bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of deep learning-based reconstruction for qualitative and quantitative DW-MRI in head and neck cancers
Authors: Paudyal Ramesh , Shah Akash , Konar Amaresha , Shin Jaemin , LoCastro Eve , Bagchi Nisha , Fung Maggie , Banerjee Suchandrima , Lee Nancy , Shukla-Dave Amita
Published: August 2024

The head and neck (HN) region have complex anatomical structures that affect the image quality of diffusion-weighted MRI. Therefore deep learning (DL)-based Reconstruction (Recon) for DW-MRI could be a promising method that can help improve image sharpness and signal-to-noise ratio (SNR) without increasing signal averaging. The present study aimed to evaluate the performance of qualitative and quantitative multiple b-value DW-MRI powered by DL-based Recon for tumors in the HN region. The DL-based recon method improved the DW image quality and SNR compared to those without DL recon.
Implicit CINE: a deep-learning super-resolution model for multi-planar real-time MRI
Authors: Vogt Nora , Isaieva Karyna , Louis Jean-Sébastien , Weihsbach Christian , Heinrich Mattias , Odille Freddy , Vuissoz Pierre-André , Felblinger Jacques , Oster Julien
Published: August 2024

Cardiac CINE MRI plays an essential role in cardiac diagnosis, but not all patients are eligible for 3D imaging, which is associated with long acquisition times. We propose a deep-learning super-resolution model to generate 3D CINE from multi-planar 2D real-time MRI using external signals for cardiac and respiratory motion estimation. The proposed neural field model is trained on a single subject and performs non-rigid motion compensation and implicit representation learning in an end-to-end manner. A preliminary study with three healthy volunteers demonstrates promising reconstruction performance and computation times compared to traditional registration-based approaches.
Reconstruction of accelerated MR cholangiopancreatography using supervised and self-supervised 3D Variational Networks
Authors: Kleineisel Jonas , Petritsch Bernhard , Bley Thorsten , Köstler Herbert , Wech Tobias
Published: August 2024

Magnetic resonance cholangiopancreatography suffers from long examination times and artifacts originating from residual motion. To shorten the acquisition protocol, we acquired data at 12-fold undersampling and investigated a 3D Variational Network (VN) architecture for reconstruction. We compared a self-supervised training scheme and a supervised network trained on synthetic data. We find that the self-supervised method is only able to provide competitive reconstructions if the network is initialized with pre-trained weights, and even then does not offer superior performance over the supervised approach. For the presented exemplary data, the supervised VN showed comparable image quality as a reference Compressed Sensing model.
Deep learning-based Motion-corrected Rapid Image Reconstruction for High-resolution Cartesian First-pass Myocardial Perfusion Imaging at 3 T
Authors: Wang Junyu , Salerno Michael
Published: August 2024

Keywords: artificial intelligence, image reconstruction, perfusion Cardiac magnetic resonance first-pass contrast-enhanced myocardial perfusion imaging is valuable for evaluating coronary artery disease1. 2D Cartesian perfusion imaging using compressed sensing (CS)-based reconstructions such as L1-SENSE2 enables fast and high-resolution imaging, but whole-heart coverage cannot be achieved without simultaneous multi-slice (SMS) acquisitions and the CS-based iterative reconstruction takes ~30 minutes per slice. To address this, we have developed a deep learning-based motion-corrected rapid image reconstruction for high-resolution Cartesian perfusion imaging at 3 Tesla, for both 2D and SMS MB=2 acquisitions, which provides fast and high-quality motion-corrected reconstruction and makes rapid online reconstruction feasible.
High impedance quadrature receivers array for magnetic resonance skin imaging at 7T
Authors: Payne Komlan , Bhosale Aditya , Zhao Yunkun , Zhang Xiaoliang
Published: August 2024

The study of skin diseases is by far among the difficult research in biomedical field. Nowadays, many techniques are available to perform skin examination. Magnetic Resonance Imaging (MRI), a non-invasive technique can provide detailed image of the skin. For such procedure, a whole-body coil can be used as the transmitter while receivers array coils are placed in close proximity of the region of interest. In this abstract we design an array of high impedance quadrature detectors with good decoupling performance for skin image at 7T.
Transceiver 8Tx/32Rx array with L-shaped loop elements for accelerated cardiac MRI at 7T: initial optimization and experimental testing.
Authors: Terekhov Maxim , Elabyad Ibrahim , Lohr David , Frey Anna , Schnitter Florian , Schreiber Laura
Published: August 2024

The concept of the L-shaped loop elements architecture with the antisymmetric arrangement was applied to develop a 8Tx/32Rx transceiver array for cardiac MRI at 7T. This work aimed to check B1+ shimming and parallel imaging capabilities of the array and to perform the initial testing in human thorax phantom and pig cadaver. Both phase-only and pTX optimization modes demonstrated the possibility for efficient shaping of B1+ with an optimized spatial homogeneity. Despite the sub-optimal geometry of the pig thorax, the array demonstrated a good B1+ coverage of the heart region with no apparent destructive interferences.
Performance comparisons of different single-channel coils using different materials
Authors: Song Chunhu , Chen Qiaoyan , Che Shao , Wang Haining , Zhang Xiaoliang , Li Ye
Published: August 2024

The ultra-flexible RF coil can fit the image subjects well and thus improve signal-to-noise ratio (SNR). In this study, four types of single-channel receiver coils using different materials with the same size were constructed. Phantom studies were performed on a 3T MRI system. As a result, the liquid metal coil can achieve a most similar performance as the conventional copper coil, while the liquid metal coil is more flexible. This demonstrates that the liquid metal coil has a good application potential in imaging curved anatomical structures.
Estimating noise figure of matching networks for low-input-impedance preamplifiers
Authors: Wang Wenjun , Heredia Juan Sánchez , Zhurbenko Vitaliy , Larsen Jan Ardenkjær
Published: August 2024

The noise figure of a matching network between a receive coil and a preamplifier with low input impedance can be estimated using relationship \(F\approx1+R_{11}/R_\mathrm{c}\). It is demonstrated how to use this relationship to choose optimal matching-decoupling network topology in terms of signal-to-noise ratio (SNR). The formula serves as an efficient tool to estimate noise figure of matching networks and is useful in low-field and high-coil-Q applications, where the noise of the matching network becomes comparable to coil noise.
Boosting Central Head SNR at 10.5T: 32-channel Hybrid RF Coil Comprised of 25 Rx-only Loops and 7 TxRx NODES Dipoles
Authors: Sadeghi-Tarakameh Alireza , Waks Matt , Grant Andrea , Thotland Jeromy , Lagore Russell , DelaBarre Lance , Auerbach Edward , Van de Moortele Pierre‐Francois , Adriany Gregor , Ugurbil Kamil , Eryaman Yigitcan
Published: August 2024

Higher signal-to-noise ratio (SNR) is the primary maxim for increasing the magnetic field strength of MRI scanners. However, RF coils comprised of loops do not capture the highest achievable SNR that is theoretically available at ultrahigh field (defined as ≥7T) MRI. In this study, we investigate the hypothesis of increasing central head SNR at 10.5T by combining loop and dipole receiver elements. For this purpose, we manufactured a 32-channel hybrid RF coil comprised of 25 receive-only loops and 7 transceiver NODES dipoles. This 32ch hybrid coil achieved ~80% higher central SNR compared to a 32ch loop array.
Longitudinal simultaneous fMRI and mesoscale calcium imaging in a mouse model of Alzheimer’s disease
Authors: Mandino Francesca , Shen Xilin , Desrosiers-Gregoire Gabriel , O'Connor David , Mukherjee Bandhan , DeLuca Kristin , Hamodi Ali , Owens Ashley , Ha Yonghyun , Qu An , Onofrey John , Papademetris Xenophon , Chakravarty Mallar , Crair Michael , Strittmatter Stephen , Lake Evelyn
Published: August 2024

Multimodal neuroimaging plays an active role in understanding clinically accessible biomarkers of health and disease. Using simultaneous mesoscopic calcium imaging and BOLD-fMRI, we examine spontaneous activity in a GCaMP-positive mouse model of Alzheimer’s disease (AD)—longitudinally—at 4, 6, and 9 months. We find that both imaging modalities show early wide-spread changes in connectivity in AD compared to controls, with diverging trends at 6months. Intriguingly, these neuroimaging changes precede typical behaviour deficits. Further, preliminary evidence of cross-modal uncoupling hints at a complex relationship between excitatory neural activity (calcium imaging data), and the BOLD signal that is affected by AD-related progression.
9 crossings per 1 bend: Tractography of contra- and ipsilateral connections in mouse optic pathways improved with ODF-Fingerprinting
Authors: Filipiak Patryk , Sajitha Thajunnisa , Shepherd Timothy , Clarke Kamri , Placantonakis Dimitris , Zhang Jiangyang , Chan Kevin , Boada Fernando , Baete Steven
Published: August 2024

Reconstruction of rodent optic pathways is particularly challenging for dMRI tractography due to the relatively small size of the crossing area in the optic chiasm and the unbalanced proportion between the contra- and ipsilateral axonal links. In this study, we replace the commonly used Orientation Distribution Function peak finding approach with our dictionary-based technique called ODF-Fingerprinting to improve the reconstruction of crossing fibers and thus correct the proportion of tracts exiting the optic chiasm. Our results from in vivo diffusion-weighted images of 18 mice show significant improvement (p<0.05) in many cases, helping decrease the discrepancies between reconstruction and gold-standard histology.
Mechanical Stiffness and Anisotropy Measured by MR Elastography during Brain Development in the Minipig
Authors: Wang Shuaihu , Guertler Charlotte , Okamoto Ruth , Johnson Curtis , McGarry Matthew , Bayly Philip
Published: August 2024

The relationship between brain development and mechanical properties of brain tissue is important but remains incompletely understood. Here we use data from magnetic resonance elastography (MRE) and diffusion tensor imaging (DTI) to estimate anisotropic mechanical properties in six female Yucatan minipigs at ages from 3 to 6 months with a transversely- isotropic nonlinear inversion (TI-NLI) algorithm. Our results show that white matter is more dissipative and anisotropic than gray matter, and reveal effects of brain development on brain stiffness and structural anisotropy. Changes in brain mechanical properties may be a fundamental biophysical signature of brain development.
Correlation Tensor Imaging Enhances Histological Differences Between Mouse Glioblastoma Subtypes
Authors: Henriques Rafael , Simões Rui , Monteiro Sara , Ianuş Andrada , Carvalho Tânia , Jespersen Sune , Shemesh Noam
Published: August 2024

Correlation Tensor Imaging (CTI) has been recently proposed as a novel methodology for resolving kurtosis sources without relying on strong multi-gaussian component assumptions. Here, CTI is harnessed to decipher kurtosis sources in two different mouse glioblastoma subtypes. Our results reveal that CTI’s kurtosis source separation resolves the underlying microstructural differences between the glioblastoma subtypes and faithfully represents their specific histopathological features. In comparison to previous diffusion MRI approaches, CTI kurtosis maps present enhanced sensitivity towards tumor differences. These first results show the potential of CTI in providing more sensitive and specific future biomarkers for monitoring tumor progression and therapy outcome.
Predicting Uncertainty of Metabolite Quantification in Magnetic Resonance Spectroscopy with Applications for Adaptive Ensembling
Authors: Merkofer Julian , Amirrajab Sina , van den Brink Johan , Veta Mitko , Jansen Jacobus , Breeuwer Marcel , van Sloun Ruud
Published: August 2024

Current deep learning methods for metabolite quantification in magnetic resonance spectroscopy do not offer reliable measures for uncertainty. Having a widely applicable measure can aid with the identification of fitting errors and enable uncertainty-based adaptive ensembling of model-based quantification and neural network predictions. In this abstract, we propose a training strategy based on a log-likelihood cost that allows joint optimization of concentration and uncertainty estimation for each individual metabolite. We show that the predicted uncertainties correlate well with the actual estimation errors and that uncertainty-based adaptive ensembling outperforms the individual estimators as well as standard ensembling.
Optimization and comparison of coil combination and spectral registration strategies for in-vivo DW-MRS
Authors: Zhou Ke , Wang Ziyan , Lin Dingyi , Hsu Yi-Cheng , Wang Min
Published: August 2024

Diffusion-weighted MRS (DW-MRS) suffers from low signal intensity and large phase errors when applying strong diffusion weighting. Coil combination and spectral registration are vital as spectra with high b-values are usually poorly reconstructed. This work aims at the optimization of post-processing pipeline with singular value decomposition (SVD)-based spectral registration and the comparison of different regimes of coil combination and spectral registration for in-vivo DW-MRS post-processing. The SNR of post-processed spectra and the metabolite diffusivities are assessed. The statistical outcomes suggest that the SVD-based spectral registration could improve the SNR of DW-MRS signal at high b-values and therefore alleviate diffusivity overestimations.
Comparison of FAST(EST)MAP and BOLERO shimming for single voxel spectroscopy at 7T
Authors: Pan Jullie , Terpstra Melissa , Kim Junghwan , Hetherington Hoby
Published: August 2024

Because of the small volumes (2 to 15cc) used in single voxel spectroscopy (SVS), field inhomogeneities over such voxels are thought to be well managed by low order shim methods, e.g., FAST(EST)MAP using 1st-2nd spherical harmonic shim terms. In this report performed at 7T (Siemens Terra) we evaluate SVS from a key region of interest (prefrontal cortex PFC) with FAST(EST)MAP in comparison with Bolero shimming, a method that specifically manages high order shim terms. High accuracy field maps and LCModel analysis of STEAM spectroscopy are evaluated.
Can NMR phytometabolomics play a role in prevention and management of obesity?
Authors: Singh Ankita , Singh Aruna , Kumar Dushyant , Jayasundar Rama
Published: August 2024

Obesity, a disorder of lipid metabolism, has become a serious health issue globally. Recently, research on pungent phytochemicals and plants with nutritional and medicinal values has gained interest in obesity management. In this study, phytochemicals (n=21) and medicinal plants (n=38) from pungent and non-pungent groups were studied using proton NMR phytometabolomics for their anti-obesity properties. Multivariate analysis of NMR data demonstrated the potential of proton NMR metabolomics in differentiating medicinal plants and their active phytochemicals with anti-obesity properties. These were further confirmed with anti-lipase assays and alkaloid analysis (indicating presence of pungent molecules) of the medicinal plants.
Feasibility of high resolution Readout-segmented echo planar imaging with simultaneous multi-slice in the assessment of rectal cancer
Authors: zhou Mi , Chen Meining , Wang Yuting
Published: August 2024

DWI has an important role in the staging and treatment response assessment of patients with rectal cancer, but its resolution is much lower than dynamic contrast-enhanced MRI and T2W images. We achieved a high-resolution scan of the rectal cancer using SMS HR rs-EPI sequences with a resolution of 1.1×1.1×2 mm3. The SMS HR rs-EPI provided a significantly better image quality and more valuable ADC than conventional HR rs-EPI when assessing rectal cancer. The pretreatment ADC values of HR rs-EPI could be utilized to distinguish well and poorly differentiated rectal cancer.
Extended multi-shell diffusion acceleration with Gaussian processes estimated reconstruction (ems-DAGER)
Authors: Ye Xinyu , Miller Karla , Wu Wenchuan
Published: August 2024

Diffusion-weighted MRI suffers from relatively long acquisition time, especially for high spatial- resolution and/or high angular- resolution acquisitions. Thus, methods to increase the acquisition speed are urgently needed. Recently, increasing attention has been paid to utilize the relations between k- and q-space points for further acceleration. Here, we extend the Diffusion Acceleration with Gaussian process Estimated Reconstruction (DAGER) to leverage shared information in multi-shell acquisitions and incorporate eddy-induced distortion correction.
Integrated shimming technique can improve ultrahigh-b-value DWI in laryngeal and hypopharyngeal squamous cell carcinoma: comparison with conventional volume shimming
Authors: Wen Yan , Long Liling , Li Chenhui , Zhang Huiting , Stemmer Alto
Published: August 2024

This study aimed to investigate the value of integrated shimming (iShim) technique in the ultrahigh-b-value DWI images in laryngeal and hypopharyngeal squamous cell carcinoma (SCC) by comparing with the conventional volume shimming technique. Our results showed that the ultrahigh-b-value DWI images with iShim technique had significantly higher image quality based on subjective (edge, artifact, and confidence) and objective (signal-to-noise ratio, contrast, and contrast-to-noise ratio) assessments compared with conventional single-shot-EPI DWI images with volume shimming. Therefore, ultrahigh-b-value DWI images with iShim technique can be well applied in laryngeal and hypopharyngeal SCC examination.
Whole Brain Simultaneous MultiSlice Filter EXchange Imaging in less than 15 minutes: Initial Results
Authors: Testud Frederik , Chakwizira Arthur , Nilsson Markus
Published: August 2024

Filter EXchange Imaging (FEXI) is sensitive to the rate of diffusional water exchange, which depends among other factors on the cell membrane permeability. FEXI maps the so-called apparent exchange rate (AXR), however, previous FEXI protocols were limited to few slices because of very long acquisition times. In this proof-of-concept work, Simultaneous MultiSlice was included in the FEXI sequence and with protocol optimization allowed for a 12-minute whole-brain scan. FEXI accelerated with or without SMS showed similar AXR values.
MR Elastography Distinguishes Between Adrenal Adenomas and Malignomas by Increased Stiffness
Authors: Webster Alexandra , Dukaczewska Agata , Mogl Martina , Meyer Tom , Hamm Bernd , Sack Ingolf , Garcia Stephan Marticorena
Published: August 2024

The ability to distinguish a benign from a malignant adrenal mass based on magnetic resonance imaging relaxation times is severely limited. For the first time at all, this study adrenal gland stiffness was investigated by using magnetic resonance elastography in healthy controls and participants with adrenal adenoma and malignoma. In healthy controls MRE was highly reproducible. Adrenal adenoma and malignoma are stiffer than healthy controls and both could be distinguished by an excellent diagnostic performance (AUC 0.8–1.0). MRE is promising non-invasive biomarker for clinically difficult differentiation of a malignancy and could prevent surgical overtreatment in the future.
Usefulness of quantitative MRI in the evaluation of pancreatic fibrosis
Authors: Sotozono Hidemitsu , Kanki Akihiko , Fukukura Yoshihiko , Maeba Kiyoka , Yamamoto Akira , Tamada Tsutomu
Published: August 2024

We sought to clarify the value of quantitative MRI for evaluating pancreatic fibrosis. Longer T1 relaxation time and lower D within the pancreas parenchyma were significantly related to pancreatic fibrosis score based on histopathological evaluation. T1 relaxation time and D may be sensitive indicators of fibrosis within the pancreas parenchyma.
Fast 3D free-breathing simultaneous T1 and T1ρ mapping for noncontrast myocardial tissue characterization at 3T
Authors: Qi Haikun , Hu Junpu , Xu Jian , Zhu Jiayu , Botnar René , Prieto Claudia , Hu Peng
Published: August 2024

Relaxation parameters T1 and T1ρ have shown promising results for endogenous assessment of myocardial tissue. However, mapping of the whole moving heart is challenging. This study proposes a novel free-breathing joint T1 and T1ρ mapping technique with near-isotropic spatial resolution, whole left ventricle coverage and short acquisition time of 5-6min. A diaphragmatic navigator was leveraged for prospective motion correction and retrospective motion mitigation. The T1ρ preparation module was optimized to be robust to field inhomogeneities and applicable to 3T. Phantom results indicated good accuracy of the proposed technique, and in vivo feasibility was demonstrated in healthy subjects.
Cardiac MR Susceptibility-weighted Imaging Detects Intramyocardial Hemorrhage of Acute Myocardial Infarction: comparison with T1 / T2 mapping
Authors: Wen Jinyang , Huang Lu , Zhou Xiaoyue , Xia Liming
Published: August 2024

Diagnosis of intramyocardial hemorrhage (IMH) in ST-segment elevation myocardial infarction (STEMI) patients following reperfusion treatment is critical for determining prognosis. This study investigated the feasibility of susceptibility-weighted imaging (SWI) to detect IMH in STEMI patients that underwent reperfusion therapy by comparing the diagnostic performance and image quality with T1/T2 mapping. SWI showed excellent diagnostic performance in detecting IMH among STEMI patients that underwent reperfusion treatment and was comparable with T1/T2 mapping. SWI is a sensitive technique to accurately diagnose IMH in STEMI patients following reperfusion treatment.
Quantification of bilateral kidney oxygen consumption with MOTIVE-bSSFP
Authors: Deshpande Rajiv , Langham Michael , Cheng Cheng-Chieh , Wehrli Felix
Published: August 2024

Kidney oxygen consumption rate increases during the early stages of diabetes, ultimately leading to hypoxia of renal tissue. Thus, a reliable non-invasive approach to quantify kidney metabolism has significant clinical potential. Here, an approach to quantify the kidney oxygen utilization of both kidneys is reported. The method relies on the MOTIVE-bSSFP pulse sequence to measure SvO2 and blood flow rate in the inferior vena cava, above and below the branching of the renal vessels. Conservation of mass yields an expression to compute bilateral renal metabolic rate of oxygen.
Uncertainties in baseline cerebral oxidative metabolism mapping by gas-free and dual-calibrated fMRI: a simulation-based comparison
Authors: Zhong Xiaole , Chen J. Jean
Published: August 2024

Calibrated BOLD fMRI is becoming a method of choice in assessing baseline cerebral oxidative metabolism (CMRO2), with gas-free calibrated fMRI being an non-invasive alternative to the more established gas-calibrated fMRI methods. However, the relative repeatabilities of these two approaches are unknown, each depending on a unique set of input measurements. This study uses analytical simulations to investigate the sensitivity of baseline OEF and CMRO2 estimates to the measured inputs of each method. Our results suggest that gas-free calibrated fMRI is substantially less sensitive to input variations than gas-calibrated fMRI, demonstrating the potential for simulation-informed methodological selection.
Incorporating Untrained Neural Network Prior in PROPELLER Imaging
Authors: Saju Gulfam , Li Zhiqiang , Abiri Reza , Liu Tianming , Chang Yuchou
Published: August 2024

Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction (PROPELLER) MRI technique enables the correction of motion artifacts resulted from patient motions in a scanner. Undersampling the blades can increase data acquisition speed and reduce potential motions caused by pains in a short time but may degrade image quality. Deep neural networks may support the blade reconstruction with undersampled data but motion patterns are difficult to be acquired for building a training dataset. To avoid the acquisition of training data, this abstract proposes an untrained neural network-based PROPELLER reconstruction technique to enhance image quality with undersampled blades.
AI assisted upscaling of low-resolution cardiac MRI reduces acquisition time and yields qualitatively comparable images to standard techniques
Authors: Kravchenko Dmitrij , Isaak Alexander , Mesropyan Narine , Pieper Claus , Kuetting Daniel , Bischoff Leon , Zhang Shuo , Katemann Christoph , Peeters Johannes , Weber Oliver , Attenberger Ulrike , Luetkens Julian
Published: August 2024

AI assisted upscaling of low-resolution cine bSSFP images yields comparable image quality to conventional images with no clinically significant difference in volumetric data at a reduction of acquisition time by a factor of 1.5 to 2. Keywords: Artificial intelligence, acceleration, Superresolution, cardiac MRI
Increase in Fast-relaxing Sodium After a Brief Plantarflexion Exercise Detected by Multi-Echo UTE MRI and Biexponential Regression
Authors: Jung Kwan-Jin , Fang Hsin-Yu , Sutton Brad , Wilund Kenneth
Published: August 2024

We measured the exercise-induced change in fast and slow T2-relaxing sodium in calf muscles separately using a UTE sequence with multiple echoes. Three minutes of plantarflexion exercise resulted in an increase in the fast-relaxing sodium and no change in the slow-relaxing component. Based on the known physiology that muscle intracellular sodium increases during muscle contraction, the measured fast-relaxing sodium might represent muscle intracellular sodium. This finding is valuable in studying intra- and extracellular sodium separately.
Axial diffusivity and kurtosis derived based on DWI reflect microstructure changes in patients with in stress urinary incontinence patients
Authors: Ou Kun , Liu Weiyn , Zhang Kun
Published: August 2024

Stress urinary incontinence (SUI) is the most common form of urinary incontinence. However, in patients with SUI, the pelvic floor muscles generally have no obvious radiographic abnormalities. This study applied diffusion-weighted imaging with different analysis models and found that patients with SUI had significantly lower FA and Da values based on gaussian-distributed water movement and higher values in the Ka based on non-gaussian-distributed water movement compared to the healthy volunteers. This study showed both DTI and DKI derived parameters can detect microstructure changes in the the pubic visceral muscle of the SUI patients.
The effects of exercise on ankle mobility and lower leg hyaluronan distribution in type 2 diabetes
Authors: Menon Rajiv , Rao Smita , Raghavan Preeti , Regatte Ravinder
Published: August 2024

Type 2 Diabetes Mellitus (T2DM) is a major cause of a number of systemic pathological processes, including muscle stiffness. In this study, we examine the effects of exercise on peak ankle dorsiflexion, and ankle stiffness and investigate hyaluronan distribution with 3D-T1ρ MRI in 10 individuals with T2DM. Our findings suggest that participation in a 10-week moderate intensity exercise intervention may alter hyaluronan distribution in the compartments of the lower leg calf muscle, and is accompanied by increased dorsiflexion, reduced stiffness in individuals with diabetes, and a reduction in MRI based T1ρ measures
The Feasibility Study of Extraocular Muscle Volume in Patients with Myasthenia Gravis Based on 3D TOFMRA
Authors: Zhou Qin , Chen Pei , Yang Zhiyun , Zhao Xiaoxiao , Chen Yingxi , Wang Mengzhu
Published: August 2024

The study investigated the feasibility of TOF MAR sequence in evaluating extraocular muscle morphological changes in patients with myasthenia gravis. The results show that volume measurement of EOM based on TOF MRA imaging can effectively quantify atrophy of EOM in MG patients, which is significantly related to the poor response to medication and the long duration of the disease, meaning that it can be used as a non-invasive auxiliary diagnostic tool for prognosis evaluation of MG patients.
Design of calibration-free RF pulses for T2-weighted single-slab 3D turbo-spin-echo sequences at 7T utilizing parallel transmission
Authors: Löwen Daniel , Pracht Eberhard , Gras Vincent , Massire Aurelien , Mauconduit Franck , Boulant Nicolas , Stöcker Tony
Published: August 2024

Multi-Slice T2-weighted MR imaging is a fundamental technique in brain imaging but suffers from field inhomogeneities at ultra-high field systems. In this work we present a pulse design method which provides slab-selective universal pulses with phase-coherent excitation profiles over selected brain regions. Applied in a 3D variable flip angle turbo-spin-echo (TSE) sequence, the pulses achieve superior SNR compared to multi-slice TSE imaging and B1+ field inhomogeneity mitigation.
Investigating the impact of head position on the spatial distribution of B1+ field for a 60-ch Tx coil at 7T
Authors: Jin Hecheng , Sajewski Andrea , Santini Tales , Martins Tiago , Berardinelli Jacob , DeFranco Anthony , Aizenstein Howard , Ibrahim Tamer
Published: August 2024

In this work, we computationally and experimentally evaluated the B1+ field and SAR generated by a 60-channel Tic-Tac-Toc RF coil at 7T MRI scanner on a variety of participants, head models and head positions. On three anatomically detailed human head models, we found slight changes in the intensity and the distribution of B1+ field and SAR over the whole brain when the head was moved out from the top of the coil. This was confirmed in both simulation and experimental B1+ maps. Our results highlighted the impact of imaging setup on imaging quality.
Investigating the Optimal Number of Channels in an Array System for Human Head Imaging at 7T
Authors: Bhosale Aditya , Ying Leslie , Zhang Xiaoliang
Published: August 2024

To determine the optimal number of channels employed in an array system for Human Head imaging at 7T, we examined different multi-channel circular LC loop array systems, ranging from 4-channel to 64-channel arrays.
Bilateral Orthogonality Generating Acquisitions Method for Homogeneous T2* Images Using Dual Channel Parallel Transmission at 7T
Authors: Boga Celik , Henning Anke
Published: August 2024

The T2*contrast specifically benefits from 7T human MRI systems and is frequently used in Neuroimaging. However, B1+ and B0 inhomogeneity at 7T limits the effectiveness of the T2*. A method originally proposed to minimize channel effects in the field of telecommunications, was adopted to a dual channel parallel transmission (pTx) human 7T MRI system. Final images are obtained by the unique combination of four small angle GRE acquisitons with adjusted flip angles for each channel. The proposed method is easy to implement, robust and provides homogeneous T2* images of the whole brain.
Rapid Radiofrequency Coil Prototyping for Hyperpolarized Carbon-13 Imaging
Authors: Zavriyev Alexander , Choi John , Adebesin Bukola , Sheehan Molly , Tischfield David , Gade Terence
Published: August 2024

Dynamic nuclear polarization magnetic resonance spectroscopic imaging (DNP-MRSI) of hyperpolarized carbon-13 (HP 13C) is an exciting new imaging technique that provides valuable information about the metabolism of disease states. Though there are many hyperpolarized substrates that can be used to investigate metabolism in a variety of models, the application of this technology often requires custom radiofrequency (RF) coil design. Furthermore, different coils within the same project may provide different results. In this study, we utilized 3D printing molds to generate inductors along with printed circuit board (PCB) designs to create a high reproducibility (<1% variation) pipeline for MR coils.
Robust and Automated Processing of Deuterium Metabolic Imaging (DMI) using Spatial Prior Knowledge
Authors: de Graaf Robin , Liu Yanning , Corbin Zachary , De Feyter Henk
Published: August 2024

Deuterium Metabolic Imaging (DMI) is a novel method to generate spatial maps of dynamic metabolism. While DMI acquisition methods are simple and robust, DMI processing still requires expert user interaction, for example in the removal of extracranial natural abundance 2H lipid signals that interfere with metabolism-linked 2H-lactate formation. Here we pursue the use of MRI-based spatial prior knowledge to provide automated and objective lipid removal. Adequate lipid suppression without perturbation of brain voxels is achieved, thereby allowing the generation of distinct and reliable metabolic maps on patients with brain tumors.
Identifying the Metabolic Signatures of PPARD-Overexpressing Gastric Tumors by HP MRI and Metabolomics
Authors: Pudakalakatti Shivanand , Titus Mark , Shureiqi Imad , Zuo Xiangsheng , Bhattacharya Pratip
Published: August 2024

Peroxisome proliferator-activated receptor delta (PPARD) is a ligand-dependent nuclear transcription factor that regulates a multiplicity of pathophysiological processes vital to cell metabolism. Recent discovery of PPARD overexpressed in villin-positive gastric progenitor cells, demonstrated spontaneous development of large, invasive gastric tumors as the mice aged. These unique animal models allowed us to address the knowledge gap of PPARD-regulated downstream metabolic changes and determine the significance of changes in gastric tumorigenesis by hyperpolarized MRI, NMR spectroscopy and LC-MS. Unlike many cancer systems, we found these gastric cancer tumors are not primarily dependent on aerobic glycolysis but on fatty acid oxidation for energy.
Improving SASHA T1 precision via a deep-learning approach
Authors: Qian Xiaofeng , Fan Yingwei , Si Dongyue , Jin Yongsheng , Ding Haiyan , Guo Rui
Published: August 2024

SASHA with a 3-parameter fitting model has high T1 accuracy but low precision due to low SNR in saturation-recovery T1-weighted images. Alternatively, a two-parameter model could improve the precision with the penalty of losing accuracy. In this study, we developed a 1D neural network (DeepFittingNet) to predict SASHA T1 and alleviate the impaction from noise. We trained DeepFittingNet using simulation of SASHA with different Rician noise levels and tested it using in-vivo MR data. Results showed that T1 from DeepFittingNet had high precision and comparable accuracy to that of the 3-parameter fitting.
Cardiac MR evaluation of a myocarditis mouse model
Authors: Peters Dana , Coman Daniel , Herman Peter , Kwan Jennifer , Zhang Hanming , Chakraborty Raja , Espinoza Jeacy , Chun Hyung , Park Saejong , Baldassarre Lauren
Published: August 2024

Tools were developed to evaluate mice models of myocarditis with cardiac MRI. Cine imaging with self-gating, T2 mapping using ECG-gated multi-spin echo acquisition, and pre- and post-contrast injection T1 mapping were employed. In twelve mice, including 4 mice models of myocarditis, normal T2 values were 19ms±2ms at 11.7T, and regions of higher T2 (25±2ms) were observed in some myocarditis mice. T1 mapping showed reduced T1 after injection of gadolinium, and regions of lower T1 in myocarditis vs. normal regions. These tools will be useful in improved characterization of myocarditis in mice.
Dark right ventricular blood pool on myocardial T2 mapping in dilated cardiomyopathy: a predictor of cardiac function
Authors: Li Yajuan , Zhou Hui , Zhang Huiting
Published: August 2024

Although the T2 mapping is mainly used to evaluate myocardial water content, it is also sensitive to blood oxygenation levels, we found that in dilated cardiomyopathy the right ventricular dark right ventricular blood pool may affect the accurate quantification of myocardial T2 values. This study investigated the relationship between right ventricular blood pool on myocardial T2 mapping and indicators of cardiac function.
A clinical study using T1-mapping and ECV and late gadolinium enhancement to detect early myocardium involoved in rheumatologic diseases
Authors: Liu Ying , Tian Ping , Zheng Jianmin , Zheng Minwen
Published: August 2024

Myocardial involvement is frequently observed in rheumatologic diseases but typically remains subclinical. This study aimed to detect early subclinical cardiac involvement and to investigate characteristics of myocardial involvement by cardiac MR (CMR) imaging. In 75 of 83 patients with rheumatologic diseases, elevated global native T1 and ECV values were observed. Furthermore, 51 patients showed positive segment distribution of late gadolinium enhancement, including subendocardial contrast, intramural contrast and transmural contrast. Thus, T1-mapping, ECV and late gadolinium enhancement could detect early myocardial involvement in rheumatologic diseases patients without overt LV dysfunction.
Developing and Evaluating a Chronic Ischemic Cardiomyopathy in Swine Model by Rest and Stress CMR
Authors: zhuang baiyan , Lu Minjie , he jian , xu jing
Published: August 2024

This preclinical study has established that chronic coronary artery stenosis can induce significant myocyte loss with modest global replacement fibrosis that leads to global LV dysfunction and varying degrees of congestive heart failure.
Evaluating histotripsy treatment dosage in the brain using MRI
Authors: Gupta Dinank , Kaovasia Tarana , Choi Dave , Allen Steven , Hall Timothy , Xu Zhen , Noll Douglas
Published: August 2024

Histotripsy is a non-invasive, non-thermal focused ultrasound ablation method that mechanically breaks down the target tissue into acellular debris and has shown promising results for brain surgery. Quantifying histotripsy treatment dosage is required to avoid over/under-treatment of the target region. In this work, we assess whether T1, T2 and ADC maps can be utilized to quantify the ablation effect generated by varying histotripsy dosage post-treatment using an ex-vivo bovine brain. We show that only the ADC map is able to visualize the histotripsy ablation. Increasing histotripsy dosage results in increasing ADC.
Subject-specific χ-separation method: the effect of introducing a personalised relaxometric constant Dr
Authors: Grosso Elena , Ricciardi Antonio , D'Angelo Egidio , Palesi Fulvia , Wheeler-Kingshott Claudia Gandini
Published: August 2024

χ-separation is a recently proposed biophysical model to separate the χ-positive and χ-negative contribution of magnetic susceptibility sources in the brain. Such a model relies on assuming a certain relaxometric constant (Dr) calculated as the mean of a group of healthy subjects. Here we demonstrate that Dr is subject-specific and if used in place of the average value, it affects the χ-positive and χ-negative maps in a structured way, while their sum remains similar.
Total Field Inversion for Quantitative Susceptibility Mapping Based on Boundary Element Modeling
Authors: Zhong Haodong , Wang Yi , Li Jianqi
Published: August 2024

This study proposes a novel total field inversion method in which the background field is modeled by discrete boundary elements. In this method, the boundary value of background field and local tissue susceptibility are simultaneously estimated in one step. We validated our method with orthogonality numerical simulation and in vivo data.
Including mesoscopic frequency shifts from fibrous structure of white matter improves accuracy of QSM
Authors: Sandgaard Anders , Kiselev Valerij , Shemesh Noam , Jespersen Sune
Published: August 2024

Quantitative Susceptibility Mapping (QSM) is a highly utilized MRI modality for mapping tissue susceptibility. However, a limitation of QSM is disregarding mesoscopic field effects associated with WM microstructure and anisotropic susceptibility. Here we present a minimal extension of QSM by including frequency shifts due to the fibrous WM microstructure, while still neglecting susceptibility anisotropy and WM spherical inclusions modelling iron complexes. We find that this step already improves the accuracy of QSM as it is shown by comparison with conventional QSM using a digital phantom that includes microstructural frequency shifts from multiple sources.
Exhaustive Comparison of QSM Background Field Removal and Masking using a Realistic Numerical Head Phantom
Authors: Milovic Carlos , Fuchs Patrick , Arsenov Oriana , Kiersnowski Oliver , Murdoch Russell , Muralidharan Laxmi , Nassar Jannette , Shmueli Karin
Published: August 2024

Removing background fields is an important preprocessing step in QSM, enabling the reconstruction of fine tissue susceptibility variations in the region of interest (ROI) without being corrupted by susceptibility sources outside of this region. This requires a binary mask of the ROI and most background field removal methods are sensitive to the choice of mask. Here we compared 15 background field removal methods across 4 different masks. We found projection onto dipole fields (PDF) to perform best overall, although it is sensitive to the mask. V-SHARP and RESHARP were more robust to masking and showed good performance.
INR-QSM: unsupervised quantitative susceptibility mapping using implicit neural representation
Authors: Zhang Ming , Zhang Yuyao , Wei Hongjiang
Published: August 2024

This study introduced an unsupervised deep learning-based method for QSM reconstruction using implicit neural representation (INR-QSM), a training databases-free method for high-quality QSM reconstruction. In INR-QSM, the susceptibility map was represented as a continuous function of the spatial coordinates. A coordinate-based multilayer perceptron (MLP) parameterized this function, took the coordinate as input and predicted the susceptibility value at the corresponding spatial location. The parameters of MLP were updated by minimizing a custom cost function. Preliminary results on two different datasets demonstrated the potential of INR for unsupervised QSM reconstruction.
Design of Quadrature RF Coil for Calcium Susceptibility Imaging in Small Tissue Samples
Authors: Degitz Jacob , Valle Edith , Wright Steven , McDougall Mary
Published: August 2024

One of the earliest significant events in Duchenne muscular dystrophy (DMD) pathology is an elevated influx of calcium ions into afflicted cells. To study this event and its correlation with disease progression, a custom 22mm diameter quadrature volume coil was designed and used to obtain 1H images at 4.7T, the processing protocol was established, and comparisons were made to μCT images.
Optimized Quantitative Susceptibility Mapping of Deep Cerebellar Nuclei using the phase of 3D-EPI Multi-Parametric Mapping at 7T
Authors: Ferreira Mónica , Stirnberg Rüdiger , Völzke Yannik , Löwen Daniel , Langkammer Christian , Robinson Simon , Ropele Stefan , Klockgether Thomas , Stöcker Tony , Faber Jennifer
Published: August 2024

RF transmit field inhomogeneities at 7T usually degrade the image quality in regions such as the cerebellum and brainstem, which has so far delayed its use to study cerebellar ataxias with higher fields. We present an optimized pipeline that maximizes the QSM contrast of nuclei in the cerebellum based on multi-echo MPM data. We show that averaging the individual susceptibility maps increases the signal-to-noise ratio (SNR) and reduces the group standard deviation. We introduced a weighted averaging based on the individual acquisition SNRs. Final maps presented high contrast of the dentate nucleus and a high delineation of its denticulated silhouette.
Artificial intelligence-based denoising for clinical magnetic resonance imaging: from head to toe
Authors: Turley Dallas , Wangaryattawanich Pattana , Andre Jalal , Chailan Majid , Peeters Johannes , Van de Ven Kim , Kolokythas Orpheus
Published: August 2024

Artificial intelligence in MR is a diverse and growing field. In this work, we apply convolutional neural networks (CNN) to accelerated routine clinical protocols to investigate potential image quality improvements. For moderate increase in reconstruction time, CNNs were judged by experienced radiologists to significantly improve image quality by reducing noise and artifact.
An MR-assisted Spatiotemporal Approach for 4D Dynamic Brain PET Denoising
Authors: Yousefi Hamed , Ying Chunwei , Hamdi Mahdjoub , Laforest Richard , An Hongyu
Published: August 2024

In this study, dynamic brain PET denoising was done using registered MRI and reconstructed PET images reconstructed by the OSEM method, while maintaining TACs that were quite near to the original noisy data. The fundamental challenge to using the supervised learning approach is the lack of ground truth. The resulting spatiotemporal images improved the image quality according to various CNR, SNR, and CRC parameters while maintaining TACs that were similar to the original raw PET. This method only needs one trained network, one set of matrices for a statistical temporal PCA model, and 4D dynamic PET data as input.
Fast MRI of the cervical spinal cord by combining the deep learning-based denoising and Super-Resolution technique
Authors: Aoike Takuya , Fujima Noriyuki , Kwon Jihun , Yoneyama Masami , Tsuneta Satonori , Ishizaka Kinya , Kudo Kohsuke
Published: August 2024

SmartSpeed Precise Image (SSPI) is one of novel image reconstruction technique which combined the physics driven type deep learning-based denoising process and Super-Resolution techniques. We investigated the utility of SSPI-based single-shot turbo spin-echo sequence of the cervical spinal cord T2-weighted image with the short acquisition time. High quantitative signal-to-noise ratio and qualitative image sharpness were successfully demonstrated by using SSPI. This methodology can be useful for the better image quality and the short acquisition time in the assessment of patients with cervical spinal cord diseases.
Assessment of Charcot-Marie-Tooth disease severity using quantitative T2 and fat fraction biomarkers
Authors: Holodov Maria , Shahar Shimon , Blumenfeld-Katzir Tamar , Bendahan David , Ben-Eliezer Noam
Published: August 2024

Charcot-Marie-Tooth (CMT) is the most prevalent inherited neurological disease, commonly presenting in the first or second decade of life. Notwithstanding the ongoing advancement of non-invasive imaging, effective and sensitive tools for monitoring CMT and other neuromuscular conditions are lacking. Here we investigated the utility of the extended echo-modulation-curve (EMC) algorithm, for precise mapping of T2 relaxation times and fat fraction (FF) in CMT patients. Results indicate that quantitative T2 and FF biomarkers correlate with clinical scores. These can be useful for precise and objective monitoring of microstructural processes occurring in CMT.
Monitoring of T2 changes in skeletal muscles using multiple overlapping-echo detachment imaging
Authors: Yang Qizhi , Wang Jiechao , He Hongjian , Zhong Jianhui , Cai Congbo , Chen Zhong , Cai Shuhui
Published: August 2024

Quantitative magnetic resonance imaging (qMRI), a noninvasive imaging tool without ionizing radiation, provides quantitative physiological information, whilst its lengthy scan time hinders its application in dynamic or real-time scenarios. Herein, the MOLED, a single-shot qMRI method we proposed previously, was applied in an ischemia and post-occlusive reactive hyperemia experiment to measure the T2 variation of the musculoskeletal system. The results disclose regular T2 fluctuations of different muscles during different periods. Inter-day repeatability experiments demonstrate that our method is accuracy and reliable.
Longitudinal evaluation of fasciculation in a healthy population using muscle DTI
Authors: Heskamp Linda , Schlaffke Lara , Froeling Martijn
Published: August 2024

Spontaneous motor unit (MU) contractions (fasciculation) are a hallmark of motor neuron diseases and can be measured with motor unit MRI. Previous work used a dedicated sequence with one optimized b-value. Here, we demonstrated that muscle DTI with variable b-values can also detect fasciculation. This allows simultaneous assessment of muscle architecture and fasciculation. Furthermore, we presented a retrospective analysis of fasciculation in healthy cohort muscle DTI data. This reveals higher and more variable fasciculation in lower legs compared to upper legs, and stable fasciculation distribution in repeated measures. Fasciculation detection in patients should therefore preferably focus on the upper legs.