bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep Learning-guided Weighted Averaging for Signal Dropout Compensation in Liver DWI
Authors: Gadjimuradov Fasil , Benkert Thomas , Nickel Marcel , Maier Andreas
Published: August 2023

Signal-dropouts caused by cardiac motion are frequently observed artifacts in diffusion-weighted imaging (DWI) of the liver. When several repetitions of a given slice are affected, uniform averaging results in locally reduced liver signal. This work proposes an adaptive weighted averaging of repetitions to locally suppress signal-dropouts. Therefore, weight maps are estimated by an algorithm which computes robust patch statistics under the guidance of a learned classifier which marks corrupted repetitions. In comparison to other methods, the proposed approach enables more homogeneous liver signal and less biased quantitative maps while sacrificing little signal-to-noise ratio (SNR).
Reduced Field-of-View Intravoxel Incoherent Motion of the Human Pancreas Reflects Biphasic Response to Glucose Ingestion
Authors: Wu Chengyue , Yankeelov Thomas , Virostko John
Published: August 2023

Monitoring of the pancreatic islet is needed to assess individuals at risk for developing diabetes and facilitate development of islet-directed therapies. Pancreatic islets may be detectable due to their high vascularity. We imaged pancreas perfusion using both whole field-of-view and reduced field-of-view Intravoxel Incoherent Motion (IVIM) and found that the reduced field-of-view technique achieved similar image quality in half the time. We then performed a reduced field-of-view IVIM acquisition on four healthy controls. We found that pancreas perfusion increased dynamically in response to oral glucose challenge, exhibiting a biphasic increase that parallels the time course of insulin secretion.
Resting-state functional connectivity reductions in the cingulate gyrus in HIV exposed uninfected neonates
Authors: Fan Jia , Warton Fleur , Fry Samantha , Cotton Mark , Jacobson Sandra , Jacobson Joseph , Molteno Christopher , Little Francesca , van der Kouwe Andre , Laughton Barbara , Meintjes Ernesta
Published: August 2023

Aggressive combination antiretroviral treatment in pregnancy has significantly reduced new perinatal HIV infections giving rise to a growing population of HIV exposed uninfected (HEU) children. Children who are HEU demonstrate neurodevelopmental delay compared to their HIV-unexposed uninfected (HUU) peers. We examined resting-state functional connectivity (RSFC) in neonates exposed to HIV and ART in utero and perinatally using resting-state fMRI. Ten standard resting-state networks were identified from independent component analysis. Voxelwise group comparison between neonates who are HEU and HUU revealed localized RSFC reductions in the cingulate gyrus within 3 networks: medial somatosensory, and anterior and posterior default mode networks.
Quantitative MRI Analysis of Muscle Denervation
Authors: Li Tim , Argentieri Erin , Pedrick Emily , Sneag Darryl , Tan Ek
Published: August 2023

Macroscopic muscle volume evaluation and quantitative MRI of diffusion microstructure may provide objective, longitudinal assessment of muscle denervation. Analysis of subjects with Parsonage-Turner syndrome (neuralgic amyotrophy) showed both reduced muscle volume and reduced muscle diameter. Macroscopic muscle volume demonstrated a strong positive correlation with microscopic diffusion-based muscle diameter, and a strong negative correlation with T2-mapping. Denervated muscles exhibited longitudinal changes in quantitative MRI metrics, whereas non-denervated (control) muscles showed minimal quantitative changes.
High-precision MR thermometry of RF heating in the upper thigh at 7T using a multi-echo water-fat separation model
Authors: Kikken Mathijs , Steensma Bart , van den Berg Cornelis , Raaijmakers Alexander
Published: August 2023

A multi-echo MRT approach is presented for application in RF safety assessment and validation of thermal simulations. By water-fat separation, more accurate determination of the drift field is possible. The method was tested in the thigh at 7T, using multi-transmit coils. Precision and accuracy were improved considerably compared to a previous single-echo fat-referenced method (precision: 0.09 vs 0.19 °C). Comparison of measured temperature distributions to simulated counterparts show good relative agreement in three subjects for multiple RF shim settings. Strikingly, simulated heating magnitudes mostly underestimated the observed heating with varying extent, suggesting a role for subject-specific parameters, such as perfusion.
Efficient Bloch Simulation Based on Precomputed State-Transition Matrices
Authors: Scholand Nick , Graf Christina , Uecker Martin
Published: August 2023

The Bloch equations describe the effects of relaxation and external fields on the magnetization. Its coefficients are time-dependent, requiring computationally expensive techniques for its solution in the generic case. Currently, most techniques used in MRI are based on temporal discretization, but this requires very small time steps to achieve sufficiently small approximation errors.

In this work, we investigate a simulation technique based on a precise precomputation of state-transition matrices and compare its accuracy and efficiency with techniques based on ODE solvers and with matrix-based techniques using temporal discretization.
Beyond DW-Based Analysis of Fiber Architecture: Estimating Orientation Distributions from High Angular Resolution Susceptibility Imaging
Authors: Gkotsoulias Dimitrios , Paquette Michael , Eichner Cornelius , Müller Roland , Schlumm Torsten , Alsleben Niklas , Chen Jingjia , Jäger Carsten , Jaffe Jennifer , Pampel André , Crockford Catherine , Wittig Roman , Anwander Alfred , Liu Chunlei , Möller Harald
Published: August 2023

We present a novel approach to estimate fiber Orientation Distribution Functions (ODFs) by applying the generalized Constant Solid Angle (CSA) method to High Angular Resolution Susceptibility Imaging (HARSI) data from post-mortem chimpanzee brain. The acquisition details and analytical pipelines are presented and derived susceptibility tensor metrics and ODFs are compared to metrics derived from traditional High Angular Resolution Diffusion Imaging (HARDI). The ODFs estimated from susceptibility data indicate comparable efficiency in resolving intersecting fiber orientations compared to HARDI-ODFs and increased sensitivity to secondary direction. This suggests a potential to obtain complementary information on brain white matter microstructural properties.
Clinical correlates of brain iron and myelin changes in Multiple Sclerosis: a multi-parameter quantitative MRI study
Authors: Pontillo Giuseppe , Petracca Maria , Monti Serena , Quarantelli Mario , Lanzillo Roberta , Costabile Teresa , Carotenuto Antonio , Tortora Fabio , Elefante Andrea , Morra Vincenzo Brescia , Brunetti Arturo , Palma Giuseppe , Cocozza Sirio
Published: August 2023

In this cross-sectional study, voxel-based morphometry and voxel-based quantification analyses of longitudinal relaxation rate (R1) and quantitative susceptibility (QSM) maps, reflecting myelin and iron, respectively, were conducted on 117 patients with MS (pwMS) and 53 healthy controls. Between-group differences and correlations with clinical variables (global disability, cognitive and motor performance) were assessed. We found widespread atrophy and R1 decrease in pwMS, with smaller clusters of reduced susceptibility in the thalami and cerebral WM. While subcortical atrophy and WM iron depletion contributed to global and motor disability, deep GM atrophy and R1 decrease in lesional areas correlated with cognitive performance.
Local and Global aortic pulse wave velocity in the murine aortic arch assessed by 4D flow magnetic resonance imaging
Authors: Winter Patrick , Andelovic Kristina , Kampf Thomas , Schnell Susanne , Zernecke Alma , Bauer Wolfgang , Jakob Peter , Herold Volker
Published: August 2023

As atherosclerosis is one of the main causes of death in industrial nations, noninvasive imaging modalities for studying its underlying mechanisms are in great demand. The quantification of hemodynamic parameters such as pulse wave velocity (PWV) assessed by flow sensitive magnetic resonance imaging (MRI) is a promising tool to observe plaque progression in preclinical models. Mostly, a global PWV value is assessed, however, previous studies already pointed to heterogeneous elasticity profiles in the presence of atherosclerotic plaques. Here, we present the measurement of local PWV values in the murine aortic arch assessed by 4D-flow MRI for spatially resolved elasticity measurements.
Systematic Standardization of Deep Learning Based Accelerated MRI Reconstruction Pipelines
Authors: Gunel Beliz , Desai Arjun , Vasanawala Shreyas , Chaudhari Akshay , Pauly John
Published: August 2023

Deep learning based accelerated MRI reconstruction pipelines have potential to enable higher acceleration factors compared to traditional methods with fast reconstruction times and improved image quality. Although there have been studies regarding model architecture, loss function, and k-space undersampling patterns; the effect of scanner parameters, variations in sensitivity map estimation, training data requirement, and engineering decisions during model optimization and evaluation on the reconstruction performance remain largely unexplored. We systematically study the impact of such and show that such data extent, re-processing, and metric computation impact performance to the same or at larger extents than new architectures and loss functions.
Deep Plug-and-Play multi-coil compressed sensing MRI with matched aliasing: the Denoising-P-VDAMP algorithm
Authors: Millard Charles , Hess Aaron , Mailhe Boris , Tanner Jared
Published: August 2023

We present the Denoising Parallel Variable Density Approximate Message Passing (D-P-VDAMP) algorithm for multi-coil compressed sensing MRI with a learned prior. To our knowledge, D-P-VDAMP is the first Plug-and-Play method for multi-coil k-space data where the distribution of the training data's aliasing matches the actual distribution seen during reconstruction. We evaluate the performance of the proposed method on the fastMRI knee dataset and find substantial improvements in reconstruction quality compared with Plug-and-Play FISTA with the same network architecture in similar training and reconstruction time.
Correlations of inflammation metrics from multi echo T2 relaxation and multi-shell diffusion imaging in multiple sclerosis
Authors: Joseph Tigris , Liu Hanwen , Kolind Shannon , Zhao Guojun , Sun Peng , Carruthers Robert , Schabas Alice , Sayao Ana-Luiza , Devonshire Virginia , Tam Roger , Wayne Moore G. R. , Li David K. B. , Song Sheng-Kwei , Traboulsee Anthony , Vavasour Irene M. , Laule Cornelia
Published: August 2023

Inflammation is a key component in multiple sclerosis (MS) pathology. Quantitative MRI metrics reflecting inflammation are important for understanding disease processes in vivo. Metrics from multi-echo T2 relaxation, Diffusion Basis Spectrum Imaging (DBSI) and Neurite Orientation Dispersion and Density Imaging (NODDI) were compared in participants with MS and healthy controls. NODDI neurite density index and DBSI restricted fraction were correlated and may be sensitive to similar pathology. GMT2 correlated negatively with cellularity, but positively with oedema, suggesting oedema may be a key mechanism driving GMT2 increases. Our findings support a complementary T2 and diffusion approach to probe inflammation in MS.
The Open Science Initiative for Perfusion Imaging (OSIPI): Results from the ASL MRI Challenge
Authors: Anazodo Udunna , Pinto Joana , McConnell Flora , van Praag Cassandra , Mutsaerts Henk , Taylor Aaron , Petr Jan , Pineda-Ordóñez Diego , Dounavi Maria-Eleni , Brumer Irène , Chan Wei Siang Marcus , Toner Jack , Hu Jian , Zhang Logan , Bell Laura , Woods Joseph , Zhao Moss , Croal Paula , Paschoal Andre
Published: August 2023

The OSIPI ASL MRI Challenge is an initiative of the ASL community aiming to characterize the variability of CBF quantification arising from different pipelines. The goal of this challenge is to establish best practice in ASL data processing, understand the sources of variability, make ASL analysis more reproducible, and enable fair comparison between studies. Here, we analyzed 3 submitted entries from 7 teams registered in the challenge. The preliminary results showed pipelines based in different programming languages and analysis tools, leading to important variability in the quantitative CBF maps compared to the ground-truth.
The value of semi-quantitative parameters of Dynamic Contrast-Enhanced MRI(DCE-MRI) to predict the expression of P53 in the ovarian cancer
Authors: Lu Xulun , Li Ye , Song Qingling , Liu Ailian
Published: August 2023

P53 is a tumor suppressor gene,TP53-mutated tumors in general have an aggressive phenotype and are characterized by poor differentiation, increased invasiveness, and high metastatic potential[1]。The early enhancement rate reflects the blood perfusion in the early enhancement stage of the lesion. Tumor exhibits a higher early enhancement rate with more abundant the blood supply of the tumor. Our study proved that the wash-in rate of ovarian cancer in the p53 positive group was higher than that in the P53 negative group.
Prediction of prognosis of nasopharyngeal carcinoma after neoadjuvant chemotherapy based on radiomics and multimodal machine learning
Authors: Hu Chunmiao , Hu Zhijian , Chen Li , Zheng DeChun , Chen Yunbin , Cao Xisheng , Lu Tao
Published: August 2023

This study is the first to adopt post-NACT MR radiomics to predict the recurrence of locally advanced NPC (stages III and IVa).
Intravoxel incoherent motion improves diffusion-weighted imaging in detection of response towards neoadjuvant chemotherapy in breast cancer
Authors: Cheung Sai Man , Wu Wing Shan , Senn Nicholas , Sharma Ravi , McGoldrick Trevor , Gagliardi Tanja , Husain Ehab , Masannat Yazan , He Jiabao
Published: August 2023

Breast cancer is a major and expanding health challenge, and neoadjuvant chemotherapy (NACT) is increasingly prescribed to facilitate breast surgery in advanced breast cancer with an ongoing demand for improved imaging methods accurately reflecting disease load. Tissue perfusion, a sensitive marker of cancer metabolism, can be derived from intravoxel incoherent motion (IVIM) model, and recent Bayesian algorithm yields improved sensitivity and precision in breast cancer by us and pancreatic cancer. We therefore hypothesise that IVIM model powered by Bayesian algorithm is able to detect early treatment-induced changes in tumour perfusion and diffusion, with the potential to impact patient care pathway.
New Denoising Neural Network for Diffusion Tensor Imaging Signal-to-Noise Ratio Enhancement
Authors: Chen Po-Ting , Wang Tzu-Yi , Chen Jyh-Horng
Published: August 2023

本研究提出了一種新的神經網絡模型來提高 DTI 圖像的信噪比。從實驗結果來看，我們成功地將圖像的 SNR 提高了 3 倍，相當於減少了 9 倍的掃描時間。這將改善因信噪比不足而導致的 DTI 分析困難。
Gibbs-ringing Removal through Anti-aliased Deep Priors
Authors: Yi Jaeuk , Cui Chuanjiang , Jung Kyu-Jin , Kim Dong-Hyun
Published: August 2023

Inspired by recent usage of Deep Image Prior (DIP) in the field of MRI that utilizes a powerful low-level image prior from a neural network architecture itself without any training dataset, we conduct k-space extrapolation using the deep prior for Gibbs-ringing removal in order to build general Gibbs-ringing correction algorithm without dependency on the dataset. We further improved the existing deep prior with the addition of anti-aliasing layers. The proposed deep prior method outperformed conventional non-learning methods quantitively and qualitatively in numerical simulations and in-vivo data.
Inline artifact identification using segmented acquisitions and deep learning
Authors: Ravi Keerthi Sravan , Jimeno Marina Manso , Vaughan John Thomas , Geethanath Sairam
Published: August 2023

MR artifacts degrade image quality and affect diagnosis, requiring thorough examination by the MR technician, and reacquisition in some cases. We employ a combination of segmented acquisitions and a deep learning tool (ArtifactID) to perform more frequent updates to image quality during acquisition. ArtifactID identified wrap-around, Gibbs ringing and motion artifacts, with a mean accuracy of 99.43%. The segmented acquisitions for rescans resulted in a 12.98% time gain over the full-FOV sequence. In addition, ArtifactID alleviates burden on the MR technician via automatic artifact identification, saving image quality evaluation time and augmenting expertise.
Predicting changes in B0 field due to patient movement dynamically for MRI via Deep Learning
Authors: Motyka Stanislav , Weiser Paul , Bachrata Beata , Hingerl Lukas , Strasser Bernhard , Goranovic Dario , Hangel Gilbert , Niess Eva , Zaitsev Maxim , Robinson Simon , Langs Georg , Trattning Siegfried , Bogner Wolfgang
Published: August 2023

We proposed a U-net-based neural network to predict changes in B0 field due to patient movement. The network was trained and tested on 7T in vivo volunteer data. The method was compared against two other approaches. The estimated B0 maps were compared against the ground truth. The results suggest that prediction of B0 maps is feasible and by combination with external tracking a considerable improvement in data quality of B0-sensitive MRI methods could be achieved.
Characterisation of restricted diffusion and exchange using the velocity autocorrelation function
Authors: Chakwizira Arthur , Lasič Samo , Reymbaut Alexis , Westin Carl-Fredrik , Szczepankiewicz Filip , Nilsson Markus
Published: August 2023

Temporal velocity correlations of diffusing particles carry information about the structure of the diffusion environment. Studying high-order velocity autocorrelation functions can aid in understanding how signal is influenced by restricted diffusion and exchange, and in turn how to design experiments that are sensitive/independent to these phenomena. In this work, we employ numerical simulations on a variety of substrates to demonstrate this notion. We find that the fourth order velocity autocorrelation bears a distinctive signature of exchanging systems. In addition, we highlight that the effect of exchange on the second order velocity autocorrelation is negligible when exchange is barrier-limited.
Individualized arterial spin labeling background suppression by rapid T1 mapping during acquisition
Authors: Lindner Thomas , Austein Friederike , Guerreiro Helena , fiehler Jens
Published: August 2023

This work presents a method of rapidly acquiring a T1 map to optimize background suppression in Arterial Spin Labeling to improve the signal-to-background contrast.
Clinical evaluation and reproducibility of 3D whole-heart free-breathing joint T1/T2 quantification with isotropic resolution.
Authors: Velasco Carlos , Hua Alina , Fotaki Anastasia , Munoz Camila , Milotta Giorgia , Kunze Karl , Neji Radhouene , Ismail Tevfik , Prieto Claudia , Botnar Rene
Published: August 2023

Myocardial tissue characterization including quantification of fibrosis and oedema plays an important role in the evaluation of many myocardial diseases. T1 and T2 maps are typically acquired sequentially in 2D under several breath-holds. However, misregistration artifacts, spatial resolution and volumetric coverage remain a limitation. To address this, a high resolution, 3D whole-heart motion-compensated joint T1/T2 water/fat sequence has been proposed and validated in a phantom and in healthy subjects. Here, we demonstrate the feasibility of the proposed approach to simultaneously acquire whole-heart co-registered T1, T2 maps as well as water and fat volumes in ~9min in patients with cardiovascular disease.
Deep Learning-based Stroke Region Segmentation on Susceptibility Weighted Images in Acute Stroke
Authors: Kandpal Ankit , Jayas Tanuja , Bhattacharjee Rupsa , Gupta Rakesh , Singh Anup
Published: August 2023

SWI plays a critical role in stroke in demonstration of hemorrhagic transformation of stroke and demonstration of thrombus in the intracranial arteries. Recently it has been used to quantify the penumbra in acute stroke. It highlights venous vasculature in acute stroke due to hypoxia in the acute ischemic tissue without the need for any contrast injection and adding additional sequence that results in time penalty. The objective of this study was to develop an automatic framework for penumbra detection using only SWI images. Evaluation of segmentation results shows a dice similarity coefficient of 0.72 and a jaccard index of 0.60.
SLOW-editing for GABA/GABA+ MRSI at 7T
Authors: Weng Guodong , Radojewski Piotr , Slotboom Johannes
Published: August 2023

Purpose: whole brain in vivo detection of GABA/GABA+ using SLOW-editing at 7T.

Methods: An EPSI-based B0/B1+ robust SLOW-editing was applied in four healthy subjects. Pure GABA was measured by two different macromolecular-nulling inversion recovery pulses, namely a broadband- and a narrowband-inversion pulse.

Results: the editing GABA/GABA+ signal at 3.01 ppm are presented. The signal intensity of GABA/GABA+ ratio is 40 – 60%.

Conclusions: whole-brain in vivo GABA/GABA+-editing can be performed using SLOW-EPSI in around 10 minutes measurement time and is therefore clinically applicable.
Dual-encoding of magnetization transfer and diffusion for the characterization of tract-specific myelination
Authors: Leppert Ilana , Rowley Christopher , Campbell Jennifer , Nelson Mark , Pike Bruce , Tardif Christine
Published: August 2023

Most white matter voxels are comprised of a combination of microstructurally different tracts that kiss and cross. Conventional MRI contrasts that provide a single measurement per voxel fail to disentangle the microstructural properties of these tracts. Co-encoding diffusion with a complementary contrast offers additional insight into each tract’s individual contribution. Here we present a novel MT-prepared diffusion sequence, optimized for contrast in both MTR and orientation, acquired within a clinically acceptable scan time of under 7 min. The goal is to provide a data acquisition framework for the computation of tract-specific myelin indices and potentially more structurally specific connectomes.
Functional changes in GABA during motor learning with GABA-editing at 3T
Authors: Bell Tiffany , Craven Alexander , HugDahl Kenneth , Noeske Ralphe , Harris Ashley
Published: August 2023

Functional magnetic resonance spectroscopy (fMRS) of GABA at 3T is challenging due to the difficulties of measuring GABA levels; GABA is present in the brain at relatively low concentrations and its signal is overlapped by higher concentration metabolites. Here we use a continuous MEGA-PRESS acquisition to show changes in GABA levels measured in the sensorimotor cortex during motor learning and during a control button pressing task. This indicates GABA levels can be tracked during a functional experiment, allowing fMRS of GABA to be accessible at 3T, the more commonly used field strength.
A currentless remote decoupling circuit for receive-only endoscopic MRI coils using negative impedance converters
Authors: Marhabaie Sina , Willoquet Georges , Dubuisson Rose-Marie , Quesson Bruno , Poirier-Quinot Marie
Published: August 2023

Receive-only coils must be decoupled from the transmit coil during excitation. For conventional coils, decoupling is achieved using a resonant trap, which is switched during B1 transmit. However, in situations with very limited space like intravascular coils, this method remains problematic. We aimed to address efficient remote decoupling of a receive-only coil. We implemented an alternative approach by adding a “negative resistance” to the trap. This negative resistance is tailored in such a way that cancels out the positive resistance of the blocking trap, hence augmenting the quality factor of the trap and thus the decoupling efficiency.
Dynamic Pressure-Volume Loop Analysis using Simultaneous Real-Time Cardiac MRI and Left Heart Catheterization
Authors: Seemann Felicia , Bruce Christopher , Khan Jaffar , Ramasawmy Rajiv , Potersnak Amanda , Herzka Daniel , Jaimes Andi , Schenke William , O’Brien Kendall , Lederman Robert , Campbell-Washburn Adrienne
Published: August 2023

Pressure-volume (PV) loops can be used to derive the valuable cardiac functional parameters contractility and compliance. Conventional PV loop catheters provide unreliable volume measurements. In this study we develop and validate a method to obtain dynamic PV loops during an MRI-guided preload alteration via inferior vena cava occlusion, using simultaneous measurements of left ventricular pressure from a catheter and volume from real-time long-axis cardiac MRI. Pressure and volume signals were synchronized and used to derive contractility and compliance. Long-axis derived volumes were validated against conventional short-axis images. The method was tested in naïve, ischemic cardiomyopathy, and aortic banding swine models.
Evaluating of Deep Brain Nuclei Iron Deposition in Primary Grade 1 Hypertension Patients by QSM: A Preliminary Study
Authors: Zhang Shiyun , Wu Kunhua , Bi Guoli , Wang Shaoyu , Wu Yunzhu , Xie Guoqing , Wang Qian
Published: August 2023

Hypertension is becoming a common health problem all over the world. In this study, Quantitative Susceptibility Mapping (QSM) was used to compare the differences of iron deposition in deep brain nuclei between 28 primary grade 1 hypertension (PG1H) patients and 28 age-sex-matched healthy controls (HC). The results showed that the iron deposition in six deep brain nuclei ROIs were higher in PG1H than in HC. This study laid a foundation for exploring the relationship between the hypertension severity and iron deposition in deep brain nuclei. It was also of great significance for clinical exploration of the physiological and pathological mechanism of hypertension and the correct selection of the treatment scheme of hypertension.
Fast scan downfield MRS for NAD+ quantification in human skeletal muscle in vivo at 7 T
Authors: Nanga Ravi Prakash Reddy , Elliott Mark , Wilson Neil , Swago Sophia , Witschey Walter , Reddy Ravinder
Published: August 2023

1H downfield MRS is an emerging technique for quantification of in vivo NAD+ concentrations in human tissue. Though NAD+ can be detected in the skeletal muscle downfield spectrum (>4.7 ppm) despite its low concentration (<1 mM), quantification of [NAD+] in muscle disorders is further challenged by depleted NAD+ and long scan times. To address this challenge, we developed and optimized a downfield MRS technique for rapid measurement of NAD+ targeting calf skeletal muscle in a large voxel approach. This optimized technique has allowed us rapid measurement of NAD+ and shortened scan time considerably compared to previously published MRS techniques.
Creatine chemical exchange saturation transfer (CrCEST) MRI reproducibility in healthy adults at 3T
Authors: Coleman Zane , Khan Ayaz , Wang Shubo , Hanby Pat , Wallace Donald , Patay Zoltan , Bagga Puneet
Published: August 2023

CrCEST MRI indirectly measures creatine as it exchanges amine (-NH2) protons with free water in the skeletal muscle. When performed on the calf after plantar flexion exercise, creatine recovery data can be obtained in all four major calf muscles. While 2D CrCEST has been performed in adults before, no studies showing its reproducibility have been published. Here, we show that the essential muscles in plantar flexion movement, gastrocnemius muscles, in the calf are candidates for reproducible CrCEST data.
Simultaneous Measurement of Glu and GABA at 7T
Authors: Finkelman Tal , Furman-Haran Edna , Paz Rony , Tal Assaf
Published: August 2023

Glutamate (Glu) and γ‑aminobutyric-acid (GABA) are central neurotransmitters participating in many cognitive processes, and their combined measurement is of great relevance. Proton Magnetic Resonance Spectroscopy (1H-MRS) allows the no–invasive, in-vivo, measurement of GABA and Glu. At magnetic fields below 7T, GABA is detected by spectral editing strategies, while Glu is detected by non-editing strategies. We compared both edited and non‑edited approaches at 7T for simultaneously quantifying Glu and GABA from 21 volunteers, and found that non-edited sequences at TE=80ms provide better combined-reproducibility than either edited sequences at the same TE, or non-edited sequence at a shorter TE (42ms).
Hyperpolarized [1-13C]Pyruvate MRI of Spleen: Monitoring Immune Activation for Cervical Cancer Patient following Radiotherapy
Authors: Lin Gigin , Lai Ying-Chieh , Lu Kuan-Ying , Chen Albert , Hsieh Ching-Yi
Published: August 2023

Successful cancer therapy depends on an optimal immune response, but noninvasive tools are lacking to monitor this dynamic process. In this proof-of-concept human study, we demonstrated hyperpolarized [1-13C]pyruvate MRI of the spleen monitoring the immune activation for cancer patients at the early time point following radiotherapy, by measuring the pyruvate-to-lactate conversion rate. The ADC-based cellularity of the spleen, however, did not detect remarkable changes.
Shear-rate values in the carotid bifurcation in subjects with carotid webs, subjects with atherosclerotic lesions, and healthy subjects.
Authors: El Sayed Retta , Sharifi Alireza , Park Charlie , Haussen Diogo , Allen Jason , Oshinski John
Published: August 2023

Carotid webs (CaWs) have been linked to cryptogenic strokes and therefore quantifying different hemodynamic parameters is essential to understand the mechanism of clot formation in patients. Computational fluid dynamics (CFD) based on patient-specific geometry and PCMR inlet flow conditions was conducted on five subjects with CaWs, five subjects with mild atherosclerosis (with a similar degree of luminal narrowing), and three healthy control subjects. The total area within the carotid bifurcation that contained low shear rate values associated with clot formation is significantly larger in CaW subjects compared to subjects with atherosclerotic lesions or healthy subjects.
3D-Simulation of Flowing Spins using the Lattice Boltzmann Method with Maxwell Diffuse Reflection Boundaries
Authors: Adler Ansgar , Schaten Philip , Wang Yong , Uecker Martin
Published: August 2023

The lattice Boltzmann method (LBM) is a powerful technique to simulate complex fluid dynamical systems. The extension of the LBM to flow with a spin degree of freedom in external magnetic fields has shown promising results in 2D. Here, we describe first 3D numerical results utilizing extended kinetic-theory based boundary conditions. The simulation of a laminar pipe flow is verified on the Pouiseuille flow and shown to be able to predict signal changes caused by in-flow effects as expected from previous flow experiments.
Investigation of myelin using T1/T2 ratio imaging across multiple datasets: comparable or not?
Authors: Fumi Riona , Maksimuk Hanna , Cole James , Vos Sjoerd
Published: August 2023

Cortical T1/T2 ratios (T1/T2r) have been used to assess myelination along the lifespan and investigate demyelination in neurological diseases. Creating a comprehensive normative population from open-access datasets could facilitate widespread adoption of this technique. Here we investigate comparability between two such publicly available datasets, OASIS3 and CamCAN. We find that they vary in terms of offset, lifespan trajectory, and presence (OASIS3) or absence (CamCAN) of hemispheric asymmetry. This variability exists despite both studies use the same scanner model, and is likely increased across different scanner models and vendors. These findings indicate that combining data from different studies requires advanced normalisation.
TR dependence of phase-cycled bSSFP relaxometry in brain tissue
Authors: Schäper Jessica , Bieri Oliver
Published: August 2023

Brain relaxometry with phase-cycled bSSFP shows systematically lower T1 values, if compared to spoiled-GRE or inversion-recovery spin echo methods. One explanation can be the pronounced asymmetry in the bSSFP's frequency profile, observed for tissues. It was recently shown that this asymmetry decreases towards shorter TR, possibly leading to an adjustment of T1 estimates from bSSFP to spoiled-GRE. Here, it was investigated how T1 and T2 quantification is influenced by TR. Contrary to expectation, a stronger mismatch between bSSFP and spoiled-GRE was observed towards shorter TR. The origin of this mismatch can thus not be attributed to the bSSFP profile asymmetry.
Characterization of cardiac alterations in transgenic rat model of pulmonary arterial hypertension exposed to chronic hypoxia
Authors: El Hamrani Dounia , Magat Julie , Naulin Jérôme , Ayez Céline , Campagnac Marilyne , Perros Frédéric , Guibert Christelle , Benoist David , Quesson Bruno
Published: August 2023

Transgenic rats with Bmpr2 mutation is a model of heritable pulmonary arterial hypertension (PAH). This study aims to evaluate cardiac alterations of Bmpr2-mutants associated with a risk factor (hypoxia) by MRI and 31P-MRS. Transgenic rats exposed to chronic hypoxia showed a drastic dilatation of the RV along with an increased wall thickness and no variation of ejection fraction, thus resembling right heart failure with preserved ejection fraction. The cardiac energy balance is disturbed in Bmpr2 rats under hypoxia indicating a metabolic insult. Bmpr2 mutation associated with chronic hypoxia can aggravate right heart failure and thereby accentuated the onsets of PAH.
Quantitative analysis of dynamic-contrast enhanced MRI by dispersion analysis for improved prostate cancer diagnosis
Authors: Turco Simona , Fernandes Catarina Dinis , Miclea Razvan , Schoots Ivo , Nooijen Peet , van der Linden Hans , Barentsz Jelle , Heijmink Stijn , Wijkstra Hessel , Mischi Massimo
Published: August 2023

Multiparametric MRI, including T2-weighted, diffusion-weighted, and dynamic contrast enhanced (DCE) imaging, is the recommended imaging modality for prostate cancer (PCa). Although the role of DCE-MRI has been greatly limited in recent years, only qualitative analysis of DCE is currently performed. Here we propose magnetic resonance dispersion imaging (MRDI) to obtain quantitative parametric maps from DCE-MRI. Comparing the performance of two radiologists, our results show that some clinically-significant PCa are only found by interpretation of either mpMRI alone or MRDI maps alone, suggesting that combined interpretation of MRDI and mpMRI may improve PCa diagnosis.
Vibration measurements of the SC72 gradient versus field strength in the Iseult magnet
Authors: Boulant Nicolas , Lerman Cécile , Quettier Lionel , Dubois Olivier , Molinié Frédéric , Dietz Peter , Aubert Guy
Published: August 2023

The whole-body Iseult 11.7T CEA magnet has delivered its first images after nearly 20 years of research and development. Before reaching this long-waited step, a gradient coil–magnet interaction test campaign was run for several months at 3T, 7T, 10.2T and 11.7T on the same identical system. It included acoustics, vibrations, magnet safety system voltage and power deposition in the He bath measurements. Some vibration results versus field strength are presented here. Vibration amplitudes are shown to increase less than with B0 field strength.
Accelerated volumetric vocal tract MRI using model based deep learning
Authors: Alam Wahidul , Lingala Sajan
Published: August 2023

3D MRI is a powerful tool to safely visualize the various vocal-tract configurations during voice production [1-3]. Current accelerated 3D vocal-tract MRI schemes based on spatial total variation transform (SPTV) regularization are susceptible to non-trivial artifacts (e.g., blurring at air-tissue boundaries, patchy representation of small structures such as the epiglottis, glottis). In this work, we apply a model based deep learning reconstruction scheme that can significantly accelerate 3D vocal-tract imaging. We demonstrate it to produce images with high-spatial fidelity, natural-looking like contrast, and significantly robust to artifacts seen with current SPTV based schemes.
Automatic vascular segmentation of neck TOF MRA images based on 3D CNN model
Authors: Qiu Wei , Wei Hanyu , Chen Shuo , Li Rui
Published: August 2023

Accurate and fast automatic Carotid artery segmentation of time of flight(TOF) MRA plays an important role in the auxiliary diagnosis of carotid artery disease. Considering the complexity and uncertainty of doctors’ manual segmentation of neck vessels, automatic segmentation algorithms are required in clinical practice. A segmentation model based on 3D Convolutional neural network (CNN) was proposed to segment carotid arteries from TOF MRA images. With innovative adjustment of the network architecture and parameters for carotid application, our model showed better performance than other baseline models on private dataset.
White matter perivascular space enlargement in cerebral small vessel disease indicates cerebral amyloid angiopathy pattern changes
Authors: hong hui , zhang minming
Published: August 2023

The enlargement of white matter perivascular space(PVS) is highly CAA related, however lack of studies investigated its role in stable pattern CSVD patients, we hypothesis that CSVD patients with white matter PVS enlargement indicates a CAA pattern changes.

Here we compared patients with and without white matter PVS enlargement from imaging manifestation, imaging mechanism and clinical cognitive ability. We foud that patients with PVS enlargenmet showed a pattern similar to previous symptomatic CAA, that is more lobar microbleed, more interstitial fluid retention and significantly lower global cognitive ability. Extra dignosis and treament should be carried out to this pattern CSVD.
Comparison of MAPSS- vs UTE-based T1rho Sequences in the Knee
Authors: Carl Michael , Moazamian Dina , Lombardi Alecio , Afsahi Amir , Ma Yajun , Du Jiang
Published: August 2023

We compared two different T1rho sequence approaches and assessed their performance for quantitative musculoskeletal imaging. We found that using either a MAPSS or UTE acquisition after T1rho preparation resulted in similar T1rho decay values for tissues of moderate to long T2s (e.g., cartilage or meniscus). The UTE acquisition sequence, however, was also readily able to obtain T1rho decay values for tissues with short T2s (e.g., tendons), thereby facilitating whole knee assessment.
Super Resolution Segmentation of the Scapula from Clinical MRI
Authors: Caliva Francesco , Wong Victoria , Su Favian , Lansdown Drew , Pedoia Valentina
Published: August 2023

We propose a deep learning approach to simultaneous super resolution and segmentation. We experiment our framework on the challenging task of generating 3D high-resolution axial shoulder MRI from 2D clinical MRI sequences, and demonstrate the ability to produce precise 3D scapula bone models. With an extensive experimental study, we show that with super-resolution, it is possible to produce high resolution bone models, which are invaluable for surgeons in the pre-operative planning of patients with various shoulder conditions. This method has the potential to reduce patients' need for undergoing CT scans, hence preventing exposure to radiation.
Improved Modelling of ADC Distributions makes Therapeutic co-clinical Trials possible with very small animal numbers
Authors: Tar Paul , Thacker N.A. , Babur M. , Lipowska-Bhalla G. , Cheung S. , Little R. , Williams K.J. , O'Connor J.P.B.
Published: August 2023

In oncology, preclinical experiments using MRI often evaluate spatially complex and heterogeneous tumor micro-environments which have non-Gaussian data and small sample sizes, with cohorts typically of 10 animals or less. As a consequence, conventional use of t-tests that evaluate distribution parameters such as means and percentiles can be ineffective. Further, the cohort-level nature of such analyses also limits investigations to groups of tumors rather than identifying individually responding tumors. In contrast, Linear Poisson Modelling (LPM) enables quantitative analysis of complex data, can operate in small data domains and can also provide per-tumor assessments 2.ideal for co-clinical trials.
Quantitative T1D assessment in lipid membranes: Jeener-Broekaert NMR vs. ihMT MRI
Authors: Hertanu Andreea , Soustelle Lucas , de Rochefort Ludovic , Grélard Axelle , Loquet Antoine , Dufourc Erick J. , Varma Gopal , Alsop David C. , Duhamel Guillaume , Girard Olivier M.
Published: August 2023

The dipolar order relaxation time (T1D) is a probe of membrane dynamics and microstructure and could serve to further understand the relationship between the myelin membrane integrity and its biological function. In this work, the ability of quantitative inhomogeneous Magnetization Transfer (qihMT) to estimate the several T1D components of a synthetic lipid membrane system, a surrogate for the myelin membrane, was evaluated by comparison with the gold standard method for T1D quantification, the NMR Jeener-Broekaert (JB) sequence.
Use of Phase Resolved Functional Lung Imaging (PREFUL) to Assess Response to Kaftrio® Therapy in Cystic Fibrosis
Authors: Peggs Zachary , Brooke Jonathan , Safavi Shahidehalsadat , Prayle Andrew , Ng Christabella , Alappadan Jan , Bradley Christopher , Cooper Andrew , Munidasa Samal , Zanette Brandon , Santyr Giles , Barr Helen , Smyth Alan , Hall Ian , Francis Susan , Gowland Penny
Published: August 2023

Phase resolved functional lung imaging (PREFUL) was carried out before and 12 weeks after commencement of Kaftrio® therapy in a small Cystic Fibrosis (CF) group, and in healthy controls (HC). No significant differences were found in measures characterising the PREFUL signal between HC and CF, or before and after Kaftrio® therapy. This could be explained by the small sample size or lack of age matching. It was found that fractional ventilation measures with PREFUL can be sensitive to subjective thresholding and the method of image registration. Also, the impact of irregular breathing patterns, especially in patients, should be further explored.
Meniscal deformation MRI study using knee joint axial loading device and finite-element-model
Authors: Jogi Sandeep , Thaha Rafeek , Rajan Sriram , Mahajan Vidur , Venugopal Vasantha , Mehndiratta Amit , Singh Anup
Published: August 2023

The meniscal-extrusion may disturb the stability of the knee-joint, and depicts laxity in the meniscal-hoops. The degraded meniscal site usually show changes in the MR images (T1, T2, and Proton-Density-weighted images). However, the laxity of a specific meniscal segment and its effect on adjacent segment’s deformation is unknown. The current study attempt to address this problem using MRI data (with and without loading) and a finite-element-model. Each meniscal-hoop’s (lateral and medial) lengths, thickness, and meniscus-extrusion was measured to evaluate load-bearing changes. Medial meniscus hoop’s Anterior-meniscal-length(ML), Posterior-ML, Central-ML, and meniscus-extrusion show substantial change(>5%) during load.
Compressed sensing and the use of 3D UTE acquisition for high-resolution accelerated 23NA imaging at 3T
Authors: Villarreal Cameron , Shen Xin , Ozen Ali , Ilbey Serhat , Chiew Mark , Alhulial Ahmad , Pogue Evan , Emir Uzay , Chan Deva
Published: August 2023

There is a need for methods to detect early compositional changes during musculoskeletal diseases like osteoarthritis, but current diagnostic tools . Sodium (23Na) MRI enables quantification of sodium content which is correlated with cartilage health. However, several limitations preclude its widespread clinical use including long scan times and low resolution. We have developed a UTE 23Na MRI sequence with rosette acquisition capable of overcoming some of these limitations. In this study we demonstrate the feasibility of reducing our acquisition time through compressed sensing while conserving signal quality in a healthy human knee.
Optimization of combined spin- and gradient-echo EPI in fMRI via in- and through-plane acceleration
Authors: Keeling Elizabeth , Bergamino Maurizio , Ragunathan Sudarshan , Quarles C. , Stokes Ashley
Published: August 2023

BOLD-fMRI is widely used to study brain activity but suffers from signal dropout near air-tissue interfaces and lack of sensitivity to microvasculature. A combined spin- and gradient-echo (SAGE) acquisition, previously implemented for perfusion MRI, may be able to reduce signal dropout and provide sensitivity to microvasculature for fMRI applications. SAGE-fMRI presents its own challenges, namely lack of full brain coverage and poor temporal and spatial resolution. These challenges can be overcome by combining in-plane and through-plane acceleration factors. This study aims to optimize the SAGE-fMRI protocol, balancing acceleration of acquisition with image quality.
Deep learning based image reconstruction for improved 3D multiparameter mapping and synthetic MR imaging
Authors: Hwang Ken-Pin , Learned Kim , Takei Naoyuki , Lebel R. , Johansson Peter , Shin David , Wang Xinzeng , Petersen Catharina , Warntjes Marcel , Banerjee Suchandrima , Chi Linda
Published: August 2023

Brain data with high grade glioma were acquired with a 3D multiparameter mapping sequence and reconstructed with a novel deep learning based method (DL Recon). Synthetic images created from maps fitted to the reconstructed images were rated by experienced radiologists for image quality and diagnostic utility. Images from the DL Recon workflow consistently rated equal to or better than those created from conventional reconstruction. We find that the SNR and resolution benefits of 3D DL Recon extend to improve the resulting relaxation maps and subsequent synthetic images.
GESSE Measurements at varying spin echo times in human brain at 7T
Authors: Shaw Ross , Gowland Penny , Bowtell Richard
Published: August 2023

Simultaneous measurements of R2 and R2’ using the Gradient Echo Sampling of a Spin Echo (GESSE) sequence were made at multiple spin echo times in four volunteers. Secondary measurements of R2 and R2* were made using classical Spin Echo and Gradient Echo approaches. The variation in measured relaxation rates are explored and show a general overestimation of transverse relaxation in white and grey matter when measured with GESSE suggesting a lack of complexity in the model used to describe the GESSE signal.
Generating MRI reporter genes using a Protein Optimizing Evolving Tool (POET)
Authors: Bricco Alexander , Miralavy Illiya , Bo Shaowei , Perlman Or , Farrar Christian , McMahon Mike , Banzhaf Wolfgang , Gilad Assaf
Published: August 2023

Reporter genes for MRI allow for the non-invasive observation and evaluation of gene and cell therapies which are being rapidly developed. Traditional methods of gene optimization failed to improve reporter gene quality. We developed and employed a novel machine learning program called the Protein Optimizing Evolving Tool (POET). Using POET we have discovered peptides which provide more contrast than prior efforts and also display properties that challenge prior knowledge on the functions of these genes.
Investigation of correlation between surface current and coupling using conventional coils and shielded coaxial cable coils operating at 7T
Authors: Costa Giovanni , Güler Sadri , Baltus Peter , Paulides Maarten , Zivkovic Irena
Published: August 2023

One of the major challenges in the design of multichannel arrays for UHF MRI is minimizing coupling between elements. Shielded-coaxial-cable (SCC) coils have been recently proposed as highly decoupled elements per se: however, the decoupling mechanism of SCC coils is still not determined. In this work, we examined the relationship between coupling, surface current density uniformity, and the total current on coil conductor through measuring and simulating three different 2-coils arrays. While no correlation was observed between surface current density uniformity and interelement coupling, a negative correlation was observed between the coupling and the total current on coil conductor.