bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumor-induced modifications of resting-state networks in patients with glioma
Authors: Pasquini Luca , Napolitano Antonio , Schmid Maurizio , Jenabi Mehrnaz , Peck Kyung , Holodny Andrei
Published: November 2024

Motivation: Gliomas affect the whole brain causing widespread network modifications. Goal(s): This study investigated the tumor effect on multiple brain networks using resting-state functional MRI. Approach: 147 glioma patients and 200 healthy controls (HCs) were included. After pre-processing, group-independent and group information-guided component analyses were used to extract brain networks. The cosine similarity of each patient’s network was compared to HCs. Chi-squared test was used to test associations with tumor location and grade. Results: Cognitive networks are selectively vulnerable to tumor growth. Functional alterations extend beyond tumor boundaries, and increase with WHO-grade. Tumor location in known eloquent areas exerts widespread effects on brain networks. Impact: We developed a methodology to quantify tumor-induced alterations of individual brain networks. These alterations extend beyond tumor boundaries, vary with network’s function, tumor location and grade. Understanding such abnormalities is crucial for managing cognitive disabilities before and after surgery.
Brain network evaluated by functional-guided reinforcement learning effective connectivity indicates theraputic effect in tinnitus patients
Authors: Lv Han
Published: November 2024

Motivation: We hypothesize that the investigation of brain FC may serve as a foundational step in exploring EC. Goal(s): To enhance the precision of identifying effective connectivity between distinct brain regions. Approach: We adopts the actor-critic framework with an encoder-decoder model as the actor network. The encoder utilizes the Transformer model, and the decoder employs a bidirectional long-short-term memory (LSTM) network with attention. Results: Tinnitus patients were feature by enhanced information output of the motor network, somatosensory network, and the visual network. Effective treatment is featured by a similar pattern of FGEC network between tinnitus patients after treatment and the healthy controls. Impact: The pattern of FGEC network can be regarded as a direct evidence to indicate the effectiveness of sound therapy for tinnitus patients prior to treatment.
An fMRI single-subject study with severe reading impairment – a new paradigm towards personalised medicine
Authors: Maccarone Francesca , Bonino Margherita , Giubergia Alice , Mascheretti Sara , Lampis Valentina , Mauri Chiara , Agarwal Nivedita , Peruzzo Denis
Published: November 2024

Motivation: Typically, fMRI studies predominantly rely on group comparisons, often lacking direct applications at an individual subject level, whether for research or clinical purposes. Goal(s): We aimed to unveil the power of fMRI studies using an fMRI experiment to highlight the brain’s area of abnormalities in a 9 years old child experiencing severe reading impairment. Approach: Three fMRI tasks were used to characterize different reading network sections that were compared to an age matched control group via Crawford-Howell t-test. Results: The study subject showed a different activation pattern in the right insula, an area associated with reading comprehension. Impact: fMRI experiments can compare and emphasize differences in brain function at an individual subject basis in comparison to a control population. This evidence suggests the potential use of fMRI as an informative tool within the precision medicine framework.
Manganese-based nanoparticles for 1H/19F MRI and immune-activated co-therapy for tumor microenvironment response
Authors: Xu Qiuyi , Li Sha , Zhang Lei , Chen Shizhen , Zhou Xin
Published: November 2024

Motivation: Simultaneous enhancing MRI signals and effectively generating and activating immune cells is a significant challenge when using one contrast agent. Goal(s): This work aims to develop nanoparticles of guiding tumor synergistic therapy using 1H/19F MRI while activating the STING pathway. Approach: FMBI nanoparticles were designed for enhancement of 1H/19F MRI and activation of the immune system. Results: FMBI nanoparticles responsively release Mn ions in the tumor microenvironment to enhance the signals of 1H/19F MRI and improve immune pathway activity and anti-tumor efficacy. Impact: Our synthesized FMBI nanoparticles are a STING pathway-activatable contrast agent that can be used for 1H/19F MRI-guided tumor therapy with high efficacy, which shows promise for effective tumor immunotherapy.
Development of PLGA-loaded ticagrelor magnetic microspheres: towards prevention of post PCI thrombosis.
Authors: Peng Yueyou , Liu Kunkun , Hu Qianyu , Shi Tianfeng , Meng Yanfeng
Published: November 2024

Motivation: After percutaneous coronary intervention, systemic dual antiplatelet therapy prevents thrombosis which may increase the bleeding risk, especially in populations at high risk of bleeding. Goal(s): The aim of this study was to develop PLGA-Fe3O4-Ticagrelor microspheres (PFTm), for local infusing to injured artery wall for preventing thrombosis. Approach: Firstly, the abdominal aorta of rabbits was injured by balloon, and PLGA-Fe3O4-Ticagrelor microspheres were infuded into the injured artery, and T2WI imaging was performed. Results: PFTm was successfully developed, which can effectively prevent thrombosis. Impact: This study provides a new concept of local infusion for prevention of thrombosis after PCI.
Lipid-targeted echo-planar spectroscopic imaging for in-vivo quantification of lipid composition
Authors: Lin Dingyi , Zhou Yufan , You Shiyang , Zhou Jiaqiang , Zhou Ke , Cao Yang , Cai Chunli , Hsu Yi-Cheng , Wang Min
Published: November 2024

Motivation: Investigating lipid composition in different tissues in vivo is essential. Demand exists for rapid, high-resolution chemical-shift imaging to analyze lipids. Goal(s): We aimed to employ EPSI to simultaneously target lipid signals and suppress water, enabling precise in-vivo quantification of lipid composition in various tissues for the first time. Approach: We implemented EPSI incorporating chemical-shift-selective adiabatic-refocusing pulses for lipid refocusing, with a full-automated pipeline for data reconstruction and lipid composition calculation. Results: Phantom and in-vivo experiments validate the technique's effectiveness. The technique successfully differentiates various vegetable oils and lipid emulsions precisely and quantifies lipid composition with high spatial resolution in mice’s neck and abdomen. Impact: Lipid-targeted EPSI technology surpasses traditional single-voxel spectroscopy or multi-echo chemical-shift water-fat imaging by providing higher spatial and spectral resolution, empowering researchers with deeper insights into lipid metabolism for future investigations.
An Unsupervised Deep Learning-Based Approach to Denoise Hyperpolarized 129Xe MR Images
Authors: Bdaiwi Abdullah , Willmering Matthew , Hussain Riaz , Walkup Laura , Woods Jason , Cleveland Zackary
Published: November 2024

Motivation: Hyperpolarized 129Xe (HXe) MRI is a powerful, FDA-approved modality to assess lung function. While improvements in 129Xe technology enable polarizations of ~50%, low SNR images still hinder image interpretation and quantification. With only modest improvements in polarization levels still possible, other means must be developed to improve HXe SNR. Goal(s): Developed a denoising method to improve HXe SNR. Approach: This study adapts Noise2Void (N2V) denoising for HXe imaging and evaluates its performance on ventilation, diffusion, and gas exchange images. Results: Comparison with Block Matching 3D indicates the effectiveness of N2V in reducing noise and enhancing image quality. Impact: Elevated noise levels in hyperpolarized 129Xe MR images lower image quality and quantitative accuracy and are a confounding factor for clinical interpretation. The objective of this work is to develop a 129Xe-MR image denoising technique based on unsupervised deep learning.
Routine Hyperpolarized 129Xe Measurements Utilizing a Benchtop NMR Spectrometer: Maintaining High Polarization, Automation and Measurements
Authors: Kilian Wolfgang , Gulich Samira , Riemer Thomas , Mitschang Lorenz
Published: November 2024

Motivation: Routine measurements of hyperpolarized media utilizing low-cost benchtop-NMR spectrometers should allow for sensitive bio-chemical analysis. So far, just an elaborate handling of hyperpolarized 129Xe was demonstrated. Goal(s): To deliver highly polarized 129Xe to the sample at the time of demand within the NMR spectrometer. Approach: We present the combination of a continuous-flow 129Xe polarizer with a commercial benchtop-NMR spectrometer. The gas flow into the NMR sample is time-controlled by the spectrometer pulse program and xenon gas densities are user adjustable. Results: In routine experimentation polarization transfer-losses were minimized, thus allowing for e.g., characterization and concentration determination of future contrast agents. Impact: Our work demonstrates day-to-day measurements utilizing well-established flow-through 129Xe polarizers in combination with low-cost benchtop NMR spectrometers yielding high sensitivity. Thus, utilizing the high affinity of xenon to proteins or cage molecules allows for various biological studies alike concentration determination.
Fe(II), Co(II) and Ni(II) complexed DOTA-tetraglycinates as pH and temperature biosensors
Authors: Mishra Sandeep Kumar , Zakaria ABM , Mihailovic Jelena , Maritim Samuel , Coman Daniel , Hyder Fahmeed
Published: November 2024

Motivation: Gadolinium based contrast agents (GBCAs) are reported to be toxic and associated with nephrogenic systemic fibrosis (NSF). Alternative options should be developed to minimize toxicity. Goal(s): Develop alternative biocompatible transition metal-based MRI agents for advanced imaging. Approach: Using paramagnetic high spin Fe(II), Co(II), and Ni(II) ions coordinated with well-established cyclic ligands for enhanced MRS imaging to detect cancer tumors at an early stage. Results: Fe(II)DOTA-4AmC2-, Co(II)DOTA-4AmC2-, and Ni(II)DOTA-4AmC2- were synthesized and characterized. Their in vitro pH and temperature sensing capabilities were assessed using BIRDS at 11.7T. Impact: These biocompatible pH sensors can be employed for in vivo pH mapping for early cancer diagnosis and can also be adapted for clinical applications.
Measurement of tumor extracellular pH (pHe) by a PET/MRI co-inject reagent
Authors: Liang Xiaofei , Palagi Lorenzo , Pollard Allysa , Cerda Jorge , Schuler William , Subasinghe Subasinghe Appuhamillage Amali , Pagel Mark , Dhakan Chetan
Published: November 2024

Motivation: The measurement of extracellular pH (pHe) is very important for studying the cancer development, progression, and therapeutic response. Goal(s): Accurately measure the pHe for 4T1 tumor and 0.2 pH change in vitro independent on the concentration of MRI contrast reagent. Approach: To co-inject the synthesized pH sensitive MRI contrast reagent and the PET reagent with the same pharmacokinetic functions and DCE MRI and dynamic PET scan were obtained simultaneously. Results: The pHe change of the bicarbonate treatment for the acidosis tumor type can be measured by our PET/MRI co-inject reagent. Impact: PET/MRI co-inject reagent makes it possible for the pHe measurement independent of the concentration of MRI contrast reagent.
Fast T1 Mapping to Assess Contrast Agent Clearing in the Human Brain
Authors: Telezki Vitali , Schnieder Marlena , Uecker Martin , Dechent Peter , Bähr Mathias
Published: November 2024

Motivation: Waste clearance mechanisms are essential to maintain homeostasis of the brain. Impairment of such mechanisms may play a key role in various diseases. Goal(s): To gain insights into waste clearance processes and propose characteristic metrics to describe them. Approach: We injected contrast agent intravenously and monitored clearance with serial T1 mapping utilizing fast single-shot T1 acquisition with radial FLASH and NLINV reconstruction in healthy volunteers. Results: Time-T1 values of full protocol with 35 acquisitions fit well to our exponential model and can be characterized by clearance time $$$\tau$$$ and biggest T1 difference max ΔT1. A dramatically reduced acquisition protocol gives similar results. Impact: Advanced fast single-shot T1 mapping is promising to characterize waste clearance function in the human brain. Because of a short whole brain acquisition time of 3 minutes it can be integrated easily into existing clinical protocols.
Noninvasive Visualization of Molecular Signatures of Liver Fibrosis Progression by Collagen Targeted Protein MRI Contrast Agent
Authors: Gui Zongxiang , Li Dongjun , Qiao Jingjuan , Bamishaye Sophia , Yang Jenny
Published: November 2024

Motivation: Hepatic fibrosis can develop in patients with any type of chronic liver disease which increase the risk of death for an estimated 1–2% of the world’s population. Goal(s): Our goal is to develop novel MRI contrast agents for liver diseases which enable us to detect the liver diseases at early stages. Approach: We developed the novel MRI contrast agent for precision MRI. We achieved the molecular imaging on different animal models with liver diseases. Results: Our results shows that our protein based MRI contrast agent can target the small lesions and fibrotic areas in the liver. Impact: The Protein based contrast agent with specific targeting capabilities is able to stage the liver diseases accurately.
Advanced relaxation-diffusion MRI improves lesion detection for sMRI-negative epilepsy
Authors: Ning Lipeng , Liu Qiang , Rathi Yogesh , Bubrick Ellen
Published: November 2024

Motivation: Structural MRI (sMRI) has limited sensitivity to detect lesions in about ⅓ of patients with epilepsy. There is a critical need for more sensitive imaging techniques for epilepsy imaging. Goal(s): The goal of this pilot study is to develop novel imaging techniques to improve the sensitivity for lesion detection for patients with sMRI-negative epilepsy. Approach: We acquired relaxation-diffusion MRI (rdMRI) using a fast sequence and examined novel parametric and nonparametric modeling techniques for lesion detection on a sMRI-negative patient. Results: The proposed rdMRI measures revealed a lesion in a sMRI-negative patient that is not shown using standard single-TE dMRI technique. Impact: The proposed rdMRI acqistion and modeling techniques can significantly improve lesion detections for patients with sMRI-negative epilepsy. Once validated using larger datasets, the rdMRI techniques can be applied for surgical planning for epilepsy patients without using invasive diagnosis techniques.
Personalized characterization of corpus-callosum pathology in mesial temporal lobe epilepsy using quantitative brain relaxation atlases
Authors: Bonacci Maria Celeste , Caligiuri Maria Eugenia , Piredda Gian Franco , Caneschi Samuele , Sammarra Ilaria , Chimento Ilaria , Zacà Domenico , Marechal Bénédicte , Hilbert Tom , Lober Tobias , Gambardella Antonio
Published: November 2024

Motivation: Investigate callosal integrity in mesial temporal lobe epilepsy (MTLE) using quantitative MRI. Goal(s): This study aims to investigate the distribution of quantitative T1 and T2 alterations in terms of z-scores in the midsagittal profile of the corpus callosum (CC) in patients with MTLE. Approach: MP2RAGE sequence for T1 relaxometry and GRAPPATINI for T2 relaxometry were acquired on 9 MTLE patients and the midsagittal distribution of z-scores was investigated. Results: Callosal alterations in MTLE were located in regions crossed by temporal and frontal fibers. Our findings support the hypothesis that MTLE-related pathophysiological changes extend beyond the temporal lobe and involve various cortical regions. Impact: This study provides first evidence of qMRI alterations in the corpus callosum of patients with temporal lobe epilepsy. Despite the focal nature of the syndrome, deviations from the norm included fibers connecting temporal and extratemporal cortices.
Analysis of Temporal Lobe White Matter Volume in Patients With Hippocampal Sclerosis Based on Automatic Segmentation And its Application Value.
Authors: Qin Li Jin , Nan Yan Meng , yan Song Deng , Zhuo Wang , Ling Zhang Yan , Jian Li , Bing Chen , Hui Xiong Yu
Published: November 2024

Motivation: Accurately identifying the range of white matter (WM) involved in epileptogenic lesions of temporal lobe epilepsy with hippocampal sclerosis (TLE-HS) is crucial prior to surgery. However, previous studies have been limited in their analysis of temporal lobe subregions due to technical constraints. Goal(s): Determine the extent of WM damage in TLE temporal lobe subregions to provide more imaging basis for preoperative evaluation and clinical surgical method selection. Approach: FreeSurfer software was used to perform whole-brain WM segmentation on 3D T1WI images. Results: There are differences in the extent of WM damage in temporal lobe subregions between with left TLE-HS and right TLE-HS. Impact: Automatic brain segmentation technology can be utilized to assess the degree of white matter damage in the subregions of the temporal lobe in patients with TLE-HS. Furthermore, this technology holds potential for investigating various other brain disorders.
A novel diffusion MRI acquisition scheme for optimal orientation sampling and susceptibility distortion correction at 7T
Authors: Legouhy Antoine , Callaghan Martina , Zhang Hui , Thomas David
Published: November 2024

Motivation: 7T provides higher SNR compared to clinical field strengths, but susceptibility-induced distortion compromises diffusion imaging at 7T. Current methods to accurately correct distortion require doubling of scan time. Goal(s): Develop an efficient acquisition scheme to enable distortion correction of multi-direction diffusion images without increased scan time. Approach: Two ‘half-density’ acquisitions with opposing phase-encoding directions are collected, such that their gradient orientations uniformly sub-sample the sphere in a complementary manner. Spherical harmonics are used to interpolate image pairs for distortion correction. Results: The proposed method provides distortion correction comparable to the full blip-up/blip-down approach, in half the acquisition time, while retaining the orientation density. Impact: As the clinical benefits of 7T become established, it is crucial for all sequence types to be available for use. The methods proposed here enable advanced distortion-corrected diffusion imaging to be routinely and efficiently included in 7T imaging protocols.
Practical sampling strategies for volumetric cardiac real-time MRI using stack-of-spirals at 0.55T
Authors: Kumar Prakash , Ramasawmy Rajiv , Javed Ahsan , Tian Ye , Campbell-Washburn Adrienne , Nayak Krishna
Published: November 2024

Motivation: Volumetric real-time MRI is desirable to accurately characterize beat-to-beat cardiac function in patients with arrythmia or heart failure. Goal(s): To identify practical data sampling strategies for volumetric real-time MRI and evaluate cardiac volume measurements against gated reference scans. Approach: We focus on stack-of-spirals bSSFP at 0.55T. We use simulations and in-vivo experiments to compare three sampling strategies that minimize eddy currents. Results: A Gaussian distribution of the stack-of-spirals was found to provide the best real-time image quality and most accurate LV volumes, with under-estimation of end-diastolic volume by 7.44% and over-estimation of end-systolic volume by 18.33%. Impact: Beat-to-beat cardiac function is important to measure in the context of arrhythmia, cardiac stress testing and in interventional MRI, where real-time volumetric coverage will facilitate assessment and monitoring of cardiac function.
Spiral Time Resolved Imaging (SPTI)
Authors: Liu Xiaoxi , Larson Peder , Li Yan , Xu Duan , Cui Di
Published: November 2024

Motivation: Spiral is the most efficient k-space coverage strategies in current MR gradient systems with robustness to motion and flow, but the implementation of long spiral trajectories keeps challenging due to accumulated off resonance effect and local susceptibility. Goal(s): SPTI is proposed for artifact- and distortion-free spiral imaging and quantification. Approach: Modified segmented spiral readout and subspace reconstruction were performed in SPTI technique. Results: SPTI sequence was validated in a phantom study and feasibility was evaluated on a brain volunteer. In human study, SPTI method showed consistent results with MRF-EPTI on quantitative mapping, including PD, T1, T2 and T2*. Impact: SPTI method can simultaneously quantify PD, T1, T2 and T2* mapping and is potential to expand to other body regions, especially in the liver and cardiac MRI.
Accelerated multislice MRI with patterned excitation
Authors: de Zwart Jacco , van Gelderen Peter , Wang Yicun , Duyn Jeff
Published: November 2024

Motivation: Accelerate spin echo multi-slice MRI. Goal(s): Combine echo dephasing and rephasing segments of different slices to reduce scan time. Approach: Use a composite RF pulse to excite upcoming slices while refocusing signal from a current slice. Results: Implementations at 3 T for spin echo based displacement encoding and spin echo and stimulated echo based DTI show 2-3 fold acceleration. Impact: The proposed technique can accelerate 2D multi-slice imaging techniques that rely on multiple RF pulses per slice for signal generation and acquisition. It can be combined with simultaneous multi-slice and SENSE approaches for additional acceleration.
Novel method of Ultrashort TE 4D MR Angiography – Continuous Acquisition Variable TR (CAVTR) with View Sharing.
Authors: Fukuchi Haruyuki , Akatsu Toshiya , Kusahara Hiroshi , Takano Nao , Ikenouchi Yutaka , Suzuki Michimasa , Kamagata Kohji , Wada Akihiko , Abe Osamu , Aoki Shigeki
Published: November 2024

Motivation: The conventional multi-phase Pulsed ASL UTE 4D MRA sometimes provides insufficient signal intensity to visualize hemodynamic flow characteristics in late phases. Goal(s): Our goal is to improve the visibility of multi-phase Pulsed ASL UTE 4D MRA. Approach: We developed a novel method, Continuous Acquisition Variable TR (CAVTR) UTE 4D MRA pulse sequence which utilizes continuously increasing TR. This new pulse sequence has less signal fluctuation and can avoid late phase signal reduction. We combined CAVTR with view sharing and improved late phase image quality without detriment to temporal resolution. Results: This novel method can improve clinical usability of non-contrast ASL based UTE 4D-MRA. Impact: The novel method, Continuous Acquisition Variable TR pulse sequence with View Sharing achieved both high temporal resolution and good visibility of arteries in late phases. This novel method can improve clinical usability of non-contrast ASL based UTE 4D-MRA.
Pulse Sequence Design for Gradient Arrays in MRI
Authors: Öztürk Mehmet , Babaloo Reza , Atalar Ergin
Published: November 2024

Motivation: Gradient arrays are superior compared to the conventional MR coils. However, there exists no pulse sequence design algorithm for the optimum use of the gradient array. Goal(s): This work proposes a novel pulse sequence design schema for the optimum use of the gradient arraysApproach: The algorithm utilizes a waveform optimization method. This method provides the shortest trapezoidal pulses with three inputs: the area to cover, starting and ending amplitudes. Results: The algorithm is fit for any gradient array weight matrix with an arbitrary number of channels. It can provide the shortest timing values for any imaging plane while preserving the hardware limits. Impact: There exists no pulse sequence design algorithm for the optimum use of the gradient array. We present a novel algorithm fit for any gradient array weighting with an arbitrary number of channels while providing the shortest timing values.
gSlider-TSE for high-resolution isotropic T2-weighted imaging with high contrast and high SNR
Authors: Zhang Jinyuan , Wu Yue , Xue Rong , Zhuo Yan , Zhang Zihao
Published: November 2024

Motivation: Conventional 2D-TSE offers superior tissue contrast compared to 3D-TSE, but its slice thickness is restricted by SNR and slice profile of RF pulse. Goal(s): Our objective was to achieve 0.4mm isotropic T2-weighted imaging with high contrast and high SNR. Approach: Amplitude and phase modulated gSlider pulses were developed and incorporated into 2D-TSE. Their performances were evaluated in phantom and in vivo. Results: The gSlider-TSE achieved 0.4mm isotropic imaging with high accuracy. The SNR was comparable to 8 times averaged conventional 2D-TSE image. Impact: The gSlider-TSE provides high-resolution isotropic imaging with submillimeter slice thickness and high SNR, while preserving the high contrast of conventional 2D-TSE.
Convex Gradient Optimization for the Free Running Framework
Authors: Tous Cyril , Nicoletti Martin , Ogier Augustin , Roy Chris , Yerly Jerome , Stuber Matthias
Published: November 2024

Motivation: Designing optimal gradient waveforms is a convex problem. They must satisfy gradient hardware constraints, physiological constraints, and being time-optimal. Goal(s): By shortening TE, we are more robust to motion artifact and less vulnerable to field inhomogeneities. By shortening TR and consequently TA, we can potentially minimize banding artifacts and obtain shorter scan time, increasing motion artifact robustness. Approach: The gradient optimized method “GrOpt” was integrated directly into free-running 3D-radial-bSSFP and GRE acquisitions at 3TResults: We achieved 14.0 %, 5.7% and 5.4% reduction in TE, TR and TA for bSSFP and 25.1%, 6.6% and 6.5% reduction in TE, TR and TA for GRE, . Impact: In 3D-radial-bSSFP, CVX achieves 14.0%, 5.7% and 5.4% reduction in TE, TR and TA, respectively. In 3D-radial-GRE, 25.1%, 6.6% and 6.5% reduction in TE, TR and TA was obtained, reducing the effect of inhomogeneities, motions, eddy current and scan time.
Quantitative and Qualitative Evaluation of Geometric Distortion Correction in Submillimetre fMRI for Accurate Functional Mapping at 7T
Authors: Yun Seong Dae , Shah N. Jon
Published: November 2024

Motivation: Distortion correction in EPI has been utilised in numerous fMRI studies. However, the impact of the distortion correction on submillimetre fMRI analysis remains largely unexplored. Goal(s): This work performs quantitative and qualitative evaluation of geometric distortion correction with various criteria in submillimetre fMRI at 7T. Approach: Submillimetre EPI (0.73 × 0.73 mm2) was employed for visual fMRI, and the distortion-corrected data were evaluated in terms of spatial resolution, functional mapping accuracy, and histogram distribution. Results: This work demonstrates the effectiveness of distortion correction in submillimetre fMRI, revealing substantially enhanced mapping accuracy without significant deterioration in spatial resolution or functional activation distribution. Impact: The quantitative and qualitative evaluation of EPI distortion correction presented in our work demonstrates the effectiveness of distortion correction in submillimetre fMRI at 7T, revealing substantially enhanced mapping accuracy without a significant deterioration in spatial resolution or functional activation distribution.
Applying block matching with 4D filtering (BM4D) to functional task based ASL
Authors: Marchini Charles , Sutton Brad
Published: November 2024

Motivation: Test a denoising method, block matching with 4D filtering (BM4D), to improve the performance of a low signal-to-noise modality, functional imaging using arterial spin labeling (ASL)Goal(s): Apply BM4D to improve the detection of brain activityApproach: Use task-based fMRI in human data and in simulation to test how well the BM4D denoised data corresponds to ground truth activation compared to non-denoised dataResults: The BM4D denoised data performs better than non-denoised data when spatial Gaussian smoothing is not used prior to analysis but fails to outperform when adequate spatial Gaussian smoothing is used. Impact: For functional arterial spin labeling (ASL), denoising algorithms may show an improvement in detecting brain activity in simulation, but not when comparisons are made after adequate spatial Gaussian smoothing.
Optimizing resting state fMRI data quality using Component Analysis based on Standard-deviation Attenuation (CASA) denoising
Authors: Dipasquale Ottavia , Papageorgakis Christos , Zucchelli Mauro , Casagranda Stefano
Published: November 2024

Motivation: Noise sources, including thermal noise, affect signal-to-noise ratio (SNR) in resting-state fMRI, limiting utility and impact of this type of data. Goal(s): This study aims at enhancing data quality by integrating Component Analysis based on Standard-deviation Attenuation (CASA) technique with standard denoising methods. Approach: Employing rs-fMRI data from 19 controls, we compared the regression of motion, white matter and CSF signals (MWC approach) and the integrated CASA denoising + MWC approach, based on tSNR and RSN comparison. Results: The study showed significant enhancement in tSNR employing CASA + MWC approach and led to RSNs free from artifact-related patterns seen with the MWC method. Impact: Resting-state fMRI data with our Component Analysis based on Standard-deviation Attenuation (CASA) denoising have greater signal quality and reduced contribution of unstructured thermal noise, which is greatly beneficial for reliably evaluating functional connectivity in resting state fMRI studies.
Reducing ringing artifacts in dynamic pulmonary MRI with a golden-step based interleaving approach for 3D ultra-short TE acquisition
Authors: Ding Zekang , She Huajun , Du Yiping
Published: November 2024

Motivation: In 3D radial ultra-short TE based dynamic pulmonary MRI, 3D radial k-space is usually segmented into multiple interleaves for interleaved acquisition. Motion-resolved k-space data are obtained subsequently by retrospectively binning using respiratory signals. Diaphragm drifting has been commonly observed during the scan, resulting in non-uniform spherical distribution of sampling density in motion-resolved k-space and ringing artifacts in reconstructed images. Goal(s): To reduce ringing artifacts in motion-resolved images. Approach: A golden-step based interleaving approach is proposed to mitigate adversary effect of diaphragm drifting. Results: Ringing artifacts in dynamic images acquired with conventional interleaving approach are significantly reduced in that acquired with proposed interleaving approach. Impact: Using golden-step based interleaving approach, uniform motion-resolved k-spaces can be obtained even under severe diaphragm drifting. This proposed approach has potential to reduce ringing artifacts in other non-Cartesian acquisitions and applications, such as bSSFP-based free-breathing cardiac MRI and real-time MRI.
Evaluating the reproducibility of parallel transmission in fMRI at 7T
Authors: Lu Yidi , Wu Chia-Yin , Jin Jin , Hodono Shota , Maillet Donald , Reutens David , Cloos Martijn
Published: November 2024

Motivation: While pTx has been shown to improve the temporal signal-to-noise ratio (tSNR) in fMRI, it is not clear how variations in pulse fidelity between scans modulate tSNR and how this impacts fMRI studies using pTx. Goal(s): To study whether the improved tSNR obtained with pTx in fMRI is reproducible across multiple scans of the same subject. Approach: We scanned and rescanned two subjects using both traditional and pTx excitations, and examined the variation in tSNRs between the scans. Results: Traditional and pTx excitations demonstrated comparable reproducibility in tSNR. Impact: The improved tSNRs obtained using pTx were consistent across scans of the same subject, demonstrating inter-scan variations comparable with traditional single channel excitations. Collectively, these preliminary results suggest that pTx can be used with reproducibility confidence in fMRI studies.
Zoomed imaging with calibration-free destructive B1+ shimming for rapid fMRI
Authors: Brouwer Emma , van der Zwaag Wietske , Priovoulos Nikos
Published: November 2024

Motivation: High-resolution MRI enables precise studies of specific brain regions but this comes at a cost of increased acquisition time. Goal(s): We examined if calibration-free destructive interferences can be introduced with simple static B1-shims for zoomed fMRI acquisitions. Approach: We optimised destructive B1 phase offsets and implemented these whilst assessing image quality in MPRAGE, tSNR in an EPI timeseries, flip angle distributions and |B1|. Results: Calibration-free destructive shims allowed reducing the field-of-view (50%) and acquisition-time (35%), while retaining good signal (higher B1 and similar tSNR) in the target (visual cortex). Impact: The calibration-free destructive B1 shims can be applied across brain regions with standard head coils and therefore translate across neuroscientific studies, while reducing acquisition-time and signal contributions from noise-prone areas. This may flexibly improve the spatial resolution and signal quality.
Microvascular specificity of spin-echo BOLD fMRI at 7T: the impact of EPI echo train length
Authors: Siero Jeroen C.W. , van Horen Tanya W.P. , Bhogal Alex A. , Petridou Natalia , Báez-Yáñez Mario Gilberto
Published: November 2024

Motivation: Macrovascular contributions to the BOLD signal reduce microvascular specificity, which can be alleviated by using SE sequences -refocusing local field inhomogeneities near large veins. Thus, the microvascular specificity of SE-EPI scan will rely on ETL duration, however, this dependence is not well-characterized in humans at 7T. Goal(s): Determining how microvascular-specific SE-EPI BOLD responses vary with ETL in humans at 7T. Approach: A biophysical model was developed and a validation experiment was conducted during a hyperoxic gas-challenge aiming at determining this goal. Results: Both our simulations and measurements indicate an increase in macrovascular contamination with longer ETL-durations, leading to a decrease in microvascular specificity. Impact: Through biophysical simulations and measurements, we show an increase in macrovascular contamination with longer ETL durations, leading to a substantial decrease in microvascular SE-BOLD specificity
Diffusion functional MRI with isotropic b-tensor encoding
Authors: Spencer Arthur , de Riedmatten Inès , Nguyen-Duc Jasmine , Szczepankiewicz Filip , Jelescu Ileana
Published: November 2024

Motivation: Diffusion fMRI (dfMRI) has the potential to overcome some of the limitations of BOLD fMRI. However, acquisitions with linear diffusion encoding are sensitive to the underlying fibre orientations and may therefore give variable sensitivity, particularly in white matter. Goal(s): To assess the utility of isotropic b-tensor encoding in a diffusion fMRI acquisition (iso-dfMRI). Approach: We acquired iso-dfMRI data during a visual stimulation task. We compared this to dfMRI with linear diffusion encoding (dir-dfMRI) and to BOLD. Results: Iso-dfMRI detected activity in the visual system with a larger spatial extent than dir-dfMRI and was less dependent on underlying fibre orientations. Impact: We highlight the utility of isotropic b-tensor encoding dfMRI for detecting activity independently of underlying fibre arrangement. Thus, temporal resolution can be increased compared to acquiring multiple linear encoding directions and fMRI sensitivity in white matter boosted compared to BOLD.
How Variable Are Our Rat Sensory-Evoked Functional MRI Datasets?
Authors: Galteau Marie , Lee Sung-Ho , Broadwater Margaret , Chen Yi , Desrosiers-Gregoire Gabriel , Diao Yujian , Gil Rita , Kaesser Johannes , Kim Eugene , Lambers Henriette , Liu Yanyan , MacNicol Eilidh , Reimann Henning , Selingue Erwan , Shemesh Noam , Sirmpilatze Nikoloz , Strobelt Sandra , Sumiyoshi Akira , Wank Isabel , Zhang Yongzhi , Baudewig Jürgen , Boretius Susann , Cash Diana , Chakravarty M , Chuang Kai-Hsiang , Ciobanu Luisa , Devenyi Gabriel , Faber Cornelius , Hess Andreas , Homberg Judith , Jelescu Ileana , Justicia Carles , Kawashima Ryuta , Niendorf Thoralf , Scheenen Tom , Soria Guadalupe , Todd Nick , Wachsmuth Lydia , Yu Xin , Zhang Baogui , Shih Yen-Yu , Grandjean Joanes
Published: November 2024

Motivation: We address the need for standardization and collaboration in rat sensory-evoked fMRI by providing evidence-based recommendations and open-access datasets, fostering community growth. Goal(s): We aim to assess inter- and intra-datasets variability, focusing on image acquisition and experimental protocols, and to optimize analysis by comparing hemodynamic response functions and denoising methods. Approach: We collected 17 rat datasets from 10 centers, applied standardized preprocessing, and analyzed the sensory-evoked responses at individual and groups levels. Project code is openly available. Results: Our study revealed significant diversity in rat attributes, anesthesia protocols, and imaging acquisition parameters across datasets. We are currently optimizing analyses to strengthen protocol robustness. Impact: We present evidence for the substantial heterogeneity intra- and inter-datasets of rat sensory-evoked fMRI. We will provide guidelines to enhance reproducibility, facilitate cross-laboratory comparisons, collaborations in neuroimaging research, and encourage more robust findings with potential translational applications.
Analyzing brain connectivity using a genetic reporter for MRI
Authors: van Valerie Phi , Jasanoff Alan
Published: November 2024

Motivation: Anatomical connectivity underlies brain function, but currently cannot be traced robustly in living animals. Goal(s): We sought to understand how the structure and plasticity of neuronal projections contribute to functional relationships. Approach: A genetic reporter for MRI was delivered using viral injections and visualization of the reporter was compared with histology, diffusion tractography, and resting state fMRI results. Results: We validated the new tracing tool in mice, showed that some but not all projection strengths correlate with functional measures, and demonstrated that connection strength changes relate variably to functional connectivity changes in a longitudinal model of opioid exposure. Impact: This work validates and applies a genetic reporter for fMRI that permits neuronal projections from viral injection sites to be visualized longitudinally with fidelity in individual animals. Our results help explain functional connectivity relationships in terms of circuit-level contributions.
Automated prostate segmentation model to assess prostate zonal growth pattern in patients with benign prostate hyperplasia
Authors: Xu Lili , Zhang Gumuyang , Zhang Jiahui , Zhang Xiaoxiao , Bai Xin , Chen Li , Peng Qianyu , Guo Erjia , Jin Zhengyu , Sun Hao
Published: November 2024

Motivation: Prostate growth rate analysis helps to reveal the development of benign prostate hyperplasia. Goal(s): To analyze the growth rates in different prostate zones using a previously developed segmentation model. Approach: The prostate zonal volume and morphology features (zonal width, thickness, height, and sphericity) were computed from the automatic segmentation results to calculate the annual growth rate. Results: The prostate whole gland volume and transition zone volume increased with age, while the peripheral zone volume decreased with age. Besides, prostate zonal volume growth rate varied between ages, and different locations of the prostate exhibited verified growth rates. Impact: Prostate growth rate analysis could be done efficiently with the assistance of a deep-learning-based segmentation model. Our study facilitated a detailed investigation of prostate growth patterns and found that different zones and locations of the prostate exhibited different growth rates.
T2-weighted imaging of the prostate with super-resolution deep learning reconstruction: impact on PI-QUAL assessment
Authors: Nakamoto Atsushi , Onishi Hiromitsu , Tsuboyama Takahiro , Fukui Hideyuki , Ota Takashi , Kiso Kengo , Honda Toru , Matsumoto Shohei , Kaketaka Koki , Tatsumi Mitsuaki , Tarewaki Hiroyuki , Koyama Yoshihiro , Yamashita Yuichi , Kassai Yoshimori , Tomiyama Noriyuki
Published: November 2024

Motivation: Super-resolution deep learning reconstruction (SR-DLR) can simultaneously reduce noise and improve spatial resolution. Goal(s): Our goal was to evaluate the usefulness of SR-DLR in prostate T2-weighted imaging (T2WI) with conventional and reduced acquisition times. Approach: SR-DLR was applied to both conventional acquisition time T2WI and short acquisition time T2WI. Visibility of the anatomical structures of the prostate and image quality were evaluated. Results: SR-DLR significantly improved image quality of prostate T2WI and visibility of detailed anatomical structures, especially in the small structures such as ejaculatory ducts. Impact: SR-DLR improves T2WI image quality in prostate MRI and improves the visibility of detailed anatomical structures, and has the potential to reduce acquisition time while maintaining adequate image quality for diagnosis.
wall characteristics and clinical indicators correlate with acute ischemic stroke events in patients with middle cerebral atherosclerosis
Authors: Wang Huan , Zhao Ruifeng , Liu Wenpeng , Wei Xiaocheng , Tian Hongzhe , Ren Huipeng , Li Shan
Published: November 2024

Motivation: The occurrence of acute ischemic stroke (AIS) in patients with middle cerebral artery (MCA) atherosclerosis is related to the status of atherosclerotic plaque itself and level of homocysteine (Hcy) and glycated hemoglobin (HbA1c). Goal(s): To analyze wall characteristics and clinical indicators in patients with MCA atherosclerosis with a view to finding predictors of AIS events. Approach: We gathered data from 38 participants, segregated them into the AIS and transient ischemic attack (TIA) groups, and subjected the data from both groups to statistical analysis. Results: Combined stenosis rate and Hcy have higher value for predicting AIS events. Impact: Hcy and stenosis rate were independent risk factors for AIS events in patients with MCA atherosclerosis; combined Hcy and stenosis rate had a higher predictive value of AIS events.
Single breath hold 3D isotropic whole heart coronary MRA using turbo field echo planar imaging with deep learning constrained Compressed SENSE
Authors: Kodaira Kazuo , Nagao Michinobu , Yoneyama Masami , Peeters Johannes , Katsumata Yasutomo , Hamano Hiroshi , Kato Mana , Ogawa Takumi , Hamatani Yutaka , Shiina Isao , Morita Yasuyuki , Goto Yasuhiro , Sakai Shuji
Published: November 2024

Motivation: Whole-heart-coronary-MRA (WHC-MRA) is typically performed during free-breathing, and respiratory motion is prospectively compensated by using a 1D-right-diaphragmatic-navigator. However, this method requires long acquisition time and causes a heavy burden on the patient. Goal(s): Our goal was to obtain high-resolution WHC-MRA with single-breath-hold while ensuring clinically acceptable signal-to-ratio. Approach: Turbo-field-echo-planar-imaging (TFEPI), a high-speed technique, was combined with deep learning constrained Compressed SENSE (CS-AI) and image quality was evaluated by visual evaluation and contrast-to-ratio. Results: TFEPI with CS-AI provided high spatial resolution isotoropic single-breath-hold WHC-MRA while maintaining clinically acceptable image quality and scan time compared to Compressed SENSE and SENSE. Impact: High-resolution single-breath-hold WHC-MRA with clinically acceptable image quality by 3D TFEPI with CS-AI may improve the throughput of cardiac MRI examinations, and in addition reduce patient burden.
The Value of Multimodal Atherosclerotic Plaque Imaging Coordinated Analysis in the Assessment of Cardiovascular and Cerebrovascular Events
Authors: Zheng Yonghong , Yu Shun , Dai Xiaomin , Chen Huangjing , Yang Shengsheng , Ma Mingping , Huang Feng , Zhu Pengli , Song Yang
Published: November 2024

Motivation: The coexistence of atherosclerosis in coronary, and intracranial arteries has not been comprehensively assessed. Goal(s): This study was designed to investigate the co-existence of atherosclerosis in the intracranial and coronary arteries of patients with and without ASCVD using high-resolution magnetic resonance imaging and computed tomography angiography. Approach: The ASCVD group exhibited greater artery stenosis, as well as significant differences in lipid, calcium volumes, and lipid volume ratio compared to the non-event group. Additionally, different plaque types displayed significant variations in morphology and composition. Results: There is a consistent pattern of change in plaque characteristics between intracranial and coronary arteries. Impact: High-resolution magnetitic resonance imaging (hrMRI) and coronary computed tomography angiography (CCTA) to investigate the co-existence of high-risk atherosclerotic plaques in the intracranial and coronary arteries of patients with cardiovascular events. Results showed that such plaques were present in both locations.
Automatic Carotid Plaque Segmentation Using Deep Learning Model with Multi-Head Loss Integrating Anatomical Features
Authors: Yang Long , Dong Jinhua , Yang Xiong , Mao Yufei , Cheng Guanxun , Li Ye , Liang Dong , Liu Xin , Zheng Hairong , Zhang Na
Published: November 2024

Motivation: With the assistance of prior vessel wall mask, segmentation of atherosclerotic plaque can achieve satisfactory performance. However, manual sketching of vessel wall mask is still time-consuming. Goal(s): To propose a method for fast and accurate plaque segmentation without relying on prior knowledge of vessel walls. Approach: This study proposes a deep learning model based on a multi-head loss design for automatic segmentation of carotid artery plaques, with the aim of reducing dependence on prior information of vessel walls in plaque segmentation. Results: In the independent test, the model with the multi-head loss design achieving excellent results similar to using vessel wall prior. Impact: This study achieved fully automatic and accurate plaque segmentation without manual priors, which will greatly reduce burden of radiologist to segment and quantify plaque, and also contribute to more efficient stroke risk assessment, progress monitoring, and efficacy evaluation for patient.
Signal intensity and volume of carotid intraplaque hemorrhage on MRI and ipsilateral cerebrovascular events: the Plaque At RISK (PARISK) study
Authors: Nies Kelly , Aizaz Mueez , van Dam-Nolen Dianne , Goring Timothy , Schreuder Tobien , van Orshoven Narender , Postma Alida , Bos Daniel , Hendrikse Jeroen , Nederkoorn Paul , van der Geest Rob , van Oostenbrugge Robert , Mess Werner , Kooi M. Eline
Published: November 2024

Motivation: The presence of intraplaque hemorrhage (IPH) is a strong independent stroke predictor. Higher IPH signal intensity ratios (SIR) and volumes were found in symptomatic versus asymptomatic carotid arteries. Goal(s): To determine if IPH SIR and volume are associated with the risk for ipsilateral ischemic neurovascular events in symptomatic patients with <70% carotid stenosis. Approach: Cox proportional hazards and logistic regression were used to explore the association of IPH SIR and volume to ipsilateral ischemic neurovascular events in 87 IPH-positive patients. Results: IPH SIR and IPH volume were not associated with risk for ipsilateral ischemic events during 5.1(IQR:3.1-5.6) years. Impact: No association was found between IPH SIR or volume and the risk for ipsilateral ischemic neurovascular events or new infarcts on brain MRI. Therefore, identifying the presence of IPH is sufficient for risk stratification.