bluuebunny/crossref_metadata_2025 huggingface dataset:
Motion-corrected multi-shot EPI: Viable alternative to GRE for blood sensitive imaging with improved image quality and reduced scan time
Authors: Li Zhiqiang , Murchison James , Shoshan Dori , Ooi Melvyn , Karis John
Published: August 2024

A motion-corrected 2D multi-shot EPI (msEPI) technique was compared to conventional 2D GRE to determine if it can be used as a faster technique for blood sensitive imaging in the emergency department (ED) setting. msEPI was found to be superior to GRE (p < 0.001) in motion artifact, overall image quality, and lesion detection. These results and reduced scan time make the motion-corrected 2D msEPI a viable alternative for blood sensitive imaging in the ED setting.
Minimizing SAR for SNR-Efficient Pseudo-Continuous Arterial Spin Labeling at 7T
Authors: Woods Joseph , Chiew Mark , Okell Thomas
Published: August 2024

Interest in 7T PCASL is increasing due to the large potential increases in SNR. However, PCASL is a relatively high SAR technique, requiring TRs to be extended with deadtime at 7T, which reduces SNR-efficiency and some of the benefit of moving to 7T. Here, we demonstrate that using VERSE to reduce the SAR of both the PCASL and background suppression pulses can reduce TRs by almost 25%, leading to an improvement in tSNR-efficiency compared to an equivalent non-VERSE scan. We reduced the off-resonance sensitivity that VERSE introduces to the background suppression pulses by carefully optimizing the phase waveform.
Hybrid Adiabatic Pulse with asYmmetry (HAPY): an asymmetric adiabatic pulse with an application in pulsed ASL at 7T
Authors: Chi Didi , Blunck Yasmin , Glarin Rebecca , Davey Catherine , Stäb Daniel , Pfeuffer Josef , Johnston Leigh , Jin Jin
Published: August 2024

The increased power deposition and inhomogeneity of $$$\Delta{B_0}$$$ and $$$B_1^+$$$ fields limit the application of ASL at 7T. A new type of asymmetric adiabatic pulses, Hybrid Adiabatic Pulses with asYmmetry (HAPY) along with its optimisation scheme, is proposed in this study. In simulation and phantom experiments, the proposed HAPY pulse demonstrates RF labelling pulse energy reduction and high labelling efficiency under challenging $$$\Delta{B_0}$$$ and $$$B_1^+$$$ conditions. In vivo experiments show the successful application of PICORE-PASL with HAPY labelling pulses in 7T ASL with increased temporal resolution.
K-band: A self-supervised strategy for training deep-learning MRI reconstruction networks using only limited-resolution data
Authors: Qi Han , Wang Frederic , De Goyeneche Alfredo , Lustig Michael , Shimron Efrat
Published: August 2024

Although Deep learning (DL) techniques are powerful for MRI reconstruction, their development is hindered by the need for large training datasets. We propose a self-supervised method for training DL reconstruction networks using only limited-resolution data, acquired in k-space “bands”, which are generally easier to acquire than variable-density full-resolution data. Although the network is trained using low-resolution data, during inference it can reconstruct high-resolution images. Comprehensive experiments demonstrate that k-band is robust to various acceleration factors, outperforms two other methods trained on low-resolution data, and obtains comparable performance with SSDU and MoDL, while also reducing the need for full-resolution data.
A Multi-Site Collaborative Training Effort to Improve Neuroimaging Accessibility and Capacity Development in Low- and Middle-Income Countries
Authors: Ringshaw Jessica , Bradford Layla , Miles Marlie , Bennallick Carly , Bourke Niall , Ljungberg Emil , Deoni Sean , Williams Steven , Donald Kirsten
Published: August 2024

In a multi-site global collaboration (UNITY; Ultra-Low Field Neuroimaging In The Young) implementing the novel Hyperfine 64mT low-field MRI into research on relevant health priorities in low- and middle-income countries (LMICs), capacity development has been identified as a key objective. Following an initial training wave in foundational sites including South Africa, adapted workshops have been conducted in new consortium countries including Malawi, Ethiopia, and Ghana. This has informed the development of a strategic framework for context-specific training aimed at promoting the increased success of neuroimaging in research and clinical practice, and the sustainability of MRI technology in under-resourced settings.
M4Raw: A Multi-Contrast Multi-Repetition Multi-Channel Raw K-space Dataset for Low-Field MRI Reconstruction
Authors: Lyu Mengye , Mei Lifeng , Liu Sixing , Huang Shoujin , Li Yi , Yang Kexin , Liu Yilong , Wu Ed
Published: August 2024

We release a new raw k-space dataset M4Raw acquired by the low-field MRI. Currently, it contains multi-channel brain data of 180 subjects each with 18 slices x 3 contrasts (T1w, T2w, and FLAIR). Moreover, each contrast consists of two or three repetitions (a.k.a. NEXs), leading to more than 25k trainable slices in total, which can be used in various ways by the low-field MRI community. It can be accessed via http://github.com/mylyu/M4Raw.
Vascular-water-exchange imaging to detect blood-brain barrier breakdown in Alzheimer’s disease without contrast agent
Authors: Zhang Yifan , Wang Yue , Li Zhaoqing , Li Shiping , Hsu Yi-Cheng , Shi Jiong , Sui Binbin , Bai Ruiliang
Published: August 2024

Blood-brain-barrier (BBB) impairment is an important pathophysiological process in Alzheimer’s disease (AD). However, most neuroimaging methods assessing BBB function require contrast agent injection, limiting the methods’ application. Vascular-water-exchange imaging (VEXI), a version of filter-exchange imaging (FEXI), is a contrast-agent-free method assessing BBB permeability to water. We quantitatively measured BBB permeability using VEXI in normal subjects, mild cognitive impairment patients, and AD patients and found BBB breakdown occurred specifically in the hippocampus, worsening with disease progression. In addition, BBB permeability to water showed a significant correlation with cognitive impairment. Therefore, VEXI might be a potential contrast-agent-free neuroimaging method.
Functional Abnormalities of Cerebellum in Vascular Cognitive Impairment
Authors: Ruan Zhao , Liu Weiyin , Xu Haibo
Published: August 2024

The potential prevalence of vascular cognitive impairment (VCI) is high; early diagnosis and treatment is essential for disease prognosis. In this study, compared to healthy controls (HCs), there were differences of functional connectivity (FC) between the cerebellum and cerebral regions of VCI patients, mainly involving default mode network (DMN), sensorimotor network (SMN) and frontoparietal network (FPN). Furthermore, FC between multiple sub-regions in the cerebellum reduced in patients with VCI compared to HCs. These findings may expand our understanding of the neural mechanisms of VCI in the perspective of neurovascular coupling.
Fully Automated Online Reconstruction, Registration, and Analysis Pipeline for 3D Magnetic Resonance Fingerprinting
Authors: Dupuis Andrew , Boyacioglu Rasim , Chen Yong , Hansen Michael , Chow Kelvin , Badve Chaitra , Ma Dan , Griswold Mark
Published: August 2024

In this study, to overcome some of the clinical integration issues of MRF, we present a fully automated online reconstruction and post-processing pipeline for 3D-MRF where the quantitative maps and custom reports are returned to the scanner in real time. The whole pipeline is hosted in a Kubernetes cluster which includes Gadgetron, FSL and other custom tools in discrete Docker images. To illustrate the capability of the pipeline, 3D-MRF raw datasets of healthy and brain tumor patient datasets are reconstructed in a cloud-based Gadgetron, registered to MNI space using FSL and analyzed to compare with population based regional maps.
Simultaneous Quantification of Relaxation and Diffusion using MR Fingerprinting with Self-Calibrated Subspace Reconstruction
Authors: Qiu Zhilang , Hu Siyuan , Zhao Walter , Sakaie Ken , Griswold Mark , Jones Derek , Ma Dan
Published: August 2024

We propose a self-calibrated subspace reconstruction method for multidimensional MR Fingerprinting (mdMRF) scan for simultaneous relaxation and diffusion mapping without pulsation gating. It is distortion-free, unlike EPI-based diffusion MRI. MRF images corrupted by phase errors due to bulk and physiological motions are automatically detected using an outlier detection algorithm and corrected, in order to generate artifact-free relaxation and diffusion maps.
Water Suppression of T1 map and Synthetic Inversion Recovery images in T2-based Water Suppression Synthetic MRI (T2wsup-synMRI)
Authors: Kimura Tokunori , Yamagishi Natsumi , Masuda Yuki , Ito Mitsuyo
Published: August 2024

The purpose of this study was to propose a new technique to provide water suppression (wsup) T1 maps by modifying our already proposed T2wsup technique, then to assess the effects of wsup-T1 on longitudinal magnetization (Mz) in synthetic MRI images of FLAIR and DIR by a simulation and an in-vivo MR study. The errors in DIR at CSF-tissue mixed portions were non-negligible with std-T1 but could be reduced with wsup-T1. The T2wsup-SynMRI technique can provide 3 kinds of water suppressed quantitative maps and the same contrasts synthetically as the acquired IR sequences of FLAIR and DIR.
Using deep learning to identify LNM and LVSI of endometrial cancer from conventional MRI: a preliminary two-center study
Authors: Wang Yida , Zhang He , Zhao Xiance , Yang Guang
Published: August 2024

We developed a multi-task deep learning model using multi-parametric MRI to simultaneously predict lymphatic nodes metastasis (LNM) and lymphatic vascular space invasion (LVSI) in patients with endometrial cancer. Cross-modality attention mechanism was integrated with the model to learn the within and cross modality-speciﬁc features which could enhance the performance of network. In this study, we also treated endometrial cancer regions as the anatomical prior knowledge to capture the discriminative information from the whole MR images. The results showed the proposed model predicted LNM and LVSI with a high accuracy in both internal and external test datasets.
Identifying pathological differentiation of cervical squamous cell carcinoma with APTw and IVIM
Authors: Xin Zhonghong , Lei Junqiang , Peng Jianhong , Lu Xiande , Nan Jiang , Zhang Yaping , Wang Xiaohui , Zhu Jun , Lian Jianxiu
Published: August 2024

The pathological differentiation of cervical squamous cell carcinoma (CSCC) determines the therapy method and prognosis. APTw, DWI and IVIM sequences were performed for predicting pathological differentiation. 27 patients with well-moderately differentiation, 13 patients with poorly differentiation and 15 healthy volunteers were enrolled. APT SI, ADC, D*, D and f values were calculated for comparing among different groups. Results showed parameters except D* differed significantly between CSCC and normal. There were statistically significant differences in AUC of APT SI, D and f between well-moderately group and poorly differentiated group. APTw and IVIM can be used to identify pathological differentiation of CSCC.
Cotyledon-Specific Flow Evaluation of Rhesus Macaque Placental Injury using Ferumoxytol Dynamic Contrast Enhanced MRI
Authors: Chen Ruiming , Seiter Daniel , Keding Logan , Vazquez Jessica , Antony Kathleen , Simmons Heather , Johnson Kevin , Stanic Aleksandar , Liu Ruo-Yu , Shah Dinesh , Golos Thaddus , Wieben Oliver
Published: August 2024

Placental blood flow is a marker that reflects the health of the utero-placental vasculature. Dynamic contrast-enhanced (DCE) MRI is more robust than arterial spin labeling and can be utilized in animal models to provide cotyledon-specific blood flow and blood volume measurements in vivo throughout gestation. This study investigated the distribution of blood flow to the placental at a cotyledon level in pregnant rhesus monkeys before and following the injection of Tisseel (a fibrin sealant) and MCP1 (an inflammatory response inducer) to assess the predictabilities of flow for placental injury.
Repetitive Mild Traumatic Brain Injury Induces Significant Changes on Functional Connectivity with Different Impact Numbers in Rats
Authors: Kao Yi-Han , Lu Chia-Feng , Hsieh Bao-Yu , Kao Yu-Chieh
Published: August 2024

In the current study, we discussed about changes of brain connectivity through rsfMRI and behavioral performances following repetitive mild traumatic brain injury (rmTBI) with different impact numbers and intervals. In rats with larger impact number but longer inter-injury interval, may show anxiety-like behavior with the significant reduction of connectivity in their DMN.
Abnormal spontaneous brain fluctuations present in retired football players
Authors: Danielli Ethan , Sharma Bhanu , Nowikow Cameron , Noseworthy Michael
Published: August 2024

Novel methods are required to understand the scale of potential brain changes in collision sport athletes. with many former athletes having developed neurocognitive deficits or neurological disorders. This study used resting state functional MRI (rsfMRI) to examine if retired professional football players (n=18) had functional brain abnormalities based on a personalized amplitude of low-frequency fluctuations (ALFF) and Z-scoring approach. Brain injuries were identified if the ALFF Z-score exceeded 3 standard deviations from the healthy control mean. Thirty regions were abnormal in more than half of the retired athletes. Cerebellar and central, sub-cortical brain regions were most often seriously abnormal.
Distortion-corrected cervical spine diffusion-weighted imaging at 3.0T
Authors: Sun Zheng , Wu Peng , Zhao Xiance , Deng Kan
Published: August 2024

Diffusion-weighted imaging (DWI) could benefit the detection and evaluation of the spine and spinal cord pathologies. Traditional single-shot EPI (SS-EPI) DWI suffers from a large geometry distortion due to the inhomogeneous B0 field and the low bandwidth in the phase encoding direction. This work demonstrated the application of an EPI geometry correction method for the cervical spine which can improve the geometry accuracy of the DWI images.
Mouse sleep fMRI with simultaneous electrophysiology at 9.4T
Authors: Yu Yalin , Qiu Yue , Tong Chuanjun , Liang Zhifeng
Published: August 2024

Simultaneous electrophysiology and fMRI could provide both macroscopic and microscopic observations, but it is highly technically challenging and not widely used in sleep research. We developed mouse sleep fMRI based on simultaneous electrophysiology at 9.4T and allowed manifestation of the full sleep cycle (NREM/REM) during fMRI. The results revealed global state-dependent patterns. Rich state transition epochs demonstrated that state transitions were global, irreversible and sequential phenomenon, which can be predicted using LSTM RNN models. Importantly, simultaneous hippocampal recording revealed enhanced sharp-wave ripple triggered global patterns during NREM than awake state, which may attribute to co-occurrence of spindle events.
Multivariate Classification of fMRI Time Series with Fused Window Transformers
Authors: Bedel Hasan , Şıvgın Irmak , Dalmaz Onat , Dar Salman , Çukur Tolga
Published: August 2024

Functional MRI (fMRI) experiments serve a key role in advancing our understanding of human brain function during normal and disease states. Analysis of high-dimensional fMRI data can significantly benefit from recent deep learning approaches, yet existing methods are insufficiently sensitive to the contextual representations in fMRI data across diverse time scales. Here, we present a novel transformer model for fMRI analysis that effectively captures local and global dependencies in fMRI data. Comprehensive demonstrations are provided that show the superior performance of BolT in gender and disease detection against state-of-the-art learning-based methods.
Age-related differences in dynamic cerebrovascular reactivity based on CO2-response modelling
Authors: Milbourn Colette , Shams Seyedmohammad , Chen Jean
Published: August 2024

Cerebrovascular Reactivity (CVR) was measured in healthy, young and older adults. Specifically, dynamic CVR (dCVR) was measured as the carbon dioxide (CO2)-response function. This was estimated by deconvolving a sinusoidal hypercapnic time course from simultaneously acquired blood oxygen level dependent (BOLD) fMRI data using a canonical-correlation (CCA) based approach. The results demonstrate differences in dCVR amplitude and rise time between age groups. This proof-of-concept study establishes the feasibility of dCVR modelling for the study of aging.
Combined fMRS and fMRI During Reinforcement Learning in a Large Cohort at 7T: When Does Cognitive Processing Occur?
Authors: Finkelman Tal , Furman-Haran Edna , Aberg Kristoffer , Paz Rony , Tal Assaf
Published: August 2024

We present multimodal functional MRS-fMRI-Behavioral data, which demonstrates how the E/I balance changes in the dACC during a reinforcement learning paradigm. The E/I balance decreases during rest periods between tasks, supporting a consolidation phase that is invisible to BOLD-fMRI. Additionally, we find a significant negative correlation between both GABA and glutamate, and the mean z-score of the BOLD signal from the spectroscopic voxel, during the decision-making game. We suggests that the elevation in Glu is related to cellular activity rather than neuronal activity, indicating a GABAergic activation during the task.
Single-shot GABA Editing at 7 Tesla
Authors: An Li , Araneta Maria Ferraris , Loutaev Inna , Turon Tara , Johnson Christopher , Hong Sungtak , Shen Jun
Published: August 2024

Two-step editing techniques have been widely used to detect the GABA H4 signal at 3.01 ppm with the dominant creatine methyl proton signal cancelled by subtraction. However, subtraction is inherently sensitive to patient movements and system instability. In this work, a single-shot spectral editing technique is developed to detect the GABA H2 resonances at 2.28 ppm in the human brain at 7 Tesla. Although GABA H2 is partially overlapped by glutamate H4, we demonstrate that GABA-glutamate correlation originating from spectral overlap can be reduced to practically zero, therefore suppressing the overlapping effect of glutamate H4 on GABA H2 without subtraction.
Intra-Subject Stability and Reproducibility of 7 T FID-CRT-MRSI
Authors: Lazen Philipp , Spurny-Dworak Benjamin , Bogner Wolfgang , Hingerl Lukas , Strasser Bernhard , Lanzenberger Rupert , Rössler Karl , Trattnig Siegfried , Hangel Gilbert
Published: August 2024

We evaluated the intra-subject stability of CRT-FID-MRSI at 7 T in a cohort of 15 volunteers. Two magnetic resonance spectroscopic imaging acquisitions were performed consecutively and metabolite concentration estimates (CEs) were calculated using internal water referencing. The resulting metabolic maps were segmented in 55 brain regions. For analysis, the CEs of both acquisitions were compared and coefficients of variations (CVs) were calculated. We saw high stability in almost all volunteers, with CVs being well below 5% in the brain regions generally associated with good data quality.
High-resolution single-breath-hold 3D MRCP using accelerated 3D Gradient and Spin-Echo (GraSE) with Compressed SENSE
Authors: Ogawa Takumi , Nagao Michinobu , Goto Yasuhiro , Yoneyama Masami , Peeters Johannes , Shiina Isao , Hamatani Yutaka , Kodaira Kazuo , Kato Mana , Sakai Shuji
Published: August 2024

Breath-hold MRCP has gained more attention in routine clinical MRI, but its limited scan time during the breath-hold period often results in poor signal-to-noise ratio (SNR) and spatial-resolution. Despite being a single breath-hold method, 3D gradient and spin-echo (GraSE) sequence has been reported to provide high image quality. In this study, accelerated GraSE sequence combined with Compressed SENSE has been developed to obtain high-resolution MRCP images with a single breath-hold.
Predicting FDG PET from Multi-contrast MRIs using Deep Learning in Patients with Brain Neoplasms
Authors: Ouyang Jiahong , Chen Kevin , Rosenberg Jarrett , Zaharchuk Greg
Published: August 2024

PET is a widely used imaging technique, but it requires exposing subjects to radiation and is not offered in the majority of medical centers in the world. Here, we proposed to synthesize FDG-PET images from multi-contrast MR images using a U-Net-based network with attention modules and transformer blocks. The experiments on a dataset with 87 brain lesions in 59 patients demonstrated that the proposed method was able to generate high-quality PET from MR images without the need for radiotracer injection. We also demonstrate methods to handle potential missing or corrupted sequences.
The MRI-based 3D-ResNet-101 deep learning model for predicting preoperative grading of gliomas: a multicenter study
Authors: Li Darui , Hu Wanjun , Gan Tiejun , Liu Guangyao , Ma Laiyang , Ai Kai , Zhang Jing
Published: August 2024

The preoperative accurate and non-invasive prediction of glioma grading remains challenging. To accurately predict high-or low-grade gliomas, we constructed a 3D-ResNet101 deep learning model with data from a multicenter. These data were obtained from the Second Hospital of Lanzhou University, with 708 glioma patients, and the TCIA database, with 211 patients. The areas under the curve of the 3D-ResNet-101 deep learning model are 0.97 and 0.89 in the test cohort and external test cohort, respectively. This new method can be used for non-invasive prediction of glioma grading before surgery.
Whole-Heart Cardiovascular Magnetic Resonance Angiography (CMRA) with iNAV-based Non-Rigid Motion-Corrected Reconstruction at 0.55T
Authors: Castillo-Passi Carlos , Crabb Michael , Muñoz Camila , Kunze Karl , Neji Radhouene , Irarrazaval Pablo , Prieto Claudia , Botnar Rene
Published: August 2024

In this work, we demonstrate the feasibility of free-breathing whole-heart magnetic resonance angiography (CMRA) at 0.55T. We implemented an image navigator (iNAV)-based non-rigid motion-corrected reconstruction with 100% respiratory scan efficiency and patch-based low-rank (PROST) denoising. The research sequence was validated on three healthy subjects, showing that whole-heart CMRA provides good depiction of the coronary arteries at 0.55T in under 6 minutes scan time.
Interactive Cardiac Magnetic Resonance Imaging using jointly optimized spiral acquisition and deep artifact suppression network.
Authors: Jaubert Olivier , Montalt-Tordera Javier , Knight Dan , Arridge Simon , Steeden Jennifer , Muthurangu Vivek
Published: August 2024

Interactive MR sequences have relatively low spatial and temporal resolution due to the limited acquisition and reconstruction time available. We propose to jointly optimize a variable density spiral acquisition and deep artifact suppression network (via a bandit-based approach) to maximize acquisition and reconstruction efficiency and provide interactive high spatio-temporal resolution images. The proposed approach was characterized in simulations and demonstrated prospectively in-vivo, offering promising performance with improved image quality and good handling of abrupt scan-plane changes.
Intra-bin correction and inter-bin compensation of respiratory motion in free-running 5D whole-heart MRI
Authors: Roy Christopher , Milani Bastien , Yerly Jérôme , Si-Mohamed Salim , Tenisch Estelle , Rutz Tobias , Prsa Milan , Romanin Ludovica , Bustin Aurélien , Piccini Davide , Stuber Matthias
Published: August 2024

In this work, we develop, validate, and apply a novel reconstruction framework for intra-bin correction and inter-bin compensation of respiratory motion in cardiac and respiratory motion-resolved free-running whole heart 5D MRI. We demonstrate respiratory resolved images with reduced artifact and without compressing the underlying physiological motion providing a means to increase the acquired resolution, accelerate the acquisition, or investigate respiratory driven changes in cardiac output and blood flow, potentially leading to new MRI driven biomarkers for cardiovascular disease
Fully ungated, free-breathing, 3D T2* mapping for imaging hemorrhagic Myocardial Infarction
Authors: Guan Xingmin , Yang Hsin-Jung , Sykes Jane , Zhang Xinheng , Tang Richard , Christodoulou Anthony , Sharif Behzad , Li Debiao , Prato Frank , Dharmakumar Rohan
Published: August 2024

T2* CMR is widely used for detecting hemorrhagic myocardial infarction (MI). However, the conventional T2* CMR (2D breath-held, ECG-gated, multi-gradient-echo T2*) can suffer from limited spatial resolution and motion artifacts. We have recently developed a time-efficient, fully ungated, free breathing, 3D T2* mapping approach using a low-rank tensor (LRT) framework to address the above issues.
Sliding-Window Dynamic Functional Connectivity Of Resting-State Spinal Cord fMRI Reveals Specific Interaction Patterns
Authors: Dindar Sukru Samet , Ricchi Ilaria , Kinany Nawal , Van De Ville Dimitri
Published: August 2024

In recent years, while the exploration of spontaneous brain activity has shifted from static methods (i.e., examining average connectivity patterns over the entire run) towards dynamic approaches (i.e., accounting for the non-stationarity of resting-state fluctuations), the non-stationary nature of intrinsic activity in the spinal cord has seldom been studied. Here, we propose to probe time-varying functional connectivity patterns in the spinal cord using a sliding-window correlation approach, as commonly employed in the brain. Our results suggest the potential of this approach to unravel ventral-ventral and dorsal-dorsal correlation patterns, while also emphasizing their time-varying nature.
Spatial distribution of hand-grip motor task activity in spinal cord fMRI
Authors: Hemmerling Kimberly , Hoggarth Mark , Sandhu Milap , Parrish Todd , Bright Molly
Published: August 2024

A unilateral isometric hand-grip task was used to elicit motor neuron activation in spinal cord fMRI. As predicted, activation was lateralized to the ipsilateral hemicord. However, active voxels were also observed outside of the ventral horn and superior to C7. Reduced spatial precision and sensitivity in activation estimates, particularly along the cord axis, may be due to the combination of inter-individual differences in anatomy, imperfect registration to the standard spinal cord template, additional sensory activity associated with performing the task, and co-contraction of muscles not directly involved in hand-gripping.
Neurodegeneration within upper spinal cord is associated with brain gray matter volume atrophy in early stage of cervical spondylotic myelopathy
Authors: Kuang Cuili , Zha Yunfei , Liu Weiyin
Published: August 2024

Associations between cross-sectional area and white matter area within the rostral spinal cord and gray matter volume in left supplementary motor area and right middle cingulate gyrus suggest a concordant change pattern and adaptive mechanisms for neuronal plasticity underlying remote neurodegeneration in early cervical spondylotic myelopathy. The atrophy of cross-sectional area within the upper spinal cord and gray matter volume loss in right postcentral gyrus can serve as potential neuroimaging biomarkers of early structural changes within spinal cord and brain preceding marked clinical disabilities in patients with cervical spondylotic myelopathy.
Effects of MT-weighting, respiratory navigation, and biological variables on multi-echo gradient echo signal and contrast in the lumbar cord
Authors: O'Grady Kristin , Vasamreddy Kritin , Sweeney Grace , Prock Logan , Houston Delaney , Combes Anna , McGonigle Trey , Vandekar Simon , Clarke Margareta , Witt Atlee , McKnight Colin , Landman Erik , Robison Ryan , Bagnato Francesca , Smith Seth
Published: August 2024

Improvements are needed in advanced anatomical imaging of the lumbar spinal cord. We implemented a T2*-weighted multi-echo gradient echo (mFFE) sequence that enables visualization of CSF, gray and white matter with an in-plane resolution of 0.65x0.65mm2. Use of an MT-weighted pre-pulse and a respiratory navigator decreased SNR, but did not affect CNR, and qualitatively improved image quality and possibly multiple sclerosis lesion conspicuity. CNR/SNR were robust to biological factors known to affect signal quality (e.g. age, weight). The proposed sequence holds potential for improved visualization of anatomy, pathology, and morphometric measurements in the lumbar cord.
7T fMRI in the Cervical Spinal Cord Under Noxious Thermal Stimulation
Authors: Seifert Alan , Vannesjo S
Published: August 2024

FMRI of the spinal cord is challenging due to its small size, necessitating high resolution. Increasing B0 to 7T enables higher spatial resolution, and also enhances BOLD signal. However, challenges related to B0 homogeneity complicate spinal cord fMRI at 7T. We present group-level stimulus task fMRI results in the spinal cord at 7T, and compare the performance of single-shot and multi-shot 2D EPI protocols. Single-shot at 0.75mm in-plane resolution was most sensitive to activation, while multi-shot at 0.60mm provided the best-localized clusters. The best choice of protocol depends on the importance of sensitivity versus spatial localization for a given experiment.
Harmonization of Spinal Cord Diffusion Tensor Imaging Data from a Multi-Site, Multi-Scanner Study using Longitudinal ComBat
Authors: Middleton Devon , Li Yutong , Chen Andrew , Shinohara Russell , Woo John , Flanders Adam , Faro Scott , Krisa Laura , Mohamed Feroze
Published: August 2024

This study uses longitudinal ComBat data harmonization on a multi-site/multi-scanner spinal cord DTI study with a traveling cohort imaged on four scanners. The results show considerable improvement in correlation between scanners as well as decerased coefficient of variation. This approach has potential benefits for large, multi-site spinal cord studies.
7T MRI Reveals Abnormal Iron Deposition and Microstructure in Premanifest and Manifest Huntington’s Disease
Authors: Yao Jingwen , Morrison Melanie , Jakary Angela , Avadiappan Sivakami , Glueck Julia , Driscoll Theresa , Geschwind Michael , Nelson Alexandra , Xu Duan , Hess Christopher , Lupo Janine
Published: August 2024

We used QSM and DTI at 7T to investigate iron dysregulation and microstructure disruption in subcortical regions in Huntington’s disease (HD). We observed significant volume loss and increased iron deposition in the striatum and globus pallidus, and increased FA in the striatum. The deep cerebellar nuclei (dentate nuclei) showed a unique transient increase in volume and susceptibility in premanifest patients, implicating it as a new marker of HD disease progression that is sensitive to the pre-symptomatic window of HD. We also found varying relationships between imaging features in different brain regions, warranting further analyses of subregional changes.
Investigating application of multi-echo, multi-delay arterial spin labeling (ASL) to study endothelial exchange of water
Authors: Levendovszky Swati , Vaclavu Lena , Flores Jaqueline , Peskind Elaine , Iliff Jeffrey , van Osch Matthias
Published: August 2024

We applied multi-echo Hadamard encoded ASL imaging to study blood flow (CBF) and trans-endothelial exchange of water (Tex) as markers of vascular function to study two common risk factors of dementia; aging and sleep deprivation. We found that older adults had significantly lower CBF, and shorter Tex compared to young adults. In the same young adults, we compared CBF and Tex after a normal night of sleep and after sleep deprivation. Both CBF and Tex were insignificantly lower when measured after sleep deprivation compared to measurements after normal sleep.
Chronic stress impacts energy metabolism and triggers motor neuropathy in an Optineurin knockout mouse model
Authors: Dey Bedaballi , Roy Dipak , Chakravarty Sumana , Swarup Ghanshyman , Kumar Arvind , Patel Anant
Published: August 2024

Amyotrophic Lateral Sclerosis (ALS) is the most common adult-onset progressive motor neurodegenerative disease. To study whether in vivo loss of the multifunctional adaptor protein Optineurin (OPTN) triggers ALS, a whole-body optineurin knock-out (Optn KO) mice was generated. In the absence of a clinical phenotype, we investigated the role of chronic stress as a potential ‘determinant’ of motor phenotype in Optn deficient background. Progressive motor impairment was observed after 30 days from chronic variable mild stress (CVMS) exposure in KO stressed mice. This occurs as a result of neurodegeneration and reactive gliosis associated with neuronal glucose hypometabolism and astroglial hypermetabolism.
Distinct patterns of microstructural changes in mouse models of ALS/FTD with mutations in Tardbp, Fus and C9orf72
Authors: Bach Aurea Martins , Tisca Cristiana , Tachrount Mohamed , Milioto Carmelo , Carcolé Mireia , Spring Shoshana , Nair Remya , Cunningham Thomas , Fisher Elizabeth , Isaacs Adrian , Nieman Brian , Lerch Jason , Miller Karla
Published: August 2024

Amyotrophic lateral sclerosis (ALS) and Frontotemporal dementia (FTD) form a disease spectrum with shared clinical, pathological and genetic features. The most common mutations in ALS/FTD are in the genes C9Orf72, TARDBP and FUS. We used post-mortem diffusion kurtosis imaging to assess microstructure imaging phenotypes in mouse models of ALS/FTD with mutations in these genes. While mice with mutation in Tardbp presented reduced FA and MO in various white matter tracts, no difference could be detected in mice with mutation in Fus, and increased MO in a portion of the corpus callosum was observed in mice with mutation in C9orf72.
The interaction between first-episode schizophrenia and age based on gray matter volume and its molecular analysis: A multimodal MRI study
Authors: Chen Jingli , Wei Yarui , Xue Kangkang , Cheng Jingliang
Published: August 2024

We aimed to investigate the interaction characteristics of schizophrenia and onset age and its underlying molecular mechanisms by using T1-weighted high-resolution magnetic resonance imaging (3DT1) and the JuSpace toolbox. 150 first-episode drug-naïve schizophrenia and 119 matched normal controls were recruited and underwent 3DT1 scans. Our results show that the two main effects of factors and interaction effect in gray matter volume and their underlying molecular mechanisms have varying degrees of specificity changes. Particularly, the abnormality of the visual perception system and higher visual cognitive functions in early-onset schizophrenia (EOS) have guiding significance for the mechanism and treatment of EOS.
MR Imaging Deep Brain Stimulation of the Nucleus Basalis Meynert Restored Cognitive Function in Alzheimer’s Disease Model
Authors: Chang Ching-Wen , Lin Yi-Chen , Ko Chiung-Yuan , Lo Yu-Chun , Chen Ting-Chieh , Li Ssu-Ju , Wang Mu-Hua , Cho Tsai-Yu , Lin Sheng-Huang , Chen You-Yin
Published: August 2024

Alzheimer’s disease (AD) is an intricate neurodegenerative disease. Nucleus Basalis of Meynert (NBM), a key region of the cholinergic system that provides acetylcholine to cortex, has been shown to be target for deep brain stimulation (DBS) in AD. The 5×FAD mouse model was used to investigate the change of behavioral tasks, resting-state functional MRI, and acetylcholinesterase (AChE) assay were applied in this study. We found that NBM-DBS may play an important role in modulating cognitive function and spatial working memory in 5×FAD mice. Increasing functional connectivity and decreasing AChE activity may be the biomarkers for AD individuals.
Ultra-low-field Magnetization Transfer Imaging with Low SAR
Authors: Su Shi , Zhao Yujiao , Lau Vick , Xiao Linfang , Ding Ye , Hu Jiahao , Zhang Junhao , Man Christopher , Leong Alex , Wu Ed
Published: August 2024

At high field, magnetization transfer (MT) imaging suffers from the high specific absorption ratio (SAR) issue due to the usage of high power off-resonance MT RF pulses, and on-resonance saturation caused by B0 field inhomogeneity. At ultra-low-field (ULF), the low SAR and low absolute B0 inhomogeneity (in Hz) greatly facilitates the application of strong and versatile MT pulses without the confounding on-resonance saturation in practice. We demonstrate brain MT imaging at ULF first the first time using a 0.055 Tesla MRI platform with an extremely low SAR.
An Implant-Friendly Coil System for Imaging Deep Brain Stimulation at 3T MRI
Authors: Kutscha Nicolas , Bhusal Bhumi , Mahmutovic Mirsad , Chemlali Chaimaa , Vu Jasmine , Hansen Sam-Luca , Golestanirad Laleh , Keil Boris
Published: August 2024

A prototype of an adjustable DBS-friendly Tx/Rx 3T coil system was built and evaluated with measurements and numerical simulations characterizing its image quality and SAR profile. The work envisions the use of novel MRI hardware that will make 3T MRI fully accessible to patients with DBS implants.
Assessment of MRI-related heating with excess deep brain stimulation extension wires at 3 tesla
Authors: Vijayakumari Anupa , Lowe Mark , Walter Benjamin , Sakai Joseph , Tanabe Jody , Wojcik Richard , Bhattacharyya Pallab
Published: August 2024

When implanting a DBS system, the excess amount of extension wires is looped and placed in different regions (near the skull burr holes or in the chest), depending on the neurosurgeon/institution. In this study, we tested three different DBS configurations with excess extension wires looped behind the IPG. A phantom with a DBS device (lead model B33005, IPG Percept B35200, and Extension wire model B34000) was used to perform this study. We observed that the temperature rise was higher with one loop placed behind the IPG compared to two or no loops.
All-inclusive Safety Models Limit Imaging Performance at 7T
Authors: Kopanoglu Emre
Published: August 2024

Safety models on scanners are patient-position unaware and may include multiple patient positions to ensure safety. This may lead to overestimation of the specific absorption rate (SAR) and limit scanning performance. This study investigates the effect of an all-inclusive safety model on SAR estimation for parallel-transmit and quadrature-excitation at 7T. Results show that more than 4-fold SAR overestimation can be commonly observed. RF shimming suffered the most, with 11-fold overestimation at the worst-case and more than 4-fold overestimation in 37% of cases. RF shimming also offered the lowest peak local SAR and may be unnecessarily penalized by overconservative safety models.
Layer dependent changes of neural activity underlying laminar fMRI
Authors: Zaldivar Daniel , Bohraus Yvette , Logothetis Nikos , Goense Jozien
Published: August 2024

How accurately fMRI reflects the underlying laminar differences in neural processing? In the current study we investigated the relationship between neural activity and fMRI signals across different cortical layers. We found layer and frequency dependent differences in neural activity during the presentation of visual stimulus that elicits positive and negative BOLD response.
High-resolution and rapidly-acquired T2 mapping using deep-learning reconstruction and parallel imaging in evaluation of knee cartilage
Authors: Liu Weiyin , Wu Xiaxia , Zha Yunfei
Published: August 2024

T2 mapping reflects biochemical composition of tissues such as cartilage, tendon, ligament, meniscus without requirement for a contrast injection or special MRI imaging hardware, and there are numerous available techniques for post-processing of T2 images. However, scan time and signal-to-noise ratio are critical factors in clinical implementation. With the development of parallel imaging in combination of deep-learning based reconstruction algorithm, high-resolution and reproducible T2 mapping was potentially achieved to identify cartilage injury or degeneration in spite that T2 relaxation time cannot directly refer to previous studies but showed high consistency with the same acceleration factor for T2 mapping.
Quantification of muscle fat fraction and water T2 via RF phase-modulated 3D gradient-echo imaging
Authors: Vermeulen Eléonore , Baudin Pierre-Yves , Lapert Marc , Marty Benjamin
Published: August 2024

Intramuscular fat fraction (FF) is a frequently used biomarker of neuromuscular disease severity while water-T2 has been identified as a biomarker of disease activity. In this feasibility study, we explored the possibility to exploit RF phase-modulated 3D gradient-echo imaging to obtain multi-parametric mapping adapted to the study of skeletal muscles. Monte Carlo simulations were conducted to evaluate the robustness to noise of this proposed approach. An in vivo proof of concept on healthy volunteers was performed.
De-noising of 4D real-time joint motion images using a convolutional neural network trained on static data
Authors: Hales Laurel , Desai Arjun , Mazzoli Valentina , Chaudhari Akshay , Kogan Feliks
Published: August 2024

We demonstrated the potential applying a noise removal machine learning network trained on images without motion, on a set of similar real-time images acquired with motion.
Uncoupling of Anaerobic Glucose Metabolism and Oxidative Phosphorylation following Acute Electroconvulsive Shock in Mice Brain
Authors: Sarawagi Ajay , Patel Anant
Published: August 2024

Electroconvulsive therapy (ECT) is an established treatment for drug-resistant depression. However, the impact of ECT on neurotransmitter pathways is not clear. The cerebral metabolic rates were measured post ECS in mice using 1H-[13C]-NMR spectroscopy in conjunction with intravenous [1,6-13C2]glucose infusion. The concentrations of lactate, alanine, GABA, and choline were increased in the prefrontal cortex post 3.5 min of ECS. The concentrations of alanine-C3 and lactate-C3 increased after 3.5 min of ECS. In contrast, glutamatergic and GABAergic neurometabolic activity was reduced 3.5 min post ECT, and restored in an hour. These data indicate the dominance of glycolysis in the post-ictal period.
Identification of Quantitative Susceptibility Biomarkers for First Episode Psychosis using XGBoost
Authors: Franco Pamela , Montalba Cristian , Caulier-Cisterna Raul , García Marisleydis , González Alonso , Undurraga Juan , Crossley Nicolás , Tejos Cristian , Uribe Sergio
Published: August 2024

Several studies have demonstrated altered neurochemicals in deep-brain nuclei of psychosis patients. These alterations suggest a dopamine dysfunction in subcortical areas. QSM images quantify magnetic susceptibility changes in the brain. These changes are usually associated with iron concentrations and co-factor in dopamine pathways of the neurons. We propose a method based on machine learning to discriminate between psychosis patients and healthy controls by looking at the magnetic susceptibility of 9 deep gray matter nuclei, obtaining a precision of 91.6%.
DGE MRI detects altered glucose uptake and utilization upon microglia activation in Alzheimer’s disease
Authors: Chen Zilin , Huang Jianpan , Su Haoyun , Chong Wai Po , Chan Kannie W.Y.
Published: August 2024

Immune cell activation is a hallmark of Alzheimer’s disease (AD). Microglia activation impairs with glucose metabolism, which may serve as early biomarker for AD. Here, we employed dynamic glucose-enhanced (DGE)-MRI to assess glucose uptake and clearance in AD, and study its relationship with microglia based on our previous study. We observed an increase in microglia in AD than WT, accompanied with relatively high parenchymal glucose uptake and low CSF clearance. We believe further studies to associate the underlying molecular and cellular pathology of AD with DGE-MRI could benefit the identification of AD in early stages.
Golden-angle radial automated phase-cycled bSSFP for fat-water decomposition with SPARCQ: validation in a custom phantom and in vivo
Authors: Mackowiak Adèle , Yerly Jérôme , Pierzchala Katarzyna , Peper Eva , Rossi Giulia , Bastiaansen Jessica
Published: August 2024

The Signal Profiles Asymmetries for Robust multi-Compartment Quantification (SPARCQ) framework uses the off-resonance information encoded in phase-cycled bSSFP (PC-bSSFP) data to estimate fat fraction (FF). In order to strengthen previous validation work as well as open the range of applicability of the technique, in this work a 2D radial bSSFP sequence with integrated automated phase-cycling was designed and the accuracy of SPARCQ was tested in vitro on a larger FF range than previously reported. Comparisons to reference methods and sampling schemes indicate that the proposed automated 2D radial sampling scheme allows accurate FF mapping with SPARCQ while improving scan efficiency.
Influence of gadolinium, field-strength and sequence on quantified perfusion values in phase-resolved functional lung MRI
Authors: Glandorf Julian , Brunzema Fynn , Klimes Filip , Behrendt Lea , Voskrebenzev Andreas , Gutberlet Marcel , Grimm Robert , Wacker Frank , Vogel-Claussen Jens
Published: August 2024

The aim of this study is the evaluation of the influences of previously applied gadolinium-based contrast media, differing field strength and differing imaging sequence on the lately proposed perfusion quantification for PREFUL MRI. The results indicate severe alterations and distortions of the quantified perfusion parameters after gadolinium administration and depending on the field strength and on the applied sequence type. The results show, that future multicenter studies need to strictly adhere to an identical imaging protocol using the same field strengths to generate comparable results across all sites.
Using diffusion-relaxation MRI to estimate the inner radius of co-electrospun axon-mimicking fibres
Authors: Canales-Rodríguez Erick , Pizzolato Marco , Zhou Feng-Lei , Barakovic Muhamed , Thiran Jean- Philippe , Jones Derek K. , Parker Geoffrey , Dyrby Tim
Published: August 2024

A new approach for estimating inner axon radii from intra-axonal T2 relaxation times was recently proposed. However, further validations are required before this technique can be used widely. The main aim of this study is to validate this T2-based pore size estimation technique in phantoms comprising co-electrospun hollow axon-mimicking fibres designed to have non-circular cross-sections and different radii distributions. For this purpose, a diffusion-relaxation MRI dataset was acquired with a 7T preclinical scanner, from which the intra-fibre T2 times and pore sizes were estimated. The resulting pore sizes were compared to those measured from Scanning Electron Microscope images.
Towards whole-brain, quantitative characterisation of microscopy-derived microstructure in the BigMac dataset
Authors: Howard Amy , Huszar Istvan , Zhu Silei , Kor Daniel , Roumazeilles Lea , Jbabdi Saad , Miller Karla
Published: August 2024

The BigMac dataset is an open access resource combining in vivo MRI, postmortem MRI and multi-contrast microscopy data in a single, whole macaque brain. Here we perform data-driven segmentation of the BigMac histology slides to extract quantitative microscopy metrics for myelin, cell density, and cellular morphology (e.g. soma size and packing). Utilising high-quality MRI-microscopy registrations, we work towards building 3D volumes of quantitative microscopy derived metrics obtained at high resolution. This “ground truth” atlas of how cellular distributions vary across the brain is then directly related to co-registered diffusion MRI acquired in the same tissue.
Highly Resilient 3D Aortic Hemodynamics derived directly from Aortic Geometry using AI
Authors: Berhane Haben , Maroun Anthony , Ebrahimkhani Mahmoud , Bagci Ulas , Allen Bradley , Markl Michael
Published: August 2024

Aortic hemodynamic quantifications are vital for patient management. While 4D Flow MRI provides comprehensive aortic hemodynamics, it is hampered by long-acquisition times and cumbersome pre-processing. In this study, we developed an AI for the prediction of systolic 3D blood flow velocity vector fields with 3D aortic geometry as the only input. We performed testing on 248 BAV and 104 TAV datasets, using the systolic velocity vector fields from the 4D flow MRI as the ground-truth. Generally, we saw very strong agreement between the AI and the 4D flow and resilience to geometric changes (volume, dimension) in the input segmentation.