bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a model-based image reconstruction technique for accelerated point spread function encoded echo planar imaging
Authors: Meyer Nolan , In Myung-Ho , Black David , Campeau Norbert , Welker Kirk , Huston John , Bernstein Matt , Trzasko Joshua
Published: August 2024

A model-based image reconstruction (MBIR) platform was developed for accelerated point spread function encoded echo planar imaging. Beginning with retrospectively truncated data, images were reconstructed with the enhanced MBIR framework. These were compared by a team of neuroradiologists with images obtained using standard reconstructions from non-truncated datasets. Scores were assigned for evaluation criteria including high-contrast resolution (HCR), low-contrast detectability (LCD), signal to noise ratio (SNR), artifacts, and overall preference. Nonparametric statistical test results indicate preference for MBIR in HCR, LCD, and overall preference, with comparable results for SNR and artifacts. MBIR thus facilitates PSF-EPI acceleration, enhancing clinical practicality.
Diffusion Weighted MR Imaging Using Low Rank Reconstruction for Multi-shot Variable Auto-Calibrating (vARC) Sampling with Volume Coil
Authors: Jain Nitin , Reddy Ashok Kumar , Das Rajdeep , Rajamani Sajith , Sundaresan Rajagopalan , Agarwal Harsh , Reddy M Ramasubba , Venkatesan Ramesh
Published: August 2024

Diffusion weighted MR imaging (DWI) is key to pathology detection in anatomies such as brain, abdomen and prostate. Echo planar imaging (EPI) provides a rapid means to acquire DWI. EPI with variable k-space sampling scheme and an auto-calibrating image reconstruction technique, vARC, has recently been shown to reduce distortion in DWI and improve the image quality in single channel volume coil/body coil acquisitions. Here, we propose a new low rank reconstruction technique for robust reconstruction and improved image quality for DWI acquired using vARC’s EPI multi-shot acquisition scheme with single channel body coil.
2D U-Net based myocardium segmentation for quantitative sequences with limited data: demon co-registration approach
Authors: Rebbah Habib , Boutelier Timothé
Published: August 2024

Obtaining databases with expert’ manual segmentations to train U-Net is an essential but also a time-consuming operation. We explore here the effect of expanding such a database to other cases with a demon co-registration algorithm. The purpose is to speed up the manual steps but also to allow the development of segmentation algorithms for new cases. We illustrate our approach with MOLLI’ masks expanded to T2 and perfusion data.
Detection and tracking enhancement using 4-channels local standalone resonators for catheterized interventional MRI at 3T
Authors: Payne Komlan , Zhao Yunkun , Ying Leslie , Zhang Xiaoliang
Published: August 2024

Catheter-based RF coils are preferred over conventional external coils due to the weak detection signal from intermediate field region. One of the major issues using catheter RF coils is the design payload (feeding network, preamplifier, balun) associated with the limited space of the catheter. The technique also lacks efficient way to track the catheter during the procedure. To overcome these challenges, we propose 4-channel standalone and wireless resonators to amplify the local B1 field while a body coil is used as the transceiver. The receive B1 fields with and without the local resonators are obtained for field enhancement analysis.
MR Thermometry by Quadratic Phase MR Fingerprinting
Authors: Garrow Sarah , Peters John , Grillo Abby , Boyacioglu Rasim , Keenan Kathryn , Griswold Mark , Grissom William
Published: August 2024

PRF-shift thermometry is the current standard for MR-based temperature monitoring in interventional procedures and works by converting gradient-recalled image phase changes to temperature changes. However, the long TE required for phase contrast increases sensitivity to artifacts from motion. We propose to address this using quadratic phase MR fingerprinting (qRF-MRF) which is robust to spurious artifacts. We implemented a qRF-MRF sequence that sweeps continuously across resonance frequencies and is highly sensitive to heating-induced resonance frequency changes. The sequence was used to monitor laser heating in a phantom, with comparison to GRE thermometry.
Feasibility of fast single-phase volumetric cardiac MR-thermometry
Authors: Rogers Charlotte , Mooiweer Ronald , Kowalik Grzegorz , Neji Radhouene , Razavi Reza , Botnar Rene , Roujol Sebastien
Published: August 2024

A novel fast simultaneous multi-slice black blood cardiac thermometry sequence is presented which allows multiple slices to be acquired in the same cardiac phase. A double inversion recovery pre-pulse is introduced to allow blood suppression and to optimise the pre-pulse strategy and therefore reduce acquisition time. Simultaneous multi-slice (SMS) imaging is integrated to further reduce the acquisition time of the multiple slices. Thermometry results obtained with this technique show an average temperature stability of 1.0±0.4°C in healthy subjects.
A New-found Approach to Temperature Monitoring Utilizing a Magnetic Field Map
Authors: Kim Sangwoo , Oh Sukhoon
Published: August 2024

We showed a new approach of MR temperature mapping without the oil-based phase reference of the conventional proton resonance frequency shift method (cPRFS), named as delta field-corrected temperature mapping (DFCTM). The performance of the DFCTM was compared with measurements using fiber optic thermal sensor and the cPRFS at the human-tissue mimicking agar-gel phantom. The sensor–measured temperature range was 6.05 ℃, while the DFCTM exhibited about 5.93 ℃. It exhibited a difference of -0.12 ℃ and the RMSE of the DFCTM was 0.16 ℃ for the entire experiments, which means that it could realize a temperature monitoring without oil phantoms.
Optimized diffusion-prepared 3D-MRF for rapid high-resolution whole-brain T1, T2, proton density, ADC and FA mapping
Authors: Cao Xiaozhi , Liao Congyu , Zhou Zihan , Zhong Zheng , Li Zhitao , Dai Erpeng , Iyer Siddharth , Hannum Airel , Yurt Mahmut , Schauman Sophie , Chen Quan , Wang Nan , Yan Yifan , He Hongjian , Skare Stefan , Zhong Jianhui , Kerr Adam , Setsompop Kawin
Published: August 2024

In this work, a diffusion preparation was implemented into the 3D spiral-projection MRF sequence to introduce additional diffusion weighting and enables whole-brain T1, T2, PD, ADC and FA mapping with 1-mm isotropic resolution within 10min. To maximize the diffusion signal and image-encoding efficiency, a diffusion-preparation without an amplitude stabilizer is employed, where robustness against phase variations is achieved using a combination of M1-compensated encoding, cardiac-gating, and an eddy-current compensating pre-pulse gradient. The MRF acquisition scheme and subspace reconstruction were also modified to enable effective data sharing across diffusion directions, which increase acceleration capability and improve mapping quality.
Time-dependence in Tensor-Valued Encoding in Ex Vivo Rat Heart
Authors: Foster Richard , Lasič Samo , Lundell Henrik , Szczepankiewicz Filip , Khazin Leah , Plein Sven , Dall'Armellina Erica , Yuldasheva Nadira , Schneider Jürgen , Teh Irvin
Published: August 2024

Tensor-valued encoding is a promising technique for improving specificity in assessing the myocardial microstructure, but can be confounded by time-dependent diffusion (TDD). Here, the influence of TDD on q-space trajectory imaging (QTI) was examined in ex vivo rat heart, using 17 diffusion encoding waveforms with different frequency content and b-tensor shapes. We report apparent over/underestimation of QTI parameters when waveforms had different sensitivity to TDD, and demonstrate a means of frequency matching that reduced the apparent bias. Acquiring QTI at higher frequencies may provide greater sensitivity to intracellular structures, complementing QTI at lower frequencies.
Diffusion diffraction in disordered systems
Authors: Jespersen Sune , Novikov Dmitry
Published: August 2024

We identify a new regime for the diffusion signal in non-confining disordered systems with locally varying diffusivity. It occurs at long times and large diffusion wavevectors, reminiscent of diffusion diffraction in closed pores. Remarkably, while for free diffusion the signal is exponentially strongly dephased, scattering off heterogeneities results in a much weaker, power-law decrease of the signal, thereby offering an enhanced sensitivity to the medium’s structure. In particular, we show how correlation functions of the medium’s microstructure to arbitrary order can be measured. We compare our theoretical predictions for the second order correlation function to numerical simulations with good agreement.
Bony structure enhanced synthetic CT generation using Dixon sequences for pelvis MR-only radiotherapy
Authors: Liang Xiao , Bai Ti , Godley Andrew , Shen Chenyang , Wu Junjie , Meng Boyu , Lin Mu-Han , Medin Paul , Yang Yulong , Jiang Steve , Deng Jie
Published: August 2024

Synthetic CT (sCT) image generated from MRI by unsupervised deep learning models tends to have large errors around bone area. To generate better sCT image quality in bone area, we propose to add bony structure constrains in the loss function of the unsupervised CycleGAN model, and modify the single-channel CycleGAN to a multi-channel CycleGAN that takes Dixon constructed MR images as inputs. The proposed model has lowest mean absolute error compared with single-channel CycleGAN with different MRI images as input. We found that it can generate more accurate Hounsfield Unit and anatomy of bone in sCT.
Functional Connectivity and Clinical Characteristics in Gilles de la Tourette Syndrome
Authors: Torrecuso Renzo , Mueller Karsten , Müller-Vahl Kirsten , Möller Harald
Published: August 2024

Gilles de la Tourette syndrome (GTS) is characterized by the expression of tics and frequently co-occurs with comorbidities including obsessive compulsive disorder (OCD), depression, and attention deficit/hyperactivity disorder (ADHD). For a better discrimination of GTS’ manifestation in brain networks, we analyzed resting-state fMRI data from patients with “GTS only” (no comorbidities) and “GTS plus” (with comorbidities) based on clinical ratings. Our findings suggest that increased intrinsic connectivity of insular cortex with putamen are causally related to GTS while decreased connectivity of the frontal pole, medial temporal and superior frontal gyrus is likely to be related to comorbidities.
GABA Alterations Associated with Social Cognition Deficits in Youth with Autism Spectrum Disorder Compared to Early-Onset Psychosis
Authors: Jalal Rhideeta , Nair Aarti , O'Neill Joseph , Gutierrez Hector , Laulette Kristen , Rshtouni Mary , Karlsgodt Katherine , Bearden Carrie , Bartnik-Olson Brenda
Published: August 2024

Proton magnetic resonance spectroscopy (1H-MRS) can provide valuable information about cortical activity and metabolite concentrations. Previous research using MRS has found alterations in the concentrations of neurotransmitters in neuropsychiatric disorders, notably in autism spectrum disorder (ASD) and early-onset psychosis (EOP). We used 1H-MRS to quantify signals associated with neurotransmitters in the dorsal anterior cingulate cortex (dACC), a brain region underlying social cognition, by measuring metabolite concentrations and its relationship to social impairments, in youth with ASD or EOP, and typically developing (TD) youth.
Repeated Electroconvulsive Shock does not Affect Cognition and Neurometabolism in Mouse Brain
Authors: Sarawagi Ajay , Patel Anant
Published: August 2024

Electroconvulsive therapy is an effective treatment for chemo-resistant depression. The impact of electroconvulsive shock (ECS) on cognition and neurometabolism is not clear. The memory of mice was evaluated using Y-maze test. The rates of glucose oxidation (CMRGlc(ox)) were measured by 1H-[13C]-NMR spectroscopy together with an infusion of [1,6-13C2]glucose after 24 hours and 3 months of the repeated ECS. The spontaneous alternation was decreased after 24 h and 1 month of repeated ECS, and was restored after two months. The CMRGlc(ox) was reduced in PFC after 24 h of ECS. These changes were normalized after 3 months of ECS.
Diagnosis of Autism Spectrum Disorder Using Age-Specific Brain Morphological Features
Authors: Zhou Dongyue , Zhang Yunge , Xiong Siting , Zhao Wei , Cong Fengyu , Li Huanjie
Published: August 2024

Autism Spectrum Disorder (ASD) diagnosis based on sMRI can be more objective than clinical scales due to high heterogeneity. However, accuracies on large heterogeneous datasets were not high. We used age-specific features based on ABIDE II dataset to distinguish ASD and control. In the meanwhile, we combined two kinds of age-specific structural features including regional and interregional features using multiple kernel learning (MKL) to complement each other. Results showed that our procedure achieved accuracy of more than 85 percent on discriminating ASD from control.
Long-term effects of childhood trauma subtypes on adult brain function
Authors: Liu Qin , Liu Weiyin , Cai Jianjian , Tian Tian
Published: August 2024

Childhood trauma is prevalent in our society, but little is known about why and how different forms of early traumatic experiences exert long-term effects on differential brain function in adulthood. This study aimed to measure experience-specific neural correlates of distinct subtypes of childhood trauma. Our data showed the differential associations of abusive and neglectful experiences with brain function in adulthood. These experience-specific associations could underpin potentially differential risks of specific forms of psychiatric sequelae in adulthood. More attention to maltreated children and timely psychological treatment are needed to reduce the incidence of psychosis.
A Triple-nuclear four-channel RF coil for Simultaneous acquisition of 1H/19F/23Na MR imaging at 3T
Authors: Li Nan , Du Feng , Zhang Xiaoliang , Liu Xin , Zheng Hairong , Li Ye
Published: August 2024

As the lower natural abundance of X-nuclei, it is important to enhance that the signal-to-noise ratio (SNR) of the X-nuclei is as high as possible by designing a well-designed multiple-tuned coils. In this study, a new triple-tuned RF coil system capable of 1H / 19F / 23Na imaging was proposed. The performance of the triple-tuned coil was evaluated compared to their counterpart single-tuned coils by the numerical electromagnetic simulation. Imaging tests at 3T MRI were performed on the phantom by using the triple-tuned RF coil.
Investigating Dipole Antennas as 1H Transmit Elements for a 1H/31P Calf Coil at 7 T
Authors: Cap Veronika , Meyerspeer Martin , Roat Sigrun , Laistler Elmar , Frass-Kriegl Roberta
Published: August 2024

Different dipole antenna types as 1H transmit elements for metabolic 1H/31P MRS studies of the human calf were investigated. In simulations, the dipole elements and a loop coil were compared in terms of transmit efficiency and SAR. A three-element array of the best-performing design was simulated and constructed, and its transmit performance was found to be comparable to a four-element loop array. Investigating the interaction between a dipole transmit element and a receive-only loop placed underneath, efficient geometric decoupling was observed. This can be exploited to improve the receive sensitivity (homogeneity, depth) by using transceiver dipoles together with receive-only loops.
First MR Images acquisition with decoupled High Temperature Superconducting surface coils
Authors: Dubuc Camille , Labbé Aimé , Marhabaie Sina , Thibault Clément , Ginefri Jean-Christophe , Briatico Javier , Poirier-Quinot Marie
Published: August 2024

A promising strategy to tackle the issue of decoupling High-Temperature Superconducting (HTS) surface coils during emission is to exploit nonlinearities of the HTS coil electromagnetic response. In this work, we present the first Magnetic Resonance Images acquired with a decoupled HTS surface coil and the required coil’s features to obtain these images. The change of the HTS coil Q-factor values leads to different decoupling levels (DL) of the HTS coil and the presence or absence of B1 artifacts on the images.
Modeling and selection of T1 and T2 tissue mimics for 0.0065T, 0.064T, 0.55T MRI using agarose with manganese, gadolinium, copper, or nickel
Authors: Jordanova Kalina , Tian Ye , Shen Sheng , Martin Michele , Poorman Megan , Teixeira Rui , Nayak Krishna , Rosen Matthew , Keenan Kathryn
Published: August 2024

There is re-emerging interest in MRI fields ≤0.55T as well as quantitative MRI (qMRI) methods. Physiologically relevant reference objects are needed to adapt qMRI techniques to lower fields. We investigate materials as tissue mimics for brain imaging at 0.0065T, 0.064T, 0.55T, for white matter, gray matter, fat, cerebrospinal fluid, and blood. We create samples composed of agarose and paramagnetic salts and measure relaxation across field strengths. Samples suitable to mimic each tissue are presented for each field strength. This work will facilitate qMRI development for fields ≤0.55T by providing accessible mimic compositions to the community.
Repeatability, Distortion and SNR comparison of diffusion-weighted imaging techniques on an MR-Linac
Authors: Nair Prashant , Navest Robin , Goodburn Rosie , Lecoeur Bastien , Oelfke Uwe , Wetscherek Andreas
Published: August 2024

DW-acquisitions with high ADC accuracy, precision and low geometric distortion are necessary for using ADC maps for treatment planning and response assessment in MR-guided radiotherapy on MR-Linacs. We measured SNR, ADC bias, repeatability coefficient and marker distances on the NIST phantom for DW-EPI, DW-TSE and SPLICE protocols. Two volunteers were scanned in the head and neck region. The investigated TSE-based protocols showed ADC bias and DW-EPI demonstrated better repeatability. Spectral fat-suppression techniques led to higher SNR than using STIR. SPLICE DWI could be an alternative to diffusion EPI with reduced distortion and comparable SNR, if low-high profile order is used.
Reproducibility of Whole-Body Variable Flip Angle T1 Mapping Using Only Two Flip Angles
Authors: Lamb Alistair , Atkinson David , Punwani Shonit , Zhang Hui , Barnes Anna
Published: August 2024

We investigate the feasibility of whole-body (WB) variable flip angle (VFA) T1 mapping using linear least squares fitting with only two flip angles (FAs) in order to obtain WB T1 maps within a clinically viable timeframe. This could enable its use as an imaging biomarker in metastatic cancer. We assessed the agreement across eight subjects in a variety of abdominal tissues between T1 estimates fitted using eight FAs and just 2 FAs. We found that VFA T1 mapping can be achieved by acquiring only two FAs with minimal loss to precision, providing the lower FA is between 2.5° and 7.5°.
7T cross-vendor repeatability study of cartilage T2 values using DOSMA on qDESS images
Authors: Asay Jessica , Balaji Krithika , Gatti Anthony , Desai Arjun , Mendoza Michael , Huo Zimu , Chaudhari Akshay , Kogan Feliks , Lally Peter , Bangerter Neal , Gold Garry
Published: August 2024

Cartilage T2 relaxation times (T2), used to detect early knee osteoarthritis, lack standardization in acquiring and processing data, making comparisons between studies difficult. Standardizing image post-processing could possibly control for biases. Here, we assess qDESS cartilage T2 repeatability across two different sites and 7T scanner vendors with identical automatic segmentation and T2 mapping software. Within-site repeatability was good (ICC≥ 0.75) for most cartilage regions, while cross-vendor repeatability was good for the tibial and femoral posterior cartilage. This preliminary study shows standardizing acquisition and post-processing can lead to repeatable T2 values across different vendors.
Multi-Echo FLORET UTE MRI
Authors: Willmering Matthew , Krishnamoorthy Guruprasad , Plummer Joseph , Bdaiwi Abdullah , Walkup Laura , Cleveland Zackary , Pipe James , Woods Jason
Published: August 2024

FLORET UTE MRI has been used for many applications including lung, brain, musculoskeletal, and multinuclear imaging. The appeal of the pulse sequence comes from its high SNR and sampling efficiencies. With recent improvements minimizing artifacts, high-quality FLORET images are obtained routinely. However, acquisition of multiple echoes has not been investigated. Here, we determined the feasibility and optimal pulse-sequence design of multi-echo FLORET. Collecting echoes independently, but interleaved, produces the highest quality images, especially for ≥3 echoes. Furthermore, additional echoes provide improvements to image quality and add clinically useful contrast like T2*.
A Data Augmentation Framework to Improve R-peak Detection in ECG Recorded in MRI Scanners
Authors: Mehri Maroua , Aublin Pierre , Calmon Guillaume , Odille Freddy , Oster Julien
Published: August 2024

Detecting R-peaks in ECG using deep learning (DL) requires large, annotated datasets. Such datasets with the MRI-specific magneto-hydrodynamic (MHD) effect, do not exist currently. We propose a robust data augmentation framework using records available online, adding realistic MHD artifacts to augment the training dataset. MHD artifacts were modelled from eight 3T MRI-ECG records, and added to 75 non-MRI-ECG records. The R-peak detection was evaluated on six 3T MRI-ECG records. Compared to a DL model trained without data augmentation, the number of false positives and missed detections were reduced by 57.6% and 16.4%, the overall error was decreased by 25%.
2D U-Net for left heart segmentation for CINE sequences, deal with new target data: comparison of 3 approaches
Authors: Rebbah Habib , Gautier Guillaume , Boutelier Timothé
Published: August 2024

In the case of U-Net based segmentation algorithms, we propose to explore a common question of the medical image research teams: using already existing algorithm or train a new one specific to the target data. We compared for the cardiac CINE case three approaches: using an algorithm trained with external data, train a new one with the taget data from scratch, and fin-tune the first one with the target data.
Cine MRI reconstructed from 3T contrast-enhanced free-running 5D coronary MRA: comparison to standard 2D cine MRI
Authors: Ito Haruno , Ishida Masaki , Takafuji Masafumi , Takase Shinichi , Komori Yoshiaki , Piccini Davide , Bastiaansen Jessica , Yerly Jérôme , Stuber Matthias , Sakuma Hajime
Published: August 2024

Cine MRI derived from 3T contrast-enhanced free-running 5D whole-heart coronary MRA (free-running cine MRI) was compared with standard 2D cine MRI in 30 patients with suspected CAD. In a selected patient, temporal width was optimized to 50 ms. Then, in the remaining 29 patients, free-running cine MRI provided good agreement in LV volume and function quantification with standard 2D cine MRI with a good inter-observer reproducibility. The results suggest that free-running cine MRI allows for a shorter scan protocol by skipping the standard 2D cine MRI.
Vibration Exposure in Brain MR Elastography
Authors: Bishe Safoura Sadegh Pour Aji , Pepin Kay , Heilman Jeremiah , Shan Xiang , Yin Ziying , Ehman Richard
Published: August 2024

Magnetic resonance elastography (MRE) requires application of mechanical vibrations to assess the stiffness of tissue noninvasively and quantitatively. This study assessed the levels of vibration exposure in brain tissue during a typical brain MRE exams performed for clinical research. Voxel-level vibration exposure levels throughout the brain were measured in 45 subjects in this IRB approved study. Histograms of voxel-level vibration in all cases demonstrated maximum exposure levels that were well below the very conservative EU 2002 Directive 2002/44/EC of the European Parliament guideline for total body vibration.
Realistic simulated MR Elastography data generated from in vivo brain images
Authors: Jyoti Dhrubo , Caban-Rivera Diego , Kramer Mary , Diano Alexa , Johnson Curtis , Van Houten Elijah , Paulsen Keith , Mcgarry Matthew
Published: August 2024

Simulations can play an important role in validating the accuracy of MR elastography (MRE) inversion algorithms. A realistic brain MRE simulation is created through a finite element model from in vivo MRE data, with 20 randomly generated simulated brains created by assigning properties of anatomical segmentations of brain structures within a range given by a published MRE atlas. Multi-frequency and multi-direction synthetic MRE data was generated via boundary conditions from in vivo measured motions to allow a range of inversion algorithms to be tested. These data will be supplied to the MRE study group for an inversion reconstruction challenge.
A Biomechanical Analysis Framework for Co-Correlation of 7T MR Elastography Measures and Amyloid Beta Deposition
Authors: Triolo Emily , Langan Mackenzie , Khegai Oleksandr , Alipour Akbar , Ferreira-Atuesta Carolina , Pionteck Aymeric , Sutkowski Jonathan , Hedden Trey , Balchandani Priti , Kurt Mehmet
Published: August 2024

Previous studies have implied the future use of MRE metrics to track disease progression and as a tool for AD diagnosis, potentially replacing or augmenting methods that use ionizing radiation. In this pilot study, we have therefore developed a novel framework for performing ultrahigh field (7T) MRE at high resolution on subjects who have previously undergone PET scans and performing joint analysis of biomechanical and pathologic markers on these subjects. We have successfully created a framework for measurement of high-resolution brain mechanical properties for co-correlation with traditional PET measures to be used on AD patients in the future.
Anisotropic MR elastography with a DTI-informed crossing fiber mechanical model
Authors: Mcgarry Matthew , Sowinski Damian , Caban-Rivera Diego , Van Houten Elijah , Johnson Curtis , Paulsen Keith , Bayly Philip
Published: August 2024

Anisotropic MRE has shown some promise in estimating mechanical properties of fiber-reinforced biological tissues. However, these methods are restricted to modeling a single fiber and ignores complexity that occurs such as regions of brain white matter with crossing fibers. Here we implement an inversion algorithm capable of modeling material with two fiber directions obtained from diffusion MRI in order to reduce model data mismatch and provide fiber-specific properties, which may show promise in correlating with brain health and function. Performance of this algorithm is demonstrated in simulation and in vivo brain data and compared with one-fiber and zero-fiber (isotropic) inversions.
MRE navigator for rapid estimation of liver stiffness.
Authors: Anders Matthias , Warmuth Carsten , Pfeuffer Josef , Tzschätzsch Heiko , Herthum Helge , Degenhardt Katja , Wieben Oliver , Schmitter Sebastian , Schulz-Menger Jeanette , Braun Jürgen , Sack Ingolf
Published: August 2024

MR elastography (MRE) can noninvasively detect liver fibrosis based on elevated stiffness values. However, a complete MRE scan is time-consuming and typically extends over multiple breath-holds. Therefore, a multi-shot gradient echo sequence with spiral readout was developed to provide full two-dimensional elastograms of the liver in less than one second. The new sequence can be used as an MRE navigator to provide immediate feedback on wave penetration and data consistency for parameter optimization prior to running full multi-dimensional MRE. Moreover, the method can be used to rapidly track potential changes in liver stiffness such as those induced by respiration.
Imaging of Propagating Broadband Transient Waves with Multi-scale MR Elastography Motion Encoding: A Validation Study
Authors: Le Yuan , Chen Jun , Rossman Phillip , Manduca Armando , Glaser Kevin , Bolster Bradley , Kannengiesser Stephan , Ehman Richard
Published: August 2024

We demonstrate imaging of the propagation of transient waves using multi-scale motion encoding gradient waveforms. Displacement values are calculated using the inverse Haar transforms. We validated the results by comparison with wave images obtained using standard MRE acquisition and processing. The approach provides the ability to image broadband motion more efficiently and accurately compared with previous methods and promises to be a useful approach for biomechanical studies of traumatic brain injury.
Measurement of Extracellular Electrical Conductivity Using Conductivity Tensor Imaging
Authors: Choi Bup Kyung , Katoch Nitish , Park Ji Ae , Kim Tae Hoon , Hur Young Hoe , Kim Jin Woong , Kim Hyung Joong
Published: August 2024

Conductivity measured at low-frequency can provide information on extracellular space (ECS), which will be useful in clinical applications such as tumor imaging and bioelectromagnetic modeling. Recently proposed conductivity tensor imaging (CTI) technique provides the anisotropic low-frequency conductivity distribution extracted from high-frequency conductivity measurement from the B1 map of MRI. The extracellular conductivity measured using CTI from three phantoms was compared with an impedance analyzer. The accuracy of the CTI technique was estimated to be high enough for most clinical applications.
8-minute Rapid Whole-brain Diffusion Spectral Imaging with Deep Learning-based Reconstruction: A Feasibility Study
Authors: Xiong Yuhui , Wei Xiaocheng , Dai Jiankun , Fan Yang , Lu Jie , Wu Bing
Published: August 2024

This study aims to shorten the diffusion spectral imaging (DSI) scan time to a clinically acceptable level while providing satisfactory complex white matter fiber structure description as well as accurate diffusion metric quantification by applying deep learning-based reconstruction. Images were acquired using conventional (≈30 min) and rapid (≈8 min) DSI sequences, and reconstructed using conventional and DL-based methods, respectively. Atlas-based fiber-tracking and diffusion metrics quantification from various advanced models were conducted. The results demonstrated that the 8-minute rapid DSI sequence combined with DL-recon can provide complex fiber structure tractography and advanced diffusion metric quantification of satisfactory quality.
Structural and functional changes in patients with temporal lobe epilepsy: a VBM and rs-fMRI study
Authors: Li jiachen , Zhang jing , Hu wanjun , Liu guangyao , Zhou liang , Ai kai
Published: August 2024

To investigate the structural and functional changes of the Temporal Lobe Epilepsy (TLE) patients, voxel-based morphometry (VBM) and resting-state functional MRI (rs-fMRI) methods were used. Our findings showed that thalamus gray matter volume decreased and performed negative correlation with self-rating anxiety scale (SAS) and self-rating depression scale (SDS). Furthermore, in rs-fMRI analysis, we found decreased functional connectivity between bilateral thalamus and right superior frontal gyrus. The results suggested that thalamus plays an important role in emotional change in TLE patients and structural and functional alterations may be related to the pathological mechanism of TLE.
Focused Ultrasound Neuromodulation combined with rs-fMRI and EEG as a preclinical tool to investigate and intervene Drug-Induced Epilepsy
Authors: Juan Yi-Jing , Zhen Xiao , Chu Po‑Chun , Chen You-Yin , Liu Hao-Li , Chen Jyh-Horng
Published: August 2024

A drug-induced epileptic animal model to investigate the feasibility of FUS neuromodulation with rs-fMRI and EEG
Development of an easy-manufacturable and cheap phantom for quality control of T1, T2 and fat fraction mapping.
Authors: Dallet Laurence , Miraux Sylvain , Maingault François , Ribot Emeline
Published: August 2024

A quality control phantom was developed through a simple and easy protocol for T1, T2 and Fat fraction mapping. The phantom is constituted of 8 tubes containing Gd-DOTA or commercially available animal fat, each at various concentrations and stabilized in agarose gels. A 3D printed bubble trap was placed on top of the gels to limit the contrast agent dilution over time. The solutions are stable for at least 6 months and the manufacturing protocol is highly reproducible.
Framewise distortion correction in Multi-echo Echo Planar Imaging
Authors: Van Andrew , Tisdall M. , Laumann Timothy , Montez David , Fair Damien , Dosenbach Nico
Published: August 2024

Echo Planar Imaging (EPI) suffers from off-resonance image distortion due to B0 inhomogeneities. These distortions are typically corrected by separate field map acquisitions, but only allow for sparse temporal sampling of B0 inhomogeneity. This approach prevents distortion correction if changes in the B0 field occur over time due to motion. Here, we present a method of correcting off-resonance distortion by computing a time series of field maps using phase information from multi-echo (ME) EPI data. We show that our method produces corrections comparable to the current standard of distortion correction, in addition to enabling frame-by-frame correction in functional MRI data.
Entropy informs about uncertainty in probabilistic brain tissue segmentation
Authors: Sierhej Agnieszka , Hall Matt , Smith Nadia , Clark Chris
Published: August 2024

Segmentation is crucial in analysing volumes of brain tissue compartments in studies of healthy development and pathological changes. Probabilistic segmentation is widely used, but the choice of threshold on probability maps has large effects on the resulting tissue volumes, and there is no consensus on optimal choice of such threshold. This work presents a way to minimise this effect by quantifying the uncertainty using Shannon entropy. Entropy map contains information about uncertainties in each individual voxel and this can be used to inform about uncertainty in MRI-based tissue segmentation.
Impacts of compressed sense-parallel imaging on lung 19F-MRI ventilation imaging measured with tissue-mimicking 1H phantoms.
Authors: Harrison Dominic , Neal Mary , Hollingsworth Kieren , Thelwall Pete
Published: August 2024

We used 1H test objects to assess the ability to detect and quantify lung ventilation defects using accelerated 19F-MRI ventilation scan protocols. The test objects replicated the spin density and relaxation properties of inhaled perfluoropropane gas and are constructed with signal voids of known dimensions to simulate ventilation defects. Scans were acquired on single- and multi-channel RF receiver arrays, with multiple compressed sensing and parallel imaging (CS/CS-PI) accelerations and scan resolutions at fixed scan duration and field-of-view (FOV). A negative relationship between acceleration and measured ventilation defect diameter was observed with increasing CS acceleration factor, but not for CS-PI scans.
Memory and learning relationships with hippocampal morphometry and multi-modal connectivity after pediatric severe TBI
Authors: Guerrero-Gonzalez Jose , Kirk Gregory , Birn Rasmus , Bigler Erin , Bowen Katherine , Broman Aimee , Rosario Bedda , Butt Warwick , Beers Sue , Bell Michael , Ferrazzano Peter , Alexander Andrew
Published: August 2024

Traumatic brain injury in adolescents is a major public health concern, leading to tens of thousands of hospitalizations in the U.S. each year. Our study aims to identify multimodality imaging biomarkers of long-term neurocognitive outcome after severe adolescent TBI. For this investigation we explored memory performance using the California Verbal Learning Test (CVLT) in relation to structural and functional connectivity of the memory network, as well as hippocampal volume and fornix microstructure.
Changes in Cellular and Vascular Phenotype in Pediatric Ependymoma Models by Multi-Parametric MRI: Effects of Tumor Size and Radiation Treatment
Authors: Manalo Jane , Griesinger Andrea , Steiner Jenna , Pierce Angela , Foreman Nicholas , Serkova Natalie
Published: August 2024

At 2022 ISMRM, we presented on simulation results of the selective size imaging using filters via diffusion times (SSIFT) in perfused irradiated cells and flank xenograft models. Here, using SSIFT and iron-oxide vessel-size imaging, we report on ependymoma (EPN) phenotypes, comparing small and large intracranial lesions: variable cell sizes fitted into SSIFT iAUC (S=14 microns small EPN, S=19 medium and S=12 large), increased vessel density index (Q=0.54 small, Q=0.62 large EPN), and low ADC (0.63x10-3 small, 0.58x10-3 mm2/s large EPN). Chemo-radiation treatment led to decreased gross tumor volumes, necrosis with decreased cell sizes and increased ADCs.
Characterising the lifespan trajectory of six essential neurometabolites in a cohort of 100 participants.
Authors: Thomson Alice , Pasanta Duanghathai , Hwa Hannah , Arichi Tomoki , Edden Richard , Chai Xiaoqian , Puts Nicolaas
Published: August 2024

We characterised the normative lifespan trajectories of brain neurometabolites, as measured by 1H-Magnetic Resonance spectroscopy (1H-MRS) from the posterior parietal cortex across 100 individuals (aged 5-40 yrs). Glutamate + glutamine (Glx), N-acetylaspartate (NAA), gamma-aminobutyric acid (GABA+) and glutathione (GSH) showed non-linear trajectories, decreasing steeply in childhood/adolescence before a gradual, significant, decline across early adulthood. Results suggest age associated changes in brain composition may contribute to the observed trajectories. Importantly, a non-linear regression modelling approach was found to be more appropriate for neurometabolite trajectories than a linear regression model and should be considered in future to prevent simplification of data trends.
Evaluation of Deep Gray Matter Iron and Myelin Changes in children with Attention-deficit/hyperactivity disorder
Authors: su shu , Chen Yingqian , Qian Long , Dai Yan , Lin Liping , Yang Zhiyun
Published: August 2024

Application of magnetic susceptibility have been consistently demonstrated in the subcortical gray matter of ADHD children, but some uncertainties remain concerning the underlying neurobiological processes. We applied quantitative susceptibility mapping and synthetic magnetic resonance imaging (SyMRI) to clarify the relative contribution of iron and myelin changes to deep gray matter changes in ADHD. We found that the iron and myelin concentration of these subcortical structures in ADHD were delayed in the developmental trajectory, which suggested that ADHD may be characterized by a delay in subcortical maturation and dysfunction in dopaminergic transmission.
Quantitative susceptibility mapping of hippocampal iron relates to pattern separation and completion in older adults at risk for Alzheimer's
Authors: Zhou Jing , Wearn Alfie , Huck Julia , Baracchini Giulia , Tremblay-Mercier Jennifer , Poirier Judes , Villeneuve Sylvia , Tardif Christine , Daugherty Ana , Gauthier Claudine , Turner Gary , Spreng R
Published: August 2024

Quantitative susceptibility mapping (QSM) was used to evaluate hippocampal iron in a cohort of healthy older individuals at elevated risk for Alzheimer’s disease (AD), and related to pattern separation and pattern completion memory performance. Our results demonstrated that elevated brain iron content in the hippocampus is strongly associated with lower performance on behavioral tests specific to memory function, ie lower pattern separation scores and higher pattern completion scores. Our findings suggest that hippocampal iron deposition may be a pathological mechanism resulting in poorer mnemonic discrimination in later life
129Xe sublimation DNP towards hyperpolarized imaging standards
Authors: Wiström Emma , Hyacinthe Jean-Noel , Lê Thanh Phong , Gruetter Rolf , Capozzi Andrea
Published: August 2024

Sample preparation of 129Xe for dDNP with different glassing solvents, radical choice and concentrations affects the electron properties as well as the overall achieved 129Xe polarization. A short T1e and/or poor mixing is improved by ad hoc solutions that results in competitive polarization values in solid state measurements. The sample preparation of 129Xe for DNP showed an improved incorporation of the gas atoms in the solvent when using ultrasonication. Applying microwave frequency modulation during the irradiation reached a higher 129Xe polarization. Extracted Xe was measured in a 1T NMR benchtop spectrometer to be 18s.
Mapping astrogliosis in the individual human brain using multidimensional MRI
Authors: Benjamini Dan , Priemer David , Perl Daniel , Brody David , Basser Peter
Published: August 2024

There are currently no noninvasive imaging methods available for astrogliosis mapping in the brain despite its essential role in the response to many disease states. In an ex vivo human brain study we used diffusion-relaxation MRI to derive a signature of astrogliosis and disentangle it from normative brain at the individual level using machine learning. We developed a within-subject anomaly detection procedure that generates MRI-based astrogliosis maps ex vivo, which were significantly and strongly correlated with co-registered histology. Our findings demonstrated spatial sensitivity and specificity in detecting reactive astrocytes, and could significantly impact the studying of injury, disease, and aging.
Differentiation of stage IA and IB endometrial cancer using texture analysis based on T2 -weighted and diffusion-weighted imaging
Authors: Sun Meiyu , Cui Shuli
Published: August 2024

In our study, Imagingomics texture analysis in DWI and T2WI showed the correlation and inverse gap of glcm, glrlm-RunLengthNonUniformityNormalized and shortRunEmphasis are more effective in identifying stage IA and IB EC. And the diagnostic efficacy combined parameter analysis were higrer and bettter than the single parameter analysis.
CSF circulation and glymphatic system of the spinal cord: pathophysiology and imaging and treatment of associated diseases
Authors: Moritani Toshio , Naganawa Shotaro
Published: August 2024

Glymphatic–lymphatic fluid transport system plays a critical role in fluid homeostasis in the spine associated with the CSF flow. Reviewed multiple diseases related to CSF circulation and glymphatic system. Intrathecal drug administration is an effective strategy to bypass the BBB via direct delivery to the CNS, especially in antibody or oligonucleotide-based therapeutics. Glymphatic system has an important role in drug-distribution from CSF to brain and spinal cord.
Application of Multi-Shot Echo Planar Imaging Diffusion Weighted Imaging of the Skull Base
Authors: Luo Hedan , Song Qingwei , Miao Yanwei , Zhang Haonan , liu Na , Zhang Yukun , Liu Ailian , Lin Liangjie
Published: August 2024

Exploring the performance of Image Reconstruction Using Image-space Sampling (IRIS)-based Multi-shot Echo Planar Imaging Diffusion Weighted imaging (MS-EPI DWI) for the skull base region.
RA synovitis segmentation based on unsupervised learning and TIC signal data on DCE-MRI
Authors: Mao YiJun , Fang Wanxuan , An Yujie , Sugimori Hiroyuki , Kiuch Shinji , Kamishima Tamotsu
Published: August 2024

Keywords: Rheumatoid Arthritis, DSC & DCE Perfusion The volume of synovitis change is one of the most important pathological features of rheumatoid arthritis. By quantitative analysis of the enhancement of synovitis, we can define the degree of the disease, and determine the treatment and diagnosis. Considering the time-consuming of manual outlining and visual assessment, this study uses machine learning methods to conduct quantitative analysis of TIC, and proposes an unsupervised learning method with excellent results, which is expected to be an alternative for the gold-standard manual synovitis contour outlining.
Comparison of 3D VANE XD Technique in T1 weighted images of Liver MRI with free-breathing technique as the Radial percentage parameter changes
Authors: Shin Hun-Yeol , Jeong Jae-Yun , Cho Seong-Bong , Dae Chang-Min
Published: August 2024

Liver examination with MRI has greater diagnostic value than other tests and is one of the more frequent examinations.[1,2] However, the ability to obtain images with good diagnostic value only when the patient breathes constantly.[3] A non-Cartesian Radial method for the collection of K-Space data enables examinations with free breathing differently. 3D VANE XD technique can be applied with mDIXON, a technique with high SNR and excellent fat suppression.[4] Therefore, the difference in Radial percentage, the parameter that most effects motion artifacts in T1 3D VANE XD and 3D-FFE techniques were compared and optimal time versus efficiency value were compared.
Application of T1 radial vibe sequence in fetal central nervous system
Authors: JIAN TIAN
Published: August 2024

Application of T1 radial vibe sequence in fetal central nervous system
The position dependence of the apparent diffusion coefficient; signal-to-noise ratio vs B1 map
Authors: TAKATSU YASUO , Nakamura Masafumi , Suzuki Yuichi , Miyati Tosiaki
Published: August 2024

The position dependence of the ADC in magnetic resonance imaging (MRI) by EPI- and TSE-DWI was assessed using phantoms based on the relationship between SNR and B1 maps. ADC decreased with distance from the center of the magnetic field for both EPI-DWI and TSE-DWI. The Pearson correlation coefficient between ADC and FA was strong and more significant than between ADC and SNR. ADC depends on the slice position and decreases with an increase in distance from the magnetic field center. Caution should be taken when comparing and quantitatively evaluating the ADC at sites shifted in the long-axis direction.
Quantitative assessment of anterior talofibular ligament quality in chronic ankle instability using T2* relaxation time
Authors: Akatsuka Yoshihiro , Teramoto Atsushi , Murahashi Yasutaka , Takahashi Katsunori , Imamura Rui , Kamiya Tomoaki , Watanabe Kota
Published: August 2024

This study investigated the feasibility of quantitative assessment of anterior talofibular ligament (ATFL) quality in chronic ankle instability (CAI) using T2* relaxation time. A prediction equation for the normal ATFL reference value was calculated in healthy volunteers. The ratio between the normal reference value and the patient's T2* value showed a significant positive correlation with the talar tilt angle on stress radiograph. There was also increasing trend in T2* values for poor ligament quality in the arthroscopic findings. T2* relaxation times are promising for quantitatively assessing ATFL quality preoperatively.
MR-safety of mixed-brand of cardiac implantable electronic devices: Comparison of RF induced heating with approved single-brand at 1.5 T and 3.0 T
Authors: Fukunaga Issei , Shibukawa Shuhei , Yatsushiro Satoshi , Tawara Kazuya , Nakai Toshiko , Abe Haruhiko , Aoki Shigeki , Miyajima Atsuko , Kuroda Kagayaki
Published: August 2024

Radio-frequency-induced heating around MR-conditional cardiac implantable electronic devices with mixed brand combinations of generator and lead were compared with the approved single brand combinations at 1.5 T and 3.0 T. The generator-lead combinations were selected from three high-share vendors (Boston Scientific, Medtronic, and St. Jude) based on the frequency in clinical practice. Temperature measurements were conducted along with ASTM2182 and ISO10974 at locations corresponding to the right ventricle, right atrium, the generator edge, and contralateral of in the ASTM phantom. The results evaluated by Mann-Whitney's U-test showed no significant difference in temperature increases between the mixed and approved combinations.
Cauvery-The River of Peace and Prosperity or War and Violence
Authors: Jaan Dr. Afsari
Published: August 2024

Water has become a vital resource for economic growth and sustainable development. Southern India is currently engaged in conflicts involving shared water resources. This case study focuses on the Cauvery River water sharing Dispute. Karnataka and Tamil Nadu, both southern Indian states rely on the Cauvery River for their water supply. Failed monsoons in 1995 ignited old debates between the two states over water access. The dispute is still in progress as the states battle out their arguments in the Supreme Court. The issue becomes more complicated and intense due to the displacement of local farmers to depend on the water from the Cauvery River for their livelihood. Crops are withering and tempers are inflamed. Threats of violence have transformed into aggressive protest ending in death, and still there is no solution. This age old problem has taken devastating form with rising population, which has given rise to regional violence giving it shades of a civil war. In this paper a small effort has been taken to present how this situation was, and is now