bluuebunny/crossref_metadata_2025 huggingface dataset:
Diffusion Kurtosis Imaging Combined with Intravoxel Incoherent Motion Imaging in Prediction of P53 Status in Rectal Cancer
Authors: Chen Anliang , Dong Deshuo , Ma Changjun , Liu Ailian , Song Qingwei
Published: August 2024

Mutant P53 promotes tumor cell proliferation, invasion, and resistance to chemotherapy. The purpose of this study was to evaluate the value of combination of DKI and IVIM for prediction of P53 expression status in rectal cancer. The results indicate that the combination of MK and D* improved the diagnostic efficiency than single parameters. DKI and IVIM imaging allows non-invasive visualization and quantification of tissue composition for prediction of P53 status in rectal cancer.
Preliminary study of DCE-MRI combined with DWI in discriminating tumor deposits from lymph node metastasis in rectal cancer
Authors: HU WEN , Chen Anliang , Liu AIlian
Published: August 2024

Tumor deposits (TDs) in rectal cancer have been shown to be an important marker of poor prognosis. Although very similar to lymph node metastasis (LNMs), TDs have unique features in terms of biology and outcome, suggesting that distinguishing between these two entities may be of great importance. Results of this study indicate DWI and DCE-MRI can effectively differentiate TDs and LNMs in rectal cancer, Combination of DWI and DCE-MRI imaging may serve as an effective noninvasive method for differentiation of TDs from LNMs in rectal cancer.
Effective axon radii across the human corpus callosum for a group of subjects: comparability between MRI and histology
Authors: Mordhorst Laurin , Ashtarayeh Mohammad , Morozova Maria , Edwards Luke J. , Jäger Carsten , Rusch Henriette , Streubel Tobias , Weiskopf Nikolaus , Morawski Markus , Mohammadi Siawoosh
Published: August 2024

Robust MRI-based axon radius estimation is sensitive to a tail-weighted estimate of the ensemble-average axon radius, i.e., the effective axon radius ($$$r_{eff}$$$). Existing validation studies of $$$r_{eff}$$$ in the human brain are confounded because the histological gold standard cannot representatively sample the tail of the axon radii distribution due to limited sample size. We compare in vivo, MRI-based $$$r_{eff}$$$ of five healthy adults against a representative histological gold standard of three donors in the human corpus callosum and demonstrate that spatial patterns of the $$$r_{eff}$$$ along the anterior-posterior axis agree between in vivo MRI and ex vivo histology.
White matter microstructure mapping using diffusion-only or diffusion-relaxation: protocol design and comparison of accuracy and precision
Authors: Liao Ying , Coelho Santiago , Szczepankiewicz Filip , Novikov Dmitry , Fieremans Els
Published: August 2024

Combining diffusion and relaxation is promising in probing the tissue microstructure in brain white matter. We designed an optimal diffusion-relaxation protocol with varying b-values, b-tensor shapes and echo times by minimizing the error of parameter estimation. We compared the Standard Model parameters estimated by diffusion-relaxation and diffusion-only data using sensitivity-specificity matrices and test-retest data on volunteers and found excellent agreement. With a comprehensive acquisition protocol, the Standard Model can accurately capture the signal content in white matter with diffusion MRI.
Validation of Intravoxel Incoherent Motion (IVIM) Methods in the Liver using the NIST Diffusion Phantom
Authors: Brown Marissa , Vasquez Juan , Clarke Geoffrey , Blangero John
Published: August 2024

Intravoxel incoherent motion (IVIM) MRI is used to measure quantitative biomarkers of liver fibrosis, but accuracy and reproducibility of various methods requires validation. Six IVIM methods with different acquisition parameters (motion control techniques, b-values, single shot EPI v. SMS) were assessed using the NIST diffusion phantom. The phantom measurements met conformance standards for percent apparent diffusion coefficient (ADC) bias and ADC linearity using a protocol modified for liver MRI. Given that no standard IVIM liver phantom has been developed, the NIST diffusion phantom is shown to work well for validation of liver IVIM acquisitions.
Deep Fourier-Space Inversion
Authors: Lambert Mathias , Silva Javier , Milovic Carlos , Tejos Cristian
Published: August 2024

Guiding the network architecture to learn to apply the kernel inversely in Fourier space allows training to be less prone to overfitting. Using simulated images from a single brain image, it is possible to satisfactorily reconstruct a susceptibility map of the abdomen. By having as input the Fourier space of the local field and the kernel of the dipole, the network learned to reduce the noise, to divide the data of the local field by the kernel where possible and to recover the data in the magic cone.
Quantitative comparison of DTI and STI principal eigenvectors
Authors: Munoz Nestor , Milovic Carlos , Langkammer Christian , Uribe Sergio , Tejos Cristian
Published: August 2024

Diffusion Tensor Imaging (DTI) and Susceptibility Tensor Imaging (STI) are two MRI techniques that produces anisotropy information and fiber direction of biological tissue. For the brain, it has been suggested that both principal eigenvectors (PEV) point towards the same direction (i.e., direction of myelinated axons). However, different resolution of both techniques might produce differences in the PEVs. We proposed a quantitative method to compare DTI and STI PEVs based on the cosine of their angular difference. As expected, we found that PEVs from STI and DTI show similar directions in white matter and that consistency is lost for gray matter and CSF.
Computationally efficient multi-echo QSM
Authors: Eckstein Korbinian , Dao Thanh , Stewart Ashley , Robinson Simon , Barth Markus , Bollmann Steffen
Published: August 2024

With increasingly popular multi-echo QSM, the combination of echoes becomes important in terms of accuracy, SNR and computation time. We compared 6 different pipelines with quantitative and Laplacian unwrapping and three different echo combination approaches, weighted averaging of QSMs, combination of the phase, and non-linear fitting. We compared the pipelines on the QSM challenge brain dataset and 7 T in vivo data and conclude that quantitative unwrapping (ROMEO) with weighted frequency combination achieves the best outcomes in terms of accuracy, SNR and computation time.
Dynamic Geometric Distortion Correction for Quantitative Susceptibility Mapping Using a Multi-Echo 2D-EPI Sequence
Authors: Kiersnowski Oliver , Fuchs Patrick , Wastling Stephen , Thornton John , Shmueli Karin
Published: August 2024

Echo planar imaging (EPI) suffers from geometric distortions, which can be corrected using reference acquisitions for single-echo EPI, or using field maps calculated from the multiple echoes in multi-echo EPI. The effect of distortion on EPI quantitative susceptibility mapping (QSM) has not been investigated. We compared static and dynamic geometric distortion correction for magnitude images and QSM using multi-echo 2D-EPI acquisitions with and without changes in head position. Multi-echo EPI corrected distortion in both magnitude and QSM images without the need for reference scans. Correcting the local field map in the QSM pipeline was optimal to reduce temporal variance.
Denoising highly accelerated T2*-weighted brain MRI using a deep learning convolutional neural network
Authors: Quah Bryan , Nair Sreekanth Madhusoodhanan , Jin Jin , Han Fei , Renner Brian , Gombos Elaina , Liu Ke Cheng , Patil Sunil , Derbyshire John , Sakaie Ken , Obusez Emmanuel , Lee Jonathan , Elliot Mark , Shinohara Russell , Schindler Matthew , Song Jae , Bilello Michel , Kaisey Marwa , Binesh Nader , Maya Marcel , Galvan Javier , Han Hui , Li Debiao , Solomon Andrew , Reich Daniel , Sicotte Nancy , Lowe Mark , Ontaneda Daniel , Al-Louzi Omar , Sati Pascal
Published: August 2024

The scan time of high-resolution T2*-weighted brain imaging using 3D echo-planar imaging (3D-EPI) can be significantly reduced by applying Controlled Aliasing In Parallel Imaging Results In Higher Acceleration (CAIPIRINHA). However, this comes at the expense of a significant reduction in image quality. In this study, we evaluated the feasibility of using a deep learning-based approach (DnCNN) to denoise highly accelerated 3D-EPI scans acquired at 3T. Our results show that DnCNN was able to efficiently denoise highly accelerated T2*-weighted brain scans while preserving anatomical and pathological details.
Enhanced-Deep-Super-Resolution Neural Network on Multiple MR Brain Images
Authors: Fiscone Cristiana , Curti Nico , Ceccarelli Matti , Manners David , Castellani Gastone , Tonon Caterina , Remondini Daniel , Lodi Raffaele , Testa Claudia
Published: August 2024

Enhanced Deep Super Resolution (EDSR) is a machine learning model aimed to improve image spatial resolution. It was previously trained with general purpose figures and, in this work, directly tested on different MR images: T1w, T2w and Quantitative Susceptibility Mapping (QSM), a quantitative imaging technique. The studied cohort included 28 healthy subjects. Without needing fine-tuning, EDSR shows excellent ability of generalization over new kind of data, improving imaging visualization and outperforming the traditional bicubic upsampling. In future applications, images of patients will be considered to test EDSR reconstruction when there is pathological tissue.
Improving SNR of high resolution multi-echo SWI using complex domain DL based denoising
Authors: C Florintina , Rajamani Sajith , Shankpal Preetham , Joel Suresh , Chatterjee Sudhanya , Patil Rohan , Venkatesan Ramesh , Sundaresan Raja , Agarwal Harsh
Published: August 2024

SWI is a high resolution MRI sequence, particularly sensitive to compounds which distort the local magnetic field making it useful in detecting blood products, calcium, etc. 3 and is used as part of brain MR imaging. The phase images are high pass filtered to remove the slow varying susceptibility changes and this is important to differentiate between para and diamagnetic substances. When this filtered phase image is used to accentuate the directly observed signal loss in the magnitude image, it is raised to a higher power and noise gets magnified as well, imparting undesirable effects in the SWI image.
Coil2Coil 3D: Improved self-supervised MR image denoising using phased-array coil images based on 3D structure information
Authors: Hong Rokgi , Park Juhyung , Lee Hayeon , An Hongjun , Lee Jongho
Published: August 2024

A deep-learning-based denoising method by extending Coil2Coil method based on 3D network was proposed. This method utilizes 3D information to conserve more tissue structure details. When tested for the synthetic noise-added images, the quantitative metrics were improved than using 2D network (PSNR: 46.57 ± 2.50 for 3D vs. 45.96 ± 2.47 for 2D). For the real-world noise, the proposed method also demonstrated qualitatively improved denoising than 2D case by conserving the structure details in MR images. Additionally, the quantitative mapping experiment for R2* showed the more accurate mapping results, suggesting improvement of the quantification by 3D denoising.
Multi-Shot M1-Nulled Pancreatic Diffusion Weighted Imaging with Deep Learning-Based Denoising
Authors: Wang Kang , Middione Matthew , Loening Andreas , Lan Patricia , Wang Xinzeng , Ennis Daniel , Brunsing Ryan
Published: August 2024

Multi-shot DWI (msDWI) may be improved by M1 motion-compensation, but at a penalty of longer TE and lower SNR. DL-based denoising has recently emerged as an option for DWI, which could help offset this TE penalty. Here we assess the impact of a commercially available DL-based denoising tool in the setting of motion-compensated msDWI.
Q-Dixon MRI and High-Speed T2-Corrected Multiecho MR Spectroscopy to Quantify Thigh Muscle Fat Content in Dialysis Patients
Authors: Zhang Wenshuang , Wang Ling , Yan Dong , Wu Yanglei , Yuan Yi , Cheng Xiaoguang
Published: August 2024

This study evaluated the correlation and consistency of proton density fat fraction (PDFF) measured by Q-Dixon magnetic resonance imaging (MRI) and high-speed T2-corrected multiecho (HISTO) magnetic resonance spectroscopy (MRS) for quantifying thigh muscle fat content in patients undergoing dialysis. Q-Dixon MRI exhibited good correlation and consistency with the HISTO MRS for thigh muscle fat quantitative measurements indicating that Q-Dixon MRI may be a reliable alternative to HISTO MRS in clinical assessment and radiological quantitative evaluation of thigh muscle fat infiltration.
1H-MRS human skeletal muscle quantification: a repeatability analysis
Authors: Amador Alejandro , Noseworthy Michael
Published: August 2024

1H-MRS of skeletal muscle presents challenges due to the highly structured arrangement of muscle fibres and their orientation to B0, complicating metabolite visibility and quantification. This study aimed to assess the repeatability of 1H-MRS in the anterior tibialis muscle in healthy volunteers by acquiring multiple spectra during and within different scanning sessions. A robust method for positioning of the voxel-of-interest was used to ensure reproducible acquisition. Data analysis was done using LCModel. Statistical analysis showed no significant difference in metabolite ratios against water across sessions, suggesting good repeatability of 1H-MRS of skeletal muscle.
Fat Free Muscle Area measurement based on clinical liver MRI workflow to assess sarcopenia
Authors: Shi Xin , Jiang Yueluan , Zhang Lei , Wang Jiping , Qiu Dongdong , Guo Shiyu
Published: August 2024

Fat free muscle area (FFMA) is an important measurement to evaluate sarcopenia and myosteatosis, and it is associated with poor prognosis in patients with chronic liver and oncologic diseases. FFMA was measured on T2WI-TSE sequence in previous study, which is not in routine MRI workflow, and the scanning time of T2WI-TSE sequence is obviously longer than T1WI edixon sequence, so we develop a method to measure FFMA by T1WI edixon sequence in clinical liver MRI sequence and explore a clinical friendly sarcopenia measurement.
Estimation of isotropic and anisotropic biomechanical properties of the lower leg muscle during muscle contraction using DTI and MR elastography
Authors: Majd Mahsa Salimi , Yang Yang , Tzschätzsch Heiko , Görner Steffen , Braun Jürgen , Sack Ingolf , Guo Jing
Published: August 2024

In this study, DTI and multifrequency MR elastography (MRE) were applied to 6 subjects to investigate the changes of fiber orientation and the biomechanical properties of the lower leg muscle during passive plantarflexion and dorsiflexion. Using the pentation angle estimated from DTI, MRE data were processed to obtain both isotropic shear wave speed (c) and anisotropic shear moduli (μ12, μ13) as well as Young’s modulus (E3). Preliminary findings showed significant changes of the biophysical properties upon lower leg muscle contraction.
Design of an improved Open-Face birdcage for human whole brain imaging at 5T
Authors: Wei Zidong , Chen Qiaoyan , He Qiang , Zhang Xiaoliang , Liu Xin , Zheng Hairong , Li Ye
Published: August 2024

The clinical experience, especially for subjects with claustrophobia, is not friendly when using the conventional shielded birdcage head coils on the ultra-high field. The closed structure also does not better support motion detection and motion correction, and other MRI functional applications. In this work, an optimized Open-Face birdcage head coil were designed based on EM simulations. The transmit efficiency, B1 uniformity, and SAR efficiency of the facial open-window birdcage coil with different configurations and a conventional shielded birdcage coil are compared. Finally, an optimized Open-Face birdcage head coil was built and evaluated on a whole body 5T MRI scanner.
A 48-channel head and neck neurovascular coil for MR vessel wall imaging at 5 T
Authors: Tan Yingchao , Chen Qiaoyan , Xu Guangzu , Zhang Lei , Zhang Na , Zhang Xiaoliang , Liu Xin , Zheng Hairong , Li Ye
Published: August 2024

Ultra-high field magnetic resonance imaging (MRI) has been increasing in use for human brain imaging. However, due to the absence of a head and neck neurovascular coil, joint imaging of intracranial and extracranial arterial vessel wall has not been applied in current ultra-high field MRI. In this study, a 48-channel head and neck receiver neurovascular coil for joint imaging of intracranial and extracranial arterial vessel wall at 5T was developed. Simultaneous high-resolution imaging of intracranial and extracranial arterial walls with an isotropic spatial resolution of 0.5 mm has been achieved, which further expands the application of ultra-high field imaging.
Predictive Value of Intrapixel Incoherent motion (IVIM) Imaging For Prognostic Factors in Breast Cancer
Authors: Fu Jian-mei , Chen Jing , Dai Gui-dong , Wu Yun-zhu
Published: August 2024

The objective of this study was to estimate the true diffusion and motion of molecules in the capillary network using the VIM biexponential model without injection of contrast media, three parameters (d value, d * value and F value) were obtained to evaluate the expression of prognostic molecules (ER, PR, Her-2, Ki-67) in breast cancer, which can guide the treatment of breast cancer more precisely.
Passive shielding design for ultra-high field MRI superconducting magnets using an integral operation with nonlinear iteration
Authors: Wang Yaohui , Wang Qiuliang , Yan Ming , Wang Weimin , Chen Zhifeng , Liu Feng
Published: August 2024

Passive shielding is a feasible approach to constrain the strong magnetic fluxes in ultrahigh field MRI superconducting magnets. However, an in-depth investigation of the passive shielding design is not well discussed in the literature and notably lacks nonlinear optimization design/analysis methods for this practice. This work developed a computation algorithm for passive shielding design, which uses an integral operation with nonlinear iteration. An exemplification for shielding a 9.4T whole-body MRI superconducting magnet showed the significant advantages of the proposed method over commercial packages. The optimized passive shielding scheme will be used in our future magnet engineering projects.
Towards high sensitivity 13C MRS of Human Brain Glycogen at 7T
Authors: Roig Eulalia Serés
Published: August 2024

Largely neglected due to its low concentration, yet brain glycogen plays an active role in brain energy metabolism and may be involved in a variety of brain diseases. The application of 13C MRS along with 13C-glucose intravenous infusion is to date the forefront method for investigating brain glycogen metabolism in vivo. Notably, the C1-resonances of glycogen and glucose have been detected non-invasively in the conscious human brain by 13C MRS at 4T after 13C-glucose infusion labelled at the C1-carbon. In this study, we explore the potential of 13C MRS at 7T with broadband 1H-decoupling towards measuring glycogen and glucose C1-resonances.
FAIR Benchmarking of 7T MRI Antennas – Case for a Standardized Protocol for RF Transmit Element Performance Assessment
Authors: Hubmann Max Joris , Nurzed Bilguun , Niendorf Thoralf , Speck Oliver , Maune Holger
Published: August 2024

This abstract proposes a standardized setup and four standardized metrics to increase 7T Tx RF antenna concept comparability and reproducibility, with the goal of a better technology transfer of antenna concepts across the MR community. Eight antenna concepts are evaluated based on power and SAR efficiency as well as mutual coupling and reliance on load changes using a rectangular phantom mimicking the average electromagnetic body properties. Based on the presented results, much information can be collected and deductions about each antenna's preferable ambits drawn. In conclusion, this work initiates a first standardized protocol for analyzing Tx RF antenna concepts.
Quasi-Static and Time-Generalized Field Computation Methods Compared to the Moment Method for Performance Evaluations of Coil Arrays in PI at UHF
Authors: Mahmutovic Mirsad , Hansen Sam-Luca JD , Shrestha Manisha , Keil Boris
Published: August 2024

In this study, we compared the quasi-static method (QSM), the time-generalized method (TGM), and the method of moments (MoM) for performance evaluations of coil arrays in parallel imaging (PI) at UHF. We have shown that the QSM and the TGM are a good approximation to the MoM solution, and that all three methods perform similarly in a comparative study with a 64-channel head coil. Furthermore, we could show, that the TGM performs better than the QSM at larger distances in the phantom, which may be beneficial for the evaluation of torso coils.
8kw non-magnetic RF power amplifier with four-way combiner for 5T MRI
Authors: Wang Jiasheng , Liu Shengping , Chen Jifeng , Rong Xinwei , Zhang Xiaoliang , Li Ye
Published: August 2024

Ultra-high-field magnetic resonance requires higher power capability and transmission efficiency. An 8 kW non-magnetic RF power amplifier with four-way combiner for 5T MRI is presented. The whole module adopts non-magnetization design to improve transmission efficiency, and the power of four MOSFETs is combined by a combiner with adjustable balance to meet the output power of 8 kW.
In-bore Reclinable Array for Pediatric Spine Imaging
Authors: Matta Charbel , Popović Milica , Farivar Reza
Published: August 2024

We constructed and tested a reclinable MR compatible chair equipped with an 8-channel spine array coil for 3T. The coil used a combination of overlap and transformer decoupling to maximize spatial resolution without modifying individual coil size. The signal to noise ratio and noise correlation matrices were used to compare the performance of the array to a 32-channel commercial array of the same type. The SNR variations were tested with respect to the inclination of the chair.
A 3T Coil Array for Improved Quantitative Susceptibility Mapping at Multiple Orientations in ex vivo Primate Brains
Authors: Chemlali Chaimaa , Gkotsoulias Dimitrios G. , Scholz Alina , Hansen Sam-Luca , Schlumm Torsten , Müller Roland , Jäger Carsten , Möller Harald E. , Keil Boris
Published: August 2024

Quantitative susceptibility mapping (QSM) with multiple object orientations is typically limited by an appropriate examination time that is appropriate for human subjects and the small range of possible rotation angles within an MRI head coil. Ex vivo QSM can overcome these limitations supporting long acquisition times and the ability to rotate the ex vivo specimen to any position. Therefore, a 3T 26-channel ex-vivo brain array coil was developed for fixed chimpanzee brains. The coil was characterized with bench and image metrics and provides increased reception sensitivity, making it well-suited for high-resolution QSM ex vivo MRI studies.
A Strategy of Whole Blood Metabolomics Based on Magnetic Resonance Spectroscopy by Mixing Blood with Silica Powder
Authors: Cheng Leo , Wang Xiaoyu , Liu Zehan , Duffy Jessica , Louissaint Abner , Takis Panteleimon
Published: August 2024

Currently, blood metabolomics analysis has to choose between serum and plasma: the former leaves blood in room temperature and therefore causing metabolic alterations; and the latter has interfering chemicals added during acquisition of samples, which make results complicated. Here, using HRMAS MRS, we studied gel samples of whole mouse blood by mixing them with silica powder. The obtained spectra agreed, in general, with the correlating serum samples, which proved the robustness of this method. Taking advantage of tiny amounts of samples (μl) and simple and rapid pretreatment, our new technique demonstrates a novel approach to metabolomic analysis and clinical applications.
Magnetic Resonance Lymphangiography Manifestations and Applications in Secondary Lymphoedema
Authors: Zhang Minge , Xie Jichen , Huang Jinbiao , Chen Yan , Wang Jingjing , Yi Liqi , Zheng Youmao , Gu Shilin , Tang Runyu , Zhang Yunfei , Dai Yongming , Yang Hai
Published: August 2024

Surgical intervention should be considered when extremity lymphedema reached clinical stage II, and the identification of lymphatic vessels from nearby veins is critical for surgery planning. In this study, we reviewed the MRL examinations of patients with secondary lymphedema. The results showed that MRL could be used to characterize the secondary lymphedema pre-operatively, and predefine treatment planning for patients who suffer secondary lymphedema.
The findings of clinical and imaging features of common ovarian sex cord stromal tumors with both Ultrasound and MRI
Authors: Meiying Cheng , Shifang Tan , Lingjie Zhang , Tian Ren , Chunxiang Zhang , Kaiyu Wang , Haiyang Li , Honglei Shang , Hui Chang , Zhexuan Yang , Jing Cao , Xin Zhao
Published: August 2024

Most of ovarian sex cord stromal tumors (OSCSTs) are benign with good prognosis, but low-grade malignant OSCSTs need special treatment. Correct preoperative diagnoses and accurate classification remain challenging. We retrospectively analyze the clinical and imaging characteristics of OSCSTs and found significant biomarkers such as maximum enhancement ratio (ERmax) and apparent diffusion coefficient (ADC) for the preoperative diagnosis and classification of common OSCSTs. It’s more helpful for preoperative diagnosis by combining of MRI and ultrasound together than by ultrasound alone, and MRI has the similar diagnostic accuracy as the combination.
The value of MR perfusion and diffusion combined with tumor marker analysis in differentiating benign and malignant ovarian tumors
Authors: Bai Jinsong , Zhang Haitao , wang shaoyu
Published: August 2024

The aim of our study was to compare the differential diagnostic efficacy of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI), apparent diffusion coefficient (ADC), serum carbohydrate antigen 125 (CA125), human epididymal secretory protein 4 (HE4) and their combined application in benign and malignant ovarian tumors, and to explore the best method for the diagnosis of ovarian tumors.
The Effect of Resolution and Voxel Size on SNR for Cardiac Diffusion Tensor Imaging
Authors: Hannum Ariel , Cork Tyler , Setsompop Kawin , Ennis Daniel
Published: August 2024

The purpose of this work is to characterize how SNR varies with slice thickness for a given in-plane resolution for cDTI. We observed that noise in cDTI is largely physiological dominated such that increasing voxel volume yields smaller gains in SNR than what is observed in a phantom. More specifically, increased slice thickness did not significantly improve cDTI metric maps for a given in-plane resolution. However, higher in-plane resolution improved MD and FA maps. Therefore, future work will evaluate the optimal in-plane resolution and slice thickness.
Semi-Automated Rejection of Corrupted Images in Cardiac Diffusion Tensor Imaging
Authors: Coveney Sam , Kelly Chris , Teh Irvin , Afzali Maryam , Mueller Lars , Das Arka , Szczepankiewicz Filip , Jones Derek , Dall’Armellina Erica , Schneider Jurgen
Published: August 2024

Cardiac Diffusion Tensor Imaging (cDTI) is prone to imaging artefacts including distortion, signal dropout, and misregistration even after post-processing. We developed a method for image rejection based on a comparison between the observed images and the corresponding set of predicted images generated by tensor models fit to the observed data. A rejection threshold to exclude images from subsequent refitting of the tensor model can be chosen by the user with a simple graphical method.
Evaluating the myocardial fibre pattern in the equine heart using DTI: Protocol development for very a large ex-vivo sample
Authors: Kershaw Lucy , Jago Rachel , Reed Jenny , Keen John
Published: August 2024

We aim to develop a protocol suitable for ex-vivo DTI of the equine heart. DTI on a large sample is challenging because this is already a low SNR technique. The main requirement for good-quality data in a formalin-fixed heart is to reduce TE as much as possible. The protocol recommendations presented here are largely common sense, but the long acquisitions required make troubleshooting extremely time consuming. We thought it important to share these findings for the benefit of other investigators
The effect of inter-individual differences and number of fiber directions on possible orientation dependence of myelin water imaging
Authors: Joseph Tigris , Morris Sarah , Kolind Shannon , MacKay Alex , Vavasour Irene , Laule Cornelia
Published: August 2024

Previous work suggests myelin water fraction (MWF) may be fibre orientation dependent. We compared MWF to fiber angle (from diffusion tensor imaging (DTI)) in white matter (WM) from 16 healthy participants using BedpostX to estimate the number of fiber directions. MWF vs. fiber angle graphs showed trends which varied between participants, suggesting that real myelination differences may be at least partly responsible for apparent orientation dependence of MWF. There were little obvious differences between trends with 1, 2, or 3+ fiber orientations in WM, suggesting number of fibers directions within a voxel does not impact orientation dependence.
Parameter inference using continuous change in degenerate biophysical diffusion models
Authors: Kor Daniel , Rafipoor Hossein , Cottaar Michiel , Jbabdi Saad , Miller Karla , Howard Amy
Published: August 2024

Biophysical modelling of diffusion MRI (dMRI) may elucidate key microstructural features. However, most models include many input parameters, making simultaneous estimations of all parameters ill-posed. To overcome this, the recently published Bayesian framework EstimatioN for CHange (BENCH) characterises changes (variation) in parameters across multiple measurements/samples, rather than inferring the actual parameters from a single measurement/sample. BENCH has been previously applied to understand group-wise changes (e.g., patients vs. controls) in biophysical parameters. Here, we adapted BENCH to interpret situations of continuous change and validate its behaviour using synthetic dMRI data from numerical simulations.
Diffusion MRI with spherical tensor encoding at high b-values reveals cerebellar grey matter abnormalities in movement disorders
Authors: Tax Chantal , Genc Sila , MacIver Claire , Nilsson Markus , Wardle Mark , Szczepankiewicz Filip , Jones Derek , Peall Kathryn
Published: August 2024

Most work on understanding movement disorder pathophysiology has focused on grey/white matter volumetric (macrostructural) and white matter microstructural effects, limiting understanding of frequently implicated grey matter microstructural differences. Using ultra-strong diffusion MRI with spherical tensor encoding, a persistent MRI signal was seen in healthy cerebellar grey matter at ultra-high diffusion-weightings. This work quantifies the proportion of this signal, previously ascertained to originate from small spherical spaces, in a clinical cohort, including patients with diagnosed movement disorders where the cerebellum has been implicated in symptom pathophysiology. Significant differences were found in individuals diagnosed with SCA6 and dystonia compared to age-matched controls.
Evolution of Microstructural Changes in a Mouse Model of Mild Traumatic Brain Injury
Authors: Rahman Naila , Xu Kathy , Budde Matthew , Brown Arthur , Baron Corey
Published: August 2024

Single mild concussive impacts remain sparsely explored by in vivo neuroimaging techniques. Multimodal microstructural MRI has shown increased sensitivity and specificity to microstructural changes in various disease and injury models. In this work, we apply oscillating gradient spin-echo (OGSE) diffusion MRI, microscopic anisotropy (µA) diffusion MRI, and magnetization transfer (MT) MRI longitudinally to increase sensitivity to smaller spatial scales, disentangle fiber orientation dispersion from true microstructural changes, and acquire myelin sensitivity, respectively. We demonstrate that multimodal microstructural MRI provides sensitivity to evolving changes following a mild impact in both acute and chronic regimes, with OGSE demonstrating higher sensitivity than µA.
Bias Correction for Improved Quantification of Hyperpolarized [1-13C]Pyruvate Cerebral Perfusion
Authors: Hu Jasmine , Vaziri Sana , Bøgh Nikolaj , Kim Yaewon , Autry Adam , Bok Robert , Li Yan , Laustsen Christoffer , Larson Peder , Xu Duan , Vigneron Daniel , Gordon Jeremy
Published: August 2024

Bias correction of hyperpolarized [1-13C]pyruvate brain MRI allows for improved quantification of cerebral perfusion. In the healthy volunteers studied, bias corrected pyruvate and ASL rCBF exhibited higher correlation than uncorrected pyruvate and ASL rCBF. We hypothesize that N4ITK bias correction can be used to remove low frequency inhomogeneities from hyperpolarized MRI before single-metabolite analyses.
Assessment of Cardiac TCA Cycle Activity with Hyperpolarized [1-13C]Acetyl-L-Carnitine
Authors: Chen Jun , Singh Tamara , Nemri Sarah , Billingsley Kelvin , Park Jae Mo
Published: August 2024

Hyperpolarized [1-13C]acetyl-L-carnitine was developed as a probe to investigate cardiac TCA cycle activity in vivo. [5-13C]Glutamate, which is produced via TCA cycle intermediate a-ketoglutarate, was successfully observed in rat heart under both fasting and fed conditions. Importantly, although pyruvate dehydrogenase activity is decreased in the fasted state, [5-13C]glutamate remained observable at appreciable levels, suggesting that [1-13C]acetyl-L-carnitine provides complementary information relative to standard assessments of pyruvate oxidation with hyperpolarized [1-13C]pyruvate. In turn, this novel probe may facilitate comprehensive metabolic analyses of acetyl-CoA uptake by the TCA cycle for various cardiac applications.
Effects of Gadolinium on the Dynamic Nuclear Polarization of [15N3] Metronidazole
Authors: Bedoya David Guarin , Joshi Sameer , Samoilenko Anna , Kabir Mohammad , Takahashi Atsushi , Ardenkjaer-Larsen Jan , Chekmenev Eduard , Yen Yi-Fen
Published: August 2024

In this work, we studied the dynamic nuclear polarization (DNP) process of [15N3]metronidazole (MNZ), an FDA-approved antibiotic that achieved good polarization (~6%) with very short polarization build-up time constants (~12min). We used Electron Paramagnetic Resonance (EPR) spectroscopy to show that a sample of [15N3]MNZ + trityl AH111501 had narrower EPR linewidth and larger magnitude than AH111501 alone, indicating an efficient polarization transfer from the radical electrons to 15N and supporting our observations of fast DNP buildup. We also demonstrated that an addition of gadolinium-based compound to the [15N3]MNZ +AH111501 sample broadened the EPR spectrum and prolonged DNP buildup as observed.
Quantitative Evaluation of kPL Dependence on Pyruvate Concentration in Anaplastic Thyroid Cancer Cell Suspensions using Hyperpolarized 13C NMR
Authors: Harlan Collin , Chen Yunyun , Martinez Gary , Sandulache Vlad , Lai Stephen , Bankson James
Published: August 2024

Metabolic imaging of hyperpolarized pyruvate can provide new insight into tumor progression and response to therapy. Pharmacokinetic modeling can be used to determine kPL, the apparent rate constant for conversion of hyperpolarized pyruvate into lactate. In this work, we sought to characterize the effect of hyperpolarized pyruvate concentration on intracellular kPL in ATC cell suspensions using a two-compartment pharmacokinetic model for kPL quantification. Improved understanding of the effects of concentration on intracellular chemical conversion rates could lead to more accurate quantification of in vivo and clinical hyperpolarized MRI imaging biomarkers of metabolism.
GRAPPA-Accelerated Flyback EPI with Controlled Aliasing for Hyperpolarized Pyruvate
Authors: Hachem Enya , Li Sung-Han , Huynh Mai , Ma Junjie , Park Jae Mo
Published: August 2024

In this study, we introduced the parallel imaging technique GRAPPA to the flyback EPI with controlled aliasing in order to accelerate the acquisition time while simultaneously reducing artifacts. The GRAPPA-accelerated flyback EPI was characterized using MR phantoms with varying SNR and acceleration factor (R) and the feasibility of simultaneous bicarbonate and lactate imaging with the proposed scheme was also demonstrated. The proposed acquisition method has potential advantages for in vivo studies with hyperpolarized substrates by shortening acquisition time, improving spatial resolution, and increasing effective flip angles.
Spatial-Adaptive Deep Learning Model and Magnetic Resonance Fingerprinting for Segmentation and Quantitative Evaluation of Cervical Cancer
Authors: Kalantar Reza , Winfield Jessica , Rata Mihaela , Lin Gigin , Lalondrelle Susan , Messiou Christina , Blackledge Matthew , Koh Dow-Mu
Published: August 2024

Quantitative magnetic resonance imaging (qMRI) can provide additional information for diagnosis and response assessment, but adoption of multi-parametric qMRI techniques has been hindered by long acquisition times and labor-intensive processing steps. Magnetic resonance fingerprinting (MRF) provides quantitative maps in a single acquisition but MRF deployment in clinical studies still requires manual delineation of volumes of interest. A spatial-adaptive deep learning framework was developed to segment cervical cancer on MRI and quantify T1 relaxation times of the tumor pre- and post-radiotherapy treatment. Our results suggest that automated segmentation models may be promising tools for quantitative tumor evaluation and treatment response assessment.
3D segmentation of MRI images of leg muscles using Convolutional Neural Networks
Authors: Schlaffke Lara , Doliwa Niklas , Markmann Marius , Rohm Marlena , Rehmann Robert , Froeling Martijn
Published: August 2024

Quantitative magnetic resonance imaging offers promising surrogate biomarkers for the early diagnosis and monitoring of pathological changes in leg muscles in patients with neuromuscular disorders. To use this in a clinical routine, automatic segmentation of muscles is needed. To investigate precision and accuracy of various Computational neuronal networks for automated segmentation of upper leg muscles, different loss function were used and quantitative outcome compared to the gold-standard of manual segmentation. The best segmentation results were achieved, with the Fokal Tversky loss function and a single input approach.
Accelerated cardiac cine imaging using deep learning: impact on left ventricular function and AI segmentation model
Authors: Liu Wenyun , Wong Chinting , Li Cheng , Yu Di , Zhu Yi , Jiang Ke , Zhang Huimao
Published: August 2024

Cardiac MRI is considered reference standard for the noninvasive assessment of ventricular volumes and function. However, long multibreath-hold acquisition time can prove difficult in patients and lead to poor image quality. In this study, we investigated the use of a deep learning-based reconstruction algorithm, named Compressed SENSE Artificial Intelligence(CS-AI), to accelerate two-dimensional cine bSSFP for cardiac MRI. The purpose of this study was to compare the image quality and performance of a CS-AI-based cine sequence between reference and accelerated methods: SENSE, Compressed-SENSE, and CS-AI, and then to investigate the impact of images reconstructed by deep learning on AI segmentation model.
A single-sided NMR approach to study structural differences of the articular cartilage tissue
Authors: Golini Carlo , Testa Claudia , Nagmutdinova Anastasiia , Bortolotti Villiam , Brizi Leonardo
Published: August 2024

In the last decade, few preliminary low-field relaxometry studies were conducted on the articular cartilage using the single-sided NMR-MOUSE device that can be useful for osteoarthritis characterization. This study aims to develop a procedure capable of quantitatively evaluating the structure of the three cartilage layers. Forty osteochondral cylindrical bovine knee specimens were analyzed obtaining four NMR parameters T1, T2, D, and α (extracted from a Double-Quantum-like sequence for solid/liquid estimation) for each cartilage layer. Significant discrimination of the three layers was found by all the parameters, making the NMR dataset sensitive to structural differences and changes due to cartilage diseases.
Deep-learning based fast spin echo magnetic resonance imaging improved clarity of nasal cartilage
Authors: Gao yufan , zha yunfei , Liu Weiyin
Published: August 2024

In this study, a comparative study of the original images (T1WI, T2WI) and ARDL images based on deep learning reconstruction (T1WI-DL, T2WI-DL) was conducted for magnetic resonance imaging of nasal cartilage. We aim to evaluate the feasibility and performance of a novel deep learning based MRI reconstruction method to show the structures of nasal cartilage, especially lower lateral cartilage. The results showed that applying ARDL to nasal cartilage MRI showed significant improvement in both SNR and CNR. we conclusion that the DL-based reconstruction algorithm was feasible to be applied to nasal cartilage MRI and improve the image quality.
Automated Principal Component Analysis of cartilage thickness, T2 times and bone shape as interpretable model for osteoarthritis progression
Authors: Gassert Felix , Hoyer Gabrielle , Lee Jenny , Gao Kenneth , Tolpadi Aniket , Pedoia Valentina , Majumdar Sharmila
Published: August 2024

In this study we used fully automatic segmentations of the bones and the cartilage of the knee to perform a principal component analysis of cartilage thickness, T2-relaxation times and bone shapes in the Osteoarthritis Initiative Dataset. We extracted and visualized the principal components which significantly contributed to a model for prediction of osteoarthritis progression to (i) show that besides mean values of these parameters also their distribution is crucial for osteoarthritis progression and (ii) prove the feasibility of visual interpretation of these components for better understanding factors associated with the disease.
Relaxation Anisotropy Mapping of Articular Cartilage at 3 T
Authors: Kantola Ville , Karjalainen Jouni , Casula Victor , Nissi Mikko , Nieminen Miika
Published: August 2024

The study of T2 and T1ρ anisotropy in musculoskeletal tissues, arising from the orientation of collagen fibrils in tissue, has so far been limited to experimental MRI systems. Here we present a method for measuring relaxation anisotropy ex vivo on a clinical MRI system. Furthermore, we aimed to quantify and compare the degrees of orientation dependence in bovine articular cartilage through anisotropy mapping. T2 and T1ρ mapping was performed on bovine stifle joint samples at multiple sample orientations. After coregistration anisotropy maps were created using Michelson contrast. The results showed large variations in anisotropy across cartilage thickness and topographical locations.
Assessment of articular cartilage in response to an impact injury using µMRI
Authors: Singh Amanveer , Mantebea Hannah , Badar Farid , Batool Syeda , Abdelmessih Gabrielle , Sebastian Talia , Newton Michael , Xia Yang
Published: August 2024

This project aimed to study the properties of articular cartilage in response to mechanical injury in rabbit knees using μMRI. Femoral cartilage bone plugs were excised 2 and 14 weeks after impact and imaged using μMRI at a resolution of 11.7 μm/pixel. Higher T2 relaxation values in affected specimens illustrated deterioration in the cartilage after impact. Furthermore, the higher T2 values in impacted samples of the 14-week batch compared to the 2-week batch indicate progressive cartilage degradation over time.
Isotropic 3D MRI determined labral tear extent correlates with hyaline cartilage loss in hip dysplasia patients
Authors: Xia Shuda , Chhabra Avneesh , Sharan Gaurav , Thakur Uma , Archer Holden , Xi Yin , Wells Joel
Published: August 2024

This study is a novel investigation into the clinical correlations between parameters measured through 3D MRI and outcomes for patients with hip dysplasia (HD). Although there were no statistically significant correlations seen between labral tear length and PROMs (p>0.05), a few non-significant correlation trends were observed. Furthermore, labral tear lengths directly positively correlated with worsening cartilage damage, the presence of subchondral bone cysts, para-labral cysts, and the number of labral tears seen.
Self-activatable photodynamic-immunotherapy based on poly(thioketal) conjugated with photosensitizers
Authors: Nianhua Wang , wang Yao , Xinqing Jiang
Published: August 2024

Photodynamic therapy is a non-invasive and controllable modality with potential as a novel cancer treatment strategy. However, the ROS production efficiency of PDT is restricted to hydrophobic characteristics and aggregation caused quenching of PSs. Herein, we designed a ROS self-activatable polymer (PTKPa) to suppress photosensitizers ACQ and elevate ROS production capacity. This platform shows therapeutic outcomes in both cells and orthotopic mouse model, which can significantly elevate the intracellular ROS level upon 660nm laser irradiation, induce immunogenic cell death (ICD) to activate antitumor immunity. This work provides a general strategy enhancing tumor photodynamic therapeutic effects.
Comparison of the Optimization of a 60-channel Transmit Coil in pTx and sTx mode at 7T
Authors: Sajewski Andrea , Santini Tales , Martins Tiago , Berardinelli Jacob , Ibrahim Tamer
Published: August 2024

The recently developed 60-channel Tic-Tac-Toe transmit coil was analyzed for use in either single or parallel transmit systems at 7T. With the 60-channel TTT coil, excellent homogeneity can be achieved and safe levels of SAR can be provided regardless of which system (sTx or pTx) is used.
Static and dynamic parallel transmission (pTx) for human cardiac MRI at 21.0 T
Authors: Nurzed Bilguun , Hieronymi Dennis , Eigentler Thomas , Aigner Christoph , Schmitter Sebastian , Niendorf Thoralf
Published: August 2024

Transmission field inhomogeneities at ultrahigh and extreme field MRI can be offset using static or dynamic pTx. Responding to the challenges and recognizing the opportunities of cardiac MRI, this abstract examines the feasibility of parallel transmission (pTx) using self-grounded bow-tie (SGBT) RF array configurations for static and dynamic B1+ homogenization of the heart at 21.0T. Our results demonstrate that static pTx provides limited performance at 21.0 T, but dynamic pTx enables uniform heart excitation at 21.0T
Accelerated Volumetric Multi-Channel pTx B1+ Mapping at 7T for the Brain and Heart
Authors: Kent James , Valkovič Ladislav , Dragonu Iulius , Chiew Mark , Hess Aaron
Published: August 2024

Ultra-high field MRI with parallel transmit offers significant advantages but B1+ maps are required to utilize its potential. Acquiring B1+ maps for each channel is time-consuming and limits the application of ultra-high field in clinical practice. In this abstract we present an approach to acquire full 3D multi-channel B1+ maps in 11 seconds. We do this by employing a time-interleaved acquisition of modes strategy using undersampled relative maps and two fast undersampled Sandwich B1+ maps all reconstructed using TxLR, a calibrationless reconstruction for transmit field maps. We demonstrate this approach with simulations and scans in phantom and in the brain.
A Fully Automated Hybrid Approach to Assessing Liver Fibrosis and Necroinflammation on Conventional MRI:A Multi-center Study
Authors: Zha Junhao , Song Yang , Ju Shenghong
Published: August 2024

To our knowledge, this is the first study developing a multi-task hybrid models incorperating conventional MR tissue texture and routine clinical biomarkers with both good accuracy and explainability in detecting fibrosis and necroinflammation. Our study used an interactive deep learning approach to automatedly segment the entire volumetric liver contours more effectively. Our CoRC models outperformed routine clinical fibrotic scores (FIB-4, APRI), and TE-LSM by discrimination, calibration in the large multicenter cohorts. Our CoRC models could be as a potential alternative when biopsy, hepatobiliary phase (HBP) images, liver stiffness measurement (LSM) are unavailable.