bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical reliability of the “Home Town Walk” fMRI paradigm for memory function localization in pre-surgical assessment of patients with Epilepsy
Authors: Sanchez-Panchuelo Rosa , Davies Nigel , Jalali Roya , Wesolowski Roman , Flintham Robert , Sawlani Vijay
Published: August 2024

Memory-activated functional MRI (fMRI) is increasingly implemented in the clinic to assess memory function and inform pre-surgical decision making in refractory epilepsy. The Home Town Walking (HTW) fMRI paradigm has been shown to activate the parahippocampal gyri (PHG) and help determine memory lateralization in epilepsy patients. However, limited data are available on the reliability of this technique in clinical practice. This study aims to assess the robustness of the HTW paradigm for localising and lateralising memory function in a consecutive clinical series of 117 Temporal Lobe Epilepsy patients. Memory-related activation patterns were observed in 76% of cases with 94% reproducibility.
Three-dimensional rigid head motion correction using the Beat Pilot Tone and Gaussian Processes
Authors: Huttinga Niek , Anand Suma , van den Berg Cornelis , Sbrizzi Alessandro , Lustig Michael
Published: August 2024

In this work we propose a framework based on Gaussian Processes to extract quantitative motion information from Beat Pilot Tones and subsequently correct rigid head motion in 2D and 3D. In a calibration phase, low-resolution images are acquired and registered to build a training set. Next, Gaussian Processes are trained to infer rigid parameters from multi-channel BPTs, exploiting automatic relevance determination of input channels. In the inference phase, rigid parameters are inferred per readout from the BPT, and high-resolution scans are corrected for motion. In practice the method could reduce the need for anesthetics and/or re-scans in e.g. pediatric patients.
Towards microstructure-informed QSM: A digital phantom study
Authors: Sandgaard Anders , Kiselev Valerij , Shemesh Noam , Jespersen Sune
Published: August 2024

Magnetic susceptibility can provide valuable information about chemical composition and microstructural organization in tissues. However, its estimation from the MRI signal phase is particularly difficult, as it depends on both magnetic tissue properties on all length scales. Here we investigate the feasibility of inverting our recently presented model of WM magnetic microstucture to estimate susceptibility. This is done on a digital brain phantom based on actual dMRI measurements of an ex-vivo mouse brain at ultra-high field.
Harmonic Field Extension for QSM with Reduced Spatial Coverage using Physics-informed Generative Adversarial Network
Authors: Jung Siyun , Jeon Soohyun , Kim Dong-Hyun
Published: August 2024

Acquisition of whole brain Quantitative Susceptibility Mapping (QSM) is time-consuming that requires the patient’s effort. On the other hand, limiting the QSM field-of-view to only the region of interest (e.g., deep grey matter) can shorten scan time and lessen the patient’s burden. However, reducing spatial coverage degrades conventional background field removal performance, resulting in an underestimation of susceptibility values. To overcome these limitations, we propose a harmonic field extension method using a physics-informed generative adversarial network. According to the experimental results, the proposed method significantly improves the accuracy of both the local field and QSM at reduced spatial coverage.
Multi-center, multi-vendor validation of PDFF-R2* mapping in an Optimized Fat-Iron Phantom
Authors: Starekova Jitka , Rutkowski David , Bae Won , Do Hung , Madhuranthakam Ananth , Malis Vadim , Mukherjee Sujoy , Lin Sheng Qing , Serai Suraj , Yokoo Takeshi , Reeder Scott , Brittain Jean , Hernando Diego
Published: August 2024

Reliable, quantitative assessment of fat and iron is important in the management of chronic liver diseases. Confounder-corrected chemical-shift-encoded (CSE)-MRI estimates proton-density fat-fraction (PDFF) and R2* as quantitative biomarkers for fat and iron, which have been shown to be highly reproducible across centers, field strengths and manufacturers. However, reproducibility in the setting of concomitantly high levels of fat and iron is poorly understood. To ensure the fidelity of CSE-MRI in clinical routine, a validation study was performed under controlled conditions on a phantom that modulates fat and iron simultaneously. Excellent multi-center and multi-vendor reproducibility of CSE-MRI PDFF and R2* was found.
Performance Evaluation of a 128-Channel head-only Receiver array at 7 Tesla
Authors: Gruber Bernhard , Stockmann Jason , Mareyam Azma , Chang Yulin , Keil Boris , Bilgic Berkin , Beckett Alexander , Feinberg David , Wald Lawrence
Published: August 2024

The performance of a 128-channel Rx-only 7T brain array was evaluated using simulations and measurements. SNR and g-factor maps show a significant performance increase for highly accelerated imaging in cortical areas from a combination of improved peripheral unaccelerated SNR and g-factor. Measured SNR in cortical areas increased by 42% from 32- to 128-ch and 18% from 64- to 128-ch. The 1/g-factor maps show an improved mean and a tighter distribution, with both effects becoming more pronounced at higher accelerations. At 6x2-fold the 128-channel array has 17.9% g-factor benefit over the 64-ch, and a 48.2% benefit over the 32-ch array.
3 Tesla 31P/1H Calf Muscle Coil for 1H and 31P MRI / MRS integrated with NIRS
Authors: Zhang Bei , Lowrance Daniel , Zaha David , Sarma Manoj Kumar , Nelson Michael Douglas , Henning Anke
Published: August 2024

In this work, we present a 3T 31P/1H calf coil with two interleaved and co-centered birdcages in one layer to provide homogenous transmit fields and good SNR for both 31P and 1H nuclei. In addition, the coil design allows for integration of a Near-infrared spectroscopy (NIRS) probe for simultaneous NIRS and MRI readouts during exercise. Simulation and phantom experimental results show that the coil provides homogeneous transmit and receive fields. In vivo experiment show that the coil provide good SNR for both 31P MRS and 1H MRI and MRS
Digital Synthesis at the Coil in a WiFi-enabled Modular Switch Mode RFPA Platform for Gradient-Free Imaging
Authors: Bolding N , Vaughn Chris , Patel Aria , Lin Snow , Dupuis Andrew , Grissom William , Griswold Mark
Published: August 2024

We present here the development of a wireless flat amplitude 2 MHz radiofrequency transmitter for under $100, focusing on the pulse synthesis stage. We gave special consideration to simplifications that can be made with high speed digital synthesis and switch mode amplifier topology. This is a component of a distributed transmit receive system, meeting the special requirements of gradient free low field quantitative imaging techniques, such as selective encoding through nutation and fingerprinting (SENF).
Cardiac Library Based Real-time Imaging (CALIBRI): towards 3D cardiac visualization during MR-guided cardiac interventions
Authors: Spakman Anne , Schrauben Eric , Merton Renske , Strijkers Gustav , Nederveen Aart , Götte Marco , Coolen Bram
Published: August 2024

We propose Cardiac Library Based Real-time Imaging (CALIBRI), which allows the use of the same data for both catheter tracking and real-time visualization of cardiac motion states. This is achieved by matching the acquired k-lines with a library of pre-acquired cardio/respiratory gated 3D CINE data. In this study, we implemented our novel method on a 3T MRI system and showed the feasibility of this approach in multiple healthy volunteers.
Simultaneous T1-T2 mapping, CINE and Multi-contrast Anatomical 3D whole-heart MRI
Authors: Garrido Nicolás , Phair Andrew , Coronado Ronal , Qi Haikun , Prieto Claudia , Botnar René
Published: August 2024

Cardiac T1-T2 mapping provides information about focal and diffuse fibrosis and inflammation of the myocardium. A recently proposed free-running 3D mapping technique allows time efficient and simultaneous whole-heart T1-T2 mapping within a single scan, with retrospective respiratory motion correction. However, this approach loses the information about the temporal contrast evolution and does not reconstruct multi-contrast 3D whole-heart images, which may carry useful clinical information in patients with myocardial infarction and, acute and subacute thrombus. In this work, we propose to extend this approach to enable joint T1-T2 mapping, CINE, and multi-contrast 3D whole-heart imaging from a single free-running scan.
Is linear subspace constraint reconstruction suitable for multi-compartment T2 imaging? Evaluation and guidelines.
Authors: Corbin Nadège , Aurélien Trotier , Petit Laurent , Sarubbo Silvio , Miraux Sylvain , Ribot Emeline
Published: August 2024

Multi-compartment T2 imaging suffers from long acquisition time. Undersampling the k-space combined with advanced iterative reconstructions could be beneficial to reach a reasonable scan duration. This work investigates the suitability of linear subspace-based reconstruction for myelin water fraction and intra-extracellular T2 mapping. Our findings suggest that subspace-based reconstruction for intra-extra cellular T2 and myelin water fraction mapping can be reliably used in combination with spatial regularization enforcing sparsity. The temporal basis can be built from extended phase graph simulations and should include at least 12 components, especially for myelin water fraction mapping.
Selective Encoding through Nutation and Fingerprinting (SENF) using Quadratic RF Phase Modulation and the Bloch-Siegert Shift
Authors: Vaughn Christopher , Bolding N , Griswold Mark , Grissom William
Published: August 2024

We demonstrate a new extension of Selective Encoding through Nutation and Fingerprinting (SENF) which is a RF spatial encoding technique that also encodes quantitative information. This SENF method uses quadratic RF phase modulation sequence with an off-resonant Bloch-Siegert pulse to induce the Bloch-Siegert shift to simultaneously encode spatial and quantitative information. We validate this method on a 47.5mT low-field scanner and in simulation.
In vivo Multi-Parameter Mapping of the Habenula using MRI
Authors: Milotta Giorgia , Green Isobel , Roiser Jonathan , Callaghan Martina
Published: August 2024

The habenula has attracted much interest in neuroscience studies because it plays an important role in the reward circuitry of the brain and is implicated in psychiatric conditions. However, imaging the habenula remains challenging due to its sub-cortical location and small size, with few reports analysing its microstructural composition in vivo. To address this gap in the literature, we performed a multi-parametric characterisation of the microstructure of the habenula by quantifying relaxation rates (R1, R2*), water content (PD) and a marker of macromolecular content (MTsat), most notably myelin, in a cohort of 20 healthy participants.
Zero-DeepSub: Zero-Shot Deep Subspace Reconstruction for Multiparametric Quantitative MRI Using QALAS
Authors: Jun Yohan , Arefeen Yamin , Cho Jaejin , Wang Xiaoqing , Gee Michael , Gagoski Borjan , Bilgic Berkin
Published: August 2024

The 3D-quantification using an interleaved Look-Locker acquisition sequence with T2 preparation pulse (3D-QALAS) has been developed and used for acquiring high-resolution T1, T2, and PD maps from five measurements within each repetition time. However, it assumes that each k-space data is acquired instantly at the first echo train length index neglecting T1 and T2 relaxation during the acquisition, which might cause blurring and biases in the reconstructed maps. In this study, we propose to reconstruct accurate quantitative T1 and T2 maps with reduced blurring compared to the conventional QALAS method using our proposed zero-shot deep subspace reconstruction method (i.e., Zero-DeepSub).
Bariatric Surgery Effects on Knee Articular Cartilage and Osteoarthritis Symptoms – a 12-month Follow-up Using T2 Relaxation Time and WOMAC Index
Authors: Lehtovirta Sami , Kemppainen Ahti , Haapea Marianne , Karppinen Jaro , Lammentausta Eveliina , Koivukangas Vesa , Kyllönen Eero , Nevalainen Mika , Lehenkari Petri , Casula Victor , Nieminen Miika
Published: August 2024

Obesity is a common risk factor for osteoarthritis (OA). We set out to study knee cartilage using T2 relaxation time, and knee OA symptoms with WOMAC OA index in obese individuals. Bariatric surgery patients were split into successful and unsuccessful weight loss groups, and compared with a control group of obese individuals over a 12-month follow-up. The lesser weight loss group displayed improvement of cartilage with lower T2 values in the lateral compartment of femoral cartilage, compared to the higher weight loss. We also observed improvement of knee symptoms in both successful and unsuccessful weight loss groups after 12 months.
Patellofemoral cartilage compression and recovery in response to loading measured with dynamic MRI using prospective motion correction
Authors: Lange Thomas , Rovedo Philipp , Hucker Patrick , Taghizadeh Elham , Izadpanah Kaywan , Zaitsev Maxim , Meine Hans
Published: August 2024

The patellofemoral cartilage compression and recovery is measured with dynamic MRI in response to a bout of in situ loading in a cohort of ten healthy subjects. To mitigate motion artifacts arising from the loading paradigm, the experiments are performed with prospective motion correction based on optical tracking. The measured cartilage compression and recovery time course in response to loading and unloading is characterized by a larger fully elastic compression component adapting instantaneously to applied load changes, and a smaller compression component, which only gradually adapts to load changes and exhibits in particular a very protracted recovery after unloading.
Assessment of knee cartilage strain using the magnetization transfer ratio and T2: an ex vivo study at 9.4T MRI
Authors: Sullivan Emily , Yung Andrew , Küpper Jessica , Bale Kirsten , Kozlowski Piotr , Wilson David
Published: August 2024

The magnetization transfer ratio (MTR) was investigated as an alternative biomarker for cartilage strain compared to T2. Six ex vivo bovine knee specimens were compressed in a 9.4T scanner and scanned at several physiological step loads. Average strain, MTR, and T2 were calculated for each voxel column throughout the full depth of cartilage, and depth-dependent trends were identified. ΔMTR changed uniformly across the cartilage volume with strain, while ΔT2 showed a more localized yet inconsistent response. This suggests that MTR may be more sensitive in measuring cartilage strain in clinical applications where image resolution is lower.
Layers-Based Analysis of Knee Articular Cartilage: Comparing T1ρ Imaging Against Quantitative Susceptibility Mapping at 3 Tesla
Authors: CHAMPAGNE ALLEN , ZULEGER TAYLOR , SMITH DANIEL , SLUTSKY-GANESH ALEXIS , WARREN SHAYLA , SENGKHAMMEE LEXIE , MANDAVA SAGAR , WEI HONGJIANG , BARDANA DAVIDE , MYER GREG , DIEKFUSS JED
Published: August 2024

The vertical microstructural organization of articular cartilage varies in its arrangement of collagen fibers, as well as the relative proteoglycan content. Knee osteoarthritis (OA) involves an inflammatory degenerative process that leads to depth-wise degeneration of the cartilaginous matrix. While quantitative MR protocols have emerged to evaluate proteoglycan content (T1ρ) and microstructural integrity (Quantitative Susceptibility Mapping; QSM), advances in layer-based analyses (e.g., superficial vs. deep) are warranted to identify the progression of diseased cartilage. We demonstrate the integrated utilization of QSM and T1ρ for characterizing depth-specific microstructural arrangement of articular cartilage, including differences in tissue organization and composition, respectively.
Feasibility of Highly-accelerated High b-value Multi-shot Diffusion Weighted Imaging by Using Parametric POCSMUSE and Kurtosis Model
Authors: Chen Shihui , Chang Hing-Chiu
Published: August 2024

High b-value DWI is promising in detection of white matter pathology and infarctions. However, the disadvantages of the acquired high b-value DWI, such as insufficient SNR and image distortions, prohibits its clinical application. Though the feasibility of computed high b-value has been estimated in prostate cancer, the parameters derived from low b-value images cannot be used for diffusion kurtosis model fitting and achieved inferior performance at high b-value. In this study, we proposed a framework based on parametric POCSMUSE and kurtosis model to generate multiple high b-value images with comparable image quality to MUSE from highly-accelerated high b-value DWI.
Bilateral asymmetry of parenchymal kinetics from ultrafast DCE-MRI predicts HER2+ breast cancer response to neoadjuvant chemotherapy
Authors: Ren Zhen , Pineda Federico , Howard Frederick , Abe Hiroyuki , Kulkarni Kirti , Nanda Rita , Jaskowiak Nora , Karczmar Gregory
Published: August 2024

We retrospectively reviewed data from 28 patients with HER2-positive breast cancer treated with neoadjuvant chemotherapy (NAC) who underwent a protocol that included ultrafast DCE-MRI (temporal resolution = 3 – 9 seconds) for the first minute after contrast administration prior to NAC. We measured quantitative kinetic background parenchymal enhancement parameters (kBPEs) from ipsi- and contra-lateral normal parenchyma separately to quantify bilateral parenchymal enhancement asymmetry. The results show that HER2-positive patients with similar pre-NAC $$$K^{trans}$$$ in ipsi-and contralateral normal parenchyma were more likely to achieve pathologic complete response post NAC.
IVIM reconstruction from highly under-sampled DW-PROPELLER acquisition data via synthetic data-driven physics-informed deep learning
Authors: Wang Jiechao , Geng Wenhua , Wu Jian , Kang Taishan , Wu Zhigang , Lin Jianzhong , Cai Congbo , Cai Shuhui
Published: August 2024

A synthetic data-driven physics-informed network (SDDPI-Net) was proposed for intravoxel incoherent motion (IVIM) mapping based on highly under-sampled diffusion-weighted turbo spin echo PROPELLER (DW-TSE-PROPELLER) data. This reconstruction network directly estimated distortion-free and artifacts-free IVIM parameters by explored data redundancy in the k-b space and IVIM bi-exponential model with synthetic training data. The results of human brain experiments show that our method can significantly improve the accuracy of IVIM maps with 6´ under-sampled DW-TSE-PROPELLER than other methods.
Low spatial-frequency ripple artifacts in layer-fMRI EPI: Identification, cause, and mitigation strategies with Dual-polarity readout
Authors: Huber Renzo , Stirnberg Rüdiger , Feinberg David , Ma Samantha , Ehses Philipp , Gulban Omer , Polimeni Jonathan , Koiso Kenshu , Ma Emily , Beckett Alexander , Stöcker Tony , Bandettini Peter , Poser Benedikt
Published: August 2024

High-resolution layer-fMRI has great potential to inform network-neuroscience. However, it is limited by EPI artifacts. Here, we discuss a class of fuzzy EPI ghosts arising from asymmetric trapezoidal gradients with ramp sampling. A meta analysis across layer-fMRI datasets finds this artifact everywhere, without exceptions. We believe that this artifact is constraining spatiotemporal resolutions more than SNR. In this abstract we aim to raise awareness for this artifact and evaluate mitigation strategies: dual-polarity EPI. We show that dual-polarity EPI allows layer-fMRI to break the barriers of current resolution limits: It allows 0.53mm imaging at 3T, and whole-brain 0.6mm fMRI at 7T.
Simultaneous Motion Compensation and Image Reconstruction During Acquisition of 3D Radial MRI
Authors: Calakli Fatih , Wallace Tess , Warfield Simon
Published: August 2024

High-resolution, 3D structural scans are susceptible to patient motion as they take several minutes or more to acquire. Radial MRI acquisitions are emerging as a motion-robust alternative to Cartesian trajectories. Most approaches involve co-registration of navigator images once the acquisition is complete. However, the time needed for co-registration of navigator images, coupled with the long reconstruction times required for high-resolution NUFFT, is a challenge for integration of motion-compensated non-Cartesian imaging into clinical protocols. In this work we developed a motion-compensated online gridding algorithm to perform adaptive motion compensated reconstruction overlapped with the acquisition.
VORTEX-SS: Encoding Physics-Driven Data Priors for Robust Self-Supervised MRI Reconstruction
Authors: Desai Arjun , Gunel Beliz , Ozturkler Batu , Hargreaves Brian , Gold Garry , Vasanawala Shreyas , Pauly John , Ré Christopher , Chaudhari Akshay
Published: August 2024

Deep learning (DL) has demonstrated promise for fast, high quality accelerated MRI reconstruction. However, current supervised methods require access to fully-sampled training data, and self-supervised methods are sensitive to out-of-distribution data (e.g. low-SNR, anatomy shifts, motion artifacts). In this work, we propose a self-supervised, consistency-based method for robust accelerated MRI reconstruction using physics-driven data priors (termed VORTEX-SS). We demonstrate that without any fully-sampled training data, VORTEX-SS 1) achieves high performance on in-distribution, artifact-free scans, 2) improves reconstructions for scans with physics-driven perturbations (e.g. noise, motion artifacts), and 3) generalizes to distribution shifts not modeled during training.
A novel deep learning method for automated identification of the retinogeniculate pathway using dMRI tractography
Authors: Li Sipei , He Jianzhong , Xue Tengfei , Xie Guoqiang , Yao Shun , Chen Yuqian , Torio Erickson , Feng Yuanjing , Bastos Dhiego , Rathi Yogesh , Makris Nikos , Kikinis Ron , Bi Wenya , Golby Alexandra , O’Donnell Lauren , Zhang Fan
Published: August 2024

We present a novel deep learning framework, DeepRGVP, for the retinogeniculate pathway (RGVP) identification from dMRI tractography data. We propose a novel microstructure-supervised contrastive learning method (MicroSCL) that leverages both streamline labels and tissue microstructure (fractional anisotropy) for RGVP and non-RGVP. We propose a simple and effective streamline-level data augmentation method (StreamDA) to address highly imbalanced training data. We perform comparisons with three state-of-the-art methods on an RGVP dataset. Experimental results show that DeepRGVP has superior RGVP identification performance.
Test-Retest Reliability of 3D Velocity-Selective Arterial Spin Labeling for Detecting Normal Variations of Cerebral Blood Flow
Authors: Xu Feng , Liu Dapeng , Zhu Dan , Hillis Argye , Bakker Arnold , Soldan Anja , Albert Marilyn , Lin Doris , Qin Qin
Published: August 2024

Velocity selective inversion (VSI) based velocity selective arterial spin labeling (VSASL) was recommended by a recent guideline paper. We conducted a test-retest study to evaluate the reliability of 3D VSI-VSASL. The correlations between repeated measures were 0.94/0.81 (within- /between-session) for individual absolute CBF and 0.99/0.98 for regional relative CBF. The intraclass correlation coefficients were 0.88/0.77 for absolute CBF and 0.92/0.85 for regional relative CBF. Between-subject variation in CBF was partially contributed by age and physiological parameters. VSI-VSASL demonstrates moderate to excellent reliability for detecting between-subject and between-region variations among healthy subjects, suggesting its merit in clinical applications.
MR neurography Aids in Detection of Longitudinal Brachial Plexus Nerve Root Alterations in Patients With Amyotrophic Lateral Sclerosis
Authors: Wang Shanshan , Man Xiao , Wang Guangbin , Chen Weibo , Chhabra Avneesh
Published: August 2024

We assessed proximal-distal longitudinal signal and size alterations of brachial plexus nerve roots in amyotrophic lateral sclerosis (ALS) patients using 3D nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation enhancement imaging (3D SHINKEI). The conclusion confirmed proximal-distal longitudinal diameters and SNR values decreased significantly for brachial plexus nerve roots in ALS patients with larger differences in slopes compared to the HC. Thus, the size and signal alterations of brachial plexus nerve roots using 3D SHINKEI can be used to supplement clinical diagnosis for ALS patients.
A brainstem-dedicated approach to assess the N1 sign using a 3T SWI
Authors: Houidef Sabrina , Arribarat Germain , Péran Patrice
Published: August 2024

Because of its anatomical situation, the brainstem is difficult to image. With whole brain acquisitions, we end up with artifactual images. Our team developed a brainstem-dedicated T2*-weighted MRI acquisition method. Using this, we imaged the brain of sixteen healthy volunteers. This sequence was repeated 5 times for each volunteer. Our MRI protocol also consisted of a three-dimensional T1-weighted whole-brain sequence. The aim was to reduce the number of acquisitions required to visualize the nigrosome-1 by using image processing methods. We quantified the quality of the images by using image quality assessment indices and had one criterion: the visualization of nigrosome-1.
Hyperpolarized xenon-129 dissolved MRI based on two-point Dixon method
Authors: Chen Hengjie , Mata Jaime F , Shim Y. Michael , Mugler John P. , Hu Xiaoping , Zhao Li , Liu An , Qing Kun
Published: August 2024

In this work, a 2-point Dixon-based method is developed to provide separation of the hyperpolarized xenon-129 dissolved-phase magnetic resonance imaging (MRI) components for pulmonary applications. Based on analysis of data from 6 healthy volunteers and 20 patients with lung disease, the separated tissue and red blood cell (RBC) components obtained from this method are highly consistent with those from the previously-described 3-point Dixon method. The 2-point Dixon based method has the potential to greatly improve the signal-to-noise ratio for dissolved-phase MRI while still maintaining accurate tissue/RBC separation.
A Noninvasive Method with Three-Dimensional MR elastography in Assessing of Liver Fibrosis and Inflammation
Authors: Wang Yikun , Zhou Jiahao , Lin Huimin , Yan Fuhua , Li Ruokun
Published: August 2024

Differentiating fibrosis and inflammation is vital important clinical distinction in patients with chronic liver disease (CLD). Liver histopathology is the worldwide reference standard for staging fibrosis and inflammation. Therefore, there is urgent need to develop non-invasive and low risk methods for staging liver fibrosis and inflammation. Current researches has been demonstrated that three-dimensional MRE allows showed higher diagnosis accuracy for staging liver fibrosis even inflammation than 2D MRE. Here, we prospectively evaluate the diagnosis efficacy of the parameters 3D MRE-derived for staging liver fibrosis and grade of inflammation in real clinical situations.
Radiation Damping at Clinical Field Strengths: How to Analyse and Avoid it to enable quantitative MRI with Dedicated Coils
Authors: Wallstein Niklas , Müller Roland , Pampel André , Möller Harald
Published: August 2024

Radiation damping (RD) is, in principial, well understood but commonly unconsidered in MRI. It results from inductive coupling of the spin system and the detection circuit, leading to nonlinearities in the Bloch equations. Previous research established that RD increases with the filling factor and quality factor of the coil and the magnetic field strength. However, little attention has been paid to a quantitative characterization. Moreover, implications for the RF pulse performance must be considered given similar timescales (milliseconds) of RD and pulse length. Our findings indicate that RD can impact typical MRI sequences and, consequently, parameters determined from their application.
Submillimeter fMRI Acquisition using a dual-echo Rosette-k-space trajectory at 3T
Authors: Nossa Gianna , Monsivais Humberto , Hong Seokkyoon , Park Taewoong , Erdil Fethi Sila , Shen Xin , Özen Ali , Ilbey Serhat , Chiew Mark , Steinwurzel Cecilia , Kourtzi Zoe , Shih Yen-Yu Ian , Emir Uzay
Published: August 2024

In this study, we overcome the technological barrier against acquiring submillimeter resolution (~ 0.5 mm) fMRI data at 3T via a novel dual-echo Rosette k-space design. This design results in fine representation of activation maps in two different functional tasks and might be a springboard in neuroimaging by providing a very high-resolution spatiotemporal dynamics of neural networks. The method will be further evolved with the feedback from the MRI community via the github platform as such for the further acceleration, inflow saturation and 3D coverage via 3D sampling and/or multiband approaches.
Magnetization-Prepared Golden-angle RAdial Sparse Parallel (MP-GRASP) MRI for Rapid Free-Breathing 3D T1 Mapping of Renal Allografts
Authors: Bane Octavia , Feng Li , Xia Ding , Al-Mubarak Haitham , Cuevas Jordan , Muthukumar Thangamani , Dyke Jonathan , Menon Madhav , Farouk Samira , Taouli Bachir , Lewis Sara
Published: August 2024

This work demonstrates rapid free-breathing 3D T1 mapping of the kidney using Magnetization-Prepared Golden-angle RAdial Sparse Parallel imaging (GraspT1). The accuracy and performance of GraspT1was prospectively compared with B1-corrected variable flip angle (VFA) T1 mapping in phantom and in 13 patients with renal transplant. In phantom, both GraspT1 and VFA enabled accurate T1 estimation compared to the gold standard. In patients, free-breathing 3D GraspT1 provided better spatial resolution for improved cortico-medullary differentiation compared to the VFA method, while achieving whole-kidney coverage and similar T1 quantification, at the expense of longer acquisition time.
Highly Accelerated and High-resolution T2 Mapping in the Kidney Based on Echo Merging Plus k-t Undersampling with Reduced Refocusing Flip Angles
Authors: Li Hao , Priest Andrew , Menih Ines , Warren Anne , Welsh Sarah , Stewart Grant , Mendichovszky Iosif , Francis Susan , Gallagher Ferdia
Published: August 2024

We developed a highly accelerated multi-echo spin-echo (MESE) method based on echo merging and k-t undersampling with reduced flip angles (TEMPURA), which can be used to either reduce the acquisition time or increase spatial resolution for multi-slice kidney T2 mapping. Compared with a standardized respiratory-gated MESE sequence, fast TEMPURA reduced the acquisition time from 3–5 minutes to one breath-hold (18 s) without degrading measurement accuracy or image quality. It also outperformed using k-t undersampling alone. High-resolution TEMPURA reduced the pixel size from 3×3 mm2 to 1×1 mm2 and greatly improved the visualization of detailed structures.
Aging-related morphology and microstructure variations: Discoveries from the Lifespan Human Connectome Project - Aging
Authors: Robinson Tyler , Sun Yutong , Chang Paul , Chen J. Jean
Published: August 2024

This study compared age-related differences in white matter morphology and microstructure across ten major tracts of the human brain using diffusion data from 535 participants of the Human Connectome Project in Aging. The results are additionally assessed for agreement with retrogenesis predictions of white matter decline in normal aging. While whole-brain relationships between morphometry and white matter integrity were identified, high variability was also observed between tracts. While our data do not fully support retrogenesis models, we demonstrate patterns that may provide partial support, and highlight the need for tract-specific studies of morphological-microstructural interactions in the aging white matter.
Use of diffusion kurtosis imaging and dynamic contrast-enhanced MRI in differentiating parotid gland tumors
Authors: Liu zijun , Wen baohong , Zhang yan
Published: August 2024

This study evaluates the usefulness of combined Diffusion kurtosis imaging (DKI) and dynamic contrast-enhanced MRI (DCE-MRI) in differentiating parotid gland tumors. DKI and DCE-MRI quantitative parameters were analyzed by using the Kruskal-Wallis H test and post hoc test with bonferroni correction or the one-way analysis of variance (ANOVA) with LSD method, and ROC curve. Our research shows that the significant parameters in stepwise diagnosing parotid gland tumors were Kep, Ktrans, and D value. Therefore, the combined use of DKI and DCE-MRI could be used to differentiate various parotid gland tumors, and it may be helpful for differentiating parotid gland tumors.
Feasibility study of using time-dependent diffusion MRI to distinguish parotid polymorphic adenoma from Warthin's tumor
Authors: Geng Di , Zhao Xiance , Wang Yishi , Xu Xiaoquan , Wu Feiyun
Published: August 2024

IMPULSED (Imaging Microstructural Parameters Using Limited Spectrally Edited Diffusion) imaging method based on time-dependent diffusion magnetic resonance imaging (MRI) could be used to quantify cell sizes. We found that several quantitative parameters derived from IMPULSED including Vin (intracellular volume fraction), d (volume-weighted mean cell size) and cellularity showed significant differences between polymorphic adenoma (PA) and Warthin’s tumor (WT) in the parotid gland. Our findings shed light on the role of IMPULSED-derived quantitative parameters in distinguishing PAs from WTs preoperatively.
A Novel MR Sequence of 3D-ZOOMit Real Inversion Recovery Imaging Improves Endolymphatic Hydrops Detection in Patients with Ménière’s Disease
Authors: Li Jinye , Sun Lixin , Hu Na , Liu Mengxiao , Wang Linsheng , Li Chuanting
Published: August 2024

In order to visualize endolymphatic hydrops in Ménière’s disease better, we compared the conventional 3D real IR and ZOOMit 3D real IR sequence. Results suggest that visualization of the endolymphatic space might be higher by zs-3D real IR compared with t-3D real IR, especially in the cochlea.
Rapid PD, T2, and T2* Mapping with 2in1-RARE-EPI and Model-Based Reconstruction in Multiple Sclerosis
Authors: Vides Jose Raul Velasquez , Herrmann Carl , Starke Ludger , Olsson Hampus , Niendorf Thoralf
Published: August 2024

One obstacle of established quantitative resonance imaging methods is the excessive scan time. This study examines the use of radially-sampled 2in1-RARE-EPI in conjunction with model-based reconstruction methods for accelerated and simultaneous PD, T2, and $$$T_{2}^{*}$$$ mapping. We demonstrate that this approach facilitates a substantial decrease in acquisition time (01:40 vs. 07:12 min) of 2in1-RARE-EPI without impairing the quality of the parametric maps. Our patient data demonstrate the applicability of model-based reconstructed 2in1-RARE-EPI for T2 and $$$T_{2}^{*}$$$ mapping of multiple sclerosis lesions.
Cardiac MR Denoising Inline Neural Network (CaDIN).
Authors: Yoon Siyeop , Assana Salah , Morales Manuel , Cirillo Julia , Pierce Patrick , Goddu Beth , Rodriguez Jennifer , Nezafat Reza
Published: August 2024

The diagnostic confidence in the interpretation of cardiac MR scans can be improved by enhancing the signal-to-noise ratio (SNR). Traditional image denoising has been studied extensively to improve SNR in cardiac MRI, but with limited success due to the resulting blurring. In this study, we sought to develop and evaluate cardiac MR denoising inline neural network (CaDIN) for improving SNR in cardiac MRI.
Towards Informative Uncertainty Measures for MRI Segmentation in Clinical Practice: Application to Multiple Sclerosis
Authors: Molchanova Nataliia , Raina Vatsal , La Rosa Francesco , Malinin Andrey , Müller Henning , Gales Mark , Granziera Cristina , Graziani Mara , Cuadra Merirxell Bach
Published: August 2024

We approach the problem of quantifying the degree of reliability of supervised deep learning models used by clinicians for automatic multiple sclerosis lesion segmentation on MRI. In particular, we quantify the correspondence of various uncertainty measures to the errors that a deep learning model makes in overall segmentation or lesion detection. The evaluation is done both on in- and out-of- domain datasets (40 and 99 patients respectively), and provides insights about the measures that can point clinicians to potential errors of an automatic algorithm regardless of the distributional shift.
Spatiotemporal Patterns of Iron Accumulation and Oxygen Metabolism in Patients with Parkinson's Disease
Authors: Yan Su , Lu Jun , Liu Weiyin , Zhu Wenzhen
Published: August 2024

The purpose of this study was to employ QSM and OEF maps to quantitatively measure iron content and oxygen metabolism levels in deep gray matter of the Parkinson’ s disease brains in different stages and explore their relationship with clinical features. Iron accumulation in SN, RN and GP significantly increased with the progression of PD severity. In contrast, OEF in CAU, PT, and DN elevated in early PD and then gradually decreased with worsening symptoms, indicating a different spatiotemporal pattern. These findings may facilitate to understand the neurobiological mechanisms in PD progression and offered complementary indicators for diagnosis and prediction.
Signal recovery around DBS leads using 2D MSI
Authors: Tong Gehua , Vaughan John , Geethanath Sairam
Published: August 2024

2D MSI was tested for recovering the closest layer of off-resonant signals near a DBS lead. The effects of slice thickness and RF profile were measured in an ASTM gel phantom with an in-plane DBS lead. Increasing the slice thickness from 1.5x to 2.5x the lead diameter reduced the apparent lead width by 8.35% and increasing the time-bandwidth product of the RF pulse by four times improved SSIM with a reference TSE image by 88.5%. A trade off between bin definition and echo times limited signal recovery at a given bin bandwidth (800 Hz / 9 bins).
Impaired xenon gas transfer observed one year after hospitalisation due to COVID-19 in patients with signs of interstitial lung disease.
Authors: Saunders Laura , Collier Guilhem , Chan Ho-Fung , Hughes Paul , Smith Laurie , Stewart Neil , Brooke Jonathan , Watson James , Meiring James , Gabriel Zoë , Newman Thomas , Plowright Megan , Wade Phillip , Eaden James , Bray Jody , Marshall Helen , Capener David , Armstrong Leanne , Rodgers Jennifer , Brook Martin , Biancardi Alberto , Rao Madhwesha , Norquay Graham , Rodgers Oliver , Munroe Ryan , Ball James , Stewart Neil , Jenkins Gisli , Grist James , Ng Kher Lik , Ho Ling-pei , Gleeson Fergus , Hall Ian , Meersmann Thomas , Pavlovskaya Galina , Harrison Arthur , Brooke Jonathan , Jacob Joseph , Swift Andrew , Rajaram Smitha , Mills Gary , Watson Lisa , Collini Paul , Lawson Rod , Thompson A A Roger , Wild Jim
Published: August 2024

Patients with signs of interstitial lung disease at 12 weeks after hospitalisation due to COVID-19 underwent 1H and 129Xe MRI. 129Xe MRI showed impaired xenon gas transfer (RBC:M and RBC:gas) at 24 and 52 weeks after hospital admission, with no longitudinal change between 24 and 52 weeks observed in 129Xe MRI metrics or PFT transfer factor. Xenon MRI metrics correlated significantly with PFT transfer factor at 24 weeks (RBC:M, RBC:gas, LmD) and 52 weeks (RBC:M, RBC:gas, LmD).
Improved 129Xe MRI of cardiopulmonary oscillations in patients with chronic thromboembolic pulmonary hypertension
Authors: Lu Junlan , Bier Elianna , Leewiwatwong Suphachart , Mummy David , Kabir Sakib , Alanezi Fawaz , Rajagopal Sudarshan , Robertson Scott , Niedbalski Peter , Driehuys Bastiaan
Published: August 2024

Dynamic spectroscopy of hyperpolarized 129Xe in red blood cells exhibits cardiopulmonary oscillations that can be used to detect both pre- and post-capillary pulmonary hypertension (PH). However, this whole-lung measurement cannot resolve spatially heterogeneous variations in oscillations. This limitation can be addressed by using keyhole reconstruction approaches to spatially resolve the oscillations. Here we demonstrate several extensions of this technique that make both the reconstruction and analysis more robust. We have used this to establish updated healthy reference distributions and demonstrate the utility of spatially resolved mapping in a cohort of patients with chronic thromboembolic pulmonary hypertension pre- and post-thromboendarterectomy.
Rapid 3D lung imaging with bSSFP stack of spiral out-in (SoSoi) sampling at 0.55T
Authors: Tian Ye , Lee Nam , Zhao Ziwei , Nayak Krishna
Published: August 2024

MRI provides radiation-free screening of many lung diseases. Its use has been limited at field strengths >1.5T, largely due to the ultra-shot T2* and low proton density in the lung. New 0.55T systems provide improved lung MRI capability since T2* is prolonged to the order of 10ms. In this work, we propose a rapid 3D bSSFP stack-of-spiral out-in (SoSoi) pulse sequence for lung imaging. The sequence can acquire 2 mm isotropic resolution image with 23 sec breathhold or 2.4 mm isotropic resolution image with 13 sec breathhold, both show great pulmonary vessels depiction.
Double-Row 16-element Folded-End Dipole Transceiver Array for Human Whole Brain Imaging at 9.4 T.
Authors: Avdievich Nikolai , Nikulin Anton , Bosch Dario , Solomakha Georgiy , Scheffler Klaus
Published: August 2024

Homogeneity and coverage of transmit (Tx) RF coils at ultra-high field (UHF,>7 T) can be improved by 3D RF shimming. This, however, requires using multi-row Tx-arrays. Dipole antennas provide unique simplicity and robustness while offering comparable Tx-efficiency and SNR to conventional loop designs. Single-row UHF dipole Tx-arrays for human head imaging have been previously described. Recently, we developed a novel type of dipole elements, a folded-end dipole, which improved the longitudinal coverage and specific absorption rate (SAR) efficiency. In this work, we developed, constructed, and evaluated a 16-element double-row transceiver folded-end dipole array for human whole-brain imaging at 9.4 T.
Radial Stack-of-Stars Abdominal MRI at 7 Tesla
Authors: Maatman I , Ypma S , Block K , Maas M , Schulz J , Scheenen T
Published: August 2024

Abdominal MRI at 7T is sensitive to transmit field inhomogeneities and motion-induced artifacts. Transmit inhomogeneities have previously been addressed using time-interleaved acquistion of modes (TIAMO), providing uniform flip angles across a large field-of-view in the body. Meanwhile, the radial stack-of-stars sequence has been shown to be well-suited for motion-corrected MRI. In this work, TIAMO and motion-corrected radial MRI were combined to create abdominal images of three volunteers at high spatial resolutions. Results showed homogeneous transmit fields in all volunteers with excellent image quality at very high resolution. However, low-resolution scans suffered from artifacts due to gradient non-linearities and residual motion.
In-vivo 3D liver imaging at 7T using kT-point pTx pulses and a 32-Tx-channel whole-body RF antenna array
Authors: Grimm Johannes , Aigner Christoph , Dietrich Sebastian , Orzada Stephan , Fiedler Thomas , Nagel Armin , Ladd Mark , Schmitter Sebastian
Published: August 2024

Using a 32-Tx-channel whole-body RF antenna array at 7T could benefit exciting large body parts as these regions often suffer from flip angle inhomogeneity or dropouts. This study compares static pTx and 3D pTx pulses with a varying number of kT-points to the CP+ mode and non-optimized shim. With static pTx, the flip angle dropouts are reduced, and 2-3 kT-points seemed to deliver the best tradeoff between flip angle homogeneity and RF power.
Rapid mesoscale 3D whole-brain MRF in the Next-Generation 7T brain scanner: challenges and advantages
Authors: Cao Xiaozhi , Liao Congyu , Beckett Alexander , Vu An , Ma Samantha , Schauman Sophie , Iyer Siddharth , Yurt Mahmut , Tong Elizabeth , Kerr Adam , Feinberg David , Setsompop Kawin
Published: August 2024

3D MRF with spiral projection trajectory was implemented on the 7T NexGen scanner to take advantage of its SNR benefit and state-of-the-art gradient system. To achieve high-fidelity and high-efficiency multi-parameter mapping at the mesoscale, novel techniques were developed to overcome several technical challenges in performing this acquisition, including spiral residual gradient compensation, trajectory measurement, water-only excitation RF pulse, B0 correction, B1+ correction and frequency response correction. The proposed technical developments enabled high-quality whole-brain T1, T2, and proton density mapping at 1-mm isotropic resolution in 1 minute, and 560mm isotropic resolution in 4-minutes scan time.
Single-shot 2D spiral and echo planar imaging at 7 and 10.5 Tesla with field monitoring and correction
Authors: Wu Xiaoping , Bratch Alexander , Radder Jerahmie , Grant Andrea , Auerbach Edward , Van de Moortele Pierre‐Francois , Adriany Gregor , Ugurbil Kamil
Published: August 2024

Interest in pursuing MRI at ultra-high field (UHF) is increasing owing to increased SNR. However, MRI at UHF presents acquisition challenges due to decreased T2* and worsened field inhomogeneities. Rapid sampling strategies such as spiral and echo planar (EPI) acquisitions have been proposed to help mitigate these challenges. Incorporation of field monitoring to UHF applications has been demonstrated to improve the reconstruction of these images thanks to direct measurement and correction of spatiotemporal phase accrual. Here we demonstrate field-monitoring-enabled spiral and EPI acquisitions using Pulseq and field cameras.
Volumetric Dynamic Imaging for Functional Kinematic Assessment of the Wrist
Authors: Zi Ruoxun , Wang Bili , Walczyk Jerzy , Brown Ryan , Petchprapa Catherine , Fishbaugh James , Gerig Guido , Block Kai , Lattanzi Riccardo
Published: August 2024

Dynamic MRI can be useful for evaluation of wrist instability. However, most available real-time MRI methods are either limited due to their 2D nature or provide only low temporal resolution and insufficient image quality. Here, we propose a novel approach for volumetric dynamic wrist examination by assembling 2D real-time data into 3D snapshots using MRI-visible markers. The method has been demonstrated for ulnar-radial deviation using a flexible wrist coil and 3D-printed support platform for guiding motion. Future work will use a high-resolution static MRI as morphological prior to segment bones on the dynamic volumes and allow for quantitative kinematic assessment.
Differentiation between myelodysplastic syndrome and aplastic anemia using transfer learning of vision transformer
Authors: Takasu Miyuki , Baba Yasutaka , Takeda Konagi , Kawai Saki , Sakane Hiroaki , Tanitame Nobuko , Tamura Akihisa , Iida Makoto , Awai Kazuo
Published: August 2024

We examined the use of a vision transformer (ViT)-based deep learning model for the task of differentiation between aplastic anemia and myelodysplastic syndrome using lumbar T1-weighted images. Three sagittal images per patient were obtained and made square using zero-padding and were resized (224 × 224). The overall accuracy and area under the curve of the pre-trained ViT model were higher than those of ViT without pre-training, ResNet-110, and BinaryNet at the optimum hyperparameters. We utilized Grad-CAM images to highlight the information that is important for decision-making. ViT combined with Grad-CAM successfully recognized variability in the distribution of bone marrow components.
Inspiratory dilatory tongue movement, as measured with tagged MRI, and intramuscular neural drive in obstructive sleep apnoea patients
Authors: Jugé Lauriane , Liao Angela , Yeung Jade , Knapman Fiona , Bull Christopher , Burke Peter , Brown Elizabeth , Gandevia Simon , Eckert Danny , Butler Jane , Bilston Lynne
Published: August 2024

As measured by tagged MRI, inspiratory tongue dilatory movement might be useful to shed new light on mechanisms controlling upper airway dilation in obstructive sleep apnoea (OSA). Nine healthy controls and 37 untreated OSA patients underwent an upper airway MRI scan and tongue intramuscular electromyography (EMG) assessment. Results identified two opposing relationships between inspiratory tongue movement and phasic EMG with variable impacts on upper airway function for controls and OSA patients. These results suggest that there are complex, and unexpected, relationships between neural drive and anterior tongue movement that suggest upper airway function cannot be predicted from EMG alone.