bluuebunny/crossref_metadata_2025 huggingface dataset:
Accelerating MR Reconstruction with encoding perturbations using a diffusion model
Authors: Chen Hongli , Shan Shanshan , Gao Yang , Gan Hongping , Liu Chunyi , Tang Fangfang , Liu Feng
Published: November 2024

Motivation: Image distortions caused by encoding perturbations and slow MR acquisitions compromise real-time MRI-guided radiotherapy treatments.Goal(s): We aim to develop and investigate a diffusion model-based method to accelerate MR reconstruction with encoding perturbations.Approach: The diffusion model was trained by 180,670 T1-weighted brain images from a public MR dataset and nonuniform fast Fourier transform was applied to operate forward encoding process with perturbations.Results: Imaging results showed that the proposed network enabled fast MR image reconstruction with corrected geometric distortions for any subsampling patterns.Impact: The developed diffusion model to accelerate MR reconstruction with perturbations. The results demonstrated that the proposed method enabled fast distortion-corrected image reconstruction for any subsampling patterns.
Deep Learning with Spatio-Channel Regularization for Accelerated Cardiac Cine
Authors: Demirel Omer , Ghanbari Fahime , Morales Manuel , Pierce Patrick , Johnson Scott , Rodriguez Jennifer , Street Jordan , Manning Warren , Nezafat Reza
Published: November 2024

Motivation: Evaluation of cardiac function with cine imaging remains long and requires repeated breath-holds that are sometimes corrupted with artifacts if patients have non-sinus rhythm or difficulty in breath-holding. Goal(s): To develop a deep learning method with spatio-channel regularization with multi-channel k-space reconstruction for accelerated cine imaging. Approach: Coil-self consistency based deep learning (DL) was implemented with 3D regularization across spatial and channel dimensions in contrast to single coil-combined image used in sensitivity encoding (SENSE). Results: Our approach at 5-fold acceleration showed quantitative improvements over SENSE-based DL on retrospectively accelerated data and showed good agreement with left ventricular (LV) measurements on prospectively accelerated data. Impact: The spatio-channel regularized DL reconstruction shortens the scan time by a factor of 5, leading to fewer breath-holds and 2–3-minute scans. This can greatly benefit patients struggling with breath-holding and accelerate the overall scan time.
Image reconstruction performance using mixed real and synthetic MR phase training data
Authors: Deveshwar Nikhil , Argentieri Erin , Rajagopal Abhejit , Majumdar Sharmila , Larson Peder
Published: November 2024

Motivation: Prospectively developing MRI datasets with raw-kspace for MRI reconstruction is difficult, expensive and time-consuming. Generating synthetic k-space with synthetic phase as training data has been shown to work comparably for training MRI reconstruction models but its hard to access paired synthetic data. Goal(s): How does training data consisting of mixed real and synthetic k-space (including synthetic phase) affect image reconstruction performance. Approach: Five variational networks were trained with varying amounts of mixed real and synthetic training data. Image quality metrics were used to evaluate the quality of reconstructed images. Results: Adding small amounts of real training data helps increase reconstruction performance. Impact: The results suggest that small addition of real training data in addition to using mostly synthetic training data can help reconstruction performance. This could be useful clinically where synthetic data can augment models trained with small amounts of real data.
Deep learning-based acceleration of compressed SENSE brain ASL MRI using 3D Cartesian TSE with improved spatial resolution
Authors: Wang Yiming , Zhang Yajing , Zhang Zhongping , Su Wengu , Ren Zhongchang , Zhao Yan
Published: November 2024

Motivation: Brain ASL images are frequently obtained at relatively low spatial resolutions, necessitating a desire for higher-resolution ASL MRI without extended scan times. Goal(s): To evaluate the potential of employing CS-AI for accelerating higher-resolution brain ASL MRIApproach: Acceleration of higher-resolution 3D Cartesian TSE ASL MRI was achieved using CS-AI at 2, 3, and 4-fold rates, and its performance was compared with SENSE. Results: CS-AI-accelerated 3D brain ASL images exhibited good SNR and quality, surpassing those acquired with SENSE, without affecting CBF quantification. Impact: This investigation may improve the clinical utility of brain ASL, particularly in quantifying perfusion alterations in small-sized lesions.
Fast, High-resolution Whole Brain SWI and QSM with CAIPIRINHA 3D-EPI and Deep Learning Reconstruction
Authors: Jin Jin , Nickel Dominik , Pfeuffer Josef , Tourell Monique , Stewart Ashley , Bollmann Steffen , Bollmann Saskia , Barth Markus , O‘Brien Kieran
Published: November 2024

Motivation: There is a strong clinical desire to accelerate the established SWI protocols. The clinical adoption of quantitative susceptibility maps (QSM) is hindered in part by long scan time and cumbersome offline QSM processing. Goal(s): This study aims to substantially accelerate the SWI/QSM acquisitions while providing high-quality inline SWI/QSM images. Approach: A flow-compensated, CAIPIRINHA-accelerated 3D echo-planar imaging (3DEPI) sequence was used to create 1-minute protocols with matching resolution to conventional sequences. Deep-learning reconstruction and super-resolution were used to enhance image quality. Results: Compared with the established approach, the 1-minute 3D-EPI protocols provided 4× to 6× speed-up, while the DL reconstruction provided superior image quality. Impact: Besides the general improvement in throughput, the 1-minute SWI protocols with improved image quality may enhance the role of MRI-SWI in acute care. The high-quality in-line QSM and susceptibility map weighted images (SWMI) will facilitate their clinical evaluation and adoption.
A first 3D negative-contrast MR image using a low-Tc SQUID detection: towards portable clinical MRI
Authors: Fiorito Marco , Saniour Isabelle , Grimaldi Eva , Couvreur Romain , Mohanty Ijee , Dassonneville Bastien , Belkhodja Yacine , Ferreira Ricardo , Jaoui Alexandre , Labat Dimitri
Published: November 2024

Motivation: At Chipiron we strive to develop the first commercial portable ultra-low field MRI scanner based on SQUID detection. Goal(s): Here, we aimed to acquire a first 3D image using SQUID-MRI at 1 mT. Approach: Using our own integrated SQUID-MRI system, we scanned a hand-made water based phantom using a GRE sequence. Results: We successfully acquired a 3D image of a phantom in 6 h with a resolution of 5x5x40 mm3. Impact: Aspiring to democratise MRI, we develop a portable ultra-low field scanner that leverages the high sensitivity of SQUID detection. Our first 3D image is just the first step that paves the way to achieving competitive image quality for clinical employment.
Reproducibility of quantitative MRI measures at Ultra-Low Field
Authors: Balaji Sharada , Wiley Neale , Dvorak Adam , Padormo Francesco , Teixeira Rui Pedro , Poorman Megan , MacKay Alex , Wood Tobias , Williams Steve , Deoni Sean , Ljungberg Emil , Kolind Shannon
Published: November 2024

Motivation: Ultra-low field scanners can vastly improve access to neuroimaging, and implementing MRI techniques to quantify microstructure allows monitoring of both neurodegenerative diseases as well as myelination trajectories during development. Goal(s): To assess the reliability of microstructure-sensitive methods at ultra-low field before large-scale deployment. Approach: The reliability of recently developed magnetization transfer (MT) imaging and T2 mapping sequences at 64mT was assessed in 5 healthy subjects through histograms, difference maps and correlation analysis in white matter. Results: Both MT ratios and T2 values were highly reproducible in the test cohort. Impact: Techniques to measure microstructure, even semi-quantitatively, can be useful for tracking myelination/demyelination. Here we demonstrate the reproducibility of two such methods: magnetization transfer imaging and T2 mapping, in a small cohort of healthy adults at ultra-low field (64mT).
An Optimized Multi-Component Imaging Method on a Homebuilt 0.5 T MRI System: Combing Intra- and Inter-Voxel Constraints
Authors: Jiang Xiaowen , Wu Zhengxiu , Chen Yi , Ni Zhonghua , Lu Rongsheng
Published: November 2024

Motivation: Applying the component imaging method to low-field MRI systems will face a main problem: low-SNR image data. Goal(s): An optimized inversion method is proposed, aiming to give better results for image data with low SNR. Approach: This paper proposes an optimized inversion method with the formula of the optimization problem combining intra- and inter-voxel constraints. Results: The optimized method shows a better convergence rate avoiding the fragmentation of component images and the appearance of pseudo peaks in the spectrum. Impact: This multi-component imaging approach can provide sub-voxel characterization and be applied to numerous applications of popular portable low-field MRI systems.
Is low field always better for imaging around passive implants?
Authors: Weaver Robert , Bowen Chris , Rioux James , Clarke Sharon , Cora Elena Adela , Volders David , Brewer Kimberly , Beyea Steven
Published: November 2024

Motivation: To investigate the performance of modernized low-field MRI relative to traditional systems for imaging near metallic devices within the clinical context. Goal(s): To evaluate whether low-field MRI can offer a significant reduction in artifacts when using routine clinical protocols. Approach: The artifact characteristics of 0.5 T, 1.5 T, and 3 T MRIs are compared in this ASTM F2119-07-based phantom study of common passive metallic devices. Results: Low-field MRI demonstrated the capability to reduce susceptibility artifacts when imaging near metal-containing medical devices. However, artifact produced by some pulse sequences diverged from the anticipated field-dependence, highlighting the sizable effects of clinical protocolling. Impact: This phantom study demonstrates that low-field MRI can image metallic devices with reduced artifact relative to 1.5/3 T systems using routine clinical protocols, highlighting opportunities for future in vivo studies involving implants and imaging in areas with magnetic susceptibility distortions.
Investigation of Optimal Readout Frequency for the Non-Uniform B0 (NuBo) Field Cycling (FC) Scanner
Authors: Sun Chenhao , Ha Yonghyun , Samardzija Anja , Sun Heng , Gross Ryan , Galiana Gigi , Constable R. Todd
Published: November 2024

Motivation: The field cycling (FC) scanner introduces an extra degree of freedom for adjusting the B0 field strength during both polarization and readout. However, the ideal readout Larmor frequency remains unexplored. Goal(s): To investigate the optimal readout Larmor frequency for the non-uniform B0 (NuBo) scanner regarding SNR, T2*, and T2 dephasing. Approach: Controlled experiments at two Larmor frequencies, 1MHz and 2MHz, were conducted. Echo trains at these two frequencies were acquired. Results: Results show that readout at a lower Larmor frequency could benefit from a longer echo train, and longer T2*, but with the penalty of a smaller initial signal amplitude. Impact: This research conducted a comparison of the trade-off between SNR, T2* and T2 decay across various readout Larmor frequencies, potentially offering insights for researchers in the field of field cycling in the future.
Relationship Between Apparent Fiber Density in Corpus Callosum and Cognitive Function.
Authors: Hayashi Naoya , Yoshimaru Daisuke , Shibukawa Shuhei , Arizono Eri , Araki Yoichi , Kawaguchi Naoki , Shimizu Soichiro , Saito Kazuhiro
Published: November 2024

Motivation: Evaluation of fiber density in the corpus callosum (CC) is expected to show a higher sensitivity in relation to cognitive function than changes in volume. Goal(s): The goal is to clarify the association between the volume and AFD of the CC5 region and neuropsychological test scores. Approach: We examined the relationship between neuropsychological test scores, and calculated AFD and CC volume for 180 patients with suspected dementia. Results: CC volume showed no significant association with neuropsychological test scores. On the other hand, AFD showed associations with several neuropsychological tests. Impact: This study demonstrated that AFD correlated better with cognitive function than the previously reported CC volume. It was indicated the superior sensitivity of AFD in assessing cognitive function in dementia diagnosis.
Dynamic Changes of Cortical Microstructure in Nasopharyngeal Carcinoma Patients After Radiotherapy: A Multi-Shell Diffusion Imaging Study
Authors: Qiu Ziru , Lin Yuhao , Lv Xiaofei , Liang Jiahui , Fu Gui , Pan Jie , Feng Yanqiu , Zhang Xinyuan
Published: November 2024

Motivation: Radiotherapy for nasopharyngeal carcinoma induces brain structural abnormalities, altering cortical microstructure. Goal(s): Longitudinally explore dynamic cortical microstructure changes over one year after Radiotherapy. Approach: We performed GM-based spatial statistics analysis (GBSS) on DTI and NODDI data, utilizing nonparametric permutation inference to identify dynamic alterations in diffusion metrics. Cortical regions were located in gray matter clusters by referring to the Desikan-Killiany atlas. Results: Bilateral temporal lobe MD reduced significantly, and NDI increased notably at six months post-RT, and these changes remained with larger clusters at 12 months. The affected gray matter regions included the entorhinal cortex, temporal pole, inferior temporal gyrus, and fusiform gyrus. Impact: The combination of DTI and NODDI allows for a more comprehensive understanding of the patterns of cortical microstructural changes induced by RT, offering the potential for early interventions in radiation-induced brain injury.
Quantitative Assessment of Renal Steatosis in Type 2 Diabetes Mellitus Patients Using IDEAL-IQ Imaging: Reproducibility and Implications
Authors: liu jian , Wu Yu , Zhang Xunlan , Nie Lisha , Wang Rongpin , Zeng Xianchun
Published: November 2024

Motivation: Renal parenchymal fat deposits play a crucial role in the development of diabetic kidney disease (DKD). Noninvasive measurement of renal parenchymal fat deposits using functional MRI provides valuable insights into the pathogenesis of DKD. Goal(s): Exploring the reproducibility of IDEAL-IQ imaging in quantifying renal lipid deposition and to investigate the differences observed in DKD patients. Approach: A total of 26 healthy participants underwent two IDEAL-IQ scans without repositioning and 96 type 2 diabetes mellitus (T2DM) patients underwent a single IDEAL-IQ scan. Results: IDEAL-IQ imaging is a reproducible technique for noninvasively quantifying renal lipid deposition. Furthermore, the technique shows promising performance in staging DKD. Impact: This study highlights the potential benefits of IDEAL-IQ imaging in evaluating renal lipid deposition in DKD patients. It contributes to a better understanding of the pathogenesis and progression of DKD, to improved diagnostic and management strategies for T2DM patients.
Kidney MR Fingerprinting and Arterial Spin Labeling (ASL) Assessments of Autosomal Recessive Polycystic Kidney Disease (ARPKD)
Authors: MacAskill Christina , Kretzler Madison , Parsons Ashlee , Gange Victoria , Hach Jenna , Larson Stephanie , Zhu Yuran , Perino Jacob , Farr Susan , Markley Michael , Pritts Nicole , Perera-Gonzalez Mireia , Clark Heather , Kuehn Bernd , Liu Ke Cheng , Yu Xin , Ma Dan , Chen Yong , Dell Katherine , Flask Chris
Published: November 2024

Motivation: There are no clinically available therapies for ARPKD. Goal(s): We evaluated the ability of T1 and T2 from MR Fingerprinting (MRF) to assess kidney cystic burden and Arterial Spin Labeling (ASL) to assess kidney perfusion to detect and stage ARPKD kidney disease. Approach: 12 ARPKD patients and 10 healthy adult volunteers were scanned on a Siemens 3T with kidney MRF and ASL MRI methods to generate kidney cortical perfusion maps. Results: Significant increases in kidney T1 and T2, and reduced perfusion were observed between ARPKD patients and healthy volunteers (p<0.001) and between ARPKD patients with early and mild-to-moderate CKD based on eGFR (p<0.03). Impact: The multi-modal MRI biomarkers in combination evaluated were able to distinctly stratify all three cohorts, including the two ARPKD patient cohorts, demonstrating the utility of a multi-modal MRI approach during future clinical trials aimed at limiting ARPKD kidney disease progression.
Clinical PC VIPR Implementation for Abdominal Hemodynamics Assessment in Patients with Renal Cell Carcinoma Tumor Thrombus
Authors: Garcia-Rodriguez Sylvana , Roldan-Alzate Alejandro , Wieben Oliver , Johnson Kevin , Shapiro Daniel , Abel E. Jason , Wentland Andrew
Published: November 2024

Motivation: 4D flow MRI provides volumetric time-resolved blood flow measurements in short scan times. Nevertheless, 4D Flow MRI techniques have not been clinically applied to abdominal neoplasms invading into the vasculature, altering blood flow and posing unique surgical problems. Goal(s): Describe the clinical implementation of 4D Flow MRI for treatment planning of RCC patients with venous tumor thrombus undergoing nephrectomy and thrombectomy. Approach: Our institution has established a 4D flow MRI workflow for blood flow assessment based on multidisciplinary collaboration and several other factors. Results: Clinical 4D flow for treatment planning of RCC patients has been successfully implemented at our institution. Impact: 4D flow MRI allows for comprehensive non-invasive assessment of the abdominal circulation in the clinical setting. The methodology presented here has provided unvaluable input to the care team of patients with complicated cases of advanced RCC during treatment planning.
Development and First Application of Combined Testicular Magnetic Resonance Fingerprinting and ADC Mapping in Healthy Volunteers
Authors: de Oliveira Correia Eduardo Thadeu , Dupuis Andrew , Boyacioglu Rasim , Griswold Mark , Chen Yong , Thirumavalavan Nannan , Bittencourt Leonardo Kayat
Published: November 2024

Motivation: Azoospermia care often requires performing microdissection procedures for sperm extraction that are unsuccessful in 50% of men. Goal(s): Investigate the feasibility of a combined MRF and diffusion mapping protocol of the testicles, as well as quantify the normal ADC, T1 and T2 values of the left and right testicles. Approach: Regions of interest were annotated on ADC and T1 maps, these were copied to T2 maps. Results: Mean ADC, axial T1 and T2 values were similar between left and right testicles. Mean coronal T1 and T2 values of the left testicles were higher than those of the right testicles. Impact: The acquisition of a dedicated protocol for combined MRF and diffusion mapping of the testicles is feasible. This work paves the way for prospective studies investigating non-invasive characterization of the testicles in patients with obstructive and non-obstructive azoospermia.
Predictors of 0.55T Respiratory Navigated Lung MRI Degradation
Authors: Schonour Richard , Tang Felicia , Bowers Kiara , Su Pan , Larson Peder , Ohliger Michael , Lee Yoo Jin , Liu Jonathan , Yang Yang , Sohn Jae Ho
Published: November 2024

Motivation: The image quality generated using respiratory triggered sequences on low-field scanners is sometimes degraded, and it is currently not well known what causes this. This degradation can lead to image misinterpretation. Goal(s): Our goal was to determine possible predictors of image quality degradation in low-field lung MRI. Approach: Six radiologists graded anatomic 0.55T MRI images, and then analysis of patient clinical history, demographics, and respiratory navigation was conducted to determine any patterns. Results: We found that clinical conditions including fibrotic interstitial lung disease and pulmonary artery pathologies, as well as descriptors such as increased body mass index can predict image quality degradation. Impact: Our observation of degradative predictors serves as the foundation for research into altering of 0.55T MRI parameters to limit the degree of degradation, so that at-risk patients can still be scanned on these low-field machines with optimal image quality.
Brain Cortical Changes in Pediatric and Adolescent Patients with Intermittent Exotropia Basic Type: SBM Analysis on MRI Morphological Data
Authors: Zhao Xin-zhi , Shi Qing-lei , Chen Wan Yi , Fang Yi , Li Huixin , Mao Jie , Wang Ren-zhi , Liu Zhaohui , Wan Xiang
Published: November 2024

Motivation: Basic type of intermittent exotropia (IXT) is one of the most common strabismus subtypes in children and adolescents, yet a clear consensus of its etiology and treatment approach is still lacking. Goal(s): To discover abnormal brain cortical structures related to this disease and explore the central nervous system mechanisms of IXT. Approach: Basic type IXT patients and healthy volunteers were recruited, cortical structures extracted from their whole-brain MRI morphological data were compared using the SBM method. Results: Distinct differences of cortical thickness and curvature between the two groups were found, located in the right rostral middle frontal cortex and the left precuneus. Impact: Our results suggesting that the primary pathological changes in this disease may differ from traditional perspectives. Based on these findings, we have proposed a new pathogenic hypothesis and introduced novel treatment recommendations.
Assessments of brain volume and cerebral perfusion across ages in patients with Duchenne muscular dystrophy
Authors: Govaarts Rosanne , Doorenweerd Nathalie , Broek Emma , Václavů Lena , Hollingsworth Kieren , Niks Erik , Straub Volker , Kan Hermien
Published: November 2024

Motivation: Lower total brain and grey matter volume and reduced cerebral perfusion have been shown cross-sectionally in Duchenne muscular dystrophy (DMD) patients compared to healthy controls (8-18 years old). Goal(s): We aimed to assess changes of these findings over time. Approach: We analyzed both; data from adults with DMD and longitudinal data. Results: Our results show that the difference in total brain volume, grey matter volume and perfusion persist into adulthood, but that the rate of change over ~3 years did not differ between DMD and healthy controls. This suggests that structural brain changes in DMD are not progressive over this timeframe. Impact: Widespread brain alterations have been observed in the progressive muscle wasting condition DMD, along with neurocognitive and behavioral changes. In contrast to the muscle phenotype, our study showed stable reductions in brain volume and perfusion indicative of non-progressive pathology.
GABA and Glx levels in relapsing-remitting multiple sclerosis correlate with clinical disability
Authors: Shi Ying , Wang Qi , Lian Jianxiu , Lin Liangjie , Liu Pengfei
Published: November 2024

Motivation: Multiple sclerosis (MS) is a leading cause for clinical disability in youth and middle-aged people. Goal(s): Multiple researches have implicated glutamine–glutamate complex (Glx) and gamma- aminobutyric acid (GABA) as key roles in neuronal signalling and other central functions. In MS patients, dysfunctional Glx excitation and/or GABA inhibition may contribute to neurological symptoms and disease progression. Approach: To identify the relationship between metabolic abnormalities and clinical disability, the metabolism of brain tissue was investigated by using MEscher-GArwood Point RESolved Spectroscopy. Results: Decreasing levels of GABA+/tCr and increasing levels of Glx/tCr were found in the precentral gyrus and postcentral gyrus VOIs of MS patients. Impact: GABA and Glx detected by MEGA-PRESS MRS were utilized for investigating correlations between metabolic abnormalities in brain tissue and clinical disability.
Study of Neurometabolic Alterations in Multiple Sclerosis Using Fast High-Resolution 3D 1H-MRSI
Authors: Bo Bin , Sheng Tianyang , Tang Weijun , Zhao Yibo , Li Yudu , Jin Wen , Guo Rong , Chen Xiangjun , Liang Zhi-Pei , Li Yao
Published: November 2024

Motivation: Multiple sclerosis (MS) is characterized by diverse metabolic alterations. 1H-MRSI provides a unique capability for non-invasive mapping of neurometabolites but is often limited in resolution, scanning time, and brain coverage. Goal(s): Our goal was to demonstrate the feasibility of high-resolution whole-brain 1H-MRSI for characterizing metabolic alterations in MS. Approach: 3D 1H-MRSI scanning using SPICE technology (scan time: 10 minutes, resolution: 2×3×3 mm3, FOV: 240×240×120 mm3) was performed on 44 MS patients. Results: N-acetylaspartate (NAA), myo-inositol (mI), creatine, and choline levels altered among different lesion types and peri-plaque regions. NAA and mI/NAA differentiated RRMS and PMS patients in association with clinical scores. Impact: High-resolution whole-brain 1H-MRSI provides a promising tool for non-invasive metabolic imaging to characterize MS pathophysiology.
Identification of 9.4T MRI sequences for enhanced cellular visualisation of Multiple Sclerosis lesions
Authors: Giacomelli Elisabetta , Callegari Ilaria , Galbusera Riccardo , Bahn Erik , Ocampo-Pineda Mario , Lu Po-Jui , Cagol Alessandro , Leupold Jochen , Dhital Bibek , Weigel Matthias , von Elverfeldt Dominik , Kiselev Valerij G. , Stadelmann Christine , Granziera Cristina
Published: November 2024

Motivation: Accurately analyzing cell presence in multiple sclerosis (MS) lesions via magnetic resonance imaging (MRI) cannot be achieved without histopathological validation. Goal(s): Identification of biomarkers in MRI responsible for capturing microstructural alterations in brain tissues. Approach: Investigation of relations in the ratio between lesion and normal-appearing white matter (NAWM) in voxel values of postmortem 9.4 T MRI scans and in cell density values of histochemical images of three MS lesions. Results: We identified effective MRI sequences enhancing the contrast between the different features of the lesions and the NAWM and linked them to different cell type presence, as detected via quantitative histochemical analysis. Impact: The establishment of a robust connection between MRI data and histochemical features will improve our understanding of the MS lesions development and its impact on the brain microstructure.
Pathophysiology of Multiple Sclerosis (MS) Lesions Identified by Quantitative Ultra High Spatial Resolution (UHSR) MRI
Authors: Prasad Arvind , Sakaie Ken , Lowe Mark , Jones Stephen , Ontaneda Daniel , Chen Jacqueline , Nakamura Kunio , Obusez Emmanuel , Mahajan Kedar
Published: November 2024

Motivation: Remyelination is proposed as a strategy for neural repair in multiple sclerosis. Imaging biomarkers quantifying myelin are expected to play an important role for advancing remyelinating therapies. Goal(s): To assess quantitative T2* (QT2*) as an indicator of myelin density. Approach: MRI of a fixed MS brain hemisphere was used to identify lesions in gray and white matter. The lesions were subsequently analyzed with histology. Results: Significant correlations between QT2* and myelin histology were observed within and among lesions. Impact: Histology provides information on pathophysiology in exquisite detail but cannot be performed on the whole brain. This study demonstrates how quantitative UHSR can direct histology while evaluating potential imaging biomarkers for myelin density.
Temporal and spatial changes in Cerebral Blood Flow during fatigue resulting from maximum isometric contraction of the forearm
Authors: Brownbill Gemma , Murray Abby , Fitzsimmons Nora , Dekerle Jeanne , Stone James , Asllani Iris
Published: November 2024

Motivation: While fatigue is a common symptom in neurological conditions such as Multiple Sclerosis and Parkinson's, there is currently a lack of MRI studies that have investigated the CBF response to fatigue. Goal(s): To use ASL MRI to capture dynamic changes in CBF as muscles fatigued during maximal isometric effort. Approach: ASL CBF images were acquired pre, during, and post exercise on 7 healthy volunteers. Results: Primary motor cortex, supplementary motor cortex, putamen, and anterior cerebellum showed an increase in CBF followed by a gradual return to the baseline with a delay between the start of the decrease in CBF and the fatigue onset. Impact: As the use of MRI in neurological diseases involving fatigue continues to grow, the concurrent measurement of CBF alongside other physiological parameters holds the potential to yield valuable insights that could contribute to advancement of effective treatments and preventive strategies.
Normal appearing white matter and tracts in patients with multiple sclerosis: susceptibility properties and clinical disability evaluation
Authors: Fiscone Cristiana , Panzera Ivan , Manners David , Bartiromo Fiorina , Vornetti Gianfranco , Pollarini Virginia , Rundo Leonardo , Lodi Raffaele , Zaccagna Fulvio , Castelli Mauro , Lugaresi Alessandra , Tonon Caterina
Published: November 2024

Motivation: Magnetic susceptibility is influenced by myelin concentration, playing a significant role in the pathogenesis of MS as a demyelinating disease. Goal(s): This study aims to investigate normal-appearing-white-matter in MS patients using QSM, focusing on the cortico-spinal tract and optic radiation, to find non-invasive biomarkers of pre-clinical inflammatory activity. Approach: The automated implemented pipeline relies on the acquisition of multiple MR sequences. Several susceptibility histogram properties were considered and correlated with disability scores. Results: A decrease in myelin concentration was detected in MS group, consistently with the pathophysiology. Correlations between susceptibility and clinical disability occur, distinguishing clinical phenotypes and levels of motor impairment. Impact: Studying the normal-appearing-white-matter tracts using QSM reveals decrease in myelin concentration within cortico-spinal tract and optic radiation in MS patients. Variations were observed between different clinical phenotypes and various levels of motor impairment, suggesting biomarkers for early diagnosis and prognosis.
Investigation of Clear Cell Renal Cell Carcinoma Grades using Diffusion Relaxation Correlation Spectroscopic Imaging with Optimized Analysis
Authors: Luo Yuansheng , Song Yang , Wu Guangyu , Zhu Mengying
Published: November 2024

Motivation: The evaluation of diffusion-relaxation correlation spectrum imaging (DR-CSI) without prior knowledge has not been investigated. Goal(s): To differentiate high-grade from low-grade clear cell renal cell carcinoma using DR-CSI spectra in an equal separating analysis. Approach: The DR-CSI spectrum was segmented into multiple equal subregions from 2*2 to 9*9 and was evaluated based on their accuracy and repeatability. Results: Interreader agreement decreased as divisions in the equipartition model increased (from 0.859 to 0.920). Accuracy increased from 2x2 to 9x9 model (0.68 for 2x2, 0.69 for 3x3 and 4x4, 0.70 for 5x5, 0.71 for 6x6, 0.78 for 7x7, and 0.75 for 8x8 and 9x9). Impact: This study validated an method for extracting information from DR-CSI spectra based on the differentiation of high-grade from low-grade ccRCC without prior knowledge. It provides a reference for processing DR-CSI spectra, helping this technology be applied to other clinical scenarios.
Multi-site Scanner Characterisation for Global Ultra-low Field MR Imaging
Authors: Ljungberg Emil , Padormo Francesco , Evans John , Clemensson Petter , Kolind Shannon , Lafayette Samson , Bennallick Carly , Bradford Layla , Donald Kirsten , Khosa Able , Vokhiwa Maclean , Shama Talat , Pepper Michael , De Canha Alexica , Sekoli Lydia , Van Rensburg Jeanne , Hollander William , Karaulanov Todor , Williams Steve , Deoni Sean
Published: November 2024

Motivation: Combining data from multiple sites is necessary in order to reach large sample sizes. This can be challenging, especially with portable ultra-low field (ULF) systems where conditions can vary. Goal(s): To characterise image quality across multiple sites using ULF-MRI for future data harmonization. Approach: Acquisition of QA scans across sites with centralised analysis for cross-sectional and longitudinal assessment. SNR and T2w contrast were calculatedResults: SNR was consistent within site, but some variation between sites. Image contrast was consistent, but extra care should be taken with software updates. Impact: Quality assurance is essential for portable ultra-low field MRI. Our results demonstrate that SNR and contrast are useful metrics for image quality characterisation. This paves the way for harmonization of in vivo data in global studies using ultra-low field MRI.
Challenges and recommendations for MRI protocol development in clinical practice: a UK based survey.
Authors: Grech-Sollars Matthew , Elbert Holly , Lopez Maria Yanez
Published: November 2024

Motivation: MR protocol development in a clinical setting is essential for running an optimal MRI service within Radiology. However, there is no clear path to implementation. Goal(s): The purpose of this study was to understand the varied nature of MR protocol development within the clinical setting in the UK. Approach: We conducted a survey on MR protocol development, and approached MR Physicists, Radiographers and Radiologists within the UK. Results: Results highlighted the current lack of resources, particularly scanner and staff time. Respondents also highlighted the importance of implementing processes, enabling communication and disseminating results. Impact: Establishing good practice in MRI protocol development can lead to major improvements within the radiological workflow, including efficiency and image quality gains for higher quality diagnosis and increased patient throughput.
RIMLA: Reproducibility-Informed Method for Longitudinal Assessment
Authors: Ravano Veronica , Andelova Michaela , Piredda Gian Franco , Sommer Stefan , Caneschi Samuele , Roccaro Lucia , Krasenky Jan , Kudrna Matej , Uher Tomas , Corredor-Jerez Ricardo , Disselhorst Jonathan , Maréchal Bénédicte , Hilbert Tom , Thiran Jean-Philippe , Richiardi Jonas , Horakova Dana , Vaneckova Manuela , Kober Tobias
Published: November 2024

Motivation: Estimating longitudinal changes in imaging biomarkers is challenging due to the multiple sources of variation during acquisition that can influence the analysis of MRI data. Goal(s): To provide a robust estimate of longitudinal changes based on the comparison of cross-sectional imaging biomarkers from different time points. Approach: We introduce RIMLA, a Reproducibility-Informed Method for Longitudinal Assessment that quantifies longitudinal imaging biomarker changes while accounting for the robustness of the underlying image processing algorithm. Results: As a first application, we show that RIMLA allows to identify multiple sclerosis lesion subtypes characterized by statistically significant enlargement or shrinkage over time. Impact: The here introduced Reproducibility-Informed Method for Longitudinal Assessment (RIMLA) allows to robustly detect small longitudinal changes in quantitative biomarkers. This increase in sensitivity can lead to better informed clinical decisions, for example during treatment monitoring or disease progression follow-ups.
Quality assurance of quantitative MRI protocol for a hypoxia imaging clinical study in glioblastoma
Authors: Wang Yu-Feng , Drummond James , Mueller Marco , Keall Paul , O'Brien Kieran , Booth Jeremy , Yim Jackie , Parkinson Jonathon , Silvester Shona , Bailey Dale , Back Michael , Luton Heidi , Waddington David , Brighi Caterina
Published: November 2024

Motivation: A quantitative MRI (qMRI) protocol was developed for a clinical study aimed at identifying regions of tumour hypoxia in glioblastoma patients. Technical validation of qMRI biomarkers requires thorough testing of the protocol against reference standards. Goal(s): To assess and report accuracy, repeatability, and reproducibility of the qMRI protocol. Approach: Test-retest scans of the NIST systems phantom were acquired on two 3T MAGNETOM VIDA scanners. Accuracy, repeatability and reproducibility of T1, T2 maps, and calibrated T1 maps from dynamic oxygen enhanced imaging were assessed. Results: qMRI parameters acquired with the study protocol showed accuracy, repeatability and reproducibility comparable to published literature findings. Impact: Accuracy and precision (repeatability and reproducibility) of a qMRI protocol for glioblastoma hypoxia imaging were quantified. T1, including calibrated dynamic values, showed high accuracy and precision. T2 showed low accuracy compared to published findings. T2 and T2* showed moderate precision.
Translating multiparametric, quantitative MRI from 3T to 7T: A preliminary study.
Authors: Abbas Zaheer , Worthoff Wieland , Oros-Peusquens Ana-Maria , Shah N. Jon
Published: November 2024

Motivation: Quantitative MRI at clinical strengths is well-established, yet RF inhomogeneity at ultrahigh-field strength, such as 7T, complicates tissue-specific measurement. Goal(s): To extend quantitative water content mapping from clinical to ultrahigh-field MRI. Approach: We utilize a modified variable flip angle method to acquire high-resolution parametric maps at 7T within 7.5 minutes. Results: Method validity is affirmed by comparing water content and relaxometry data from a healthy cohort against 3T benchmarks and reported literature. Impact: This technique paves the way for advanced brain tissue analysis at ultrahigh-field MRI (7T), crucial for accurate neurological assessment.
Quantification of downstream metabolites in healthy participants using 7T DMI following [2H2] glucose and [2H7] glucose ingestion
Authors: Cocking Daniel , Damion Robin , Simpson Elizabeth , Auer Dorothee , Bowtell Richard
Published: November 2024

Motivation: Most Deuterium Metabolic Imaging (DMI) studies have employed doubly labelled D2-glucose, but fully labelled D7-glucose produces higher deuterium concentrations in the brain, providing higher signal-to-noise-ratio measurements and additional information about metabolism. Goal(s): We carried out a detailed comparison of 7T DMI measurements in the brain in 15 participants who ingested either D7-glucose or D2-glucose. Approach: 3D 2H CSI data was acquired at 7T at natural abundance and then every 15 minutes for ~65- minutes following ingestion of 0.75 g/kg of labelled glucose. Results: Larger signals and concentrations were measured following D7-glucose ingestion, D7/D2 signal ratios were explained by differing numbers of labels. Impact: Deuterium metabolic imaging (DMI) using labelled glucose forms a powerful tool for mapping glucose metabolism. D7-glucose produces higher deuterium concentrations in the brain, providing a higher signal-to-noise-ratio that would be valuable in studies of metabolism in health and disease.
MRI assessment of skin and muscle sodium (23Na) and fluid volume in haemodialysis patients
Authors: Prestwich Ben , Noble Rebecca , White Kelly , Taal Maarten , Selby Nicholas , Francis Susan
Published: November 2024

Motivation: To improve understanding of sodium and water balance in haemodialysis patients. Goal(s): To study sodium stores in leg muscle and skin in younger and older healthy individuals, and haemodialysis patients, and to assess sodium and water changes following a single haemodialysis session. Approach: Sodium (23Na) MRI of calf skin and muscle in younger older and haemodialysis(HD) patients. 23Na MRI, and 1H mDIXON and T2 relaxometry to study sodium and water content to haemodialysis. Results: Haemodialysis led to a significant reduction in muscle sodium whilst skin sodium showed little detectable change, 1H muscle T2 values showed a significant reduction. Impact: Sodium (23Na) MRI of muscle allows the study of sodium storage with age and in dialysis patients. 23Na and proton (1H) T2 mapping enable the assessment of changes in sodium storage and fluid status in haemodialysis patients.
Dynamic 2D fitting of 3D deuterium metabolic imaging data acquired in human brain at 7T
Authors: Frese Sabina , Clarke William , Jbabdi Saad , Strasser Bernhard , Bogner Wolfgang , Bader Viola , Hingerl Lukas , Motyka Stanislav , Krssak Martin , Trattnig Siegfried , Scherer Thomas , Lanzenberger Rupert , Niess Fabian
Published: November 2024

Motivation: Dynamic deuterium metabolic imaging (DMI) data are currently evaluated by first fitting the spectral and then the temporal domain (1D), leading to great fit uncertainty. This might be improved by fitting both domains simultaneously (2D). Goal(s): To compare dynamic 2D-fitting of time-resolved 3D-DMI data of the human brain and compare its performance to conventional 1D-fitting. Approach: Simulated and in vivo DMI data were fitted using 1D- and 2D-fitting algorithms and results were compared in terms of precision and accuracy. Results: 2D-fitting yielded higher precision and accuracy than 1D-fitting for simulated DMI data. For in vivo data, both fitting approaches yielded similar results. Impact: Improving fitting accuracy to estimate the underlying metabolic kinetics from dynamic deuterium metabolic imaging (DMI) data is crucial, while establishing DMI towards clinical application. 2D-fitting approaches (simultaneous spectral and temporal fitting) could potentially improve overall robustness of the methodology.
Detecting glucose metabolism abnormality in Six-Month-Old AD mice using deuterium magnetic resonance imaging
Authors: Yang Ganghan , Wan Qian , Peng Hao , ZHou Yang , Duan Junyi , Li Jiaxu , Zhang Shiyi , Xiao Enhua , Liu Xin , Li Ye , Zou Chao
Published: November 2024

Motivation: Impaired brain energy metabolism at early stage is found to be the driving factor of Alzheimer’s Disease (AD) progression. Goal(s): The study aim to investigate the potential of using deuterium magnetic resonance imaging to characterize the glucose metabolism in AD mouse model. Approach: Deuterium magnetic resonance spectroscopic imaging with the administration of [2,3,4,6,6’-2H5]-D-Glucose in 5xFAD and C57 mice. Results: Our preliminary results indicate higher glutamine/glutamate (Glx) production rate in 5xFAD mice compared to normal mice, especially in the hypothalamus region. Impact: Our work may shed light on developing new method in the early detection of AD based on the glucose metabolism abnormality.
A data-driven approach for improved quantification of in-vivo metabolic conversion rate of hyperpolarized [1-13C]pyruvate
Authors: Kim Yaewon , Nickles Tanner , Lee Philip , Bok Robert , Gordon Jeremy , Larson Peder , Vigneron Daniel , Ohliger Michael
Published: November 2024

Motivation: Accurate quantification of metabolism in hyperpolarized (HP) 13C MRI is essential for clinical application. However, kinetic model parameters such as flip angle are often uncertain, leading to model mismatch. Goal(s): We aimed to develop a data-driven approach to quantify the HP pyruvate-to-lactate conversion rate (kPL) for with improved accuracy. Approach: To validate our method, we conducted numerical simulations and animal studies with HP 13C-pyruvate and applied this method to human abdominal data. Results: Our findings revealed that the data-driven kinetic fitting method can improve model-data fits by correcting flip angle and relaxation errors, resulting in more accurate kPL determination. Impact: Using the new data-driven kinetic fitting method to quantify HP 13C-pyruvate metabolism, accurate kPL can be obtained even in the presence of B1 inhomogeneity. This improvement may prove to be clinically valuable in improving tumor staging or assessing treatment-response.
Portable polarizer for clinical-scale metabolic MRI of hyperpolarized pyruvate
Authors: Korchak Sergey , Felger Jan , Moll Denis , Schroeder Henning , Glöggler Stefan
Published: November 2024

Motivation: The limited availability and accessibility of cost-effective quantities of 13C-hyperpolarized metabolites, such as pyruvate, acts as a significant barrier to the advancement and practical clinical implementation of metabolic-driven molecular imaging, especially in early-stage cancer detection. Goal(s): Objective is to develop a portable device capable of delivering sufficient, clinically relevant doses of hyperpolarized pyruvate to support medical applications. Approach: We employ the Parahydrogen-Induced Polarization with Side Arm Hydrogenation approach, which offers a faster (~1min) and more cost-efficient alternative to the prevailing state-of-the-art technology, dissolution Dynamic Nuclear Polarization. Results: Our polarizer routinely produces a 40ml dose of hyperpolarized 13C-pyruvate-d3, containing a concentration exceeding 100mM. Impact: Enhancing accessibility to clinically relevant hyperpolarized pyruvate will empower more MR research groups to leverage its potential. This development also paves the way for easier translation to clinical settings, ultimately benefiting cancer patients by supporting early detection and diagnosis capabilities.
Optimal, AUC-Derived Coil Combination Coefficients for Hyperpolarized 13C Imaging
Authors: Wang Qing , Walker Christopher , Harlan Collin , Boyce Ryan , Sony Cade , Lai Stephen , Bankson James
Published: November 2024

Motivation: B1-maps that are used for optimal combination in array coils are generally unavailable for hyperpolarized (HP) MRI. Alternative methods for determining optimal combination coefficients are needed. Goal(s): To show that optimal combination coefficients can be derived from area-under-the-curve (AUC) and noise measurements to maximize SNR in HP MR imaging and spectroscopy. Approach: We derive combination coefficients from AUC and noise covariance measurements, simulate noisy HP 13C-pyruvate and 13C-lactate signals, and analyze the SNR of combined signals using this method compared to sum-of-squares (SoS) combination. Results: Simulated 13C HP signals that were combined using this approach demonstrated higher SNR compared to the SoS method. Impact: The optimal combination coefficients for HP 13C in MR imaging and spectroscopy can be derived from AUC and noise covariance measurements. This straightforward method can enhance SNR for HP 13C MRI.
Employ diffusion kurtosis imaging in conjunction with the XGBoost model to unveil white matter abnormalities in pediatric autism
Authors: Shen Yanyong , Zhao Xin , Wang Kaiyu , Sun Yongbing , Zhang Xiaoxue , Wang Changhao , Yang Zhexuan , Feng Zhanqi , Zhang Xiaoan
Published: November 2024

Motivation: The diagnosis of Autism Spectrum Disorder (ASD) poses a substantial challenge, primarily due to the lack of a definitive biomarker. Goal(s): Our primary objective is to uncover white matter irregularities prevalent in pediatric autism. Approach: Our study leveraged Tract-Based Spatial Statistics (TBSS) analysis to scrutinize deviations in the white matter microstructure in ASD, and we implemented an eXtreme Gradient Boosting (XGBoost) model to effectively differentiate between individuals with ASD and healthy controls. Results: Through the TBSS analysis, we identified notable disparities between groups. Moreover, the XGBoost model demonstrated exceptional proficiency in accurately classifying individuals with ASD and healthy controls. Impact: This study delved into the white matter microstructural alterations in individuals with ASD by examining DKI data and its associated white matter tract integrity (WMTI) metrics. Additionally, our machine learning findings offered fresh perspectives toward objectively diagnosing ASD.
Altered brain structural and functional network in children and adolescents with drug-resistant epilepsy
Authors: Li Xuhong , Zhang Tijiang
Published: November 2024

Motivation: Epilepsy is widely regarded as a brain network disorder. However, few studies have investigated the interaction between brain structural networks and functional networks in epilepsy. Goal(s): To investigate the topological alterations of brain networks in children and adolescents with drug-resistant epilepsy. Approach: Global graph theoretic network measures of global properties, nodal properties and rich club organizational properties were computed. Results: Aberrant topological attributes and connectivity patterns have been found in DRE. Rich-club connectivity was lower in patients with DRE than that in controls. Impact: Altered Dc in the left pallidum may provide a new theoretical basis for clinical treatment of DRE. The present findings enhanced our understanding of the neurophysiologic mechanisms associated with DRE.