bluuebunny/crossref_metadata_2025 huggingface dataset:
EPG-based optimization of the SNR of the phase-cycled bSSFP in phase-based electrical conductivity mapping
Authors: Lamy Julien , Savigny Flavy , de Sousa Paulo Loureiro
Published: August 2024

Phase-based electrical conductivity mapping requires high SNR due to the instability of the reconstruction. Electrical conductivity can be measured by the phase-cycled bSSFP, a high-SNR sequence which is also weighted by other biophysical parameters but for which no complete analytical model exist. In this work, we use EPG-based simulations to investigate how the bSSFP signal varies with the flip angle, the phase step and the pulse duration in a diffusive, two-pools model of the brain white matter at 3 T. We show that our simulations agree with in-vivo acquisitions and establish guidelines to optimize the SNR of the phase-cycled bSSFP.
Differential quantification of cortical and medullary perfusion through Gaussian Mixture Model based segmentation on transplanted renal MRI
Authors: Oyarzun-Domeño Anne , Cía Izaskun , Echeverria-Chasco Rebeca , Fernández-Seara María , Martin-Moreno Paloma , Garcia-Fernandez Nuria , Bastarrika Gorka , Navallas Javier , Villanueva Arantxa
Published: August 2024

Renal perfusion quantification is of importance in the post-operative surveillance of the allograft in translated patients. Together with cortical perfusion measurement, there is a strong interest in the quantification of medullary perfusion values, which requires an additional segmentation step of renal compartments. We applied Gaussian Mixture Models over renal MRI dataset to automatically extract the labels for each compartment to separately calculate cortical and medullary perfusion values. Proposed method showed performance metrics above 85% against ground truth labels and correlation coefficient above 96% and 58% for cortical and medullary perfusion values comparing with ground truth perfusion values.
Accelerated MRI near metallic implants at 0.55T using hexagonal sampling
Authors: Barlas Bahadir Alp , Keskin Kubra , Hargreaves Brian A , Nayak Krishna S
Published: August 2024

Metallic implants cause severe distortions in the magnetic field that are best mitigated using multi-spectral acquisitions that require longer scan time. At conventional field strengths, this is compensated by aggressive use of parallel imaging. However, at low-field strengths (<1.5T), available parallel imaging factors are reduced because body noise dominance prevents the use of dense arrays with smaller elements. Hexagonal sampling (in ky,kz space) was previously proposed as a way to achieve 2-fold reduction in imaging time without introducing additional artifacts. In this work, we demonstrate applicability of the hexagonal sampling for 0.55T multi-spectral imaging near metal.
High resolution pulmonary imaging on a commercial 0.55T MRI scanner
Authors: Javed Ahsan , Ramasawmy Rajiv , Su Pan , Benkert Thomas , Majeed Waqas , Chow Kelvin , Campbell-Washburn Adrienne
Published: August 2024

We determined the feasibility of diagnostic high resolution pulmonary imaging on a commercial 0.55T scanner and compared the image quality to a ramped down prototype 0.55T scanner. 0.55T scanners can improve accessibility of MRI, due to their lower cost, ease of installation, and wider bore geometry. Previously, we showed robust pulmonary imaging at 0.55T using a prototype scanner with high performance gradients. In this work, we leverage our robust self-gated, concomitant and motion corrected reconstruction pipeline to enable diagnostic pulmonary imaging on a commercial 0.55T scanner with lower gradient performance.
Investigating the Relationship between Lung Volume and the Lung-Diaphragm Signal at 3T: Implications for Ventilation Measures
Authors: Peggs Zachary , Brooke Jonathan , Paul Jan , Bradley Christopher , Cooper Andrew , Bolton Charlotte , Hall Ian , Francis Susan , Gowland Penny
Published: August 2024

The relationship between lung volume and lung MR signal is key to quantifying ventilation using 1H MRI. This relationship was probed using a highly accelerated 3D FFE acquisition at 3T. Linear regression between the percentage change in lung-diaphragm navigator signal and lung volume showed that the relationship between these parameters was not always linear, especially in patient groups. Polynomial regression was used to assess the extent of the hysteresis between inspiration and expiration, with more hysteresis observed in chronic obstructive pulmonary disease (COPD) patients.
Metronome-paced Tachypnea-Induced Dynamic Hyperinflation on Pulmonary cine MRI in Chronic Obstructive Pulmonary Disease: SPIROMICS HF Study
Authors: Zhang Xuzhe , Prince Martin , Cooper Christopher , Backman Michael , Dashnaw Stephen , Hoffman Eric , Ambale-Venkatesh Bharath , Lima Joao , Agarwal Prachi , Schroeder Joyce , Vogel-Claussen Jens , Bluemke David , Finn John , Barr R. , Shen Wei
Published: August 2024

Metronome-paced tachypnea-induced dynamic hyperinflation of the lungs is typically assessed with spirometry; this method does not measure the dynamic change in lung volume over time. We implemented metronome-paced tachypnea with cardiopulmonary cine MRI. We developed an automated lung area segmentation algorithm using unsupervised domain adaptation (UDA) to measure dynamic hyperinflation in a SubPopulations and Intermediate Outcomes In COPD and Heart Failure Study (SPIROMICS HF) sample (n=65). Preliminary results showed that the integration of metronome-paced tachypnea and pulmonary cine MRI can quantify dynamic hyperinflation; dynamic hyperinflation identified on MRI appears to be associated with COPD severity.
Assessment of pulmonary function in pulmonary embolism using phase-resolved functional pulmonary MRI (PREFUL-MRI) under free breathing
Authors: Ouyang Tao , Tang Yichen , Zhang Chen , Vogel-Claussen Jens , Voskrebenzev Andreas , Jia Xiuqin , Yang Qi
Published: August 2024

This study investigated the difference in pulmonary function (including perfusion and ventilation defects) using PREFUL-MRI between pulmonary embolism patients and healthy volunteers. Three coronal slices were acquisitor with MAGNETOM Prisma 3T MR scanner per subject. The results showed that perfusion and ventilation defect percentages derived from PREFUL-MRI in PE patients were higher than in healthy subjects. And the PREFUL-MRI parameters showed a strong correlation with spirometry parameters in PE patients. Our study suggests that PREFUL-MRI allows for the quantification of lung function under free breathing and non-contrast in PE patients, making this a promising tool for future monitoring of patients
Full cardiac cycle coverage T2* mapping detects early myocardial changes in hypertrophic cardiomyopathy
Authors: Laghzali Oumaima , Lehmann Sandra , Periquito Joao dos Santos , Pohlmann Andreas , Carrier Lucie , Niendorf Thoralf , Waiczies Sonia , Ku Min-Chi
Published: August 2024

Most cases of hypertrophic cardiomyopathy (HCM) are detected at a stage when the heart has experienced significant damage. The aim of this study is to detect subtle changes in the myocardium before the appearance of overt symptoms of HCM. We show that myocardial T2* mapping can detect early changes throughout the full heart cycle in a HCM mouse model that represents the human genetic heart disease. This could potentially provide a biomarker for early stages of HCM that might be useful for non-invasive diagnoses.
Solid state NMR in white matter: Unconventional 31P→1H cross polarization interrogates the proton pool
Authors: Ensworth Alex , Knight Cariad-Arianna , Kozlowski Piotr , Laule Cornelia , MacKay Alex , Michal Carl
Published: August 2024

Tools to better characterize myelin health are urgently needed. We demonstrate the use of the solid-state NMR techniques cross polarization (CP) and WIdeline Separation (WISE) to directly probe the phosphorous (31P) of phospholipid myelin bilayers and characterize protons (1H) involved in CP. This work demonstrates the feasibility of unconventional CP from 31P→1H in porcine spinal cord and investigates the contributing 1H. The results of this work provide crucial insight into the characteristics exploitable by CP in myelin and reinforce the potential of a two-step transfer of semi-solid 31P signals into aqueous 1H, providing a more direct and myelin-specific MRI signal.
Values of golden-angle radial-VIBE in DCE-MRI in laryngeal and hypopharyngeal squamous cell carcinoma: comparison with conventional VIBE
Authors: Wen Yan , Long Liling , Li Chenhui , Zhang Huiting , Zhong Xiaodong
Published: August 2024

This study aimed to investigate the value of a dynamic contrast-enhanced (DCE)-MRI with golden-angle radial volumetric‑interpolated breath‑hold examination (radial-VIBE) research application sequence by comparing with conventional VIBE in patients with laryngeal and hypopharyngeal squamous cell carcinoma (SCC) under free breathing conditions. Our results showed that compared with conventional contrast-enhanced VIBE images with single phase, the morphological radial-VIBE images of multitemporal synthesis 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. Therefore, radial-VIBE can be used in DCE‑MRI examination in laryngeal and hypopharyngeal SCC in the free breathing state.
Common Carotid Arteries as Surrogate to the Internal Carotid Arteries in the MRI Quantification of Neurovascular Compliance
Authors: Nabbout Marianne , Langham Michael , Wehrli Felix
Published: August 2024

Neurovascular compliance (NVC) is a vascular property involving the intracranial vascular arterial tree expressed as the arterial blood volume in response to a transient systolic blood pressure increase. NVC attracted attention due to its association with neurovascular diseases. We computed the NVC at the common carotid arteries with cine phase-contrast MR. This measure was shown to be significantly correlated with the quantification of the actual NVC in N=17 subjects (r= 0.84; p= 0.00002). Aortic pulse wave velocity, marker of aortic stiffness, was not found to be correlated with any of the two NVC computations.
Predictive value of myocardial strain on myocardial infarction size in ST-segment elevation myocardial infarction with preserved LVEF
Authors: Li Bin , Su Guohai , Wang Qiang , Wang Jian , Yue Xiuzheng , Ma Yingjie , Wang Peng , Li Yang , Tian Jing
Published: August 2024

With the development of the emergency system, we can see more and more acute ST-segment elevation myocardial infarction patients with preserved left ventricular ejection fraction.the predictive value of myocardial strain as determined by cardiac magnetic resonance (CMR) for myocardial infarct size could not been clarified by previous investigations in STEMI patients with preserved LVEF. The present study reveals incremental value of global circumferential strain (GCS), determined by CMR, for the prediction of infarction size after STEMI, above and beyond LVEF as well as global longitudinal strains. The findings of this study suggest that GCS may represents a potential marker of infarct size and may be used to better guide drug therapy. It may be beneficial to use GCS to determine the infarct size and prognosis of post-MI patients who do not qualify for contrast imaging.
First Results of Novel Contrast Agent Based on Ultrasmall Paramagnetic Nanoparticles for T1-Weighted MRI
Authors: Chaim Khallil , Uchiyama Mayara , Guimaraes Robson , Araki Koiti , Leite Claudia
Published: August 2024

MRI is one of the best imaging techniques in clinical analysis because it is non-invasive and has high resolution. Contrast agents are used to further improve these images, as they increase the level of soft tissue detail, differentiating regions of interest. Currently, Gd-based contrast agents have important precautions. In this work we present a new nanoparticle based on iron oxide, with 4 nm and positive contrast (T1-weighted). Thus, effects similar to gadoteric acid, with reduced signal persistence and partial renal excretion, indicating great stability, this new paramagnetic nanoparticle has great potential to be applied as a contrast agent in MRI.
Comparing Diagnostic Performance and Quality of NeuroMix (NM) to Routine Brain MRI Sequences
Authors: Milshteyn Eugene , Griffin Harry , Chang Yi Shuen , Sprenger Tim , Skare Stefan , Maclellan Christopher , Soman Salil
Published: August 2024

The focus of this study is to assess the diagnostic performance of NeuroMix, a single push-button, novel, fast multi-contrast MRI sequence, to that of routine brain scans that typically consist of multiple sequences. NeuroMix has the ability to provide several different contrasts in about 3.5 minutes with only one prescription and prescan. While the sequence has initially shown to be fast and motion-robust, more evaluation is needed across the various contrasts compared to gold standard, optimized sequences routinely used in the clinic. Here we present initial qualitative and quantitative comparisons between NeuroMix and routine scans across a variety of patients.
High Resolution Image Quality Improvement of T2 FLAIR Coronal Hippocampal Imaging by Deep Learning Reconstruction
Authors: Jing Yang , Ge Li , Tao Wu , Gang Qi , Cheng Zhao , Jie Lu
Published: August 2024

Deep learning reconstruction (DL Recon) method can improve the image signal-to-noise ratio and contrast-to-noise ratio without prolonging the scanning time and affecting the signal intensity difference of bilateral hippocampus. It can improve the image quality of hippocampus toe and surrounding small lesions dramatically as in Fig.1.
Complex Quasi-Newton Proximal Methods for the Image Reconstruction in Compressed Sensing MRI
Authors: Hong Tao , Fessler Jeffrey , Hernandez-Garcia Luis
Published: August 2024

This work studies a complex quasi-Newton proximal method (CQNPM) for MRI reconstruction using wavelets or total variation (TV) based regularization. Our experiments show that our method is faster than the accelerated proximal method [1,2] in terms of iteration and CPU time.
High-resolution single-shot spiral diffusion-weighted imaging at 7T using the expanded encoding model and compressed sensing
Authors: Dubovan* Paul , Varela-Mattatall* Gabriel , Santini Tales , Gilbert Kyle , Menon Ravi , Baron Corey
Published: August 2024

Reconstruction problems involving the expanded encoding model and field monitoring are typically solved using least squares optimization with the conjugate gradient method and early stopping as an implicit form of regularization. However, this is likely a suboptimal strategy for low SNR acquisitions, such as accelerated or high-resolution diffusion MRI. Hence, in this work we present an extension to the matMRI reconstruction toolbox that incorporates compressed sensing regularization. Results demonstrate that the expanded encoding model and compressed sensing regularization are complementary tools that mitigate artifacts from phase perturbations while permitting lower SNR conditions for high-resolution single-shot spiral diffusion-weighted imaging.
A clinical application of deep learning reconstructed myocardial late gadolinium enhancement on short-breath-hold patients
Authors: Lu Xuefang , Liu Weiyin , Yan Yuchen , Liu Changsheng , Gong Wei , Wang Yan , Zhao Yilin , Quan Guangnan , Zha Yunfei
Published: August 2024

SNR and CNR are essential for radiologists to precisely assess the signal enhancement in myocardia tissues. High-resolution late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is important but often possess low SNR and takes long scan time. Compared with original PSMDE (PSMDEO), AIRTM Recon DL-based PSMDE (PSMDEDL) effectively and significantly improved SNR, CNR and image quality without extra scan time. High-resolution PSMDEDL images also accelerated diagnossis speed of identifying defected tissues from noisy but normal myocardial tissues and elevated the diagnosis confidence despite no statistically different diagnostic performance between PSMDEDL and PSMDEO images.
Susceptibility artifacts during MR-guided laser interstitial thermal therapy: characterization and temperature-based control solutions
Authors: Martina De Landro , Giraudeau Céline , Verde Juan , Ambarki Khalid , Korganbayev Sanzhar , Odeen Henrik , Gallix Benoît , Saccomandi Paola
Published: August 2024

The use of Magnetic Resonance Thermometry (MRT) has been proposed to intraoperatively guide laser interstitial thermal therapy (LITT) thanks to its ability to provide multidimensional temperature measurements. PRF-based MRT thermometry holds significant benefits, but it is still limited by susceptibility artifacts that significantly affect the accuracy of measured temperature maps. These artifacts lead to a negative temperature distribution with a double-lobe shape around the laser applicator. In this work, artifacts appearing in MRT images during LITT and linked to magnetic field distortion related to susceptibility variations are characterized in ex-vivo livers. We further propose an approach to avoid their appearance.
Thermometry of frozen tissue during cryoablation at 1.5T with a novel 3D spiral staircase UTE sequence (SSCUTE) – A feasibility study
Authors: Krishnamoorthy Guruprasad , Browne Jacinta , Lu Aiming , Woodrum David , Pipe James
Published: August 2024

This study assessed the feasibility of thermometry of frozen tissue during MRI-guided cryoablation at 1.5T using a novel 3D spiral staircase UTE sequence (SSCUTE). MRI data using the SSCUTE sequence were continuously acquired along with temperature measurements during several freeze-thaw cycles in ex-vivo porcine specimens. A calibration curve was obtained using temperature measurements and corresponding MRI data. MRI-estimated temperature maps were generated with high accuracy using the calibration curve on a validation dataset. Our work demonstrated the feasibility of thermometry of frozen tissue using SSCUTE sequence at 1.5T, which could be an essential step in clinical adoption of this technique.
Deep learning-based synthesis of TSPO PET from T1-weighted MRI images only
Authors: Ferrante Matteo , Inglese Marianna , Brusaferri Ludovica , Loggia Marco , Toschi Nicola
Published: August 2024

Chronic pain-related biomarkers can be found using a specific binding radiotracer called [11C]PBR28 able to target the translocator protein (TSPO), whose expression is increased in activated glia and can be considered as a biomarker for neuroinflammation. One of the main drawbacks of PET imaging is radiation exposure, for which we attempted to develop a deep learning model able to synthesize PET images of the brain from T1w MRI only. Our model produces synthetic TSPO-PET images from T1W MRI which are statistically indistinguishable from the original PET images both on a voxel-wise and on a ROI-wise level.
AI-based mapping from MRI to MR thermometry for MR-guided laser interstitial thermal therapy using a conditional generative adversarial network
Authors: Sadatamin Saba , Robbins Steven , Tyc Richard , Waspe Adam , Kahrs Lueder , Drake James
Published: August 2024

MR-guided laser interstitial thermal therapy (MRgLITT) is a minimally-invasive treatment for brain tumors where a surgeon inserts a laser fiber along a fixed trajectory. Repositioning the laser is invasive and predicting thermal spread close to heat sinks is difficult. To address this problem, MR thermometry prediction using artificial intelligence (AI) modeling will be developed to aid the surgeon to determine whether a selected laser position is ideal before the treatment starts. AI algorithms will be trained to model the nonlinear mapping from anatomical MRI planning images to MR thermometry. A surgeon will choose a better fiber trajectory by AI model.
Amyloid-Beta Axial Plane PET Synthesis from Structural MRI: An Image Translation Approach for Screening Alzheimer’s Disease
Authors: Vega Fernando , Addeh Abdoljalil , Elmenshawi Ahmed , MacDonald M. Ethan
Published: August 2024

In this work, an image translation model is implemented to produce synthetic amyloid-beta PET images from structural MRI that are quantitatively accurate. Image pairs of amyloid-beta PET and structural MRI were used to train the model. We found that the synthetic PET images could be produced with a high degree of similarity to truth in terms of shape, contrast and overall high SSIM and PSNR. This work demonstrates that performing structural to quantitative image translation is feasible to enable the access amyloid-beta information from only MRI.
Diffusion kurtosis and elastography of uncinate fasciculus relate to dysfunctional emotion regulation and anxiety in youth
Authors: Matyi Melanie , Church Leah , Rudoler Jeremy , Bounoua Nadia , Wieand Kaleigh , McIlvain Grace , Johnson Curtis , Spielberg Jeffrey
Published: August 2024

Mechanistic theories seeking to explain the onset of anxiety in adolescence propose that delayed myelination of the uncinate fasciculus (UF) confers risk for anxiety onset through, in part, deficits in regulation of emotions. Thus, we examined the relationship between two independent assays of UF structural integrity and measures of both dysfunctional emotion regulation and anxiety. We found that less UF structural integrity is related to more dysfunctional emotion regulation and anxiety. Furthermore, we found that dysfunctional emotion regulation mediates the relationship between UF structural integrity and anxiety.
Mapping altered cortical microstructural maturation with diffusion kurtosis imaging in children with autism
Authors: Ouyang Minhui , Sindabizera Kay , Zhu Tianjia , Berman Jeffrey , Edgar J. Christopher , Huang Hao
Published: August 2024

The cellular and molecular processes inside the cerebral cortex play a critical role in typical brain development and neuropsychiatric disorders. Altered cytoarchitecture across brain regions in autism spectrum disorder (ASD) was found with histology. Here, we noninvasively mapped the whole-brain cortical cytoarchitectural maturation in 52 children aged 6-9 years with ASD and 59 age-matched typically developmental (TD) children with diffusion kurtosis imaging (DKI). Significant cortical mean kurtosis increases in the temporal and frontal regions were found in TD children with almost flat mean kurtosis changes in ASD observed, suggesting altered underlying cortical cytoarchitectural maturation in ASD.
Design and Construction of a quadruple-nuclear transceiver coil array for 1H/19F/23Na/31P MRI at 3T
Authors: Du Feng , Li Nan , Zhang Xiaoliang , Liu Xin , Zheng Hairong , Li Ye
Published: August 2024

Multinuclear MRI has been demonstrated as a crucial tool for comprehensively characterizing tumor pathology and monitoring tumor treatment response as it can provide biochemical, physical, and functional as well as structural information. The objective of this work is to develop a quadruple-nuclear transceiver coil array for 1H/19F/23Na/31P MRI at 3T to simultaneously detect multinucleal signals. The phantom studies were performed on self-developed 3T MRI system to verify the performance. These results proved that uniform excitation and highly sensitive acquisition in the region of interest were achieved by utilizing the proposed RF coil and indicated the fesibility for multinuclear MRI applications.
Dielectric Loaded Stretchable and Flexible Surface RF Coil
Authors: Hashemi Seyedamin , Kandala Sri Kirthi , Sohn Sung-Min
Published: August 2024

This study presents a novel receive radiofrequency coil that enhances the signal-to-noise-ratio (SNR) and field-of-view (FOV) in magnetic resonance images. The fabricated coil is loaded by a mixture of dielectric material (TiO2) and an elastomer offering stretchability and flexibility. The functionality of the coil compared to a typical surface coil was assessed using phantom imaging at 7T. The SNR (in dB), signal intensity, and uniformity are improved by 14.75%, 25%, and 87.76% by using a TiO2-loaded coil, respectively. This design method will be invaluable for uneven sample shapes and a very close place to a subject.
DUDE: Diffusion tensor imaging with Ultra-short echo time Double Echo steady state – a proof of concept
Authors: Sommer Stefan , von Deuster Constantin , Hilbert Tom , Nanz Daniel
Published: August 2024

The quality of echo-planar diffusion images can suffer from severe distortions and signal dropouts, especially in regions with high susceptibility gradients and rapidly decaying (short T2*) signal. To overcome these problems, we implemented a diffusion sensitive UTE-DESS sequence. The acquisition along six distinct diffusion directions allows for fitting of a diffusion tensor. We show the feasibility of Diffusion tensor imaging with Ultra-short echo time Double Echo steady state (DUDE) at 3T and present preliminary results in the brain of a healthy volunteer.
Density-Controllable Spiral Trajectory Design Combined with CS-UTE Improves High-Resolution Single Breath-Hold Lung Imaging
Authors: Cao Yupeng , Zhao Jun , Tang Weinan , Liu Wentao , Han Dong
Published: August 2024

Single breath-hold high-resolution lung imaging is challenging due to the short T2* and scan efficiency. The stack-of-spirals UTE enables fast lung imaging in a single breath hold. However, fast scanning of stack-of-spirals results in a long readout time, introducing adverse effects of the short T2* of the lung. Herein, we proposed a density-controllable spiral trajectory (DCST) design method to design a short readout time trajectory concurrently satisfying the criteria of optimal compressed sensing (CS), reducing the adverse effect of the short T2*. The short readout time trajectory combined with CS-UTE improves the single breath-hold high-resolution lung imaging.
Fast consensus optimisation in diffusion MRI modeling
Authors: St-Jean Samuel , Nilsson Markus
Published: August 2024

This work explores how to obtain parameter maps from a diffusion MRI model under 30 seconds and how to leverage multiple plausible solutions into a consensus solution using a framework similar to MR fingerprinting. The method is tested with a two compartments model and a mean kurtosis model and compared with a standard optimisation solver. Visual improvements are shown on parameter maps, showing less implausible values than the standard method, but without the use of constraints or assumptions. Access to a distribution of plausible values allows to compute most likely value from this distribution in the case of parameter degeneracies.
Training Strategies for Convolutional Neural Networks in Prostate T2 Relaxometry
Authors: Bolan Patrick , Saunders Sara , Gross Mitchell , Kay Kendrick , Akcakaya Mehmet , Metzger Gregory
Published: August 2024

This work uses convolutional neural networks (CNNS) with two training strategies for estimating quantitative T2 values from prostate relaxometry measurements, and compares the results to conventional non-linear least squares fitting. The CNN trained with synthetic data in a supervised manner gave lower median errors and better noise robustness than either NLLS fitting or a CNN trained on in vivo data with a self-supervised loss.
Comparison of activation functions for optimizing deep learning models solving QSM-based dipole inversion
Authors: Graf Simon , Küchler Nora , Wohlgemuth Walter , Deistung Andreas
Published: August 2024

Deploying deep learning models for quantitative susceptibility mapping is driven by optimizing hyper-parameters and using suitable architectures. We investigated the impact of activation functions on network model training. ELU-, leaky ReLU- and ReLU-models with 16 and 32 initial channels were tested for solving dipole inversion on synthetic susceptibility data. All models showed convergence after completing 100 training epochs. However, the 16-channel-ELU-model achieved low losses after only 20 training epochs and showed similar reconstruction performance to the 32-channel-ELU-model. Using the ELU activation allows the use of smaller network models resulting in fewer memory requirements and less training time.
Comparison of R1, R2* and PDFF mapping by simultaneous multi-relaxation-time Imaging (TXI) method in hepatic disease
Authors: Wang Yishuang , Huang Tianxiang , Chen Meining , YAN XU , Yin Longlin
Published: August 2024

MR multiparametric quantitative techniques have an important role in liver-related diseases. We achieved simultaneous proton density fat fraction(PDFF), R2*and R1 quantification of different liver diseases using a simultaneous multi-relaxation-time Imaging(TXI) technique. We observed differences of PDFF,R2* and R1 mapping between healthy volunteers and patients with cirrhosis,HCC,metastatic carcinoma of liver,and liver transplantation. Rapid scanning increases usage of this method in the clinic. These quantitative values can be biomarkers for assessing liver function and liver tissue characterization.
Recovery of T2 distribution from quantitative T2-weighted MRI with physically-driven deep learning
Authors: Ben-Atya Hadas , Freiman Moti
Published: August 2024

Recovery of T2 distribution of tissue from MRI data acquired at multiple echo times has the potential to be used as a biomarker for the assessment of various pathologies, including stroke and epilepsy, investigation of neurodegenerative diseases, and tumor characterization. Current deep neural networks (DNN) for T2 distribution recovery are highly sensitive to variations in the acquisition parameters such as different echo times. We present a new physically-driven DNN model that encodes the TE acquisition parameters as part of its architecture. Our model accurately recovers the T2 distribution, regardless of variations in SNR and in the acquisition parameters.
Joint Distribution Modeling for Accelerated T1rho Reconstruction
Authors: Liu Congcong , Cui Zhuo-Xu , Liu Yuanyuan , Cao Chentao , Cheng Jing , Zhu Yanjie , Wang Haifeng , Liang Dong
Published: August 2024

Traditional hand-craft designed methods to accelerated T1rho mapping have limited characterisation capabilities, while deep learning methods lack the interpretability. On the other hand, the joint distribution is the most direct and accurate way to characterize the correlation between different images. Therefore, we attempt to propose a joint distribution estimation method and use it to construct a T1$$$\rho$$$ reconstruction model. In particular, we use a score-based diffusion model to model the joint distribution of acquired T1rho-weighted images. Moreover, the corresponding reconstruction model is solved using the Langevin gradient descent method. Finally, numerical experiments validate the effectiveness of the proposed method.
Quantification of Lesion Volume Differences in Structural Epilepsy in 7T and 3T
Authors: Chambers Stefanie , Haider Lukas , Lazen Philipp , Kasprian Gregor , Koren Johannes , Diehm Robert , Moser Katharina , Tomschik Matthias , Wais Jonathan , Winter Fabian , Zeiser Vitalij , Gruber Stephan , Aull-Watschinger Susanne , Traub-Weidinger Tatjana , Baumgartner Christoph , Feucht Martha , Dorfer Christian , Bogner Wolfgang , Trattnig Siegfried , Pataraia Ekaterina , Rössler Karl , Hangel Gilbert
Published: August 2024

In this study, structural lesions in 3T and 7T of 12 patients suffering from intractable focal epilepsy were co-registered and manually segmented using ITK-SNAP. The rendered volumes were compared with reference to 3T lesional size in FLAIR, T1 and T2-weighted sequences. Additionally, a WMS sequence was compared to 3T FLAIR as well as 7T FLAIR. Our findings illustrate that on average, 7T showed larger lesion volume in all sequences except WMS.
In vivo γ-aminobutyric acid alterations as a biomarker of the therapeutic effect of MRI-negative temporal lobe epilepsy
Authors: Wu Shuohua , Wang Qianqi , Zhai Huige , Zhang Yiwen , Wu Pu-yeh , Yan Gen , Wu Renhua
Published: August 2024

Current diagnosis of MRI-negative TLE relies on clinical history and EEG or IEEG. However, IEEG is invasive and fails to monitor therapeutic effects dynamically. It is necessary to screen for effective biomarkers. We used MEGA-PRESS technique to investigate role of GABA and other metabolic alterations in TLE. We demonstrated that GABA, NAA, NAA+NAAG, and Glu levels in MTL were significantly different between epileptic and contralateral sides, and increasing index of GABA values is associated with increasing index of seizure frequency. These findings suggested that GABA is an effective biomarker for lateralization and therapeutic effect monitoring in patients with MRI-negative TLE.
Structural and functional changes in drug-naïve Rolandic epilepsy and their associated gene expression profiles
Authors: Yin Yu , Liu Heng
Published: August 2024

Combining structural and functional neuroimaging analyses with brain transcriptional data, the present study investigated GMV and fALFF changes in children with RE as well as their underlying gene transcriptional profiles. VBM and fALFF analyses showed altered GMV and fALFF in brain regions associated with behavioral and cognitive regulation. Transcription-neuroimaging spatial correlation analyses further identified genes correlated with GMV and fALFF changes in RE, respectively. Moreover, functional enrichment analysis demonstrated that RE-related genes were enriched for the regulation of biological process. These findings may provide us with important knowledge for understanding the pathophysiological basis of this disease.
Computer-controlled non-metallic phantom platform to simulate head motion with two degrees of freedom
Authors: Horne Jacob , Taylor Reggie , Xu Tong
Published: August 2024

A computer-controlled non-metallic head phantom platform was designed and constructed from 3D-printed parts. Driven by pneumatic stepper motors, the platform can simulate head motion with two degrees of freedom: tilting and rolling, with angular step resolution of 0.0833 degree and 0.227 degree, respectivily. A "neck/spine" design allows different static head phantoms to be mounted to the platform while still be able to fit inside standard head coils. The platform was tested on a PET/MRI scanner and successfully produced motion artifact with simulated motion.
Reliable Glutamate Measurements at 3T: Which Sequence should I Choose?
Authors: Durham Philip , Monsivais Humberto , Nossa Gianna , Foti Daniel , Zhou Xiaopeng , Dydak Ulrike
Published: August 2024

This meta-analysis discusses the intra- and inter-subject variability of glutamate measurements in MRS, comparing widely used sequences on clinical scanners (PRESS, sLASER, MEGA-PRESS, MEGA-sLASER, HERMES). To minimize variance in glutamate measurements, the authors recommend sLASER over PRESS, non-edited over edited MRS, and OFF over DIFF spectra.
Optimizing a Clinically Feasible 31P Liver MRSI Protocol at 3T
Authors: Bozymski Brian , Ooms Nathan , Dydak Ulrike
Published: August 2024

Optimizing a clinically feasible 31P liver MRSI protocol on a 3T SIEMENS system through the lens of a diffuse fatty liver disease study. Protocol practicality is driven primarily by scan length, patient comfort, and data quality. Voluntary scanning subjects, ranging from healthy to overweight, are sourced from the university population. Both a dual-tuned, 8-channel 1H/31P phased array coil (wrapped around the whole torso) and an 11-cm-diameter flexible surface coil are available for use. Techniques, testing results, and relative advantages of either are discussed in detail, as well as the implications for each choice in a clinical setting.
Influence of Gradient Polarity in Magnetic Resonance Spectroscopy at 3T using HERMES
Authors: Susnjar Antonia , Susnjar Antonia , Nossa Gianna , Dydak Ulrike
Published: August 2024

To overcome acquisition downfalls of HERMES edited magnetic resonance spectroscopy at 3T, we have conducted critical optimization for four clinically relevant brain regions in neurological disorders by finding the optimal voxel rotation that affects gradient order to enhance data quality and reproducibility.
Workflow and performance measures for integrating magnetic field monitoring with an 8-channel pediatric head coil for 7T MRI
Authors: Sprang Christian , Yazdanbakhsh Pedram , Couch Marcus , Feizollah Sajjad , Tardif Christine , Rudko David
Published: August 2024

Ultra-high field MRI is particularly susceptible to dynamic magnetic field fluctuations. To address this, commercial field probes were integrated into an 8-channel dipole Tx/Rx 7 T pediatric head coil. Coil performance was assessed before and after probe integration. Probe performance was compared on and off the coil. After probe integration, reflection coefficients were maintained below -10dB in all channels, noise correlation was shown to improve, and maximum SNR was shown to decrease. Probe performance did not change substantially once mounted on the coil. Future work will aim to address the reduction in SNR observed after probe integration.
A 3T Helmholtz coil with either reduced or maximized radiation damping effects
Authors: Müller Roland , Wallstein Niklas , Pampel André , Möller Harald
Published: August 2024

Radiation damping (RD) effects may confound experiments targeted at the quantification of MR contrast parameters, in particular, in experiments in small ex-vivo specimens performed with dedicated coils supporting a high filling factor. To address this problem, a long-known principle during reception with coil arrays (preamplifier decoupling) was also applied in the transmit branch of the TxRx switch. Furthermore, adding an extra λ/4 cable between coil and TxRx switch allows to switch between minimum and maximum RD with otherwise almost equal coil characteristics. This may be further exploited for for testing pulse sequences with regards to potential RD effects.
Differences in vascularity between recurrent glioblastoma and brain metastasis using dynamic contrast enhanced MRI
Authors: Fajerzstein Sapir , Artzi Moran , Blumenthal Deborah , Limon Dror , Aizenstein Orna , Bokestein Felix , Avisdris Netanell , Ben Dafna , Bashat
Published: August 2024

High grade glioma (HGG) and brain-metastasis are known to have different vascularity. Dynamic contrast-enhanced (DCE) was suggested to assess disease progression, and to differentiate between tumor recurrence and radiation necrosis. However, previous methods did not relate to the differences in vascularity of the two tumor types and often offer the same method and same threshold values. We show differences between groups with: higher vascularity, slightly increased permeability, higher percent of arteries overlapping of the tumor, and differences in several radiomics features, in recurrent HGG compared with recurrent brain-metastasis. Future studies should relate to these differences between the two tumor types.
Evaluation of a Wearable Bluetooth Sensor at 0.55T
Authors: Munoz Felix , Nayak Krishna , Khan Yasser
Published: August 2024

Compatibility of Bluetooth low energy (BLE) wearable sensors in the MRI environment will enable the creative use of wearable devices to monitor vital signs such as heart rate, respiration rate, blood pressure, temperature, and biochemical markers during a scan. In this work, we demonstrate efficacy of BLE sensors at the novel 0.55T MRI field strength and evaluate the noise in a wearable caused by rapidly switching MRI gradients, as well as MRI noise/artifacts introduced by a BLE wearable.
Heterogeneous regional growth process and speed in marmoset brain: multi-modal longitudinal MRI study
Authors: Uematsu Akiko , Fukushima Makoto , Hata Junich , Murayama Ayako , Kishi Noriyuki , Hayashi Takuya , Okano Hideyuki
Published: August 2024

“The soul of a child of three is the same at 100” may be also true among all the primates. Here, we delineate the robust value changes of T1w, T2w, and DTI metrics for the first 2 to 3 months after birth in common marmoset brain. Different temporal changes across brain regions were found by Fixel-based analysis, suggesting that different neuronal contributors of age-related structural changes. Integrating multi-modal MRI images provided more detailed insight of tissue property changes especially through development as compared with a single-modal image analysis.
Structural and Functional Brain Alterations in Children with Autism Spectrum Disorder
Authors: Zhou Di , Hua Ting , Zhao Xiance , Tang Guangyu
Published: August 2024

MRI is an important tool available to detect brain functional and structural abnormalities of autism spectrum disorder (ASD) patients. In this study, we found that children with ASD have increased changes in structure and both increased and decreased changes in function in the brain, which suggests that there may be some underlying pathogenic mechanism in the brain of ASD. With the combination of brain structural and functional analysis can provide a new imaging perspective for understanding the neural mechanism of ASD.
Univariate and multivariate individual-specific tract-based spatial statistics (iTBSS) for white matter microstructure anomaly detection
Authors: Guerrero-Gonzalez Jose , Venkatesh Jothi , Ferrazzano Peter , Alexander Andrew
Published: August 2024

Tract-based spatial statistics (TBSS) is a voxel-based analysis (VBA) method for diffusion MRI (dMRI) data along a skelentonized representation of the brain white matter. When applied to group-level analyses of dMRI data, TBSS has been shown to improve sensitivity, objectivity, and interpretability. In this work, we introduce individual-specific tract-based spatial statistics for anomaly detection in white matter micro-structure. Results from implementation on severe pediatric TBI brains reveal heterogenous patterns of atypical white matter.
QSM Based Decreased Iron Deposition Correlates with Reduced Neurodevelopmental Status in Children with Autism Spectrum Disorder
Authors: Du Lei , Ye Fang , Liu Bing
Published: August 2024

To investigate potential correlations between the susceptibility values of certain brain regions and the severity of disease or neurodevelopmental status in children with autism spectrum disorder (ASD). 18 ASD children and 15 healthy controls (HC) were recruited. 11 brain regions as regions of interest. Pearson and Spearman partial correlation analysis was used to depict the correlations between the susceptibility values, the ABC scores, and the GDS scores in ASD group. We found that the susceptibility value of the right globus pallidus was positively correlated with the GDS-fine motor scale score.
Imaging sexual dimorphism in white matter across the lifespan: A rat model of healthy ageing
Authors: Cerdá Antonio Cerdán , Martínez-Tazo Patricia , Canals Santiago , De Santis Silvia
Published: August 2024

White matter microstructure evolves across the lifespan due to maturation and degeneration. Recently, MR imaging in humans uncovered region- and sex-specific trajectories of microstructural integrity decline, suggesting prolonged neoteny in the female brain. Here, using advanced diffusion-weighted MRI, we characterize the­­­­ contribution of different cell-specific white matter biomarkers in a longitudinal rat model of healthy ageing, from puberty to early senescence. Our results validate the use of a rat model of healthy ageing for dissecting longitudinal brain ageing patterns, replicate the sexual dimorphism found in humans and points at myelin as the neurobiological substrate driving the observed sex difference.
Comprehensive evaluation of carotid body tumor complicated with carotid plaque by high resolution vascular wall imaging in plateau area
Authors: Sun Xindong , Bao Haihua
Published: August 2024

This study investigated risk factors for Carotid body tumor(CBT) in plateau areas, compared the incidence of CBT at high altitude group and low altitude group, and investigated the relationship between CBT and ipsilateral carotid plaque. The results showed that the incidence of CBT was higher at high altitude group than at low altitude group, and CBT will increase the incidence of ipsilateral carotid plaque.high resolution magnetic resonance vascular wall imaging(HR-VWI) has more advantages in the diagnosis of carotid body tumor than conventional MR Imaging.
MRI-Driven Lorentz Force-based Mechanical Removal of Arterial Occlusions
Authors: Phelan Martin , Sitti Metin
Published: August 2024

MR angiography provides high resolution visualization of blood vessels for analyzing arterial occlusions. However, these conditions require the use of a guidewire/catheter for treatment. Catheters integrated with microcoils for actuation under the high (3-7 Tesla), uniform magnetic field within magnetic resonance (MR) scanners have enabled mechanical removal of arterial occlusions. This work introduces an electromagnetic rotablation design, allowing direct tip torque control for both steering and drilling. Results demonstrate in vitro rotational thrombectomy with torque outputs up to 12 mN·m under MR guidance. These results indicate the high MRI external field can provide rotablation for difficult-to-reach areas of the vasculature.
Modelling Whole-Lung and Regional Carbon Monoxide Transfer Factor with Hyperpolarized 129Xe MRI in Asthma and COPD Patients
Authors: Pilgrim-Morris Jemima , Smith Laurie , Astley Joshua , Saunders Laura , Collier Guilhem , Biancardi Alberto , Tahir Bilal , Marshall Helen , Hardaker Latife , Fihn-Wikander Titti , Hughes Rod , Thompson Roger , Stewart Neil , Wild Jim
Published: August 2024

Hyperpolarized 129Xe ventilation and dissolved-phase MRI metrics were used to predict the carbon monoxide transfer factor (TLCO) in the lungs of patients with asthma and/or Chronic Obstructive Pulmonary Disease (COPD) using two linear regression models: (1) an existing analytical model based on physiology and (2) a machine learning model, which also included patient age and sex in the prediction. The machine learning model was further extended to create TLCO maps, providing a regional visualization of this gold standard measure of gas transfer.
An exploratory study to investigate the effect of light music on whole-heart coronary MRI
Authors: Wang Weiwei , Wu Yang , Sun Peng , Li Haixia , Jiang Yanyan , Ma xiaojing
Published: August 2024

Whole-heart coronary magnetic resonance angiography (MRA) is a noninvasive, contrast-free, and radiation-free technique for evaluating the origin, morphology, and stenosis of coronary arteries. Nonetheless, a patient's anxious mood results in a longer scan time or lower imaging quality. Previous research has shown that listening to music can alleviate anxiety in patients with coronary heart disease (CHD). In this study, we found no statistical difference in scanning time and imaging quality with CS acceleration factors (AFs) of 2,4,6 in the music and no-music groups. Music may not be necessary during coronary MRA scanning with the CS technique.
Autophagic accumulations are related to diffusion parameters in non-fat infiltrated muscles of the Pompe mouse
Authors: Rohm Marlena , Russo Gabriele , Helluy Xavier , Froeling Martijn , Manahan-Vaughan Denise , Vorgerd Matthias , Schlaffke Lara
Published: August 2024

In Pompe disease a mutation in the alpha-glucosidase gene leads to accumulation of glycogen and autophagosomes. Previously, we reported changes in diffusion in patient muscles. To identify histopathological correlations, the quantitative MRI protocol was translated to a mouse model, using DTI sequences in a monthly interval to scan the hind limb of pre-symptomatic mice. Subsequently, immunofluorescence stainings and glycogen assay were carried out to correlate glycogen accumulation and autophagic buildup with diffusion changes. No fat-infiltration was detected, while FA increases significantly compared to wildtype. Changes in diffusion parameters were correlated to autophagic buildup but did not correlate with glycogen accumulations.
Is Veterinary MRI feasible in a human facility?
Authors: Luchow Shiami , Ramadan Saad
Published: August 2024

Magnetic resonance imaging is continuing to grow for clinical diagnosis in veterinary practice. Although MRI is the gold standard for imaging the central nervous system and musculoskeletal pathology in animals, the use of MRI is limited due to the difficulty in accessing and the higher running cost. It is a limited resource disadvantaging many vet animals and their owners of care and cost. Is it feasible for a human MRI facility to image animals? This paper discusses how this was achieved at the Hunter Medical Research Institute Imaging Centre, Newcastle, Australia, and the safety procedures that were necessary for approval.