13:45 | | IntroductionJoseba Alonso Spanish National Research Council (CSIC, Q2818002D), Spain |
13:57 | 0154.
| Field Cycling Imaging: a novel very low field modality to characterize breast cancer Vasiliki Mallikourti1, James Ross1, Oliver Maier2, Katie Hanna3, Ehab Husain4, Gareth Davies1, David Lurie1, Gerald Lip4, Hana Lahrech5, Yazan Masannat4, and Lionel Broche1 1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, United Kingdom, 2Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria, 3Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom, 4Breast Unit, Aberdeen Royal Infirmary, Aberdeen, United Kingdom, 5University Grenoble Alpes, Inserm U1205, BrainTech Lab, Grenoble, France Keywords: Low-Field MRI, Low-Field MRI, breast cancer Motivation: Field Cycling Imaging (FCI) has never been used in clinics and its capability in medical diagnosis has not yet demonstrated. Goal(s): Our goal was to demonstrate the capabilities of FCI as an imaging modality to diagnose breast cancer by measuring the T1 variations at low field from 2.3 to 200 mT. Approach: Ten patients were imaged with our recent FCI prototype scanner and images were compared with standard clinical imaging and histology. Results: FCI provides relevant biomarkers of molecular dynamics that detect tumours and discriminate invasive from non-invasive tumours. In addition, FCI is insensitive to breast density and provides accurate tumour delineation. Impact: FCI, which uses variant low field strengths, could complement clinical
imaging without contrast agents non-invasively and could improve the estimation of tumour size
and resection margins, even for dense breasts, including DCIS which is often
under/over-estimated in clinical imaging. |
14:09 | 0155. | Spatiotemporal encoding MRI at a portable low field system without parallel imaging Yueqi Qiu1,2, Ke Dai1,2, Sijie Zhong1,2, Hao Chen1,2, Lucio Frydman3, and Zhiyong Zhang1,2 1School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, 2National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy (NERC-AMRT), Shanghai Jiao Tong University, Shanghai, China, 3Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel, Rehovot, Israel Keywords: Low-Field MRI, Low-Field MRI, SPEN, Field Inhomogeneity, less distortion, low SAR Motivation: Geometric distortions in echo-planar acquisitions pose challenges for correction in portable low-field MRI due to significant field inhomogeneities. Goal(s): Our goal was to apply spatiotemporal encoding (SPEN) MRI at a 110 mT portable low-field system, aiming for nearly distortion-free echo-planar images. Approach: We leveraged the low SAR in low-field MR to optimize the SPEN technique for substantial gains in sensitivity. SPEN-based 2D imaging ,3D imaging and DWI were compared with EPI-based imaging and EPI TopUp correction results. Results: Approximately distortion-free SPEN acquisitions including robust 2D, 3D imaging and DWI demonstrated the potential clinical values of SPEN in the portable low field systems. Impact: SPEN MRI provides a unique and robust fast echo
planar acquisition approach to obtain nearly distortion-free images at low-cost
portable low field systems, thereby expanding the prospects for rapid imaging,
navigation, and functional imaging in portable low-field MRI. |
14:21 | 0156.
| Low Field MRI as a Potential Equalizer: Addressing Healthcare Disparities Through Socioeconomic Status and MRI Access in the United States Michael Bermingham1, Mikkael Lamoca1, Roman Czornobil1, Abby Dale1, Amelia Amelia Gilbert1, Jeffrey Burnette1, James Myers1, Sandra Rothenberg 1, and Iris Asllani1,2 1Rochester Institute of Technology, Rochester, NY, United States, 2University of Sussex, Brighton, United Kingdom Keywords: Low-Field MRI, Health Care Economics, MRI value Motivation: While the USA boasts one of the highest numbers of MRIs per million inhabitants, the impact of social determinants of health on accessibility remains uncertain. This issue becomes particularly relevant as Low Field MRI could level the playing field and mitigate existing inequities. Goal(s): Primary goal was to investigate the relationship between MRI availability and poverty rate in the US. Approach: We tested the correlation between poverty rate and both the quantity and geographical distribution of MRIs. Results: The number of MRI units exhibited an exponential decline (R2=0.9823) with the poverty rate, with geographical location and other pertinent socioeconomic factors playing a role. Impact: LF MRI has attributes that make it particularly suitable for implementation in low-middle income countries (LMICs). Nevertheless, features like affordability and portability can also potentially be pivotal in addressing healthcare disparities within the US. |
14:33 | 0157.
| Finding common ground: Subject grounding to reduce electromagnetic interference at 46 mT Beatrice Lena1, Bart de Vos1, and Andrew Webb1 1C.J. Gorter MRI Center, Radiology Department, Leids Universitair Medisch Centrum, Leiden, Netherlands Keywords: Low-Field MRI, Low-Field MRI, EMI reduction Motivation: Electromagnetic interference (EMI) reduction is essential to utilize low-field point-of-care MRI devices in different environments with different noise conditions. Goal(s): Improving EMI reduction by subject grounding Approach: Noise scans and brain images were acquired with and without subject grounding. This is done with normal imaging conditions and when adding broadband noise or single frequency EMI. Results: The SNR of the images was improved by a factor of ~4 when grounding the subject and adding broadband EMI to the experiment. A factor ~2 improvement in SNR was observed for the single frequency EMI and a factor of 1.5 improvement for the normal imaging conditions. Impact: Subject grounding effectively reduced EMI interference. It may be relevant to investigate whether this setup would be able to reduce EMI from medical equipment, or general environmental EM noise in typically challenging POC settings (ICU, emergency room, in remote locations) |
14:45 | 0158.
| Inter-Channel Correlation-based EMI Noise Removal for Shielding-Free Low-field Portable MRI Yiman Huang1,2, Shuxian Qu2,3, and Xiaotong Zhang1,2,3,4 1College of Electrical Engineering, Zhejiang University, Hangzhou, China, 2MOE Frontier Science Center for Brain Science and Brain-machine Integration, Zhejiang University, Hangzhou, China, 3The Interdisciplinary Institute of Neuroscience and Technology, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China, 4Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China Keywords: Low-Field MRI, Low-Field MRI Motivation: The current electromagnetic interference (EMI) noise removal approaches for low-field portable magnetic resonance imaging (MRI) only focus on single receive coil EMI removal, which ignores noise relationship among coil elements of RF coil arrays. Goal(s): Our goal was to remove EMI noise in receive coils not only related to EMI detectors, but also among receive coil elements. Approach: A signal correlation matrix was constructed from signals acquired by EMI coils and receive coils, and decorrelation matrix was calculated for EMI noise removal. Results: Phantom results and pilot in vivo human brain images showed that the proposed method have better EMI noise removal rate. Impact: The
proposed EMI noise removal method for unshielded low-field MRI can better improve
signal-to-noise ratio (SNR) compared to state-of-the-art methods, which enable
the EMI noise removal for array coils in low-field portable MRI application. |
14:57 | 0159.
| Cervical Spine MRI on a RF Shielding-Free 0.05T MRI Scanner Yujiao Zhao1,2, Christopher Man1,2, Vick Lau1,2, Shi Su1,2, and Ed X. Wu1,2 1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China Keywords: Low-Field MRI, Low-Field MRI Motivation: To develop low-cost and patient-friendly MRI scanners to address global healthcare disparities. Goal(s): To demonstrate cervical spine (C-spine) MRI on a low-cost and RF shielding-free 0.05T MRI scanner. Approach: Typical imaging protocols were implemented on a newly developed 0.05T MRI scanner. The scanner is compact, RF shielding-free, and acoustically quiet during scanning. Further, a deep learning electromagnetic interference (EMI) elimination method and a data-driven reconstruction strategy were designed. Results: The deep learning EMI elimination method effectively removed EMI noise, and the data driven reconstruction method suppressed image noise and artifacts while increasing spatial resolution, leading to significantly improved image quality. Impact: We demonstrate
high-quality C-spine MRI on a low-cost and shielding-free 0.05T MRI
scanner through exploiting computing power and extensive high-field
MRI data. These developments will lead to a new generation of affordable,
patient-centric, and computing-powered MRI scanners. |
15:09 | 0160.
| Connectomics at 64 mT Álvaro Planchuelo-Gómez1,2, James Gholam1, Joshua Ametepe1, Francesco Padormo3, Leandro Beltrachini1, Mara Cercignani1, and Derek K Jones1 1CUBRIC, Cardiff University, Cardiff, United Kingdom, 2Imaging Processing Laboratory, Universidad de Valladolid, Valladolid, Spain, 3Hyperfine, Inc., Guildford, CT, United States Keywords: Low-Field MRI, Brain Connectivity, Connectomics Motivation: Neuroscience MRI research, including assessment of structural connectomics, has been largely limited to high-resource settings. Goal(s): To democratise assessment of brain connectivity by demonstrating the first ever diffusion-weighted imaging (DWI)-based connectomics at 64 mT. Approach: 15-direction DWI data were acquired at 64 mT. Whole-brain tractograms were recovered after deep learning based denoising and constrained spherical deconvolution. Whole-brain adjacency matrices and graph-theory parameters were extracted, and their test-retest agreement and variability assessed. For one subject, results were compared to high-field MRI. Results: Global graph-theory parameters (e.g., small-worldness) showed high test-retest agreement. However, inter-hemispheric connectivity was overestimated at 64 mT compared to high-field results. Impact: Our unique combinations of low-field (64
mT) diffusion-weighted imaging, denoising, spherical deconvolution and
connectomics opens up new research opportunities, allowing the assessment of
structural connectivity and network neuroscience studies of under-served
populations where this has never previously been possible. |
15:21 | 0161.
| OPM-MEG/ULF-MRI Hybrid System: towards acquisition of both MR image and neural magnetic field Hiroyuki Ueda1, Takenori Oida2, Takahiro Moriya2, Akinori Saito2, Yosuke Ito1, and Motohiro Suyama2 1Department of Electrical Engineering, Kyoto University, Kyoto, Japan, 2Hamamatsu Photonics K.K., Hamamatsu, Japan Keywords: Hybrid & Novel Systems Technology, Low-Field MRI Motivation: To overcome the limitations of signal co-registration in MEG, we constructed MEG/MRI hybrid system. Goal(s): To demonstrate feasibility of this system. High-sensitivity OPMs in a reasonable magnetic shield with MRI system. Approach: Phantom experiments. Phantom includes triangle coil and MEG measures its magnetic field. MRI scanned this phantom with 3D-SE sequence. Results: We recognized signal peak generated by 100 nAm current dipole moment in amplitude spectrum density visually. We also confirmed the structure of the phantom in 3D MR images. Impact: We made MEG/MRI hybrid system for the purpose of accurate signal co-registration between them. MEG employed scalar-mode
OPM, and its noise level was 367 fT/rHz. We scanned phantom using 7-mT MRI
scanner and confirmed its structure. |
15:33 | | DiscussionJoseba Alonso Spanish National Research Council (CSIC, Q2818002D), Spain |