bluuebunny/crossref_metadata_2025 huggingface dataset:
7T metabolic MRI in mesial temporal lobe epilepsy
Authors: Jacobs Sarah , Shams Zahra , van der Kolk Anja , Bhogal Alex , Wijnen Jannie , Siero Jeroen , van Eijsden Pieter , Versteeg Edwin , Mühlebner Angelika , Van Hecke Wim , Klomp Dennis , Zijlmans Maeike , Wiegers Evita
Published: August 2024

We combined quantitative susceptibility mapping (QSM) and single voxel (SV) 1H magnetic resonance spectroscopy (MRS) at 7 tesla (7T) with the aim to characterize mesial temporal lobe epilepsy (mTLE). We discovered in 9 patients that the distribution of quantified susceptibly is negatively skewed in epileptogenic hippocampi compared to contralateral hippocampi, meaning more positive susceptibility values: an indicator for iron deposition. No differences in metabolite ratios could be seen in 7 patients between hippocampi, however our small sample size precludes any final conclusions.
Structural changes within the temporal lobe in mesial temporal lobe epilepsy at 7 Tesla
Authors: Langan Mackenzie , Verma Gauarv , Fields Madeline , Marcuse Lara , Balchandani Priti , Feldman Rebecca
Published: August 2024

Here we outline a preliminary analysis using a novel method leveraging ultra-high field neuroimaging to measure detectable differences in vasculature within the temporal lobe that may not be detectable at lower field strengths. We provide a tool for detection and quantification of vessels, perivascular spaces, and volumetric changes within the temporal lobe which may be relevant to uncover possible underlying neuroinflammatory processes in mesial temporal lobe epilepsy (MTLE) patients. In our analysis, we found a significant association between volumetric measures of the temporal lobe and vascular and perivascular markers, in patients with lateralized MTLE which may underlie epileptogenic processes.
Transcriptomic Signatures of Brain Regions Vulnerable to Anatomical and Metabolic Changes in Temporal Lobe Epilepsy
Authors: Li Jiwei , Huang Hui , Cai Bingyang , Yuan Siyu , Luo Jie
Published: August 2024

Imaging transcriptomics could bridge the gap between connectome and transcriptome. In this study, we selected brain regions that were vulnerable to hypometabolism, and those vulnerable to atrophy, then investigated transcriptional signatures and cell-type composition differences that may contribute to TLE-related brain structural and metabolic changes. We found hippocampus and entorhinal were found to be most vulnerable brain regions in both anatomical and metabolic changes in TLE patients. Enrichment analysis found that differential expression genes most significantly enriched in neuroactive ligand-receptor interaction pathway. Inhibitory neuron, microglia and oligodendrocyte precursor cells showed significant difference between vulnerable regions and relatively healthy regions.
2D Self-Navigation Improves Respiratory Motion Tracking Compared with 1D Self-Navigation in 3D Left Atrial LGE using XD-GRASP Reconstruction
Authors: Hong KyungPyo , Gunasekaran Suvai , Elbaz Mohammed , Katsaggelos Aggelos , Nazarian Saman , Passman Rod , Kholmovski Eugene , Kim Daniel
Published: August 2024

Previously described left atrial (LA) late gadolinium enhancement (LGE) using a stack-of-stars k-space sampling pattern with XD-GRASP reconstruction may produce blurry LA wall due to signal variation of inversion-recovery-prepared 1D self-navigation caused by arrhythmia. We hypothesize 2D image self-navigation would be less sensitive to arrhythmia for motion tracking in XD-GRASP framework. In this study, we developed a free-breathing, LA LGE pulse sequence with isotropic spatial resolution using a stack-of-stars sampling pattern and 2D self-navigation and compared its performance against conventional 1D self-navigation in patients with atrial fibrillation. Results show that 2D self-navigation improves respiratory motion tracking compared with 1D.
MR SIGNATURE MATCHING (MRSIGMA) FOR VOLUMETRIC MRI WITH LESS THAN 300MS LATENCY ON A 1.5T MR-LINAC SYSTEM
Authors: Siddiq Syed , Murray Victor , Tyagi Neelam , Borman Pim , Raaymakers Bas , Wu Can , Otazo Ricardo
Published: August 2024

The MR-Linac system offers a platform to adapt and monitor radiotherapy of tumors affected by continuous motion in real-time. However, real-time MRI technology is restricted to 2D imaging, which limits performance. MR Signature Matching (MRSIGMA) is a recently developed real-time 3D MRI technique with the MR-Linac as a target. However, MRSIGMA was tested only in a non-real-time scenario. This work develops a real-time implementation of MRSIGMA on the Elekta Unity 1.5T MR-Linac, including raw data transmission to an external computer, deep learning 4D reconstruction and correlation-based matching to demonstrate total imaging latency lower than 300ms.
Individualized representation learning of resting-state fMRI
Authors: Han Kuan , Choi Minkyu , Wang Xiaokai , Murguia Amaya , Liu Zhongming
Published: August 2024

We describe a generalizable, modular and explainable model for individualized representation learning of resting-state fMRI. The model consists of a “deep” base which learns representations that are unique to each individual brain through self-supervised learning, and “shallow” adds-on which are trained with supervised learning for different tasks of behavior prediction. The model is scalable to allow some add-on modules to be trainable without affecting others, and is explainable to identify brain structures responsible for individualized behavioral prediction.
Deep Brain Stimulation of Nucleus Accumbens Alters Brain Functional Connectivity and Metabolism to Enhance Memory-Related Cognitive Function
Authors: Li Ssu-Ju , Chen Ting-Chieh , Lo Yu-Chun , Lin Yi-Chen , Chang Ching-Wen , Wang Mu-Hua , Cho Tsai-Yu , Lin Sheng-Huang , Chen You-Yin
Published: August 2024

Deep brain stimulation (DBS) has been a well-established treatment for cognitive dysfunction. However, cognitive dysfunctions were demonstrated to be associated with the metabolic syndrome. Nucleus accumbens (NAc) in the dopaminergic pathway is associated with glucose metabolism, considered to be a promising DBS targeted region to be investigated. Resting-state functional MRI, behavioral test, bioenergetic analysis and electron microscopy were applied in this study. We found increased functional connectivity, enhancement in cognitive behavior, increased energy metabolism and mitochondrial biomass after NAc-DBS.
The impact of white matter microstructure with multi-fiber populations on gradient-echo frequency maps and QSM
Authors: Chen Lin , Mao Deng , Gilbert Guillaume , Versluis Maarten , van Zijl Peter , Li Xu
Published: August 2024

A hollow cylinder fiber model (HCFM) with two orientation-dispersed fiber populations was used to characterize white matter microstructure-based susceptibility effects. The resulting TE-dependent frequency shifts were fitted with a curve function parameterized by a microstructure induced frequency difference (Δf) and bulk susceptibility induced frequency shift (Cf). Local frequency and QSM reconstruction using the fitted Cf versus using weighted echo averaging were compared by a head phantom and in vivo human brain data. Δf provided a useful contrast to illustrate the underlying white matter microstructure and Cf helped to improve the quantification accuracy of tissue magnetic susceptibility using QSM.
In silico brain data in ADEPT, A Database for MR-Electrical Properties Tomography applications
Authors: Meerbothe Thierry , van den Berg Cornelis , Mandija Stefano
Published: August 2024

This work presents ADEPT, A Database for MR-Electrical Properties Tomography applications. ADEPT is an open database that contains simulated MRI field data from electromagnetic simulations on brain models with and without tumor inclusion for EPT reconstructions. These data can serve as common ground to benchmark EPT reconstruction methods developed in different centers and will alleviate the computational burden for the creation of simulated data for training data-driven EPT methods. In the future, the database will be openly accessible and will be extended with phantom and in-vivo data. Other centers are also encouraged to share their data.
Probing underlying biophysical mechanisms of electrical properties change by pathogenesis at the microscopic cellular level
Authors: Liu Henghui , Xu Guofang , Ren Yinhao , Liu Feng , Nan Xiang , Han Jijun
Published: August 2024

Magnetic resonance electrical properties tomography provides a non-invasive approach to extracting pixel-wise electrical properties by B1 field mapping. However, there is a void in our understanding of the underlying biophysical mechanism of electrical properties changes accompanied by pathogenesis at the microscopic cellular level. In this work, we build a microscopic tissue model to study fatty liver disease, which focuses on exploring the relationship between fat fraction and electrical properties. Our findings could bridge microscopic lesions and pixel-wise EPT images and may offer a novel strategy for retrieving electrical properties via fat quantification techniques such as Dixon directly.
A 32-Channel 3D-Printed-Loop Receive Array with Direct High-Impedance Preamplifiers for Brain Imaging at 7T
Authors: Gapais Paul-François , Luong Michel , Giacomini Eric , Vignaud Alexandre , Nizery François , Maitre Gabriel , Hosseinnezhadian Sajad , Dubois Marc , Georget Elodie , Amadon Alexis
Published: August 2024

A fully customized 32-channel receive array has been designed, fabricated and evaluated using MR experiments at 7T. The design is made of non-geometrically decoupled loops arranged in two layers of large and small loops. Copper loops are 3D printed from additive manufacturing, preamplifiers are home-built, and an easy implementation procedure is proposed. Receive array performances shows SNR comparable to the Nova Medical reference coil while being superior at the top of the coil and for parallel imaging accelerated in the vertical direction.
In vivo performance of a wearable coil vest for 3 T breast MRI (BraCoil)
Authors: Obermann Michael , Nohava Lena , Frass-Kriegl Roberta , Soanca Onisim , Ginefri Jean-Christophe , Felblinger Jacques , Laistler Elmar
Published: August 2024

Recently, we introduced the “BraCoil”, a wearable coil for prone and supine breast imaging designed to overcome several shortcomings in clinical breast MRI. Here, we present in vivo performance tests on 12 volunteers with different breast volumes ranging from 495 mL (bra size 70A) to 3020 mL (90D). SNR gain up to a factor of three over a commercial breast coil was found. Acceleration factors up to 6x4 can be used with reasonable g-factors. High-quality in vivo images with different contrasts are presented.
Improved Simultaneous Intracranial Vessel Wall Imaging and dynamic MRA Using Low-rank Reconstruction
Authors: Zhang Kaiyu , Chen Zhensen , Guo Yin , Wang Xin , Canton Gador , Balu Niranjan , Hatsukami Thomas , Yuan Chun , Ma Xiaodong
Published: August 2024

Acquiring multi-contrast images of intracranial vessels from one single MRI sequence is beneficial for comprehensive neurovascular disease diagnosis. Vessel wall (VW) images and dynamic MRA (dMRA) can be obtained from a time-efficient multi-contrast sequence named iSNAP. However, the previously adopted k-space sharing reconstruction method generated high-quality dMRA but low-quality VW images. In this study, we aim to develop a novel low-rank-based image reconstruction method to reconstruct VW and dMRA from highly undersampled 4D MRI. High quality VW images with sharper wall delineation are obtained, while hemodynamic information from dMRA is preserved.
Free-running 3D-CINE MRI of patients with congenital heart disease using inter-bin compensation of cardiac motion
Authors: Milani Bastien , Roy Christopher , Ledoux Jean-Baptist , Rotzinger David C. , Si-mohamed Salim , Masi Ambra , Yerly Jerome , Rutz Tobias , Prsa Milan , Schwitter Jurg , Stuber Matthias
Published: August 2024

We present in this work a 3D-CINE whole-heart reconstruction that we developed for free-running 3D‑radial fully self-gated acquisitions. The reconstruction is compressed-sensing-based with temporal-total-variation (tTV) regularization, which is known to corrupt or compress motion and to blur moving structures. In order to solve these drawbacks, we regularize by an improved tTV equal to the one-norm of the sum of the motion-corrected-residuals between adjacent frames. While this strategy has already been applied for various trajectories, it has never been applied for 3D-radial in free-running. In this study, we demonstrate quantitatively and qualitatively that this strategy in fact improves image quality.
Locally low-rank denoising in transform domains.
Authors: Moeller Steen , Johnson Casey , Buko Erick , Toth Ferenc , Metzger Greg , Mangia Silvia , Michaeli Shalom , Ponticorvo Sara , Canna Antonietta , Ugurbil Kamil , Akcakaya Mehmet
Published: August 2024

The concept of transform processing domain with locally low rank denoising is proposed as T-NORDIC and demonstrated for MSK and brain applications. The improvements on quantitative maps may be leveraged for faster acquisitions by relaxing the number of averages needed to obtain sufficient SNR for high resolution acquisitions and for application of low rank denoising to common clinical acquisitions.
7T MR DTI and Tractography of a 1-Week Postmortem Fixed Human Brainstem-Cerebellum: Novel Imaging Methodology Producing Extraordinary Images
Authors: Hanalioglu Sahin , Mignucci-Jiménez Giancarlo , Bahadir Siyar , Fuentes Alberto , Mathew Ethan , Turner Gregory , Preul Mark
Published: August 2024

Diffusion-tensor imaging (DTI) is routinely used to estimate the pattern, orientation, and directionality of white matter tracts in human living subjects. However, diffusion imaging of ex-vivo brain specimens is complex due to the diffusivity properties of fixed brain tissue. We developed a novel methodology for tractography of a 1-week postmortem fixed human brainstem and cerebellum specimen utilizing a deterministic fiber tracking algorithm on a 7T MR DTI diffusion scheme registered to an MNI space through landmark-based affine registration. The results showed highly detailed tractography images and agreement between left and right crossing and non-crossing fibers.
Tractwise perfusion-microstructure relationships in the aging white matter based on the Lifespan Human Connectome Project - Aging
Authors: Robinson Tyler , Sun Yutong , Chang Paul , Chen J. Jean
Published: August 2024

This study examined baseline and age-related differences in white matter perfusion and microstructural integrity across ten tracts of interest using 535 adult subjects of the Human Connectome Project in Aging. Whole-brain and tractwise relationships were identified between age, cerebral blood flow, mean diffusivity, and fractional anisotropy. Additionally, regional differences in age-related perfusion and microstructural trajectories were identified, representing one of the first direct examinations of regional variation in white matter perfusion in aging.
In-vivo water gap mapping as a new myelin packing marker
Authors: Shaharabani Rona , Mezer Aviv
Published: August 2024

We established a new in-vivo measurement of the myelin water gap that can serve as a biomarker for myelination packing. In postmortem studies, it was shown that the water layer gap between healthy myelin membranes is compact. However, it changes during the demyelination and remyelination processes in MS patients. We developed a biophysical model based on the water fraction and multi-compartment T2 to estimate the water gap. Next, we designed a lipid phantom system with varying water gaps and validated it using Cryo-TEM. Our model successfully estimates the water gap in-vitro and shows a reliable estimation for in-vivo healthy volunteers.
Cross-subject variability of the optic radiation anatomy: a large-scale analysis
Authors: Herlin Bastien , Uszynski Ivy , Chauvel Maëlig , Poupon Cyril , Dupont Sophie
Published: August 2024

Optic radiations are tracts of importance for neurosurgery, especially their path within the temporal lobe. Using an advanced analysis pipeline relying on probabilistic tractography and fiber clustering, we processed the diffusion MRI data of the 1065 subjects of the HCP cohort and reconstructed a reference optic radiation bundle. From it, we subsequently extracted the optic radiations of each subject to study the variability of their morphometry. We identified a higher variability of their rostral extent, with a significant left-right difference (median distance to the temporal pole +/- standard deviation: left: 28.8 +/- 2.3 mm, right: 29.2 +/- 2.1 mm, p=1.10-8).
T1 and T2 Mapping Using Highly Sparse Unsuppressed Water Signals from MRSI Scans with Generalized Series-Assisted Low-Rank Tensor Modelling
Authors: Li Yudu , Guo Rong , Zhao Yibo , Jin Wen , Ma Chao , Luo Shirui , Fakhri Georges , Li Yao , Jaromin Maria , Kindratenko Volodymyr , Sutton Brad , Liang Zhi-Pei
Published: August 2024

MR spectroscopic imaging (MRSI) without water suppression provides a unique opportunity to use the unsuppressed water spectroscopic signals for T1 and T2 mapping. This work presents a new image reconstruction method for reconstructing the T1/T2 maps from the highly sparse MRSI data. This method uses a novel generalized series-assisted low-rank tensor model to absorb the high-quality reference MRSI images to constrain the spatial-spectral-parametric variations. Experimental results demonstrated very encouraging reconstruction performance.
Data acquisition strategies to mitigate cardiac-induced noise in quantitative R2* maps of the brain
Authors: Raynaud Quentin , Dardano Thomas , Roy Christopher , Yerly Jérôme , Kober Tobias , van Heeswijk Ruud B. , Lutti Antoine
Published: August 2024

Cardiac pulsation enhances the noise level in MR images of the brain and reduces the sensitivity of the data in studies of brain disease. We propose two data acquisition strategies that mitigate cardiac-induced noise in quantitative brain maps of the MRI parameter R2*. The first strategy sets the number of samples at each k-space location according to the local level of cardiac-induced noise. The second strategy adjusts data acquisition in real-time to acquire the data most sensitive to cardiac-induced noise during the diastolic period of the cardiac cycle.
Dixon-Based B0-Navigation to Correct B0 Drift and B0 Fluctuations in Radial Stack-Of-Stars Multi-Echo Gradient Echo Imaging
Authors: Stelter Jonathan , Wu Mingming , Raspe Johannes , Braun Philipp , Boehm Christof , Weiss Kilian , Karampinos Dimitrios
Published: August 2024

Multi-echo gradient-echo imaging is known to be affected by temporally varying B0 effects, including B0 drifts and respiratory motion-induced B0 fluctuations. The radial stack-of-stars trajectory enables the oversampling of the k-space center and has been previously employed for B0-navigation without the consideration of fat. The present work develops a methodology for Dixon-based B0-navigation to correct for B0 drift and B0 fluctuations in stack-of-stars multi-echo gradient-echo imaging for body imaging. Simulations and in vivo measurements show the advantage of the Dixon-based B0-navigation in correcting quantification errors in proton density fat fraction, T2* and field-map, when using stack-of-stars multi-echo gradient-echo acquisitions.
Diffusion-weighted MRI of the spinal cord near metal implants: A rapid TSE approach with multispectral imaging and reduced field of view
Authors: Li Zhiqiang , Ooi Melvyn , Murphy Rory , Karis John , Dortch Richard
Published: August 2024

Diffusion-weighted (DW) spinal cord MRI based on single-shot EPI suffers from strong geometric distortion and signal loss artifacts. While strategies have been developed to reduce these artifacts in DW-EPI, their application in spinal cord DWI is challenging when metal implants are present near the spine. A multispectral DW-PROPELLER has been proposed to overcome this challenge; however, this requires long scan times. In this work, we developed a single-shot TSE technique with multispectral imaging and reduced FOV to achieve fast speed / increased SNR for spinal cord DWI near metals. Volunteer and patient results demonstrated reduced artifacts and improved speed/SNR performance.
Clinical DIADEM diffusion-weighted-imaging (DWI) of the brain: Comparison with commercially available DWI techniques.
Authors: In Myung-Ho , Campeau Norbert , Trzasko Joshua , Kang Daehun , Welker Kirk , Huston John III , Shu Yunhong , Bernstein Matt
Published: August 2024

A novel distortion-free multi-shot diffusion-weighted-imaging (DWI), termed DIADEM (Distortion-free Imaging: A Double Encoding Method), was compared with commercially available state-of-the-art DWI techniques for clinical brain imaging. High-resolution distortion-free DWI is feasible within ﻿clinically acceptable acquisition times using the DIADEM technique, and demonstrated better performance than current commercially available DWI techniques.
Distortionless, free-breathing, and respiratory resolved 3D diffusion weighted imaging of the abdomen
Authors: Lee Philip , Zhou Xuetong , Wang Nan , Hargreaves Brian
Published: August 2024

Abdominal imaging is frequently performed with uncomfortable breath holds, or respiratory triggering to reduce the effects of respiratory motion. Diffusion weighted sequences provide a useful clinical contrast but have prolonged scan times due to low SNR. These scans cannot be reliably completed in a single breath hold, and respiratory triggering has low scan efficiency. We present a respiratory resolved, diffusion-prepared 3D sequence that obtains distortionless diffusion weighted images during free-breathing. We describe techniques to address the myriad of challenges including: 3D shot-to-shot phase correction, respiratory binning, diffusion encoding during free-breathing, and robustness to off-resonance.
A Simultaneous Measurement of Opposite-Phase-Encoding EPI in a Single fMRI session for the Reduction of Acquisition Time and SAR at 7T
Authors: Yun Seong Dae , Genc Erhan , Shah N. Jon
Published: August 2024

In high-resolution fMRI using EPI, geometric distortions typically seen in reconstructed images significantly hinder the accurate mapping of activated voxels. One method to correct for distortions is to acquire EPI data with an opposite phase-encoding direction. However, this method is usually implemented with an additional run of the same protocol, leading to a redundant measurement of parallel imaging calibration scans. Here, we present an EPI scheme that measures the opposite-direction data in a single fMRI session, substantially reducing the total acquisition time. We demonstrate more accurate functional mapping with the distortion correction in submillimetre whole-brain visual fMRI at 7T.
Semi-Supervised Learning for Spatially Regularized Quantitative MRI Reconstruction - Application to Simultaneous T1, B0, B1 Mapping
Authors: Zimmermann Felix , Kofler Andreas , Kolbitsch Christoph , Schuenke Patrick
Published: August 2024

Typically, in quantitative MRI, an inverse problem of finding parameter maps from magnitude images has to be solved. Neural networks can be applied to replace non-linear regression models and implicitly learn a suitable spatial regularization. However, labeled training data is often limited. Thus, we propose a combination of training on synthetic data and on unlabeled in-vivo data utilizing pseudo-labels and a Noise2Self-inspired technique. We present a convolutional neural network trained to predict T1, B0, and B1 maps and their estimated aleatoric uncertainties from a single WASABITI scan.
Attention please: deep learning can reproduce fractional anisotropy microstructure maps with reduced input data but loses clinical sensitivity
Authors: Gaviraghi Marta , Ricciardi Antonio , Palesi Fulvia , Brownlee Wallace , Vitali Paolo , Prados Ferran , Kanber Baris , Wheeler-Kingshott Claudia Gandini
Published: August 2024

Quantitative maps obtained with diffusion weighted (DW) imaging such as fractional anisotropy (FA) are useful in pathologies. Often, to speed up acquisition time, the number of DW volumes acquired is reduced. We investigated the performance and clinical sensitivity of deep learning (DL) networks to calculate FA starting from different numbers of DW volumes. Using 4 or 7 volumes, clinical sensitivity was affected because no consistent differences between groups were found, contrary to our “one-minute FA” that uses 10 DW volumes. When developing DL for reduced acquisition data, the ability to generalize and biomarker sensitivity must be assessed.
Towards whole brain mapping of the hemodynamic response function
Authors: Guidi Maria , Mangini Fabio , Moraschi Marta , Mascali Daniele , Fratini Michela , Mangia Silvia , Frezza Fabrizio , Giove Federico
Published: August 2024

We characterized a deconvolved haemodynamic response function (dHRF) across the whole cortex exploiting a sine series expansion in a cohort of young healthy subjects from the Human Connectome Project. We report, for different tasks and brain regions, the amplitude, latency, time-to-peak and full-width at half maximum of the fitted BOLD response and of the dHRF. We show that each of those parameters vary throughout the cortex and, to a smaller extent, across subjects. Additionally, the use of a flexible model, like the one we explored in this study, reveals that the HRF in some brain regions deviates from canonicity.
Estimation of CSF pulsations at the craniospinal junction using pseudo-continuous arterial spin labeling
Authors: Im JaeGeun , Kim JunHee , Park SungHong
Published: August 2024

To measure CSF pulsation and CBF signals simultaneously with pCASL, we measured the influence of pCASL label pulse on the CSF signal at the craniospinal junction and compared the CSF signal differences and PC stroke volume to estimate CSF pulsation with pCASL. Our results showed that the variability of CSF signals at the nearby position from label pulses was negatively correlated with PC stroke volume. Based on this, the labeling pulse used for CBF tagging in pCASL also can be used for CSF pulsation estimation, and it will allow us to measure CBF and CSF pulsation simultaneously.
3D quantitative-amplified Magnetic Resonance Imaging (3D q-aMRI)
Authors: Terem Itamar , Wang Nan , Condron Paul , Younes Kyan , Abderezaei Javid , Feng Berthy , Kumar Hari , Vossler Hillary , Kurt Mehmet , Bouman Katherine L. , Mormino Elizabeth , Holdsworth Samantha , Setsompop Kawin
Published: August 2024

Amplified Magnetic Resonance Imaging (aMRI) is a pulsatile brain motion visualization method that delivers ‘videos’ with high contrast and temporal resolution. aMRI has been shown to be a promising tool in various neurological disorders. However, aMRI currently lacks the ability to quantify the sub-voxel motion field in physical units. Here, we introduce a quantitative-aMRI (q-aMRI) algorithm, which quantifies the sub-voxel motion of the 3D aMRI signal and validates its precision using phantom simulations with realistic noise. In-vivo experiments on healthy volunteers demonstrated repeatability of the measurements, and differences in brain motion were observed in subjects with positive/negative amyloid PET.
Brain PET Synthesis from MRI Using Joint Probability Distribution of Diffusion Model at Ultrahigh Fields
Authors: Taofeng Xie , Chentao Cao , Zhuoxu Cui , Fanshi Li , Zidong Wei , Yanjie Zhu , Ye Li , Dong Liang , Qiyu Jin , Guoqing Chen , Haifeng Wang
Published: August 2024

MRI and PET are important modalities and can provide complementary information for the diagnosis of brain diseases because MRI can provide structural information of brain and PET can obtain functional information of brain. However, PET is usually missing. Especially, simultaneous PET and MRI imaging is not achievable at ultrahigh field in the current. Thus, synthetic PET using MRI at ultrahigh field is essential. In this paper, we synthetic PET using MRI as a guide by joint probability distribution of diffusion model (JPDDM). Meanwhile, We utilized our model in ultrahigh fields.
Brain glutathione levels decrease with age and correlate with cognitive function
Authors: Hu Xin , Zhao Min , Yang Jing , Xu Longji , Chen Weibo , Ren Fuxin , Gao Fei
Published: August 2024

Cognitive impairment and the improvement of oxidative stress are common in the aged. GSH is a key player to defend oxidative stress and avoid ferroptosis. We aim to explore the variation of brain GSH levels with age including anterior cingulate cortex, posterior cingulate cortex and occipital cortex, and to test whether GSH levels in these regions are associated with cognitive function. Our findings indicate that oxidative stress and ferroptosis abnormality caused by the decreased GSH levels may contribute to cognitive decline of the aged without a regional specificity manner.
Abnormal brain function and connectivity in patients with convergence insufficiency: A resting-state functional MRI study
Authors: Wanng Yuxia , Wu Ye , Sun Huaiqiang , Li Fei
Published: August 2024

Convergence insufficiency (CI) is the most common binocular vision disorder in optometric clinics relevant to the dysfunction of the specific neural circuit, while the neural mechanism is unknown. Using the fractional amplitude of low-frequency fluctuations fALFF and seed-to-voxel analysis, we found increased fALFF in the left cerebellum crus 1 and increased functional connectivity between the left cerebellum crus 1 and the right cerebellum crus 1 in patients with CI than healthy controls, which showed positive correlations with the severity of symptoms. These findings provide evidence of altered brain function features underlying neurobiological mechanisms of patients with CI.
Combining radiomic features with background parenchymal enhancement from DCE-MRI data for predicting treatment response in breast cancer
Authors: Slavkova Kalina , Cohen Eric , Chitalia Rhea , Thakran Snekha , Mankowski Walter , Nguyen Alex , Horng Hannah , McDonald Elizabeth , Feldman Michael , DeMichele Angela , Kontos Despina
Published: August 2024

Our objective is to predict pathological complete response (pCR) outcome to neoadjuvent chemotherapy in breast cancer patients. We combine radiomic features with background parenchymal enhancement -- computed from standard-of DCE-MRI data from the ISPY-2 trial -- and model treatment outcome via multivariable logistic regression. During training and testing, we demonstrate that models including BPE alongside radiomic and clinical covariates yielded the highest AUC values among all tested regression models, thus improving the prediction of pCR outcome.
Quantitative measurement of renal oxygenation in human using QSM and pCASL
Authors: Jung Yujin , Ahn Hyun-Seo , Park Sung-Hong
Published: August 2024

Measuring the renal oxygenation level is important because it is related to the progress of kidney diseases such as chronic kidney disease. In this study, we noninvasively quantified and mapped the renal metabolic rate of oxygen (RMRO2) using quantitative susceptibility mapping and pseudo-continuous arterial spin labeling and evaluated the results using the caffeine challenge. The results demonstrated higher renal oxygenation in the medulla than the cortex, and lower renal oxygenation on the caffeine day compared to the control day, as expected. This technique can be applied to identifying patients at risk of kidney diseases with no contrast agent.
Rapid In Vivo Prostate Microstructure MRI using Diffusion-Relaxation Correlation Spectrum Imaging with Random Matrix Theory-Based Denoising
Authors: Zhang Zhaohuan , Shih Shu-Fu , Sung Kyunghyun , Raman Steven , Wu Holden
Published: August 2024

Diffusion-Relaxation Correlation Spectroscopic Imaging (DR-CSI) has shown promises for quantifying prostate microscopic tissue compartments for prostate cancer characterization, but in vivo DR-CSI faces challenges such as lower signal-to-noise ratio (SNR), and signal averages could lead to prolonged scan time. This work investigated the combination of DR-CSI with random matrix theory-based denoising to take advantage of the large number of TE-b values contrast encodings to improve SNR, and enables rapid in vivo prostate microstructure MRI in <6min at 3T.
Assessment of Rotator Cuff Muscle Fat and Fibrosis Using Quantitative UTE Magnetization Transfer Imaging and Modeling
Authors: Suprana Arya , Tang Qingbo , Orozco Elisabeth , Jang Hyungseok , Jerban Saeed , Du Jiang , Ma Yajun , Chang Eric
Published: August 2024

At present, there is a lack of available tools to non-invasively evaluate rotator cuff muscle fibrosis. Prior studies have suggested that magnetization transfer measurements may be useful for quantifying collagen when acquired with an ultrashort echo time technique. However, the increased presence of fat after muscle injury may confound these measurements. In this study, a rat model of chronic massive rotator cuff tearing was used with UTE-T1 and UTE-MT mapping without and with fat suppression to show that muscle collagen and fibrosis could be quantified.
En Route to Fine-Grained Neurosignatures in the Individual Brain: Evaluating Methodology to Boost Spatial Accuracy & Sensitivity of BOLD fMRI
Authors: Ceja Igor Tellez , Gladytz Thomas , Starke Ludger , Tabelow Karsten , Niendorf Thoralf , Reimann Henning
Published: August 2024

In recent years, fMRI at ultrahigh magnetic field strengths (≥7T) has shifted from group analyses to probing neural processing in the individual brain. Identifying neurosignatures requires detection of BOLD effects with high sensitivity and spatial accuracy. Yet, it remains a challenge to enhance the sensitivity of fMRI for the BOLD effect without blurring the spatial details. Here, we assess the quality of the Gaussian, spatial adaptive non-local means (SANLM) and the adaptive weights smoothing (AWS) filters by employing a synthetic fMRI dataset as ground truth. AWS provides superior localization of the BOLD activations with high sensitivity at reasonable noise levels.
A shortened MOLLI for renal T1 mapping
Authors: Periquito Joao , Sharma Kanishka , Soe Kywe , Alhummiany Bashair , Fulford Jonathan , Shelley David , Gooding Kim , Shore Angela , Mansfield Michael , Sourbron Steven
Published: August 2024

A recent consensus recommends MOLLI-type methods for T1-mapping in the kidney, but these are slow due to the need for full relaxation between inversions. Acceleration can be easily achieved on routine MOLLI-sequences by repeating preparation pulses before complete relaxation, but this requires more accurate signal modelling. Here we propose a broadly applicable model-based approach which inverts a signal model built on Bloch simulations of magnetisation propagation. The method is validated on phantom data and a two-centre cohort of 50 patients with diabetic kidney disease.
Quantitative BOLD MRI for Estimating Intra-renal Oxygen Availability: Are Kidneys Hypoxemic in CKD?
Authors: Prasad Pottumarthi , Li Lu-Ping , Hack Bradley , Leloudas Nondas , Sprague Stuart
Published: August 2024

Kidney BOLD MRI measurements are not specific to oxygen availability especially when comparing different cohorts because R2* also depends on fractional blood volume (fBV) and hematocrit (Hct). In this study, we have estimated fBV using ferumoxytol and Hct by blood sampling. Using these we show Quantitative BOLD MRI can characterize oxygen availability in quantitative terms. For the first time, we show that kidney cortex is normoxemic in healthy controls while moderately hypoxemic in CKD. Medulla is mildly hypoxemic in controls while moderately hypoxemic in CKD.
Improving tractography using high angular resolution diffusion imaging in rodent kidney
Authors: Maharjan Surendra , Wallace Abigail , Jewett Megan , Chen Neal , Wang Nian
Published: August 2024

Diffusion tensor imaging (DTI) has been widely used to study renal microstructure. However, DTI-based tractography failed to track tubules throughout the kidney. Here, we aim to determine whether high angular resolution diffusion imaging (HARDI) could improve the tractography in the complicated tubular architectures of rodent kidney.
Predicting carotid plaque vulnerability by macrophage-targeted nanocluster-enhanced high-resolution vessel wall imaging
Authors: Gong Yan , Wu Menglin , Fu Dingwei , Guo Yu , Lu Xiudi , Zou Ying , Zhang Xiang , Zhu Jinxia , Zhang Xianchang , Li Xue , Xia Shuang
Published: August 2024

Ischemic stroke can be attributed to the sudden rupture of high-risk atherosclerotic plaques. Therefore, identifying vulnerable plaque is essential for preventing acute vascular events. Increasing evidence has established that macrophages play a vital role in the pathogenesis of atherosclerosis. Using the black-blood technique, an imaging approach that suppresses blood signals to highlight the arterial wall, and a macrophage-targeted contrast agent, plaque vulnerability could be quantitatively assessed for the macrophage burden. This in vivo animal study non-invasively evaluated the plaque vulnerability, which may provide information on the clinical risk stratification.
MR Multitasking-based Multi-dimensional Assessment of Cardiovascular System (MT-MACS): Initial Clinical Experience
Authors: Xiao Jiayu , Chen Yang , Liu Xin , Hu Zhehao , Li Debiao , Christodoulou Anthony , Garg Parveen , Fong Michael , Wilcox Alison , Yang Qi , Fan Zhaoyang
Published: August 2024

Cardiovascular diseases are common causes of mortality and morbidity globally. An MR MultiTasking based 3D Multi-dimensional Assessment of Cardiovascular System (MT-MACS) technique has recently been developed to provide multi-contrast, cardiac phase-resolved imaging of the whole heart and thoracic aorta in a single scan without the need for ECG triggering or respiratory navigation. We aimed to assess the performance of MT-MACS in patients with suspicious cardiovascular diseases. We demonstrated the feasibility of using MT-MACS in a routine clinical setting. More importantly, it achieved good image quality in most patients with almost perfect inter-reader agreement and diagnostic accuracy.
Deep learning for automatic detection and contouring of parotid gland tumors on MRI
Authors: Zhang Rongli , Ai Qi Yong , Wong Lun , Deng Qiao , King Ann
Published: August 2024

Parotid gland tumors (PGTs) are often asymptomatic and an incidental finding on MRI that can be overlooked. We constructed an accurate artificial intelligence (AI) tool trained on fat-suppressed T2-weighted MRI to automatically identify patients with PGTs with an accuracy of 94.3% (99/105), a sensitivity of 94.0% (47/50) and a specificity of 94.5% (52/55). For identified PGT patients, automatic segmentations of the tumor and gland were performed and achieved dices of 77.2% and 86.3%, respectively. The proposed AI tool may assist radiologists by acting as a second pair of eyes to ensure incidental PGTs on MRI are not missed.
Automatic facial nerve tractography in patient with vestibular schwannoma
Authors: Lu Chenxi , Tong Qiqi , Chen Mantao , Zheng Xiujue , Zhong Jianhui , He Hongjian
Published: August 2024

Facial nerve tractography has recently been recognized as a valuable tool for predicting risk before vestibular schwannoma surgery to preserve function. Due to complexity of tissue structure, professional experience is usually required to manually adjust tracking parameters and place exclusion ROIs for optimal tractography. A pipeline for automatic facial nerve tractography will significantly lessen surgeons' workload. Here, we proposed a fiber growing method for adjusting the angle threshold adaptively and removed track outliers. Results show that the proposed method achieves good consistency with the manual method. The pipeline would have great potential for assisting clinic surgeries for vestibular schwannoma.
Quantitative ΔR1 and PK Mapping Supports Tumor Habitat Delineation and Anti-Angiogenic Response Prediction of Vestibular Schwannoma
Authors: Zhu Xiaoping , Lewis Daniel , Li Ka-Loh , Lloyd William , Waqar Mueez , Djoukhadar Ibrahim , Coope David , King Andrew , Cootes Timothy , Jackson Alan
Published: August 2024

In this study we sought to undertake histogram and habitat analyses of tumoural DCE-MRI derived microvascular kinetic parameters and quantitative relaxation rate changes (ΔqR1) in patients with sporadic and neurofibromatosis type 2 (NF2) related vestibular schwannoma (VS). We demonstrate that within imaged VS tumours there is considerable intratumoural heterogeneity in DCE-MRI derived microvascular metrics and ΔqR1, with distinct intratumoural regions or habitats displaying high Ktrans, vp and ΔqR1 values respectively. We furthermore demonstrate within a cohort of NF2-related VS undergoing anti-angiogenic (bevacizumab) therapy that both pre-treatment Ktrans and ΔqR1 are predictive of later tumour volumetric response at 90 days post-treatment.
Optimisation of an MRI protocol to assess the effects of noise exposure on the auditory pathway
Authors: Dewey Rebecca , Guest Hannah , Millman Rebecca , Prendergast Garreth , Plack Christopher , Francis Susan
Published: August 2024

Recent findings suggest that noise exposure can cause substantial damage to the auditory nerve, without damage to the sensory hair cells or loss of threshold sensitivity. It is unclear which physiological measures are most sensitive to neural damage. Here, a comprehensive MRI protocol (neurography, high-resolution DTI of the auditory nerve and brain, morphometry, T1-myelination mapping, and resting-state functional connectivity) to study the ascending auditory pathway (auditory nerve, auditory brainstem, and cortex) is described. 200 participants will be recruited with varying noise exposure levels, with the aim of identifying diagnostic tests indicative of future hearing loss.
Spiral-based multi-contrast imaging protocol for a full brain MR exam in 2 minutes
Authors: Li Guangqi , Zhang Yajing , Guo Hua
Published: August 2024

Fast multi-contrast brain exams are highly desirable in clinical practice. Spiral sampling has high efficiency in terms of spatial encoding. Thus it holds great potential for many MRI applications. In this work, we optimized a fast multi-contrast brain imaging protocol based on multi-shot spiral acquisitions. Six contrasts (T1W-FLAIR, T2W, PDW, T2*W, T2W-FLAIR, DWI) and apparent diffusion coefficient (ADC) maps with an in-plane resolution of 1.0 mm2 for a full brain MR exam can be obtained in about 2 minutes.
Delta-relaxometry with contrast-enhanced MR Fingerprinting: phantom validation and application to tumor imaging
Authors: Deng Shengwen , Zhao Walter , Jordan David , Badve Chaitra , Ma Dan
Published: August 2024

The influence of hemodynamics and contrast concentration can be eliminated with ratios between delta-relaxometry in contrast-enhanced MR Fingerprinting (MRF). This delta ratio can be used to characterize the in vivo contrast-specific tissue response, beyond the conventional T1/T2 shortening effect. In this abstract, we: 1) developed a MRF-based strategy to image the concentration-independent, contrast-specific tissue response using delta-relaxometry; 2) validated reproducibility and linearity of delta-relaxometry in phantom experiments; 3) reported the novel Delta-relaxometry image contrast distinct from current clinical image contrasts; and 4) illustrated the sensitivity of delta-relaxometry in brain tumor characterization and classification.
Real-time Multi-Contrast 4D MRI using Motion Transfer for Low-Latency Volumetric Motion Tracking on a 1.5T MR-Linac System
Authors: Wu Can , Murray Victor , Siddiq Syed , Tyagi Neelam , Reyngold Marsha , Crane Christopher , Otazo Ricardo
Published: August 2024

Real-time multi-contrast 4D MRI is proposed by transferring motion from 4D T1-weighted images to 3D T2-weighted images and performing fast signature matching based on T1-weighted 3D radial stack-of-stars acquisitions. The proposed approach exploits the anatomical correlations between T1-weighted and T2-weighted images and fast acquisition of T1-weighted data to generate real-time multi-contrast volumetric motion information for adaptation and monitoring of radiation treatment of tumors affected by respiratory motion on an MR-Linac system. The feasibility of the proposed method was demonstrated on patients with pancreatic cancer.
Oxygen-enhanced and glucose-enhanced MRI for dual mapping of hypoxia and glucose uptake in tumours at high spatial resolution
Authors: Dickie Ben , Kisby Thomas , Rowling Emily , Chung Julius , Babur Mohammad , Christie Lidan , Jin Tao , Kostarelos Kostas , Williams Kaye , O'Connor James
Published: August 2024

We have developed a non-invasive imaging protocol for dual assessment of hypoxia and glucose uptake in tumours using oxygen-enhanced MRI and glucoCESL MRI, and test feasibility in GL261 glioblastoma and MOC2 head and neck cancer mouse models. GL261 tumours had a lower non-perfused fraction (p = 0.0015), a trend to higher glucose enhancing fraction (p = 0.07) and a smaller hypoxic glucose refractory fraction (p= 0.021). The normoxic glucose enhancing fraction was significantly larger than the normoxic glucose refractory fraction (p < 0.0001) in both models. These imaging tools will be used to assess the effects of hypoxia modifying drugs.
MRI relaxometry to measure the oxygen partial pressure and viscosity of the vitreous humour of the aging eye
Authors: Pan Xingzheng , Lie Alyssa , Martis Renita , Pontre Beau , Lim Julie , White Thomas , Donaldson Paul
Published: August 2024

The vitreous humour is a clear, gel-like fluid to provide structural support to the eye. Recently, it has been shown that the vitreous is important in regulating oxygen levels within the back of the eye. However, with ageing, the vitreous undergoes liquefaction, and as a result, oxygen is able to be move more freely throughout the vitreous, which increases the exposure of tissues such as the lens to oxygen. In this study, we developed MRI-based protocols to clinically monitor the oxygen levels and the fluid viscosity of the vitreous and applied these protocol in a cohort of elderly partipants.
Towards a multi-parametric MRI-based myelin marker for detecting enhanced myelination in the Gli1-/- mouse brain
Authors: Lee Choong Heon , Holloman Mara , Brady Jacob , Salzer James , Zhang Jiangyang
Published: August 2024

Although multiple MRI-based myelin marker have been introduced, their sensitivity and specificity remained limited. Multi-parametric MRI can potentially enhance myelin mapping, but validation remains challenging. In this study, we compared myelin histology from the Gli1-/- mouse brain, which has enhanced myelination, with MRI markers based on relaxation, magnetization transfer, and diffusion properties from the same animals. We found varying degrees of correlation between MRI markers and myelin basic protein signals in multiple brain regions. Partial least square regression analysis demonstrated that multi-parametric MRI can indeed improve myelin mapping and provided information for further optimization.
In-vivo imaging of the human thalamus: a comprehensive evaluation of structural imaging approaches for thalamic nuclei differentiation at 7T
Authors: Martinez Cristina Sainz , Marques José P. , Bonanno Gabriele , Hilbert Tom , Tuleasca Constantin , Cuadra Meritxell Bach , Jorge João
Published: August 2024

The ability to non-invasively image the thalamus and its different nuclei would be highly valuable to neuroscience and neuroradiology, but has remained challenging. Here, we initiated a comprehensive practical review of recent thalamic imaging approaches at 7 Tesla, based on T1, T2, T2* and susceptibility properties. These were all acquired on the same in-vivo brain, to avoid anatomical variability confounds. The images were qualitatively compared to histological atlases. Upon systematic assessment, QSM and GM/WM-optimized MP2RAGE proved the most valuable to differentiate specific nuclei. To our knowledge, this is the most comprehensive evaluation to date of thalamic imaging modalities at 7T.