1
|
Jian CB, Wu YY, Lin MH, Gao HD, Chen CY, Leong SK, Tzou DLM, Hwang DW, Lee HM. A Facile NMR Method for Pre-MRI Evaluation of Trigger-Responsive T 1 Contrast Enhancement. SMALL METHODS 2024:e2301603. [PMID: 38459640 DOI: 10.1002/smtd.202301603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/09/2024] [Indexed: 03/10/2024]
Abstract
There is a growing interest in developing paramagnetic nanoparticles as responsive magnetic resonance imaging (MRI) contrast agents, which feature switchable T1 image contrast of water protons upon biochemical cues for better discerning diseases. However, performing an MRI is pragmatically limited by its cost and availability. Hence, a facile, routine method for measuring the T1 contrast is highly desired in early-stage development. This work presents a single-point inversion recovery (IR) nuclear magnetic resonance (NMR) method that can rapidly evaluate T1 contrast change by employing a single, optimized IR pulse sequence that minimizes water signal for "off-state" nanoparticles and allows for sensitively measuring the signal change with "switch-on" T1 contrast. Using peptide-induced liposomal gadopentetic acid (Gd3+ -DTPA) release and redox-sensitive manganese oxide (MnO2 ) nanoparticles as a demonstration of generality, this method successfully evaluates the T1 shortening of water protons caused by liposomal Gd3+ -DTPA release and Mn2+ formation from MnO2 reduction. Furthermore, the NMR measurement is highly correlated to T1 -weighted MRI scans, suggesting its feasibility to predict the MRI results at the same field strength. This NMR method can be a low-cost, time-saving alternative for pre-MRI evaluation for a diversity of responsive T1 contrast systems.
Collapse
Affiliation(s)
- Cheng-Bang Jian
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
- Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Taipei, 11529, Taiwan
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Ying-Yann Wu
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Ming-Huang Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Hua-De Gao
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Chong-Yan Chen
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Shwee Khuan Leong
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Yang Ming Chiao Tung University, Taipei, 11529, Taiwan
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 30093, Taiwan
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Dennis W Hwang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Hsien-Ming Lee
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| |
Collapse
|
2
|
Hodel J, Vernooij MW, Beyer MK, Severino M, Leclerc X, Créange A, Wahab A, Badat N, Tolédano S, van den Hauwe L, Ramos A, Castellano A, Krainik A, Yousry T, Rovira À. Multiple sclerosis imaging in clinical practice: a European-wide survey of 428 centers and conclusions by the ESNR Working Group. Eur Radiol 2023; 33:7025-7033. [PMID: 37199796 DOI: 10.1007/s00330-023-09701-1] [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: 09/16/2022] [Revised: 01/23/2023] [Accepted: 03/09/2023] [Indexed: 05/19/2023]
Abstract
OBJECTIVES To evaluate compliance with the available recommendations, we assessed the current clinical practice of imaging in the evaluation of multiple sclerosis (MS). METHODS An online questionnaire was emailed to all members and affiliates. Information was gathered on applied MR imaging protocols, gadolinium-based contrast agents (GBCA) use and image analysis. We compared the survey results with the Magnetic Resonance Imaging in MS (MAGNIMS) recommendations considered as the reference standard. RESULTS A total of 428 entries were received from 44 countries. Of these, 82% of responders were neuroradiologists. 55% performed more than ten scans per week for MS imaging. The systematic use of 3 T is rare (18%). Over 90% follow specific protocol recommendations with 3D FLAIR, T2-weighted and DWI being the most frequently used sequences. Over 50% use SWI at initial diagnosis and 3D gradient-echo T1-weighted imaging is the most used MRI sequence for pre- and post-contrast imaging. Mismatches with recommendations were identified including the use of only one sagittal T2-weighted sequence for spinal cord imaging, the systematic use of GBCA at follow-up (over 30% of institutions), a delay time shorter than 5 min after GBCA administration (25%) and an inadequate follow-up duration in pediatric acute disseminated encephalomyelitis (80%). There is scarce use of automated software to compare images or to assess atrophy (13% and 7%). The proportions do not differ significantly between academic and non-academic institutions. CONCLUSIONS While current practice in MS imaging is rather homogeneous across Europe, our survey suggests that recommendations are only partially followed. CLINICAL RELEVANCE STATEMENT Hurdles were identified, mainly in the areas of GBCA use, spinal cord imaging, underuse of specific MRI sequences and monitoring strategies. This work will help radiologists to identify the mismatches between their own practices and the recommendations and act upon them. KEY POINTS • While current practice in MS imaging is rather homogeneous across Europe, our survey suggests that available recommendations are only partially followed. • Several hurdles have been identified through the survey that mainly lies in the areas of GBCA use, spinal cord imaging, underuse of specific MRI sequences and monitoring strategies.
Collapse
Affiliation(s)
- Jérôme Hodel
- Department of Radiology, Groupe Hospitalier Paris-Saint Joseph, Paris, France.
| | - Meike W Vernooij
- Department of Radiology and Nuclear Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Mona K Beyer
- Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | | | - Xavier Leclerc
- Department of Neuroradiology, Lille University Hospital, Lille, France
| | - Alain Créange
- Department of Neurology, AP-HP, Henri Mondor University Hospital, Université Paris Est Créteil, 4391, Creteil, EA, France
| | - Abir Wahab
- Department of Neurology, AP-HP, Henri Mondor University Hospital, Université Paris Est Créteil, 4391, Creteil, EA, France
| | - Neesmah Badat
- Department of Radiology, Groupe Hospitalier Paris-Saint Joseph, Paris, France
| | - Sarah Tolédano
- Department of Radiology, Groupe Hospitalier Paris-Saint Joseph, Paris, France
| | - Luc van den Hauwe
- Department of Radiology, Antwerp University Hospital, Antwerp, Belgium
| | - Ana Ramos
- Neuroradiology, Department of Radiology, University Hospital, 12 de Octubre, Madrid, Spain
| | - Antonella Castellano
- Neuroradiology Unit and CERMAC, IRCCS Ospedale San Raffaele and Vita-Salute San Raffaele University, 20132, Milan, Italy
| | - Alexandre Krainik
- Department of Neuroradiology, University Hospital of Grenoble, Grenoble, France
| | - Tarek Yousry
- Lysholm Department of Neuroradiology, UCLH National Hospital for Neurology and Neurosurgery, London, UK
- Neuroradiological Academic Unit, University College London Queen Square Institute of Neurology, University College London, London, UK
| | - Àlex Rovira
- Section of Neuroradiology, Department of Radiology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| |
Collapse
|
3
|
Koshkina O, Rheinberger T, Flocke V, Windfelder A, Bouvain P, Hamelmann NM, Paulusse JMJ, Gojzewski H, Flögel U, Wurm FR. Biodegradable polyphosphoester micelles act as both background-free 31P magnetic resonance imaging agents and drug nanocarriers. Nat Commun 2023; 14:4351. [PMID: 37468502 DOI: 10.1038/s41467-023-40089-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 07/12/2023] [Indexed: 07/21/2023] Open
Abstract
In vivo monitoring of polymers is crucial for drug delivery and tissue regeneration. Magnetic resonance imaging (MRI) is a whole-body imaging technique, and heteronuclear MRI allows quantitative imaging. However, MRI agents can result in environmental pollution and organ accumulation. To address this, we introduce biocompatible and biodegradable polyphosphoesters, as MRI-traceable polymers using the 31P centers in the polymer backbone. We overcome challenges in 31P MRI, including background interference and low sensitivity, by modifying the molecular environment of 31P, assembling polymers into colloids, and tailoring the polymers' microstructure to adjust MRI-relaxation times. Specifically, gradient-type polyphosphonate-copolymers demonstrate improved MRI-relaxation times compared to homo- and block copolymers, making them suitable for imaging. We validate background-free imaging and biodegradation in vivo using Manduca sexta. Furthermore, encapsulating the potent drug PROTAC allows using these amphiphilic copolymers to simultaneously deliver drugs, enabling theranostics. This first report paves the way for polyphosphoesters as background-free MRI-traceable polymers for theranostic applications.
Collapse
Affiliation(s)
- Olga Koshkina
- Sustainable Polymer Chemistry Group, Department of Molecules and Materials, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands.
| | - Timo Rheinberger
- Sustainable Polymer Chemistry Group, Department of Molecules and Materials, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Vera Flocke
- Department of Molecular Cardiology, Experimental Cardiovascular Imaging, Heinrich Heine University, Düsseldorf, Germany
| | - Anton Windfelder
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Giessen, Germany
- Laboratory of Experimental Radiology, Justus Liebig University, Giessen, Germany
| | - Pascal Bouvain
- Department of Molecular Cardiology, Experimental Cardiovascular Imaging, Heinrich Heine University, Düsseldorf, Germany
| | - Naomi M Hamelmann
- Biomolecular Nanotechnology Group, Department of Molecules and Materials, MESA+ Institute of Nanotechnology, University of Twente, Enschede, The Netherlands
| | - Jos M J Paulusse
- Biomolecular Nanotechnology Group, Department of Molecules and Materials, MESA+ Institute of Nanotechnology, University of Twente, Enschede, The Netherlands
| | - Hubert Gojzewski
- Sustainable Polymer Chemistry Group, Department of Molecules and Materials, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Ulrich Flögel
- Department of Molecular Cardiology, Experimental Cardiovascular Imaging, Heinrich Heine University, Düsseldorf, Germany.
| | - Frederik R Wurm
- Sustainable Polymer Chemistry Group, Department of Molecules and Materials, MESA+ Institute of Nanotechnology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands.
| |
Collapse
|
4
|
Colwell ZA, DelaBarre L, Idiyatullin D, Adriany G, Garwood M, Vaughan JT, Sohn SM. Standalone RF Self-Interference Cancellation System for In-Vivo Simultaneous Transmit and Receive (STAR) MRI. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2023; 17:610-620. [PMID: 37171925 PMCID: PMC10393087 DOI: 10.1109/tbcas.2023.3275849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Demonstrated is a standalone RF self-interference canceller for simultaneous transmit and receive (STAR) magnetic resonance imaging (MRI) at 1.5T. Standalone STAR cancels the leakage signal directly coupled between transmit and receive RF coils. A cancellation signal, introduced by tapping the input of a transmit coil with a power divider, is manipulated with voltage-controlled attenuators and phase shifters to match the leakage signal in amplitude, 180° out of phase, to exhibit high isolation between the transmitter and receiver. The cancellation signal is initially generated by a voltage-controlled oscillator (VCO); therefore, it does not require any external RF or synchronization signals from the MRI console for calibration. The system employs a field programmable gate array (FPGA) with an on-board analog to digital converter (ADC) to calibrate the cancellation signal by tapping the receive signal, which contains the leakage signal. Once calibrated, the VCO is disabled and the transmit signal path switches to the MRI console for STAR MR imaging. To compensate for the changes of parameters in RF sequences after the automatic calibration and to further improve isolation, a wireless user board that uses an ESP32 microcontroller was built to communicate with the FPGA for final fine-tuning of the output state. The standalone STAR system achieved 74.2 dB of isolation with a 94 second calibration time. With such high isolation, in-vivo MR images were obtained with approximately 40 mW of RF peak power.
Collapse
|
5
|
Johannsen KM, de Carvalho E Silva Fuglsig JM, Hansen B, Wenzel A, Spin-Neto R. Magnetic resonance imaging artefacts caused by orthodontic appliances and/or implant-supported prosthesis: a systematic review. Oral Radiol 2023; 39:394-407. [PMID: 36178613 DOI: 10.1007/s11282-022-00652-9] [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: 06/23/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022]
Abstract
OBJECTIVES Dental materials, including orthodontic appliances and implants, are commonly mentioned as a possible source of artefacts in magnetic resonance imaging (MRI). The aim of the present study was to undertake a systematic review of the relevant literature on MR image artefacts due to dental materials, limited to orthodontic appliances and implant-supported dental prosthesis, on both technical and diagnostic levels. METHODS The MEDLINE (PubMed) bibliographic database was searched up to September 2020. The search was limited to studies published in English, using the search string: (MRI or magnetic resonance) and (artefact or artifact) and (dental or ortho or implant or restoration or restorative). The studies were assessed independently by three reviewers, focusing on the following parameters: MRI sequences, tested materials, assessed parameters, efficacy level and outcome. RESULTS The search strategy yielded 31 studies, which were included in this systematic review. These studies showed that metallic dental materials, commonly present in orthodontic appliances and implant-supported dental prosthesis led to diverse types/severities of artefacts in MR images. Fifteen studies were in vivo, based on human subjects. The studies differed substantially in terms of tested materials, assessed parameters, and outcome measurements. CONCLUSIONS Metallic dental materials cause artefacts of diverse types and severities in MR images of the head and neck region. However, the diagnostic relevance of the investigated artefacts for the diverse MRI applications is yet to be studied.
Collapse
Affiliation(s)
- Katrine Mølgaard Johannsen
- Department of Dentistry and Oral Health, Oral Radiology, Aarhus University, Vennelyst Boulevard 9, 8000, Aarhus, Denmark.
| | | | - Brian Hansen
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Ann Wenzel
- Department of Dentistry and Oral Health, Oral Radiology, Aarhus University, Vennelyst Boulevard 9, 8000, Aarhus, Denmark
| | - Rubens Spin-Neto
- Department of Dentistry and Oral Health, Oral Radiology, Aarhus University, Vennelyst Boulevard 9, 8000, Aarhus, Denmark
| |
Collapse
|
6
|
Yoshida R, Machida Y. Modulation transfer function measurement of three-dimensional T 1-weighted turbo spin echo sequence with low refocusing flip angles using single-plate method. Radiol Phys Technol 2023; 16:346-353. [PMID: 36966438 DOI: 10.1007/s12194-023-00711-8] [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: 10/03/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/27/2023]
Abstract
This study aimed to demonstrate the usefulness of modulation transfer function (MTF) measurements using the single-plate method to evaluate changes in resolution properties that are dependent on three parameters: echo train length (ETL), low refocusing flip angle (RFA), and start-up echo in three-dimensional T1-weighted turbo spin echoes (TSE) with a low RFA and to optimize these parameters. Although the MTFs were slightly degraded with an RFA of 120°, they were considerably degraded with an RFA of ≤ 90°. On the other hand, the MTF of low RFA was greatly improved by setting the start-up echo, allowing setting a long ETL. The single-plate method provided a clear and easy evaluation of the resolution properties of low RFA TSE. Furthermore, this method allows us to visualize changes in the signal intensity of each echo in k-space, depending on the sequence variation. These results suggest that the MTF measurement using the single-plate method is useful for evaluating the resolution properties of TSE sequences and optimizing the measured parameters.
Collapse
Affiliation(s)
- Rei Yoshida
- Department of Radiology, Kurihara Central Hospital, 3-1-1 Miyano Chuo, Tsukidate, Kurihara, Miyagi, 987-2205, Japan.
- Health Sciences, Tohoku University Graduate School of Medicine, 2‑1 Seiryo‑machi, Aoba‑ku, Sendai, Miyagi, 980‑8575, Japan.
| | - Yoshio Machida
- Health Sciences, Tohoku University Graduate School of Medicine, 2‑1 Seiryo‑machi, Aoba‑ku, Sendai, Miyagi, 980‑8575, Japan
| |
Collapse
|
7
|
Aebischer K, Ernst M. Echo modulations under homonuclear decoupling. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 347:107360. [PMID: 36563419 DOI: 10.1016/j.jmr.2022.107360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 12/08/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
A simple Hahn echo in a single-spin system with a static Hamiltonian can lead to echo modulations if the static Hamiltonian contains a component along the direction of the echo pulse. These modulations manifest as side bands in the Fourier transform of the echo decay. Experimentally, echo modulations that can be explained by such a model have been observed under homonuclear decoupling in solids where pulse imperfections can lead to residual effective fields in the interaction frame that have arbitrary orientations in space. We show analytically that such echo modulations are significantly reduced in intensity using double-echo sequences in agreement with experimental observations. Using pulse shapes for homonuclear decoupling that mimic and amplify the pulse distortions expected from pulse transients, we show that these effective fields can be one explanation for the observed reduction in echo modulations going from a single to a double Hahn-echo sequence.
Collapse
Affiliation(s)
- Kathrin Aebischer
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland
| | - Matthias Ernst
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland.
| |
Collapse
|
8
|
Cluceru J, Lupo JM, Interian Y, Bove R, Crane JC. Improving the Automatic Classification of Brain MRI Acquisition Contrast with Machine Learning. J Digit Imaging 2023; 36:289-305. [PMID: 35941406 PMCID: PMC9984597 DOI: 10.1007/s10278-022-00690-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 06/22/2022] [Accepted: 07/22/2022] [Indexed: 10/15/2022] Open
Abstract
Automated quantification of data acquired as part of an MRI exam requires identification of the specific acquisition of relevance to a particular analysis. This motivates the development of methods capable of reliably classifying MRI acquisitions according to their nominal contrast type, e.g., T1 weighted, T1 post-contrast, T2 weighted, T2-weighted FLAIR, proton-density weighted. Prior studies have investigated using imaging-based methods and DICOM metadata-based methods with success on cohorts of patients acquired as part of a clinical trial. This study compares the performance of these methods on heterogeneous clinical datasets acquired with many different scanners from many institutions. RF and CNN models were trained on metadata and pixel data, respectively. A combined RF model incorporated CNN logits from the pixel-based model together with metadata. Four cohorts were used for model development and evaluation: MS research (n = 11,106 series), MS clinical (n = 3244 series), glioma research (n = 612 series, test/validation only), and ADNI PTSD (n = 477 series, training only). Together, these cohorts represent a broad range of acquisition contexts (scanners, sequences, institutions) and subject pathologies. Pixel-based CNN and combined models achieved accuracies between 97 and 98% on the clinical MS cohort. Validation/test accuracies with the glioma cohort were 99.7% (metadata only) and 98.4 (CNN). Accurate and generalizable classification of MRI acquisition contrast types was demonstrated. Such methods are important for enabling automated data selection in high-throughput and big-data image analysis applications.
Collapse
Affiliation(s)
- Julia Cluceru
- Center for Intelligent Imaging, Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA
| | - Janine M Lupo
- Center for Intelligent Imaging, Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA
| | - Yannet Interian
- MS in Analytics Program, University of San Francisco, San Francisco, CA, USA
| | - Riley Bove
- Department of Neurology, MS and Neuroinflammation Clinic, University of California San Francisco, San Francisco, CA, USA
- Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
| | - Jason C Crane
- Center for Intelligent Imaging, Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
| |
Collapse
|
9
|
MacKinnon MJ, Wang TWW, Shih YYI. Mouse Brain MRI: Including In Vivo, Ex Vivo, and fcMRI for the Study of Microcephaly. Methods Mol Biol 2023; 2583:129-148. [PMID: 36418731 DOI: 10.1007/978-1-0716-2752-5_12] [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] [Indexed: 11/24/2022]
Abstract
With its sensitivity to soft tissue, MRI is a powerful tool for the study of the neuroanatomical manifestations of a variety of conditions, such as microcephaly-related morbidities that are not easily visualized by other imaging techniques, such as CT. In addition to structural imaging, more recently, researchers have found changes in brain function in a wide range of neurological conditions-highlighting the utility of MRI for the study of microcephaly.In this methods chapter, basic mouse preparation and the acquisition of data for in vivo anatomical MRI will be discussed. Additionally, we will provide our protocol for the perfusion and fixation of brain tissue with gadolinium contrast agent. Following that, the process of optimization of system parameters will be shown for anatomical imaging of in vivo and ex vivo brain tissue. Lastly, the chapter will detail a protocol for fcMRI along with a discussion of considerations specific to functional imaging.
Collapse
Affiliation(s)
- Martin J MacKinnon
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tzu-Wen W Wang
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yen-Yu I Shih
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| |
Collapse
|
10
|
Nicastro M, Jeurissen B, Beirinckx Q, Smekens C, Poot DHJ, Sijbers J, den Dekker AJ. To shift or to rotate? Comparison of acquisition strategies for multi-slice super-resolution magnetic resonance imaging. Front Neurosci 2022; 16:1044510. [PMID: 36440272 PMCID: PMC9694825 DOI: 10.3389/fnins.2022.1044510] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/18/2022] [Indexed: 07/27/2023] Open
Abstract
Multi-slice (MS) super-resolution reconstruction (SRR) methods have been proposed to improve the trade-off between resolution, signal-to-noise ratio and scan time in magnetic resonance imaging. MS-SRR consists in the estimation of an isotropic high-resolution image from a series of anisotropic MS images with a low through-plane resolution, where the anisotropic low-resolution images can be acquired according to different acquisition schemes. However, it is yet unclear how these schemes compare in terms of statistical performance criteria, especially for regularized MS-SRR. In this work, the estimation performance of two commonly adopted MS-SRR acquisition schemes based on shifted and rotated MS images respectively are evaluated in a Bayesian framework. The maximum a posteriori estimator, which introduces regularization by incorporating prior knowledge in a statistically well-defined way, is put forward as the estimator of choice and its accuracy, precision, and Bayesian mean squared error (BMSE) are used as performance criteria. Analytic calculations as well as Monte Carlo simulation experiments show that the rotated scheme outperforms the shifted scheme in terms of precision, accuracy, and BMSE. Furthermore, the superior performance of the rotated scheme is confirmed in real data experiments and in retrospective simulation experiments with and without inter-image motion. Results show that the rotated scheme allows regularized MS-SRR with a higher accuracy and precision than the shifted scheme, besides being more resilient to motion.
Collapse
Affiliation(s)
- Michele Nicastro
- imec-Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Ben Jeurissen
- imec-Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- Lab for Equilibrium Investigations and Aerospace, Department of Physics, University of Antwerp, Antwerp, Belgium
| | - Quinten Beirinckx
- imec-Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Céline Smekens
- imec-Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- Siemens Healthcare NV/SA, Groot-Bijgaarden, Belgium
| | - Dirk H. J. Poot
- Biomedical Imaging Group Rotterdam, Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands
| | - Jan Sijbers
- imec-Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Arnold J. den Dekker
- imec-Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| |
Collapse
|
11
|
You S, Reyes M. Influence of contrast and texture based image modifications on the performance and attention shift of U-Net models for brain tissue segmentation. FRONTIERS IN NEUROIMAGING 2022; 1:1012639. [PMID: 37555149 PMCID: PMC10406260 DOI: 10.3389/fnimg.2022.1012639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/12/2022] [Indexed: 08/10/2023]
Abstract
Contrast and texture modifications applied during training or test-time have recently shown promising results to enhance the generalization performance of deep learning segmentation methods in medical image analysis. However, a deeper understanding of this phenomenon has not been investigated. In this study, we investigated this phenomenon using a controlled experimental setting, using datasets from the Human Connectome Project and a large set of simulated MR protocols, in order to mitigate data confounders and investigate possible explanations as to why model performance changes when applying different levels of contrast and texture-based modifications. Our experiments confirm previous findings regarding the improved performance of models subjected to contrast and texture modifications employed during training and/or testing time, but further show the interplay when these operations are combined, as well as the regimes of model improvement/worsening across scanning parameters. Furthermore, our findings demonstrate a spatial attention shift phenomenon of trained models, occurring for different levels of model performance, and varying in relation to the type of applied image modification.
Collapse
Affiliation(s)
- Suhang You
- Medical Image Analysis Group, ARTORG, Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | | |
Collapse
|
12
|
Blind image quality assessment of magnetic resonance images with statistics of local intensity extrema. Inf Sci (N Y) 2022. [DOI: 10.1016/j.ins.2022.05.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
13
|
Lachowicz D, Stroud J, Hankiewicz JH, Gassen R, Kmita A, Stepień J, Celinski Z, Sikora M, Zukrowski J, Gajewska M, Przybylski M. One-Step Preparation of Highly Stable Copper-Zinc Ferrite Nanoparticles in Water Suitable for MRI Thermometry. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2022; 34:4001-4018. [PMID: 35573108 PMCID: PMC9097161 DOI: 10.1021/acs.chemmater.2c00079] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/01/2022] [Indexed: 05/03/2023]
Abstract
Superparamagnetic ferrite nanoparticles coated with a polymer layer are widely used for biomedical applications. The objective of this work is to design nanoparticles as a magnetic resonance imaging (MRI) temperature-sensitive contrast agent. Copper-zinc ferrite nanoparticles coated with a poly(ethylene glycol) (PEG) layer are synthesized using a one-step thermal decomposition method in a polymer matrix. The resulting nanoparticles are stable in water and biocompatible. Using Mössbauer spectroscopy and magnetometry, it was determined that the grown nanoparticles exhibit superparamagnetic properties. Embedding these particles into an agarose gel resulted in significant modification of water proton relaxation times T 1, T 2, and T 2* determined by nuclear magnetic resonance measurements. The results of the spin-echo T 2-weighted MR images of an aqueous phantom with embedded Cu0.08Zn0.54Fe2.38O4 nanoparticles in the presence of a strong temperature gradient show a strong correlation between the temperature and the image intensity. The presented results support the hypothesis that CuZn ferrite nanoparticles can be used as a contrast agent for MRI thermometry.
Collapse
Affiliation(s)
- Dorota Lachowicz
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - John Stroud
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - Janusz H. Hankiewicz
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - River Gassen
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - Angelika Kmita
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Joanna Stepień
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Zbigniew Celinski
- Center
for the Biofrontiers Institute, University of Colorado Colorado Springs, 1420 Austin Bluffs Pkway, Colorado Springs, Colorado 80918, United States
| | - Marcin Sikora
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Jan Zukrowski
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Marta Gajewska
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
| | - Marek Przybylski
- Academic
Centre for Materials and Nanotechnology, AGH University of Science
and Technology, 30-059 Krakow, Poland
- Faculty
of Physics and Applied Computer Science, AGH University of Science
and Technology, 30-059 Krakow, Poland
| |
Collapse
|
14
|
Dual-Echo Turbo Spin Echo and 12-Echo Multi Spin Echo Sequences as Equivalent Techniques for Obtaining T2-Relaxometry Data: Application in Symptomatic and Asymptomatic Hereditary Transthyretin Amyloidosis as a Surrogate Disease. Invest Radiol 2022; 57:301-307. [PMID: 34839307 DOI: 10.1097/rli.0000000000000837] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVES Multi spin echo (MSE) sequences are often used for obtaining T2-relaxometry data as they provide defined echo times (TEs). Due to their time-consuming acquisition, they are frequently replaced by turbo spin echo (TSE) sequences that in turn bear the risk of systematic errors when analyzing small structures or lesions. With this study, we aim to test whether T2-relaxometry data derived from either dual-echo TSE or 12-echo MSE sequences are equivalent for quantifying peripheral nerve lesions. Hereditary transthyretin (ATTRv) amyloidosis was chosen as a surrogate disease, as it allows the inclusion of both asymptomatic carriers of the underlying variant transthyretin gene (varTTR) and symptomatic ATTRv amyloidosis patients. MATERIALS AND METHODS Overall, 50 participants with genetically confirmed varTTR (20 clinically symptomatic ATTRv amyloidosis; 4 females, 16 males; mean age, 61.8 years; range, 33-76 years; and 30 asymptomatic varTTR-carriers; 18 females, 12 males; mean age, 43.1 years; range, 21-62 years), and 30 healthy volunteers (13 females, 17 males, mean age 41.3 years, range 22-73) were prospectively included and underwent magnetic resonance neurography at 3 T. T2-relaxometry was performed by acquiring an axial 2-dimensional dual-echo TSE sequence with spectral fat saturation (TE1/TE2, 12/73 milliseconds; TR, 5210 milliseconds; acquisition time, 7 minutes, 30 seconds), and an axial 2-dimensional MSE sequence with spectral fat saturation and with 12 different TE (TE1, 10 milliseconds to TE12, 120 milliseconds; ΔTE, 10 milliseconds; TR, 3000 milliseconds; acquisition time, 11 minutes, 23 seconds) at the right mid to lower thigh. Sciatic nerve regions of interest were manually drawn in ImageJ on 10 central slices per participant and sequence, and the apparent T2-relaxation time (T2app) and proton spin density (ρ) were calculated individually from TSE and MSE relaxometry data. RESULTS Linear regression showed that T2app values obtained from the dual-echo TSE (T2appTSE), and those calculated from the 12-echo MSE (T2appMSE) were mathematically connected by a factor of 1.3 throughout all groups (controls: 1.26 ± 0.02; varTTR-carriers: 1.25 ± 0.02; symptomatic ATTRv amyloidosis: 1.28 ± 0.02), whereas a factor of 0.5 was identified between respective ρ values (controls: 0.47 ± 0.01; varTTR-carriers: 0.47 ± 0.01; symptomatic ATTRv amyloidosis: 0.50 ± 0.02). T2app calculated from both TSE and MSE, distinguished between symptomatic ATTRv (T2appTSE 66.38 ± 2.6; T2appMSE 84.6 ± 3.3) and controls (T2appTSE 58.1 ± 1.0, P = 0.0028; T2appMSE 72.8 ± 0.7, P < 0.0001), whereas differences between varTTR-carriers (T2appTSE 61.8 ± 1.5; T2appMSE 76.7 ± 1.3) and ATTRv amyloidosis were observed only for T2appMSE (P = 0.0082). The ρ value differentiated well between healthy controls (ρTSE 365.1 ± 7.2; ρMSE 170.4 ± 3.8) versus varTTR-carriers (ρTSE 415.7 ± 9.8, P = 0.0027; ρMSE 193.7 ± 5.3, P = 0.0398) and versus symptomatic ATTRv amyloidosis (ρTSE 487.8 ± 17.9; ρMSE 244.7 ± 13.1, P < 0.0001, respectively), but also between varTTR-carriers and ATTRv amyloidosis (ρTSEP = 0.0001; ρMSEP < 0.0001). CONCLUSIONS Dual-echo TSE and 12-echo MSE sequences provide equally robust and reliable T2-relaxometry data when calculating T2app and ρ. Due to their shorter acquisition time and higher resolution, TSE sequences may be preferred in future magnetic resonance imaging protocols. As a secondary result, ρ can be confirmed as a sensitive biomarker to detect early nerve lesions as it differentiated best among healthy controls, asymptomatic varTTR-carriers, and symptomatic ATTRv amyloidosis, whereas T2app might be beneficial in already manifest ATTRv amyloidosis.
Collapse
|
15
|
Effect of Matrix Size Reduction on Textural Information in Clinical Magnetic Resonance Imaging. J Clin Med 2022; 11:jcm11092526. [PMID: 35566657 PMCID: PMC9103884 DOI: 10.3390/jcm11092526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/12/2022] [Accepted: 04/26/2022] [Indexed: 12/10/2022] Open
Abstract
The selection of the matrix size is an important element of the magnetic resonance imaging (MRI) process, and has a significant impact on the acquired image quality. Signal to noise ratio, often used to assess MR image quality, has its limitations. Thus, for this purpose we propose a novel approach: the use of texture analysis as an index of the image quality that is sensitive for the change of matrix size. Image texture in biomedical images represents tissue and organ structures visualized via medical imaging modalities such as MRI. The correlation between texture parameters determined for the same tissues visualized in images acquired with different matrix sizes is analyzed to aid in the assessment of the selection of the optimal matrix size. T2-weighted coronal images of shoulders were acquired using five different matrix sizes while maintaining the same field of view; three regions of interest (bone, fat, and muscle) were considered. Lin’s correlation coefficients were calculated for all possible pairs of the 310-element texture feature vectors evaluated for each matrix. The obtained results are discussed considering the image noise and blurring effect visible in images acquired with smaller matrices. Taking these phenomena into account, recommendations for the selection of the matrix size used for the MRI imaging were proposed.
Collapse
|
16
|
Diffusion-Weighted MRI in the Genitourinary System. J Clin Med 2022; 11:jcm11071921. [PMID: 35407528 PMCID: PMC9000195 DOI: 10.3390/jcm11071921] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 12/12/2022] Open
Abstract
Diffusion weighted imaging (DWI) constitutes a major functional parameter performed in Magnetic Resonance Imaging (MRI). The DW sequence is performed by acquiring a set of native images described by their b-values, each b-value representing the strength of the diffusion MR gradients specific to that sequence. By fitting the data with models describing the motion of water in tissue, an apparent diffusion coefficient (ADC) map is built and allows the assessment of water mobility inside the tissue. The high cellularity of tumors restricts the water diffusion and decreases the value of ADC within tumors, which makes them appear hypointense on ADC maps. The role of this sequence now largely exceeds its first clinical apparitions in neuroimaging, whereby the method helped diagnose the early phases of cerebral ischemic stroke. The applications extend to whole-body imaging for both neoplastic and non-neoplastic diseases. This review emphasizes the integration of DWI in the genitourinary system imaging by outlining the sequence's usage in female pelvis, prostate, bladder, penis, testis and kidney MRI. In gynecologic imaging, DWI is an essential sequence for the characterization of cervix tumors and endometrial carcinomas, as well as to differentiate between leiomyosarcoma and benign leiomyoma of the uterus. In ovarian epithelial neoplasms, DWI provides key information for the characterization of solid components in heterogeneous complex ovarian masses. In prostate imaging, DWI became an essential part of multi-parametric Magnetic Resonance Imaging (mpMRI) to detect prostate cancer. The Prostate Imaging-Reporting and Data System (PI-RADS) scoring the probability of significant prostate tumors has significantly contributed to this success. Its contribution has established mpMRI as a mandatory examination for the planning of prostate biopsies and radical prostatectomy. Following a similar approach, DWI was included in multiparametric protocols for the bladder and the testis. In renal imaging, DWI is not able to robustly differentiate between malignant and benign renal tumors but may be helpful to characterize tumor subtypes, including clear-cell and non-clear-cell renal carcinomas or low-fat angiomyolipomas. One of the most promising developments of renal DWI is the estimation of renal fibrosis in chronic kidney disease (CKD) patients. In conclusion, DWI constitutes a major advancement in genitourinary imaging with a central role in decision algorithms in the female pelvis and prostate cancer, now allowing promising applications in renal imaging or in the bladder and testicular mpMRI.
Collapse
|
17
|
Del Grande F, Hinterholzer N, Nanz D. 3D MRI: Technical Considerations and Practical Integration. Semin Musculoskelet Radiol 2021; 25:381-387. [PMID: 34547803 DOI: 10.1055/s-0041-1731059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
One of the main advantages of three-dimensional (3D) magnetic resonance imaging (MRI) is the possibility of isotropic voxels and reconstructed planar cuts through the volumetric data set in any orientation with multiplanar reformation software through real-time evaluation. For example, reformats by the radiologist during reporting allows exploitation of the full potential of isotropic 3D volumetric acquisition or through standardized retrospective reformats of thicker predefined slices of an isotropic volumetric data set by technologists. The main challenges for integrating 3D fast spin echo (FSE) and turbo spin-echo (TSE) MRI in clinical practice are a long acquisition time and some artifacts, whereas for integrating 3D gradient-recalled echo protocols, the main challenges are lower signal-to-noise ratios (SNRs) and the inability to produce intermediate, and T2-weighted contrast. The implementation of bidirectional parallel imaging acquisition and random undersampling acceleration strategies of 3D TSE pulse sequences substantially shortens the examination time with only minor SNR reductions. This article provides an overview of general technical considerations of 3D FSE and TSE sequences in musculoskeletal MRI. It also describes how these sequences achieve efficient data acquisition and reviews the main advantages and challenges for their introduction to clinical practice.
Collapse
Affiliation(s)
- Filippo Del Grande
- Clinica di Radiologia EOC, Istituto di Imaging della Svizzera Italiana (IIMSI), Lugano, Svizzera
| | - Natalie Hinterholzer
- SCMI, Swiss Center for Musculoskeletal Imaging, Balgrist Campus AG, Zürich, Switzerland
| | - Daniel Nanz
- SCMI, Swiss Center for Musculoskeletal Imaging, Balgrist Campus AG, Zürich, Switzerland.,University of Zürich, Zürich, Switzerland
| |
Collapse
|
18
|
Edelman R, Leloudas N, Pang J, Bailes J, Merrell R, Koktzoglou I. Twofold improved tumor-to-brain contrast using a novel T1 relaxation-enhanced steady-state (T 1RESS) MRI technique. SCIENCE ADVANCES 2020; 6:6/44/eabd1635. [PMID: 33115747 PMCID: PMC7608787 DOI: 10.1126/sciadv.abd1635] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
A technique that provides more accurate cancer detection would be of great value. Toward this end, we developed T1 relaxation-enhanced steady-state (T1RESS), a novel magnetic resonance imaging (MRI) pulse sequence that enables the flexible modulation of T1 weighting and provides the unique feature that intravascular signals can be toggled on and off in contrast-enhanced scans. T1RESS makes it possible to effectively use an MRI technique with improved signal-to-noise ratio efficiency for cancer imaging. In a proof-of-concept study, "dark blood" unbalanced T1RESS provided a twofold improvement in tumor-to-brain contrast compared with standard techniques, whereas balanced T1RESS greatly enhanced vascular detail. In conclusion, T1RESS represents a new MRI technique with substantial potential value for cancer imaging, along with a broad range of other clinical applications.
Collapse
Affiliation(s)
- R Edelman
- Radiology, NorthShore University HealthSystem, 2650 Ridge Ave., Evanston, IL 60201, USA.
- Northwestern Medicine, 251 E. Huron St., Chicago, IL 60611, USA
| | - N Leloudas
- Radiology, NorthShore University HealthSystem, 2650 Ridge Ave., Evanston, IL 60201, USA
| | - J Pang
- Siemens Medical Solutions USA Inc., 737 N. Michigan Ave., Chicago, IL 60611, USA
| | - J Bailes
- University of Chicago Pritzker School of Medicine, 924 E. 57th St., Chicago, IL 60637, USA
- Neurosurgery, NorthShore University HealthSystem, 2650 Ridge Ave., Evanston, IL 60201, USA
| | - R Merrell
- University of Chicago Pritzker School of Medicine, 924 E. 57th St., Chicago, IL 60637, USA
- Neurology, NorthShore University HealthSystem, 2650 Ridge Ave., Evanston, IL 60201, USA
| | - I Koktzoglou
- Radiology, NorthShore University HealthSystem, 2650 Ridge Ave., Evanston, IL 60201, USA
- University of Chicago Pritzker School of Medicine, 924 E. 57th St., Chicago, IL 60637, USA
| |
Collapse
|
19
|
Benzakoun J, Robert C, Legrand L, Pallud J, Meder JF, Oppenheim C, Dhermain F, Edjlali M. Anatomical and functional MR imaging to define tumoral boundaries and characterize lesions in neuro-oncology. Cancer Radiother 2020; 24:453-462. [PMID: 32278653 DOI: 10.1016/j.canrad.2020.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/04/2020] [Indexed: 12/19/2022]
Abstract
Neuroimaging and especially MRI has emerged as a necessary imaging modality to detect, measure, characterize and monitor brain tumours. Advanced MRI sequences such as perfusion MRI, diffusion MRI and spectroscopy as well as new post-processing techniques such as automatic segmentation of tumours and radiomics play a crucial role in characterization and follow up of brain tumours. The purpose of this review is to provide an overview on anatomical and functional MRI use for brain tumours boundaries determination and tumour characterization in the specific context of radiotherapy. The usefulness of anatomical and functional MRI on particular challenges posed by radiotherapy such as pseudo progression and pseudo esponse and new treatment strategies such as dose painting is also described.
Collapse
Affiliation(s)
- J Benzakoun
- Radiology Department, GHU de Paris, centre hospitalier Sainte-Anne, 1, rue Cabanis, 75014 Paris, France; Université de Paris, 85, boulevard Saint-Germain, 75006 Paris, France; Imabrain, Institut de psychiatrie et neurosciences de Paris (IPNP), 102-108, rue de la Santé, 75014 Paris, France; Inserm, U1266, 102, rue de la Santé, 75013 Paris, France.
| | - C Robert
- Medical Physics Department, Gustave-Roussy, 114, rue Édouard-Vaillant, 94805 Villejuif, France; Molecular Radiotherapy, Gustave-Roussy, 114, rue Édouard-Vaillant, 94805 Villejuif, France; Inserm, 114, rue Édouard-Vaillant, 94805 Villejuif, France; Paris-Sud University, Paris-Saclay University, 114, rue Édouard-Vaillant, 94805 Villejuif, France
| | - L Legrand
- Radiology Department, GHU de Paris, centre hospitalier Sainte-Anne, 1, rue Cabanis, 75014 Paris, France; Université de Paris, 85, boulevard Saint-Germain, 75006 Paris, France; Imabrain, Institut de psychiatrie et neurosciences de Paris (IPNP), 102-108, rue de la Santé, 75014 Paris, France; Inserm, U1266, 102, rue de la Santé, 75013 Paris, France
| | - J Pallud
- Université de Paris, 85, boulevard Saint-Germain, 75006 Paris, France; Imabrain, Institut de psychiatrie et neurosciences de Paris (IPNP), 102-108, rue de la Santé, 75014 Paris, France; Inserm, U1266, 102, rue de la Santé, 75013 Paris, France; Neurosurgery Department, GHU de Paris, centre hospitalier Sainte-Anne, 1, rue Cabanis, 75014 Paris, France
| | - J-F Meder
- Radiology Department, GHU de Paris, centre hospitalier Sainte-Anne, 1, rue Cabanis, 75014 Paris, France; Université de Paris, 85, boulevard Saint-Germain, 75006 Paris, France; Imabrain, Institut de psychiatrie et neurosciences de Paris (IPNP), 102-108, rue de la Santé, 75014 Paris, France; Inserm, U1266, 102, rue de la Santé, 75013 Paris, France
| | - C Oppenheim
- Radiology Department, GHU de Paris, centre hospitalier Sainte-Anne, 1, rue Cabanis, 75014 Paris, France; Université de Paris, 85, boulevard Saint-Germain, 75006 Paris, France; Imabrain, Institut de psychiatrie et neurosciences de Paris (IPNP), 102-108, rue de la Santé, 75014 Paris, France; Inserm, U1266, 102, rue de la Santé, 75013 Paris, France
| | - F Dhermain
- Radiotherapy Department, Gustave-Roussy, 114, rue Édouard-Vaillant, 94805 Villejuif, France
| | - M Edjlali
- Radiology Department, GHU de Paris, centre hospitalier Sainte-Anne, 1, rue Cabanis, 75014 Paris, France; Université de Paris, 85, boulevard Saint-Germain, 75006 Paris, France; Imabrain, Institut de psychiatrie et neurosciences de Paris (IPNP), 102-108, rue de la Santé, 75014 Paris, France; Inserm, U1266, 102, rue de la Santé, 75013 Paris, France
| |
Collapse
|
20
|
Krachkovskiy S, Trudeau ML, Zaghib K. Application of Magnetic Resonance Techniques to the In Situ Characterization of Li-Ion Batteries: A Review. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E1694. [PMID: 32260435 PMCID: PMC7178659 DOI: 10.3390/ma13071694] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 12/02/2022]
Abstract
In situ magnetic resonance (MR) techniques, such as nuclear MR and MR imaging, have recently gained significant attention in the battery community because of their ability to provide real-time quantitative information regarding material chemistry, ion distribution, mass transport, and microstructure formation inside an operating electrochemical cell. MR techniques are non-invasive and non-destructive, and they can be applied to both liquid and solid (crystalline, disordered, or amorphous) samples. Additionally, MR equipment is available at most universities and research and development centers, making MR techniques easily accessible for scientists worldwide. In this review, we will discuss recent research results in the field of in situ MR for the characterization of Li-ion batteries with a particular focus on experimental setups, such as pulse sequence programming and cell design, for overcoming the complications associated with the heterogeneous nature of energy storage devices. A comprehensive approach combining proper hardware and software will allow researchers to collect reliable high-quality data meeting industrial standards.
Collapse
Affiliation(s)
| | | | - Karim Zaghib
- Center of Excellence in Transportation, Electrification and Energy Storage, Hydo-Québec, 1806 Bd. Lionel-Boulet, Varennes, QC J3X 1S1, Canada; (S.K.); (M.L.T.)
| |
Collapse
|
21
|
Dong SZ, Zhu M, Bulas D. Techniques for minimizing sedation in pediatric MRI. J Magn Reson Imaging 2019; 50:1047-1054. [PMID: 30869831 DOI: 10.1002/jmri.26703] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/17/2019] [Accepted: 02/19/2019] [Indexed: 12/16/2022] Open
Abstract
MRI is used widely in infants and young children. However, in these young cases deep sedation or general anesthesia is often required to minimize motion artifacts during MRI examinations. Although the benefits of MR typically outweigh the potential risks of sedation when delivered by an experienced team, there are increasing concerns regarding the affect of sedation on young children. There continues to be a push to develop various strategies that can minimize the need for sedation. The present review summarizes several technical and clinical approaches that can help decrease the need for sedation in the pediatric patient. Optimization of the MRI environment, the role of child life specialists, feed-and-bundle and distraction techniques, noise-reduction methods, artificial intelligence, and MRI advances to decrease both scan times and motion artifacts will be discussed. Level of Evidence: 5 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019.
Collapse
Affiliation(s)
- Su-Zhen Dong
- Department of Radiology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Diagnostic Imaging and Radiology, Children's National Health Systems, Washington, DC, USA
| | - Ming Zhu
- Department of Radiology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Dorothy Bulas
- Department of Diagnostic Imaging and Radiology, Children's National Health Systems, Washington, DC, USA
| |
Collapse
|
22
|
Abstract
The inversion of inhomogeneous physical states has great technological importance; for example, active noise reduction relies on the emission of an inverted sound wave that interferes destructively with the noise of the emitter1, and inverting the evolution of a spin system by using a magnetic-field pulse enables magnetic resonance tomography2. In contrast to these examples, inversion of a distribution of ferromagnetic or ferroelectric domains within a material is surprisingly difficult: field poling creates a single-domain state, and piece-by-piece inversion using a scanning tip is impractical. Here we report inversion of entire ferromagnetic and ferroelectric domain patterns in the magnetoelectric material Co3TeO6 and the multiferroic material Mn2GeO4, respectively. In these materials, an applied magnetic field reverses the magnetization or polarization, respectively, of each domain, but leaves the domain pattern intact. Landau theory indicates that this type of magnetoelectric inversion is universal across materials that exhibit complex ordering, with one order parameter holding the memory of the domain structure and another setting its overall sign. Domain-pattern inversion is only one example of a previously unnoticed effect in systems such as multiferroics, in which several order parameters are available for combination. Exploring these effects could therefore advance multiferroics towards new levels of functionality.
Collapse
|
23
|
Vassiliou VS, Cameron D, Prasad SK, Gatehouse PD. Magnetic resonance imaging: Physics basics for the cardiologist. JRSM Cardiovasc Dis 2018; 7:2048004018772237. [PMID: 30128147 PMCID: PMC6093143 DOI: 10.1177/2048004018772237] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/23/2018] [Accepted: 03/21/2018] [Indexed: 12/31/2022] Open
Abstract
Magnetic resonance imaging physics can be a complex and challenging topic for the practising cardiologist. Its evolving nature and the increasing number of novel sequences used in clinical scanning have been topics of excellent reviews; however, the basic understanding of physics underlying the creation of images remains difficult for many cardiologists. In this review, we go back to the basic physics theories underpinning magnetic resonance and explain their application and use in achieving good quality cardiac imaging, whilst describing established and novel magnetic resonance sequences. By understanding these basic principles, it is anticipated that cardiologists and other health professionals will then appreciate more advanced physics manuscripts on cardiac scanning and novel sequences.
Collapse
Affiliation(s)
- Vassilios S Vassiliou
- Royal Brompton Hospital and Imperial College London, CMR Unit, London, UK.,Norwich Medical School, University of East Anglia, Bob Champion Research and Education, Norwich, UK
| | - Donnie Cameron
- Norwich Medical School, University of East Anglia, Bob Champion Research and Education, Norwich, UK
| | - Sanjay K Prasad
- Royal Brompton Hospital and Imperial College London, CMR Unit, London, UK
| | - Peter D Gatehouse
- Royal Brompton Hospital and Imperial College London, CMR Unit, London, UK
| |
Collapse
|
24
|
Fast, free-breathing and motion-minimized techniques for pediatric body magnetic resonance imaging. Pediatr Radiol 2018; 48:1197-1208. [PMID: 30078042 DOI: 10.1007/s00247-018-4116-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/26/2018] [Accepted: 03/11/2018] [Indexed: 12/26/2022]
Abstract
Magnetic resonance imaging (MRI) is the preferred imaging modality in children with complex medical issues. Patient motion and respiration remain major challenges in pediatric abdominal MRI. Young children ages 3 months to 6 years are unable to cooperate or perform breath-holding and frequently require deep sedation or general anesthesia to undergo MRI. Given the growing concerns associated with the use of sedation and anesthesia as well as the adverse impact on workflow, developing and implementing fast and motion-resistant MRI sequences are of great interest. Fast sequences such as single-shot fast spin echo and balanced steady-state free precession are useful as quick anatomical surveys on routine abdominal MRI. The widespread utilization of parallel imaging and sequences with radial k-space sampling has contributed to decreasing scan time and improving image quality, respectively. Newer strategies including compressed sensing, simultaneous multi-slice acquisition, and hybrid approaches hold the prospect of faster image acquisition that could significantly reduce the need for sedation in this vulnerable population and decrease the time of anesthesia in cases where it is indicated.
Collapse
|
25
|
Abstract
Clinical magnetic resonance imaging (MRI) offers a multitude of different techniques with which anatomical, functional and metabolic information can be gained. The technical basis of an MRI method is the so-called pulse sequence, which determines the manner in which data is acquired. Pulse sequences are differentiated between gradient and spin echo sequences. The aim of this article is to present the principal physical properties of both techniques. From these properties, specific applications arise that are routinely used in clinical practice.
Collapse
|
26
|
Mills AF, Sakai O, Anderson SW, Jara H. Principles of Quantitative MR Imaging with Illustrated Review of Applicable Modular Pulse Diagrams. Radiographics 2017; 37:2083-2105. [PMID: 28985137 DOI: 10.1148/rg.2017160099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Continued improvements in diagnostic accuracy using magnetic resonance (MR) imaging will require development of methods for tissue analysis that complement traditional qualitative MR imaging studies. Quantitative MR imaging is based on measurement and interpretation of tissue-specific parameters independent of experimental design, compared with qualitative MR imaging, which relies on interpretation of tissue contrast that results from experimental pulse sequence parameters. Quantitative MR imaging represents a natural next step in the evolution of MR imaging practice, since quantitative MR imaging data can be acquired using currently available qualitative imaging pulse sequences without modifications to imaging equipment. The article presents a review of the basic physical concepts used in MR imaging and how quantitative MR imaging is distinct from qualitative MR imaging. Subsequently, the article reviews the hierarchical organization of major applicable pulse sequences used in this article, with the sequences organized into conventional, hybrid, and multispectral sequences capable of calculating the main tissue parameters of T1, T2, and proton density. While this new concept offers the potential for improved diagnostic accuracy and workflow, awareness of this extension to qualitative imaging is generally low. This article reviews the basic physical concepts in MR imaging, describes commonly measured tissue parameters in quantitative MR imaging, and presents the major available pulse sequences used for quantitative MR imaging, with a focus on the hierarchical organization of these sequences. ©RSNA, 2017.
Collapse
Affiliation(s)
- Andrew F Mills
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
| | - Osamu Sakai
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
| | - Stephan W Anderson
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
| | - Hernan Jara
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
| |
Collapse
|
27
|
The Quantitative Structural and Compositional Analyses of Degenerating Intervertebral Discs Using Magnetic Resonance Imaging and Contrast-Enhanced Micro-Computed Tomography. Ann Biomed Eng 2017; 45:2626-2634. [PMID: 28744842 DOI: 10.1007/s10439-017-1891-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 07/20/2017] [Indexed: 01/31/2023]
Abstract
The intervertebral disc (IVD) is susceptible to degenerative changes that are associated with low back pain. Murine models are often used to investigate the mechanistic changes in the development, aging, and diseased states of the IVD, yet the detection of early degenerative changes in structure is challenging because of the minute size of the murine IVDs. Histology is the gold standard for examining the IVD structure, but it is susceptible to sectioning artifacts, spatial biases, and requires the destructive preparation of the sample. We have previously demonstrated the feasibility of using Ioversol for the contrast-enhanced micro-computed tomography (microCT) to visualize and quantitate the intact healthy murine IVD. In this work, we demonstrate utility of this approach to monitor the longitudinal changes of in vitro nucleolytic- and mechanical injury- degeneration models of the murine discs and introduce novel quantitative metrics to characterize the structure and composition of the IVD. Moreover, we compared the imaging quality and quantitation of these in vitro models to magnetic resonance imaging (MRI) and histology. Stab puncture, trypsin injection, and collagenase injection all induced detectable and significant changes in structure and composition of the discs overtime. Compared to MRI and histology, contrast-enhanced microCT produced superior images that capture the degenerative progression in these models. Contrast-enhanced microCT was also capable of monitoring the structural deteriorations via the changes in disc height and volume, and novel the nucleus pulposus intensity/disc intensity (NI/DI) parameter provides a surrogate measure of proteoglycan composition (R = 0.96). Overall, this approach allows for the nondestructive monitoring of the structure and composition of the IVD at very high resolutions.
Collapse
|
28
|
Radue EW, Weigel M, Wiest R, Urbach H. Introduction to Magnetic Resonance Imaging for Neurologists. Continuum (Minneap Minn) 2016; 22:1379-1398. [PMID: 27740981 DOI: 10.1212/con.0000000000000391] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE OF REVIEW In neuroradiology, highly sophisticated methods such as MRI are implemented to investigate different entities of the central nervous system and to acquire miscellaneous images where tissues display varying degrees of characteristic signal intensity or brightness. Compared to x-ray, CT, and ultrasound, MRI produces clearer images of tissues, body fluids, and fat. The basics of MRI may be unknown to neurologists; this article introduces MRI physics, techniques, and interpretation guidelines. RECENT FINDINGS This article discusses the basics of MRI to provide clinicians with the scientific underpinning of MRI technology and to help them better understand image features and improve their diagnosis and differential diagnosis by combining MRI characteristics with their knowledge of pathology and neurology. SUMMARY This article will help neurologists deepen their knowledge and understanding of MRI by introducing the basics of MRI physics, technology, image acquisition, protocols, and image interpretation.
Collapse
|
29
|
Porter EG, Winter MD, Sheppard BJ, Berry CR, Hernandez JA. CORRELATION OF ARTICULAR CARTILAGE THICKNESS MEASUREMENTS MADE WITH MAGNETIC RESONANCE IMAGING, MAGNETIC RESONANCE ARTHROGRAPHY, AND COMPUTED TOMOGRAPHIC ARTHROGRAPHY WITH GROSS ARTICULAR CARTILAGE THICKNESS IN THE EQUINE METACARPOPHALANGEAL JOINT. Vet Radiol Ultrasound 2016; 57:515-25. [PMID: 27478155 DOI: 10.1111/vru.12390] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 05/18/2016] [Accepted: 05/18/2016] [Indexed: 11/28/2022] Open
Abstract
Osteoarthritis of the metacarpophalangeal joint is common cause of lameness in equine athletes, and is hallmarked by articular cartilage damage. An accurate, noninvasive method for measuring cartilage thickness would be beneficial to screen for cartilage injury and allow for prompt initiation of interventional therapy. The objective of this methods comparison study was to compare computed tomographic arthrography (CTA), magnetic resonance imaging (MRI), and magnetic resonance arthrography (MRA) measurements of articular cartilage thickness with gross measurements in the metacarpophalangeal joint of Thoroughbred horses. Fourteen cadaveric, equine thoracic limbs were included. Limbs were excluded from the study if pathology of the metacarpophalangeal articular cartilage was observed with any imaging modality. Articular cartilage thickness was measured in nine regions of the third metacarpal bone and proximal phalanx on sagittal plane MRI sequences. After intra-articular contrast administration, the measurements were repeated on sagittal plane MRA and sagittal CTA reformations. In an effort to increase cartilage conspicuity, the volume of intra-articular contrast was increased from 14.5 ml, to maximal distention for the second set of seven limbs. Mean and standard deviation values were calculated, and linear regression analysis was used to determine correlations between gross and imaging measurements of cartilage thickness. This study failed to identify one imaging test that consistently yielded measurements correlating with gross cartilage thickness. Even with the use of intra-articular contrast, cartilage surfaces were difficult to differentiate in regions where the cartilage surfaces of the proximal phalanx and third metacarpal bone were in close contact with each other.
Collapse
Affiliation(s)
- Erin G Porter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 100126, Gainesville, FL.
| | - Matthew D Winter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 100126, Gainesville, FL
| | - Barbara J Sheppard
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, 100126, Gainesville, FL
| | - Clifford R Berry
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 100126, Gainesville, FL
| | - Jorge A Hernandez
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, 100126, Gainesville, FL.,Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, 100126, Gainesville, FL
| |
Collapse
|
30
|
Klamor S, Zick K, Oerther T, Schappacher FM, Winter M, Brunklaus G. 7Li in situ 1D NMR imaging of a lithium ion battery. Phys Chem Chem Phys 2015; 17:4458-65. [DOI: 10.1039/c4cp05021e] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The spatial distribution of charge carriers in lithium ion batteries during current flow is of fundamental interest for a detailed understanding of transport properties and the development of strategies for future improvements of the electrolyte–electrode interface behaviour.
Collapse
Affiliation(s)
- S. Klamor
- University of Münster
- Institute of Physical Chemistry
- 48149 Münster
- Germany
- University of Münster
| | - K. Zick
- Bruker BioSpin GmbH Silberstreifen
- 76827 Rheinstetten
- Germany
| | - T. Oerther
- Bruker BioSpin GmbH Silberstreifen
- 76827 Rheinstetten
- Germany
| | - F. M. Schappacher
- University of Münster
- MEET Battery Research Center
- 48149 Münster
- Germany
| | - M. Winter
- University of Münster
- Institute of Physical Chemistry
- 48149 Münster
- Germany
- University of Münster
| | - G. Brunklaus
- University of Münster
- Institute of Physical Chemistry
- 48149 Münster
- Germany
| |
Collapse
|
31
|
Benkert T, Bartsch AJ, Blaimer M, Jakob PM, Breuer FA. Generating multiple contrasts using single-shot radial T1 sensitive and insensitive steady-state imaging. Magn Reson Med 2014; 73:2129-41. [PMID: 24975241 DOI: 10.1002/mrm.25337] [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: 03/19/2014] [Revised: 05/07/2014] [Accepted: 06/05/2014] [Indexed: 11/11/2022]
Abstract
PURPOSE Recently, the (Resolution Enhanced-) T1 insensitive steady-state imaging (TOSSI) approach has been proposed for the fast acquisition of T2 -weighted images. This has been achieved by balanced steady-state free precession (bSSFP) imaging between unequally spaced inversion pulses. The purpose of this work is to present an extension of this technique, considerably increasing both the efficiency and possibilities of TOSSI. THEORY AND METHODS A radial trajectory in combination with an appropriate view-sharing reconstruction is used. Because each projection traverses the contrast defining k-space center, several different contrasts can be extracted from a single-shot measurement. These contrasts include various T2 -weightings and T2 /T1 -weighting if an even number of inversion pulses is used, while an odd number allow the generation of several images with predefined tissue types cancelled. RESULTS The approach is validated for brain and abdominal imaging at 3.0 Tesla. Results are compared with RE-TOSSI, bSSFP, and turbo spin-echo images and are shown to provide similar contrasts in a fraction of scan time. Furthermore, the potential utility of the approach is illustrated by images obtained from a brain tumor patient. CONCLUSION Radial T1 sensitive and insensitive steady-state imaging is able to generate multiple contrasts out of one single-shot measurement in a short scan time.
Collapse
Affiliation(s)
- Thomas Benkert
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany
| | - Andreas J Bartsch
- Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany.,Department of Neuroradiology, University of Würzburg, Würzburg, Germany.,FMRIB Centre, University of Oxford, Oxford, United Kingdom
| | - Martin Blaimer
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany
| | - Peter M Jakob
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany.,Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany
| | - Felix A Breuer
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany
| |
Collapse
|