bluuebunny/crossref_metadata_2025 huggingface dataset:
High SNR rapid T1-weighted MP-RAGE and MP-FISP using a 3D stack-of-spirals trajectory at 0.55 T
Authors: Lee Nam , Tasdelen Bilal , Nayak Krishna
Published: November 2024

Motivation: Acquiring High SNR T1-weighted MP-RAGE at low field strengths, such as 0.55T, often requires multiple averages due to reduced equilibrium polarization (~30 min for 3 averages). Goal(s): Provide high SNR MP-RAGE (and MP-FISP) within a reasonable scan time (~15 min) using an SNR-efficient readout while mitigating spatial blurring caused by static off-resonance and concomitant fields. Approach: MP-RAGE and MP-FISP sequences with a stack-of-spirals trajectory were implemented with the Pulseq framework. Spatial blurring was mitigated using the MaxGIRF framework implemented in BART. Results: Spiral MP-RAGE achieves comparable image quality and higher SNR relative to Cartesian MP-RAGE given only half of the scan time. Impact: This work demonstrates the feasibility of acquiring high SNR T1-weighted structural brain imaging at 0.55T within a reasonable scan time (~15 min). This opens opportunities for structural neuroimaging and harmonized multi-site studies via code sharing with open-source frameworks.
Cellular signatures of microstructural development in the human cerebral cortex
Authors: Genc Sila , Ball Gareth , Chamberland Maxime , Raven Erika , Tax Chantal , Yang Joseph , Palombo Marco , Jones Derek
Published: November 2024

Motivation: The adolescent brain has been well described using MRI, revealing ongoing cortical thinning and volume loss. But which underlying cellular properties drive these changes?Goal(s): To model developmental patterns of soma and neurite architecture in the human cerebral cortex. Approach: We quantified in vivo cortical neurite and soma microstructure in a sample of children and adolescents aged 8-18 years. We then analysed two human gene expression databases to determine cell-type specific profiles underlying these MR-based changes. Results: Developmental increases in neurite density and reductions in soma radius suggest increasing cortical oligodendrocyte density, supporting the model of protracted intra-cortical myelination throughout the adolescent period. Impact: Our novel study suggests that ongoing intracortical myelination underpins developmental patterns of cortical neurite and soma microstructure. Once thought to be driven by synaptic pruning, increasing cortical oligodendrocyte density may underlie previously reported patterns of cortical volume loss in adolescence.
Neurological Underpinning of Cortical Folding in the Human Fetal Brain Using In-utero MRI-Informed Computational Modeling
Authors: Chen Ruike , Xu Xinyi , Zhao Ruoke , Li Mingyang , Zhao Zhiyong , Wu Dan
Published: November 2024

Motivation: Computational models may help to decipher the neuroscientific mechanisms of cortical folding. Past simulations relied on histology or ex-vivo MRI data, which may not fully capture the complexity of in-utero brain development. Goal(s): To build a simulation model leveraging in-utero MRI data to elucidate how cortical microstructures impact fetal brain gyrification. Approach: Based on diffusion MRI-measured microstructures, we simulated cortical folding in the right temporal lobe using a computational model. Results: Differences in fiber density between sulci and gyri are critical for folding initialization and development, linked to regional differences in dendritic arborization. Simulation results agreed with experimentally measured fetal brain morphology. Impact: Our work introduced a novel computational model that utilized in-utero MRI data to simulate the cortical folding process of the human fetal brain, suggesting local differences in dendritic arborization may be one of the driving forces of cortical folding.
Higher Overall Pulsatile CSF flow Variance in Congenital Heart Disease Predict Poor Executive Function
Authors: Lee Vincent , Reynolds William , Wallace Julia , Beluk Nancy , Badaly Daryaneh , Ceschin Rafael , Lo Cecilia , Panigrahy Ashok
Published: November 2024

Motivation: Examine cerebrospinal fluid (CSF) flow abnormalities in congenital heart disease (CHD) and develop an evaluation method to measure the CSF flow variance over the entire CSF flow cycle. Goal(s): Determine CSF flow difference between CHD and healthy controls. Evaluate effectiveness of new method to measure CSF flow variance. Approach: Use phase contrast MRI to acquire CSF flow velocity over the pulsatile flow cycle. Model consensus CSF flow of study cohort and calculate each participant’s flow variance using root mean square deviation. Results: CHD had greater pulsatile CSF flow variance, especially in CHD with single ventricle. Higher flow variance predicted poor working memory outcomes. Impact: This study expands our understanding of CSF flow abnormality in CHD and its potential for predicting executive function deficit. A new method measuring CSF flow variance over the entire flow cycle offers an evaluation of CSF flow abnormalities more comprehensively.
Association of glymphatic and white matter impairment with outcomes of paediatric hydrocephalus after ventriculoperitoneal shunt
Authors: Zhao Cailei , OuYang YiPing , Zhang Gongwei , Zang Dongdong , Xia Jun , Liang Guohua , Ye Miaoting , Wang Jingsheng , Gan Yungen , Zhou Yangyang , Yang Jian , Li Xianjun
Published: November 2024

Motivation: Whether there exist association between glymphatic/white matter impairment and postoperative outcomes of paediatric hydrocephalus. Goal(s): We tried to investigate the glymphatic and white matter abnormalities in paediatric hydrocephalus using MRI metrics. Approach: Fifty-five children with hydrocephalus who underwent MRI and ventriculoperitoneal shunt surgery were prospectively enrolled. DTI metrics were analyzed. Results: Compared with controls, DTI-ALPS index decreased before surgery and recovered after surgery. The preoperative and postoperative DTI-ALPS index and FA in association fibres could predict the short-term motor and long-term cognition outcomes, respectively. Impact: The DTI-ALPS index and FA could be a sensitive biomarker of underlying neuroanatomical changes and developmental outcomes, which would benefit the decision-making of treatment plans.
The causal effect of screen uses versus reading on the brain development in early adolescents
Authors: Li Mingyang , Zhao Ruoke , Dang Xixi , Xu Xinyi , Chen Ruike , Chen Yiwei , Zhang Yuqi , Zhao Zhiyong , Wu Dan
Published: November 2024

Motivation: The causal relationships between screen use and mental health were not clear. Goal(s): We used genetic, imaging, and questionnaire data from ABCD study to investigate the causal relationships between screen use and mental health in early adolescents. Approach: One-sample Mendelian randomization analysis. Results: We found a direct causal relationship between screen use and behavior problems and an indirect effect between screen use and brain volume by the changes in reading habits. Impact: These findings provide new evidence for a causal influence of screen use and reading habits on brain development and highlight the importance of monitoring media use and related habits change in children.
The Impact of Pancreatic Cancer Glutamine Transporter Downregulation on Cachexia and Visceral Organ Metabolism
Authors: Sharma Raj Kumar , Krishnamachary Balaji , Winnard Paul , Mironchik Yelena , Penet Marie France , Bhujwalla Zaver
Published: November 2024

Motivation: We previously identified alterations in brain and plasma glutamine/ glutamate with cachexia that led us to downregulate the glutamine transporter, SLC1A5, in the cachexia-inducing patient derived Pa04C PDAC cells. Goal(s): Targeting the glutamine transporter represents a promising approach to delay tumor progression and establish a novel treatment strategy in PDAC cachexia. Approach: We performed 1H MRS to determine the metabolic changes in multiple organs of mice. Results: We identified metabolic differences in organs of mice bearing SLC1A5 downregulated tumors compared to wild type or empty vector tumors. Our data identify SLC1A5 as a target to reduce PDAC induced cachexia and associated pathways Impact: By detecting these visceral organ metabolic changes we identified potential metabolic pathways that can be targeted to reduce cachexia.
Predicting the response of I-SPY 2 breast cancer patients to treatment using a biology-based mathematical model calibrated with quantitative MRI
Authors: Patel Reshmi , Wu Chengyue , Stowers Casey , Mohamed Rania , Ma Jingfei , Rauch Gaiane , Yankeelov Thomas
Published: November 2024

Motivation: Optimizing treatment to improve outcomes necessitates a robust tool to accurately predict breast cancer response on a patient-specific basis. Goal(s): We are applying our biology-based mathematical model to I-SPY 2 breast cancer patients to test if its predictive ability generalizes to multi-site data. Approach: Quantitative contrast-enhanced and diffusion-weighted MRI data collected early during treatment were used to calibrate a mathematical model describing tumor cell movement, proliferation, and response. After calibration, the model predicts tumor status after the treatment regimen. Results: The concordance correlation coefficient between the measured and predicted 9-week change was 0.91 for tumor cellularity and 0.88 for tumor volume. Impact: The high degree of agreement between measured and predicted changes in tumor cellularity and volume in the I-SPY 2 dataset indicates that our biology-based mathematical model can potentially make accurate predictions using MRI data from multiple clinical sites.
The feasibility study of multiple functional imaging modalities in the differential diagnosis of benign and malignant bone tumors
Authors: Li Ying , Ren Cuiping , Zhang Wenhua , Zhang Yong , Cheng Jingliang , Zheng Dandan , Lin Liangjie
Published: November 2024

Motivation: The combination of multi-MRI techniques in the differential diagnosis of benign and malignant bone tumors represents a novel endeavor. Goal(s): To investigate the utility of combining DWI, IVIM, DKI and APTWI in the differential diagnosis of benign and malignant bone tumors. Approach: Relevant parameters of 45 patients were statistically compared through either the independent samples t-test or Mann-Whitney U test. Diagnostic performance was assessed using ROC curves for both individual examinations and their combined analysis in distinguishing between benign and malignant tumors. Results: The combination of multi-MRI techniques proves to be a more effective approach in distinguishing between benign and malignant bone tumors. Impact: Multimodal MRI provides biological and pathological information about the tumor cell microenvironment, and their combination proves to be a more effective approach in distinguishing between benign and malignant bone tumors.
Phase-Specific Spatiotemporal Fractal Analysis and Radiomics of Free-breathing Stress Myocardial Perfusion
Authors: Sun Changyu , Kumar Senthil , Altes Talissa
Published: November 2024

Motivation: This research advances quantitative analysis of myocardial perfusion MRI, potentially enhancing the precision of coronary microvascular disease diagnosis. Goal(s): To establish a novel spatiotemporal radiomics and fractal analysis approach, assessing myocardial perfusion patterns and complexity throughout all temporal frames of stress MRI. Approach: Employing free-breathing stress myocardial perfusion MRI, we utilized a comprehensive pixel-by-pixel spatiotemporal feature extraction, alongside phase-specific analysis, to derive global and segmental perfusion insights. Results: Preliminary results indicate our method's efficacy in motion correction and feature extraction, offering a new quantitative perspective on myocardial perfusion, potentially relevant for CMD assessment. Impact: The study introduces a framework that quantitatively captures myocardial perfusion patterns, potentially paving the way for enhanced diagnostic methods in coronary microvascular disease and facilitating a more precise approach to patient assessment.
Quantification of Cyclical Changes in Myocardial Blood Volume Using a Hybrid 3D/2D Sequence with Ferumoxytol-enhanced MRI
Authors: Unal Hazar Benan , Zeynali Shahriar , Dharmakumar Rohan , Sharif Behzad
Published: November 2024

Motivation: Intramyocardial blood volume (iMBV) variations during cardiac cycle can be an important marker for detecting ischemic heart disease. However, quantifying the change in iMBV from diastole to systole under MRI has challenges such as through-plane motion or in-flow of unsaturated spins. Goal(s): Our goal is to perform accurate quantification of iMBV variations from diastole to systole. Approach: We developed a novel hybrid 3D/2D pulse sequence with continuous golden-angle radial acquisition to suppress the confounding factors for distinguishing diastolic and systolic iMBV. Results: Our approach successfully showed that cyclic variations in iMBV can be correctly quantified under ferumoxytol-enhanced MRI. Impact: We introduced, for the first time, an approach to quantify cyclic systolic and diastolic intramyocardial blood volume variations at rest on a clinical scanner with ferumoxytol-enhanced imaging. Our method has the potential to be used for detecting ischemic heart disease
Multi-Contrast 3D Whole-Heart MRI for Intramyocardial Hemorrhage Stage Assessment in Patients with Myocardial Infarction
Authors: Liu Xin , Jing An , Zhang Chen , Kunze Karl-Philipp , Neji Radhouene , Botnar René , Prieto Claudia , Yang Qi
Published: November 2024

Motivation: Intramyocardial hemorrhage (IMH) staging can serve as a valuable reference point when exploring treatment options for this condition, but methodsfor detecting IMH staging has not been fully examined. Goal(s): This study investigated whether BOOST, a novel iNAV-based free-breathing, multi-contrast 3D whole-heart MRI sequence could detect and stage IMH. Approach: The efficacy of BOOST in diagnosing and staging IMH were compared with the performances of conventional T2* sequences. Results: BOOST, used for IMH detection at 3T, demonstrates superior sensitivity and specificity, along with good quantitative consistency, relative to T2* alone. Additionally, BOOST has substantial potential for IMH staging. Impact: The BOOST sequence can be used for future IMH staging, which will facilitate precise multi-dimensional IMH assessment, ultimately enabling accurate and targeted IMH treatment.
Association Between Epicardial Adipose Tissue volume and Microvascular Obstruction in Patients with STEMI
Authors: Mu Dan , Zhao Jinxuan , Yu Hongming , Liang Jing , Xu Biao , Zhao Xiance , Yue Xiuzheng , Zhang Zhongping , Zhang Bing
Published: November 2024

Motivation: Microvascular obstruction (MVO) after primary percutaneous coronary intervention (pPCI) is identifed as an independent risk factor for poor prognosis in patients with acute myocardial infarction (AMI). However, the clinical implications of Epicardial adipose tissue (EAT) in microvascular obstruction formation in patients with ST-segment elevation myocardial infarction (STEMI) remain unclear. Goal(s): This study aimed to evaluate the correlation between EAT and MVO volume detected by CMR in STEMI patients. Approach: Cardiac magnetic resonance (CMR) has emerged as the gold standard technique to detect the extent of MVO and evaluate EAT volume. Results: Left atrioventricular EAT mass index is an independent predictor of MVO. Impact: Measurement of EAT using CMR could be used for risk stratification and may be a promising target in developing new therapies to reduce myocardial reperfusion injury in patients with STEMI.
T1 measurement in CSF: Intrinsic compartmental differences and tracer concentration assessment in the healthy brain
Authors: Storås Tryggve , Svensson Siri , Lian Sofie , Ringstad Geir , Mossige Ingrid , Løvland Grethe , Undseth Ragnhild , Emblem Kyrre , Nordengen Kaja
Published: November 2024

Motivation: T1 mapping facilitates assessment of brain waste clearance by assessing native solutes or detection of endogenous tracers. Goal(s): To provide a method for accurate measurement of T1 in CSF, to investigate variations in intrinsic T1 of CSF and to measure tracer in CSF after intrathecal administration. Approach: A T2-weighted mixed spin-echo/inversion recovery sequence was implemented to measure T1 in CSF. Five healthy subjects were imaged prior to and four times after intrathecal gadobutrol injection. Results: Baseline R1 is lower in the ventricles than in the subarachnoid space. At 72 hours after injection, there is still gadobutrol in the subarachnoid space. Impact: Accurate T1 measurements in CSF facilitate quantitative study of brain clearance as concentration of Gd-based tracers in CSF can be established. Observed compartmental differences in intrinsic T1 of CSF indicate information on solute concentrations can be measured without endogenous tracer.
Distribution of intravenous Gadolinium-based contrast agents (GBCA) in human olfactory regions in healthy subjects
Authors: Zhou Xinyi , Cervera Sofia Garcia Del Barrio , Sun Yuanqi , Li Wei , Pacheco-Luna Licia , Sair Haris , Paez Adrian , Knutsson Linda , van Zijl Peter , Kamath Vidyulata , Bakker Arnold , Ward Bryan , Hua Jun
Published: November 2024

Motivation: Animal studies show that the olfactory pathway is a primary CSF clearance route. However, human studies using intrathecal-GBCA show that the olfactory route may be less involved in CSF clearance in humans. As most GBCA-enhanced MRI exams are still performed using intravenous-GBCA, it is essential to investigate GBCA dis-tribution in human olfactory regions after intravenous GBCA administration. Goal(s): To measure intravenous-GBCA-induced signal changes in olfactory regions. Approach: Dynamic-susceptibility-contrast-in-the-CSF (cDSC) MRI was performed in 25 healthy subjects. Results: Significant MR signal changes were detected in the olfactory regions following intravenous-GBCA. Extracranial regions showed more significant GBCA-induced changes than intracranial regions. Impact: GBCA-induced cDSC signal changes were detected in olfactory regions of healthy subjects following intravenous GBCA administration. Extracranial regions showed more significant changes than intracranial regions, stressing the importance of separating these areas when studying GBCA distribution using intravenous injection.
Simultaneous arterial, venous, and CSF flow dynamics using interleaved multi-Venc spiral imaging
Authors: Johnson Kevin , Rivera Leonardo Rivera
Published: November 2024

Motivation: Neurofluids dynamics are hypothesized to enable brain metabolite waste clearance pathways for healthy brain function including coupling between arterial, venous, and CSF fluid flow. Goal(s): To enable quantification of arterial, venous and CSF flow simultaneously leveraging interleaved multi-Venc phase contrast encoding and spiral sampling. Approach: A four-point velocity encoding scheme was integrated into a 2D golden angle spiral phase contrast sequence and used in studies of healthy subjects. The flow encoding collects multiple first moments at a fixed echo time. Results: The multi-Venc encoding scheme allowed for simultaneous measures of cardiac-resolved arterial, venous, and CSF flow. Impact: This work demonstrates a method for simultaneous arterial, venous, and CSF flow imaging for imaging neurofluid dynamics and their response to stimuli, challenges, and transient patient states.
Simultaneous 4D CSF flowmetry and BOLD fMRI using EPTI for investigation of neural activity evoked CSF flow responses
Authors: Wang Fuyixue , Reese Timothy , Rosen Bruce , Wald Lawrence , Lewis Laura , Polimeni Jonathan , Dong Zijing
Published: November 2024

Motivation: To investigate brain-wide CSF flow dynamics and how neural activity drives it. Goal(s): Develop a novel tool to simultaneously map CSF flow and T2*-BOLD fMRI with high sensitivity/specificity and effectively measure neural-activity-evoked CSF flow. Approach: Single-shot PGSE-EPTI is developed with high sensitivity to slow flow to acquire distortion-free phase-contrast flow velocity and directions, while simultaneously obtaining clean T2*-BOLD, T2, S0 contrasts with improved specificity. Results: Using the EPTI CSF flowmetry technique, brain-wide CSF dynamics were measured with high spatiotemporal details, and visual-task-evoked CSF flow responses were observed in both ventricles (global-response) and visual cortex subarachnoid space (local-response), synchronized with the simultaneously-acquired T2*-BOLD-fMRI signal. Impact: We developed a novel EPTI CSF-flowmetry technique to simultaneously map whole-brain CSF flow and T2*-BOLD-fMRI with high sensitivity/specificity for investigation of neural-activity-driven CSF flow. It successfully measured both global and local visual-task-evoked CSF flow responses in ventricles and visual-cortex subarachnoid-space.
Unpaired Image-to-Image Translation of ULF-MRI using Vision Transformers to Advance Volumetric Analyses
Authors: Hsu Peter , Marchetto Elisa , Sanger Samantha , Chandarana Hersh , Asslaender Jakob , Sodickson Daniel , Johnson Patricia , Veraart Jelle
Published: November 2024

Motivation: The image quality of ultra-low-field MRI impacts the reliability of volumetric analysis in the brain. Existing techniques that address this issue learn from synthetically generated images, leading to a domain shift problem when presented with real images. Goal(s): Development of a deep learning method trained with real ULF and HF images to robustly generate an image that can be segmented with routine software tools. Approach: We introduce a CycleGAN framework with Residual Vision Transformers to improve super-resolved images compared to existing methods. Results: The accuracy of volumetric estimations improves using our method compared to others based on clinical correlations and test-retest reliability metrics. Impact: Our new image enhancement method should allow reliable volumetric evaluation using ULF-MRI. This will allow investigators in regions with access to ULF systems to monitor brain health in a way that was previously unattainable.
Dynamic Contrast-Enhanced MRI Parameter Mapping for Cervical Cancer Using CycleGAN-like model with UNet-Vision Transformer
Authors: Jin Yuxi , Lin Gengjia , Liu Zhou , Chen Zixiang , Huang Zhenxing , Qian Yang , Wang Baijie , Zhang Na , Zheng Hairong , Liang Dong , Luo Dehong , Hu Zhanli
Published: November 2024

Motivation: DCE-MRI plays an important role in non-invasive detection and monitoring of cervical cancer, providing key information for improving diagnosis and treatment accuracy. Goal(s): DCE-MRI faces complexities and noise issues in application and needs to be optimized and improved by deep learning techniques for parameter mapping. Existing deep learning based methods suffer from limited data and model efficiency. Approach: We propose a CycleGAN-like model with UNet-Vision-Transformer generator, enhance the discriminator with gradient penalty, and pre-train the model via self-supervised image inpainting. Results: The numerical experimental results demonstrate that the proposed model is quite efficient and robust compared with other deep learning-based methods. Impact: This research offers fresh avenues for processing medical imaging data by proposing a novel and efficient deep learning model, significantly impacting the improvement of disease diagnosis. Furthermore, it provides researchers with new directions and insights, advancing scientific and technological progress.
3D Hybrid Deep Learning Solution for Subcortical Segmentation
Authors: Cao Aaron , Rao Vishwanatha , Liu Xinru , Guo Jia
Published: November 2024

Motivation: For subcortical brain segmentation, the most widely accepted tools like FreeSurfer are slow and inefficient for large datasets, while faster methods often sacrifice accuracy and reliability. Goal(s): In this study, we propose a novel deep learning based alternative and achieve consistent state-of-the-art performance within reasonable processing times. Approach: Our model, TABSurfer, utilizes a 3D patch-based approach with a hybrid CNN-Transformer architecture. Results: We evaluated TABSurfer against FreeSurfer ground truths across various T1w MRI datasets, consistently demonstrating strong performance over a leading deep learning benchmark, FastSurferVINN. Then, we validated TABSurfer on a manual reference, outperforming both FreeSurfer and FastSurferVINN based on the gold standard. Impact: Our proposed deep learning model, TABSurfer, demonstrated state-of-the-art subcortical segmentation performance and utility. TABSurfer displayed reliability across numerous datasets and outperformed well established traditional and deep learning tools in FreeSurfer and FastSurferVINN.
Healthy-to-Patients Domain-Adaptive Deep Learning for Time-Resolved Segmentation of Left Atrium in Short-Axis Cine MRI Images
Authors: Elbayumi Mohamed , Bagci Ulas , Pradella Maurice , Zilber Zachary , Greenland Philip , Elbaz Mohammed
Published: November 2024

Motivation: Addressing challenges with current deep learning (DL) techniques that struggle with domain shifts. Goal(s): To introduce a domain-adaptive technique that is able to segment the Left Atrium from MRI of patients employing model trained exclusively on healthy data. Approach: Our approach involves training exclusively on healthy data and incorporating stochastic encoding of temporal composite variations as augmentations to encode the underlying space of plausible anatomical changes and dynamics. We tested on three challenging unseen patient daatsets. Results: Our domain-adaptive approach showed significant improvement over the state-of-the-art LA segmentation model. Enabling LA segmentation of all time frames of the cardiac cycle. Impact: The proposed domain-adaptive deep learning approach addresses a fundamental challenge of training deep learning models only on healthy control datasets while maintaining high performance on unseen patients' populations. This could potentially lead to solve performance issues for limited patients cohorts.
Efficient Analysis of Myocardial Perfusion MRI with Human-in-the-loop Dynamic Quality Control: Initial Results Using the SCMR Registry
Authors: Yalcinkaya Dilek , Li Zhuoan , Youssef Khalid , Heydari Bobak , Dharmakumar Rohan , Judd Robert , Simonetti Orlando , Raman Subha , Sharif Behzad
Published: November 2024

Motivation: Accurate segmentation of free-breathing (FB) myocardial perfusion (MP) MRI is a labor-intensive yet necessary preprocessing step. A quality control (QC) tool for deep learning (DL)-based segmentation of FB MP MRI is lacking. Goal(s): Developing a DL-based dynamic QC (dQC) tool for automatic analysis of MP MRI. Approach: Using the discrepancy between patch-based segmentations, a dQC map is derived and quantified into a dQC metric. The utility of this metric in detecting erroneous segmentations is demonstrated by considering a human-in-the-loop (HiTL) framework. Results: Referral of the dQC-detected timeframes to a HiTL has markedly improved the segmentation results when compared to a random referral approach. Impact: We proposed a dynamic quality control tool for automatic segmentation and analysis of free-breathing myocardial perfusion MRI datasets. Our results show that the proposed approach has markedly improved segmentation accuracy when used within a practical and efficient clinician-in-the-loop setting.
The Efficiency Optimization of a Triple-Tuned (2H/23Na/31P) Body Coil at 7T
Authors: Kahraman-Agir Busra , Dai Jiying , Lunenburg Martijn , Gosselink Mark , Klomp Dennis
Published: November 2024

Motivation: Low B1+ field 1)increases the RF pulse duration which jeopardizes SNR in the short T2 of 23Na spins and 2)limits of the excitation bandwidth which might be insufficient to excite the full chemical shift dispersion of 31P spins. Goal(s): To improve the efficiency of a triple-tuned (2H/23Na/31P) body coil. Approach: Reducing the total loss on a birdcage design by decreasing the number of multi-tuned circuits. Results: The 8-rungs (i.e., 16 triple-tuned circuits) design wins 3dB in efficiency against a conventional 24-rungs (i.e., 48 double-tuned circuits) design, while covering one more excitation frequency, and the homogeneity is practically unaffected. Impact: The high loss of the multi-tuned circuits is a determinant in multi-tuned borecoil designs. Reducing the number of multi-tuned circuits used in the design substantially improves the B1 efficiency of a body coil facilitating even triple tuning.
Experimental reduction of peripheral nerve stimulation (PNS) using pre-excitation targeting of the potassium system (PRE-TAPS)
Authors: Ferris Natalie , Barksdale Alex , Klein Valerie , Guerin Bastien , Wald Lawrence , Davids Mathias
Published: November 2024

Motivation: Peripheral nerve stimulation (PNS) limits the current generation of MRI gradient coils. We seek a sequence-based approach to improve scanner performance without hardware changes. Goal(s): Experimentally demonstrate that pre-excitation targeting of the potassium system (PRE-TAPS) using a kHz-frequency preconditioner waveform can be used to increase PNS thresholds. Approach: We measure changes in the PNS threshold of a 1.1kHz frequency probe waveform when a 10kHz preconditioner waveform is played immediately before the probe waveform and compare measured results to our model predictions. Results: We found up to 10% greater PNS thresholds using PRE-TAPS in one subject and qualitative agreement with our PNS model. Impact: Waveform-based modulation of PNS thresholds, such as pre-excitation targeting of the potassium system (PRE-TAPS) with a kHz-frequency preconditioner waveform, may enable increased performance in PNS-limited sequences such as EPI.
A novel cumulative transfer function concept for accurate prediction of RF heating of bipolar leads
Authors: Vu Jasmine , Bhusal Bhumi , Golestanirad Laleh
Published: November 2024

Motivation: Radiofrequency (RF) tissue heating is a known safety risk for patients with cardiac implantable electronic devices (CIEDs), especially children with epicardial systems. Goal(s): We present the first cumulative transfer function based on the guidelines in ISO/TS 10974 to evaluate the RF heating of a CIED with a bipolar epicardial lead. Approach: We measured, calibrated, and validated cumulative transfer functions for predicting RF heating through in vitro experiments and electromagnetic simulations. Results: Our cumulative transfer functions accurately predicted RF heating around the electrode ends for 48 unique lead trajectories (r=0.90-0.97, p<0.05). Impact: We introduce a high-fidelity cumulative transfer function model of a CIED with a bipolar epicardial lead to enable the evaluation of RF heating of bifurcating leads during MRI.
Evaluation of Specific Absorption Rate of Tight-Fit Array Coils for Human Head MRI at 9.4T in Presence of EEG Caps
Authors: Berezko Egor , Solomakha Georgiy , Bause Jonas , Kumar Vinod , Scheffler Klaus , Avdievich Nikolai
Published: November 2024

Motivation: The electroencephalography (EEG) in combination with MRI allows performing multi-modal imaging. The presence of EEG-caps can increase SAR of tight-fit transceiver RF-arrays at Ultra-High-Field. Goal(s): To numerically evaluate SAR generated by a tight-fit array at 9.4T in the presence of EEG-caps. Approach: Numerical models of 8-channel 9.4T transceiver arrays with EEG-electrodes were constructed. B1+ and SAR were simulated for the human head voxel models using CST Studio. Results: In this work, we numerically showed that EEG-caps don’t significantly change B1+ and SAR of the arrays at 9.4T. Furthermore, the created models of the caps can be used in future simulations. Impact: We numerically showed that EEG caps don’t significantly change B1+ and SAR of the arrays at 9.4T. The developed cap models can be used in future simulations
Preliminary Results on Torso PNS Thresholds at the Ultrasonic Driving Frequency of 20 kHz using a Whole-Body Gradient Coil
Authors: McGrory Michael , Versteeg Edwin , Siero Jeroen , Klomp Dennis
Published: November 2024

Motivation: For silent whole-body MRI using ultrasonic encoding at 20kHz, very high slew rates will be experienced by body parts such as the torso with PNS risk. However, PNS thresholds for these body parts at ultrasonic frequencies are not well known. Goal(s): To estimate PNS thresholds for the torso at 20kHz. Approach: We test volunteers in a whole-body gradient coil driven at 20kHz to determine when PNS occurs and compare to simulations and current IEC guidelines. Results: PNS occurs at much higher dB/dt values than predicted by IEC guidelines at 20kHz, where we found a mean threshold value of 1316T/s for the torso. Impact: PNS is a concern for body MRI using ultrasonic encoding. Here, we show much higher measured PNS thresholds than IEC guideline predictions for 20kHz gradient switching, suggesting that whole-body silent MRI at 20kHz is possible with reduced risk of PNS.
Optimization of Flexible Metasurfaces at 7T and in vivo B1+ Correction Effects
Authors: Jacobs Paul , Wilson Neil , Brink Wyger , Swain Anshuman , Armbruster Ryan , Hanumapur Aniketh , Tisdall Dylan , Detre John , Nanga Ravi Prakash Reddy , Elliott Mark , Reddy Ravinder
Published: November 2024

Motivation: Ultra-high field imaging (≥7T) lacks transmit (B1+) field inhomogeneity due to the shortened RF wavelengths, often resulting in poor image quality. Novel metasurface designs have previously been effective at improving image quality at lower field strengths but have not yet been implemented at 7T. Goal(s): To optimize and demonstrate a novel metasurface design for in vivo usage at 7T. Approach: Empirical optimization and phantom testing produced the final design, while image enhancement was assessed via in vivo calf skeletal muscle imaging. Results: The metasurface produced a 126.5% increase in image relative SNR and a 27.6% increase in transmit efficiency. Impact: The work impacts 7T imaging by presenting a novel piece of hardware that can effectively improve image quality. Future work on this project will include further optimization via variable distributed capacitance across the metasurface.
B1 uniformity improvement of a birdcage coil with a chain mail configuration
Authors: Ruiz Rodrigo , Lazovic Jelena , Rodriguez Alfredo , Solis-Najera Sergio
Published: November 2024

Motivation: The main goal is to enhance the performance of an RF coil used in preclinical MRI imaging, specifically at a field strength of 7 T. Goal(s): The researchers proposed a modification to a standard birdcage (BC) coil. This modification involves adding a "chain mail layout" to the rungs of the coil. Approach: The idea for the chain mail layout was inspired by previous low pass wiring schemes used in chain mail coils, as reported by Mansfield. Chain mail refers to a type of flexible armor composed of interlinked metal rings. Results: Phantom images were acquired and used to compute uniformity profiles. Impact: These results obtained with the chain mail BC coil contributes to our overarching goal of achieving improved MRI coil performance for preclinical applications at 7 T.
RNN-aided metabolite quantification from incomplete FIDs in 1H-MRS of the brain
Authors: Jeong Eunho , Jang Joon , Kim Hyeonjin
Published: November 2024

Motivation: Incomplete FIDs can be obtained due to the limited sampling windows as in spectroscopic MRF and SSFP-MRSI, or due to FID truncation for removing spectral artifact. Goal(s): Developing a means of quantifying metabolites from incomplete FIDs will allow more efficient sequence design and better experimental outcome. Approach: We developed a recurrent-neural-network (RNN) for metabolite quantification from incomplete FIDs at 3.0T. The RNN was trained on simulated data and tested on in vivo data. Results: Although the performance of the RNN requires further improvement for low concentration metabolites (e.g., GABA), it may allow quantification of the major metabolites under highly limited sampling windows. Impact: Incomplete FIDs can be obtained due to the limited sampling windows as in spectroscopic MRF and SSFP-MRSI. We developed a recurrent-neural-network, which can quantify the major metabolites from the initial 64 FID data points, thereby allowing more efficient sequence design.
Image2Flow: Fast Calculation of Pulmonary Artery Flow Fields from 3D Cardiac MRI Using Graph Convolutional Neural Networks
Authors: Yao Tina , Pajaziti Endrit , Quail Michael , Steeden Jennifer , Muthurangu Vivek
Published: November 2024

Motivation: Computational fluid dynamics (CFD) is used for non-invasive cardiovascular hemodynamic assessment, but it is limited by time-consuming manual segmentation and expertise needed for simulation. Goal(s): Improve the speed and simplify volume mesh generation and CFD flow field calculation. Approach: Develop a single deep-learning model capable of reconstructing the pulmonary artery from a 3D cardiac MRI as a volume mesh and predicting CFD-like pressure and flow. Results: Our model achieves accurate pulmonary artery reconstruction with a median Dice score of 0.9. It computes CFD-like pressure and flow with median errors of 14.9% and 9.0%, respectively. Our model is ~10,000 times faster than manual calculation. Impact: Image2Flow is a single-pass deep-learning model that rapidly and accurately reconstructs pulmonary artery volume meshes from 3D cardiac MR and predicts CFD-like flow fields. Our model can potentially streamline and expedite cardiovascular haemodynamic assessment and facilitate more efficient treatment planning.
Rapid Reconstruction of Infant Cortical Surfaces with Spherical Topology
Authors: Chen Xiaoyang , Zhao Junjie , Liu Siyuan , Ahmad Sahar , Yap Pew-Thian
Published: November 2024

Motivation: Cortical surface reconstruction (CSR) is important for surface-based analysis of the structure and function of the cerebral cortex. Goal(s): We present an efficient method for simultaneous CSR and spherical mapping, all within a matter of seconds. Inherent correspondence allows easy and direct mapping of geometric features from cortical surfaces to the sphere. Approach: Our flow-based method learns velocity fields to deform a spherical template mesh to the cortical surfaces with one-to-one vertex correspondence for direct spherical mapping. Results: Using data from the Baby Connectome Project (BCP), we demonstrate that our method predicts more accurate and uniform surface meshes compared with several state-of-the-art methods. Impact: Our method provides a way for fast and accurate infant cortical surface reconstruction. The one-to-one vertex correspondence between template sphere and the cortical surfaces enables easy and direct downstream analyses.
Effects of bright light therapy on cingulate cortex dynamic functional connectivity and neurotransmitter activity in subthreshold depression
Authors: Tang Guixian , Chen Pan , Chen Guanmao , Cui Wei , Wang Ying
Published: November 2024

Motivation: Bright light therapy (BLT) is one of the effective interventions for subthreshold depression, but its neural mechanism is still unclear. Goal(s): The goal of this double-blind, randomized, placebo-controlled clinical trial was to assess the correlation between BLT and the dynamic functional connectivity (dFC) changes in the cingulate cortex along with distribution of specific neurotransmitters in subthreshold depression. Approach: A double-blind randomized controlled trialResults: BLT alleviates depressive symptoms and changes the cingulate cortex dFC variability in subthreshold depression. And pre-treatment dFC variability of the cingulate cortex could be used as a biomarker for improved BLT treatment in subthreshold depression. Impact: BLT alleviates depressive symptoms and changes the cingulate cortex dFC variability in subthreshold depression, which raises the possibility that pre-treatment dFC variability of the cingulate cortex could be used as a biomarker for improved BLT treatment in subthreshold depression.
Current mood status is associated with future brain MRI readouts, but not the other way around: insights from healthy adults in the UK Biobank
Authors: Jiang Guocheng , Swardfager Walter , Cogo-Moreira Hugo , Black Sandra , Goldstein Benjamin , MacIntosh Bradley
Published: November 2024

Motivation: The mood status of an individual can influence the brain anatomy and function. Goal(s): We studied whether the mood state is associated with brain structural and functional alteration at 2.25 years follow-up and vice versa. Approach: We focus on the regional brain volumes and task-induced function of the amygdala and primary visual cortex using T1w and task fMRI. Linear models tested for associations between mood and MRI readouts. Results: Baseline mood score is significantly associated with functional activation in the primary visual cortex. However, baseline volume and functional activation in the amygdala and primary visual cortex are not associated with future mood status. Impact: We showed that mood status is associated with future functional activation in the primary visual cortex. However, MRI estimates of anatomy and function in the amygdala and primary visual cortex demonstrated a lack of predictive power for future mood status.
A Novel Deep Learning Denoising Algorithm for Neural Signal Recovery in fMRI Scanning
Authors: Chen Bo-Wei , Lyu Zhuyuan , Yu Xiao , He Tingting , Qu Boyi , Wang Haiming , Tang Zheng , Ye Mingfeng , Chen* You-Yin , Lai* Hsin-Yi
Published: November 2024

Motivation: While fMRI infers neural activity from hemodynamic changes, the relationship between the two remains to be further clarified. Simultaneous electrophysiological recordings (Ephy) and fMRI can provide additional insights into neurovascular coupling and brain function. Goal(s): Our objective is to address the electromagnetic interference (EMI) noise in the simultaneous Ephy and fMRI recording. Approach: A deep learning-based fully convolutional neural network (FCNN) was proposed to effectively eliminate EMI noise. Simulated neural signals and tactile-evoked neural signals were implemented for training and testing. Results: FCNN significantly reducing EMI noises, maintaining spike waveform consistency and successfully retaining the most neural signals. Impact: This research proposed a universal and robust denoising approach to address electromagnetic interference during simultaneous recording of neural signals and fMRI data, which will be relevant for understanding of neurovascular coupling and brain function.
Dynamic Mode Decomposition enables low-latency high temporal resolution reconstruction for golden-angle spiral real-time MRI
Authors: Yagiz Ecrin , Ozaslan Ibrahim , Tasdelen Bilal , Jovanovic Mihailo , Tian Ye , Nayak Krishna
Published: November 2024

Motivation: Real-time MRI methods with higher spatiotemporal resolution employ undersampled non-Cartesian trajectories combined with a computationally intense reconstruction to mitigate aliasing. However, often, a low-latency, coarse-temporal resolution, low-quality reconstruction is provided online. This may hinder the scan quality in interventional and fetal imaging. Goal(s): To develop a low-latency, high-temporal resolution online reconstruction for real-time MRI. Approach: We introduce a novel method using Dynamic Mode Decomposition for low-latency, high-temporal resolution reconstruction that removes spiral aliasing. The online version is achieved by predicting and removing aliasing artifacts in upcoming frames. Results: We evaluate DMD Filtering in the context of real-time adult and fetal cardiac function assessment. Impact: The proposed technique, Dynamic Mode Decomposition filtering, achieves low-latency (<20ms/frame), high-temporal resolution reconstruction with negligible spiral aliasing artifact, and no iterations. This may be valuable for online reconstruction during interventional and fetal cardiac imaging.
Banding insensitive DESPO for T1 and T2 mapping applied to 3D prostate at 3T.
Authors: Coronado Ronal , Castillo-Passi Carlos , Besa Cecilia , Irarrazaval Pablo
Published: November 2024

Motivation: DESPO is a robust T2 brain mapping technique based on balanced steady-state free precession (bSSFP). However, it is susceptible to off-resonance artifacts, especially in areas with high susceptibility changes, such as the prostate. Goal(s): Our proposed method, DESPO+, integrates the complete bSSFP and spoiled-gradient echo (SPGR) models, using a simulation-based approach for 3D T1/T2 maps in the prostate region. Approach: We employed a simulated-based method of the full bSSFP and SPGR models incluiding off-resonance to reconstruct T1/T2/PD simultaneously. Results: DESPO+ provides off-resonance insensitive with high-resolution 3D T1/T2 mapping, synthesizing T1-weighted/T2-weighted images using a short scan time of 3.6 minutes, similar to DESPO. Impact: DESPO+ provides an off-resonance insensitive and customizable solution, enabling high-resolution 3D T1/T2 mapping and synthesized T1-weighted/T2-weighted images for the entire prostate, all achieved within a short scan time of 3.6 minutes, similar to DESPO.m
RF Power Amplifier Drift Compensation for Reliable B1 Mapping Using Bloch-Siegert Technique
Authors: Aghaeifar Ali , Scheffler Klaus
Published: November 2024

Motivation: RFPA drift affects reproducibility of B1+ mappingGoal(s): The goal of study is to investigate factors influencing RFPA output drift and introducing a real-time feedback mechanism to compensate for driftApproach: B1+ with Bloch-Siegert shift technique is measured in a repetitive manner and reproducibility of maps is assessed. The RFPA output is continuously monitored through the use of DICOs, and adjustments to the transmit voltage are made to compensate for driftResults: The findings indicate that RFPA output drift is more noticeable with extended RF pulses and shorter TR. Implementing real-time drift correction effectively minimizes drift, leading to enhanced stability in B1+ mapsImpact: Our demonstration of real-time feedback to mitigate RFPA drift enhances measurement accuracy and reproducibility. This approach can be advantageous to achieve the consistency and reliability of research, particularly in the context of multi-center studies.
Basis function compression for compact representation of high spatial orders of field variation using field monitoring
Authors: Dubovan Paul , Varela-Mattatall Gabriel , Menon Ravi , Kerr Adam , Baron Corey
Published: November 2024

Motivation: Field monitoring using field probes has shown to inaccurately estimate higher order field variations on a high-performance gradient system using the conventional fitting procedure. Goal(s): To develop and validate a new fitting approach for field monitoring measurements for improved higher order field characterizations on complex MRI systems. Approach: Perform a calibration scan by moving probes around imaging volume to accurately characterize field variations, then compress this data to preserve important field information, with the purpose of applying this information to new scans. Results: Quantitative phantom results and qualitative in-vivo diffusion images show significantly improved image quality when using the proposed fitting method. Impact: This work presents a new method for accurately calculating higher order field monitoring measurements on a head-only MRI scanner, resulting in substantially improved image quality. This may be useful for other research centers that also utilize complex, high-performance MRI systems.
Vessel-Encoded Arterial Spin Labeling at 7 Tesla
Authors: Li Hongwei , Ji Yang , Wang He , Chen Zhensen , Woods Joseph , Okell Thomas
Published: November 2024

Motivation: Vessel-encoded arterial spin labeling (VEASL) allows the visualization of collateral blood flow and blood supply to lesions, but has limited SNR. At ultra-high field, ASL benefits from significantly improved SNR and longer blood T1 relaxation time. However, B0 field inhomogeneity can reduce labeling efficiency and disrupt encoding patterns. Goal(s): Implementing VEASL robustly at 7 Tesla. Approach: Optimized ASL parameters, dynamic B0 shimming and OES-based correction methods were used to mitigate the impact of B0 field inhomogeneity. Results: Good vascular territory maps, labeling both the neck and above the circle of Willis, were achieved, including at high spatial resolution. Impact: We demonstrate the first vessel-encoded ASL perfusion maps at ultra-high field, and the vascular territory maps significantly improved after applying B0 correction techniques, with the potential to push for even higher spatial resolution.