 11/28/2022] Open
Abstract
This work’s aim was to minimize the acquisition time of a radial 3D ultra-short echo-time (UTE) sequence and to provide fully automated, gradient delay compensated, and therefore artifact free, reconstruction. The radial 3D UTE sequence (echo time 60 μs) was implemented as single echo acquisition with center-out readouts and improved time efficient spoiling on a clinical 3T scanner without hardware modifications. To assess the sequence parameter dependent gradient delays each acquisition contained a quick calibration scan and utilized the phase of the readouts to detect the actual k-space center. This calibration scan does not require any user interaction. To evaluate the robustness of this automatic delay estimation phantom experiments were performed and 19 in vivo imaging data of the head, tibial cortical bone, feet and lung were acquired from 6 volunteers. As clinical application of this fast 3D UTE acquisition single breath-hold lung imaging is demonstrated. The proposed sequence allowed very short repetition times (TR~1ms), thus reducing total acquisition time. The proposed, fully automated k-phase based gradient delay calibration resulted in accurate delay estimations (difference to manually determined optimal delay −0.13 ± 0.45 μs) and allowed unsupervised reconstruction of high quality images for both phantom and in vivo data. The employed fast spoiling scheme efficiently suppressed artifacts caused by incorrectly refocused echoes. The sequence proved to be quite insensitive to motion, flow and susceptibility artifacts and provides oversampling protection against aliasing foldovers in all directions. Due to the short TR, acquisition times are attractive for a wide range of clinical applications. For short T2* mapping this sequence provides free choice of the second TE, usually within less scan time as a comparable dual echo UTE sequence.
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Affiliation(s)
- Karl-Heinz Herrmann
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Martin Krämer
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Jürgen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
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