bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Aging and Muscle Degeneration on Metabolic Response to High-Intensity Muscle Contraction in Mice by Phosphorus-31 MRS
Authors: Kim Kihwan , Zhu Yuran , Li Yudu , Liang Zhi-Pei , Yu Xin
Published: August 2023

In this study, 31P-MRS was employed to evaluate the effects of aging and muscle degeneration on metabolic response to stimulation-induced, high-intensity muscle contraction in two age groups of C57BL/6 and mdx mice, a mouse model of moderate muscular dystrophy. Significant, age-dependent differences in mitochondrial oxidative capacity and creatine kinase activity after muscle stimulation were observed between C57BL/6 and mdx mice, suggesting a positive metabolic response to muscle contraction that can be modulated by aging and muscle degeneration.
Mouse rsfMRI connectome fingerprinting recovers subject as well as genetically encoded Ca2+ indicator loci
Authors: Mandino Francesca , Horien Corey , Shen Xilin , O'Connor David , Ge Xinxin , Herman Peter , Qu An , Onofrey John , Crair Michael , Papademetris Xenophon , Constable Todd , Lake Evelyn
Published: August 2023

We find that the connectome, from resting-state functional magnetic resonance imaging data, can be used to identify (ID) individuals across species (humans and mice). This finding hints at the potential to use these data for individualized medicine and for translational research. To this end, we interrogate how ID rates differ across species, and how the manipulations we introduce into animal models – the use of clones and genetically encoded calcium indicators (GECI) – impact the connectome. We find species-specific ID rates differ, but only require small portions of the connectome, and that GECI loci can be recovered using this framework.
Uncertainty-Aware Physics-Driven Deep Learning Network for Fat and R2* Quantification in Self-Gated Free-Breathing Stack-of-Radial MRI
Authors: Shih Shu-Fu , Kafali Sevgi , Calkins Kara , Wu Holden
Published: August 2023

MRI noninvasively quantifies liver fat and iron in terms of proton-density fat fraction (PDFF) and R2*. While conventional Cartesian-based methods require breath-holding, recent self-gated free-breathing radial techniques have shown accurate and repeatable PDFF and R2* mapping. However, data oversampling or computationally expensive reconstruction is required to reduce radial undersampling artifacts due to self-gating. This work developed an uncertainty-aware physics-driven deep learning network (UP-Net) that accurately and rapidly quantifies PDFF and R2* using data from self-gated free-breathing stack-of-radial MRI. UP-Net used an MRI physics loss term to guide quantitative mapping, and also provided uncertainty estimation for each quantitative parameter.
Direct parameter estimation of white matter model from DKI maps using recurrent neural network
Authors: Diao Yujian , Jelescu Ileana
Published: August 2023

WMTI-Watson is a widely used biophysical model that estimates microstructure parameters from the diffusion and kurtosis tensors. Here we propose a deep learning (DL) approach based on the recurrent neural network (RNN) to increase the robustness and accelerate the parameter estimation. The RNN solver achieved high accuracy, had good generality and was extremely fast in computation. The proposed DL approach is highly promising to replace the conventional nonlinear least-squares optimization in parameter estimation of WMTI-Watson model and thus estimate WM parameters from any DKI maps.
Correlation between pathophysiological functions of Glioma invasion and water dynamics by FFC-NMR in vivo
Authors: Ruggiero Maria , Itto Hamza Aït , Baroni Simona , Boutonnat Jean , Berger François , Broche Lionel , Aime Silvio , Geninatti Simonetta , Lahrech Hana
Published: August 2023

R1-dispersion profiles of in vivo glioma mouse models acquired by Fast-Field-Cycling NMR (FFC-NMR) were found to discriminate invasion from proliferation at fields below 2mT. These differences were correlated to the transcytolemmal water-exchange, demonstrating the water cell influx/outflux role in relaxation mechanisms. Hypoxia and H2O2, two major pathophysiological processes of invasion, were demonstrated to modulate relaxation. Immunohistochemistry of aquaporins AQP1 and AQP4 showed that the water-channel proteins were overexpressed in invasion but not in proliferation, suggesting that relaxations at low-field are modulated by water-exchange under the AQP1 and AQP4 control. The method can be extended to FFC imaging.
Modelling the effect of hyperoxia on the spin-lattice relaxation rate R1 of tissues
Authors: Bluemke Emma , Stride Eleanor , Bulte Daniel
Published: August 2023

The paramagnetic relaxivity effect of oxygen on longitudinal relaxation rate (R1) has been explored as a means of inferring partial pressure of oxygen in the tissue or bodily fluids, and examining tissue R1 response to hyperoxic gas breathing is used in research techniques such as oxygen-enhanced MRI. We present a 3-compartment model for estimating the hyperoxia-induced changes in R1 of tissues depending on B0, SO2, blood volume, hematocrit, oxygen extraction fraction, and changes in blood and tissue PO2. It is easy for researchers to tailor this model to their tissue of interest by substituting preferred tissue oxygen diffusion/consumption models.
Pulsed Selective Excitation in Multiphoton MRI
Authors: Han Victor , Chi Jianshu , Liu Chunlei
Published: August 2023

When multiple RF fields are applied at different frequencies, multiphoton excitation can occur when the sums or differences of integer multiples of these frequencies equal the Larmor frequency. No RF at the Larmor frequency is required. In this work, we describe the general principles of multiphoton pulsed selective excitation, providing a formalized treatment with design examples and implementations on a 3T scanner with an additional homemade z-direction (Bz) coil. With the additional Bz coil, we demonstrate additional flexibility, where the same excitation can be accomplished in several different ways with the same pulse duration.
Towards frequency robust tailored and universal pulses in the human heart at 7T
Authors: Aigner Christoph , Dietrich Sebastian , Krüger Felix , Lutz Max , Schmitter Sebastian
Published: August 2023

This work demonstrates the design and application of frequency robust, subject-tailored or universal, non-selective kT-point pulses to achieve a homogeneous flip-angle within the 3D human heart at 7T across a 1400Hz wide frequency range that includes water and six fat frequencies. Frequency robust universal pulses were computed offline based on 31 3D B1+-maps and could be used in time-critical situations for calibration-free 3D heart flip-angle homogenization. Experimental data at 7T validates the flip-angle predictions and demonstrates successful excitation of fat and water in the human heart at 7T.
Rapid B1+ Mapping using a Sandwiched Train Saturated TurboFLASH Sequence at 7T
Authors: Kent James , Valkovic Ladislav , Dragonu Iulius , Hess Aaron
Published: August 2023

Ultra-high field MRI with parallel transmit offers significant advantages but B1 transmit maps must be acquired to utilize its full potential. We designed and evaluated three new adaptations to a pre-saturation TurboFLASH B1+ mapping method. The proposed methods enabled significantly shorter TRs (on the order of 1 s), were insensitive to T1, and had comparable accuracy to the original method whilst maintaining the other desirable characteristics of the sequence. The method was shown to work in 3D allowing for volumetric B1­+ maps to be acquired in 18 seconds.
Microstructural MR Markers of Alzheimer’s Disease Pathology in Post-Mortem Human Temporal Lobe
Authors: Comrie Courtney , Dieckhaus Laurel , Beach Tom , Serrano Geidy , Hutchinson Elizabeth
Published: August 2023

Alzheimer’s is an irreversible degenerative brain disease. Current clinical MRI is capable of reporting severe brain atrophy, but fails to recognize earlier biomarkers associated with more subtle microstructural changes. Microstructural MRI techniques such as DTI, MAP-MRI, NODDI, MWF, and BPF are promising to address this challenge and may sensitively detect and distinguish tissue degeneration, tauopathies, and beta amyloid plaques. The capability of these techniques was investigated in post-mortem human temporal lobe specimens at high resolution and high image quality. Prominent findings seen were distinct differences between relaxivity and diffusivity metrics, and striking differences between DTI and MAP-MRI anisotropy metrics.
Explainable MRI: Revealing the mechanisms underlying deep learning brain disease classification
Authors: Tinauer Christian , Pirpamer Lukas , Masana Marc , Heber Stefan , Damulina Anna , Sackl Maximilian , Soellradl Martin , Schmidt Reinhold , Ropele Stefan , Langkammer Christian
Published: August 2023

Increased iron deposition in the basal ganglia is a frequent finding in patients with AD. Using R2* maps we separated Alzheimer's patients (n=115) from healthy controls (n=169) by using a deep neural network and systematically investigated the influence of the learned features using an attached relevance map generator. The highest relevances were found in and adjacent to the basal ganglia, which is in line with established histological findings and additionally confirmed by the conventional ROI-based analysis. This study demonstrates the validity of heat mapping as a means to identify novel areas of pathological tissue changes.
Transformer-based Alzheimer’s disease analyzer for multi-institutional 3D MRI images
Authors: Jang Jinseong , Hwang Dosik
Published: August 2023

We propose Transformer-based Alzheimer’s disease (AD) analyzer for 3D MRI. The proposed network can analyze 3D MRI images efficiently combining 3D CNN, and Transformer. It is possible to efficiently extract locality information for AD-related abnormalities in local brain based on CNN networks with inductive bias. Also, the transformer network is also used to obtain attention relationship among 3D representation features after CNN. Our proposed method was compared to various networks including 3D CNN and transformer with an area under curve and accuracy for AD classification in multi-institutional datasets. Also, the transformer interpretability technique-based activation map can visualize AD-related abnormality region.
Effect of Intravoxel Incoherent Motion on NODDI Diffusion Parameters in both Healthy and Psychotic Spectrum Disorder Populations
Authors: McKenna Faye , Sui Veronica , Lazar Mariana
Published: August 2023

We investigated the intravoxel incoherent imaging (IVIM) effect on neurite orientation dispersion and density imaging (NODDI) metric calculations in both healthy controls (N=36) and a clinical population of individuals with a psychotic spectrum disorder (PSD) (N=55) by extending the original model to include a microvascular blood compartment. We found that without controlling for the IVIM effect, several NODDI metrics were possibly misestimated, which subsequently affected group comparisons and results.
Hypothalamic subnuclei segmentation and diffusion tractography in Major Depressive Disorder at 7T
Authors: Langan Mackenzie , Qadi Ameen Al , Verma Gaurav , Delman Bradley , Murrough James , Balchandani* Priti , Morris* Laurel
Published: August 2023

We performed a novel 7T analysis of volumetric, microstructural and tractographic measures in the hypothalamus in MDD and matched controls. We uncovered significant differences in FA from left anterior superior and left tubular inferior, and discovered correlations between these regions and clinical measures of depression and anxiety. These findings warrant further investigations of microstructural integrity within the hypothalamus in patients with MDD and provide a basis for exploration of microstructural integrity within other neuropsychiatric disorders characterized by dysregulated mood and anxiety.
Tract- and Gray Matter- Based Spatial Statistics Show Microstructural Alterations in Autism Spectrum Disorder
Authors: DiPiero Marissa , Cordash Hassan , Prigge Molly , King Jace , King Carolyn , Lange Nicholas , Bigler Erin , Zielinski Brandon , Anderson Jeffrey , Lainhart Janet , Alexander Andrew , Dean Douglas
Published: August 2023

Advanced diffusion MRI techniques, such as Neurite Orientation Dispersion and Density Imaging (NODDI), may be used to improve characterization of gray matter (GM) and white matter (WM) microstructure of the brain. In this work, we used Gray Matter Based Spatial Statistics and Tract Based Spatial Statistics to investigate cortical GM and WM microstructural differences in individuals with autism spectrum disorder (ASD). Group differences and age by group interaction models were assessed. We demonstrate wide-spread alterations in GM and WM microstructure in ASD. Findings provide unique evidence of altered neurodevelopmental processes affecting microstructural development in ASD that persist into adulthood.
Size Matters: Correct diagnoses of MRI based renal oxygenation assessment by monitoring kidney size
Authors: Millward Jason , Cantow Kathleen , Gladytz Thomas , Waiczies Sonia , Niendorf Thoralf , Seeliger Erdmann
Published: August 2023

Tissue hypoxia occurs during acute kidney injury. MRI-based measurement of renal T2* and T2 could become a non-invasive surrogate marker of tissue oxygenation. However, the relationship between renal oxygenation and T2*,T2 is confounded by changes in the blood and tubular volume fractions, which are often accompanied by changes in kidney size (KS). We performed serial MRI scans along with clinically-realistic interventions acutely affecting renal oxygenation, applied directly while rats were in the scanner. We show that changes in KS correlate with changes in renal T2*,T2, underscoring that monitoring KS is necessary for correct interpretation of renal oxygenation derived from MRI.
Measurement of renal perfusion using ASL-MRI and renal oxygenation using BOLD-MRI in dogs: a pilot study
Authors: Hillaert Amber , Vanderperren Katrien , Pullens Pim
Published: August 2023

ASL- and BOLD-MRI have shown great potential in humans and rodents. To date, however, these techniques have not been used to image the canine kidney. Therefore, renal blood flow (RBF) and relaxation rate (R2*) were assessed using ASL and BOLD sequences on a beagle at 3T to examine the feasibility of both techniques in dogs. Mean RBF was 263.3 ± 39.0 and 277.4 ± 83.3 ml/100g/min in the right and left kidney, respectively. Mean R2* in the right kidney was 22.6 (range 14.8 - 36.8) s-1. This pilot-study demonstrates the feasibility of ASL- and BOLD-MRI for renal assessment in dogs.
Prognostic potential of multiparametric MRI in the assessment of renal allografts early after transplantation
Authors: Echeverria-Chasco Rebeca , Martin Moreno Paloma L. , Garcia-Fernandez Nuria , Vidorreta Marta , Oyarzun Anne , Larre Arantxa Villanueva , Bastarrika Gorka , Fernandez-Seara Maria A.
Published: August 2023

Purpose: to evaluate the prognostic potential of a multiparametric renal MRI protocol (perfusion, diffusion and T1) for the assessment of the allograft in the very early stages after transplantation.

Methods: 18 transplanted patients were imaged 6 days after the transplantation with ASL, IVIM and T1 mapping sequences. 2 groups were made depending on the allograft evolution (group A: no adverse events and group B: any adverse event).

Results: eGFR, album-creatinine ratio and cortical and medullary RBF were significantly higher in allografts of group A than in group B. Significant correlations between eGFR and RBF were found.
Cardiac cycle and flow compensation effects on REnal Flow and Microstructure AnisotroPy (REFMAP) MRI in healthy human kidney
Authors: Sigmund Eric , Mikheev Artem , Brinkmann Inge , Benkert Thomas , Chandarana Hersh
Published: August 2023

Diffusion-weighted imaging in renal tissue is a complex interplay of microstructural and microcirculation effects, which are often quantified with diffusion tensor imaging (DTI) or intravoxel incoherent motion (IVIM), as well as hybrid models such as Renal Flow and Microstructure AnisotroPy (REFMAP). This work measures the modulation of these effects with cardiac phase and with flow compensated (FC) diffusion gradient waveforms. Results show that both cardiac phase and FC affect diffusion metrics signficantly in cortex and medulla, and suggest that these experimental tools may in the future be leveraged to increase biophysical specificity of renal diffusion MRI metrics.
Validation of automatically measured ΔT1 values correlated with eGFR and fibrosis assessment of allograft kidneys
Authors: Aslam Ibtisam , Aamir Fariha , KASSAI Miklos , CROWE Lindsey , Seigneux Sophie , Moll Solange , BERCHTOLD Lena , VALLEE Jean-Paul
Published: August 2023

Chronic kidney disease (CKD) affects 11% of the population in Switzerland & US per year and is a major public health issue. Also, the CKD is 16th most prominent reason of life lost worldwide. MRI T1-mapping is a non-invasive way to monitor the renal prognosis. Recent studies show that the ∆T1 (cortex-medullary difference) has a strong positive correlation with fibrosis in CKD patients and is an important biomarker for CKD. This work proposes a validation of the T1-map cortico-medullary difference (ΔT1) values measured from automatically segmented cortex and medulla for eGFR and fibrosis assessment of allograft kidneys.
Develop CEST-detectable liposomes for nose-to-brain drug delivery
Authors: LAW Lok Hin , Huang Jianpan , Liu Yang , Xiao Peng , Lai Ho Chi Joseph , Chen Zilin , CHAN Kannie W.Y.
Published: August 2023

Nose-to-brain-drug-delivery is an effective route to administer drug to the brain bypassing the blood-brain-barrier(BBB). No non-invasive way to assess the delivery-efficiency available yet, especially with brain distribution. Here we investigated the imaging of nanomedicine-delivery via intranasal-administration using CEST-detectable(Iohexol loaded)mucus-penetrating-liposome(with10%PEG). The mucus-retention and penetration-efficiency was examined by in-vitro cell study and in-vivo CEST MRI after injecting the Iohexol-loaded-mucus-penetrating-liposome(Ioh-Lipo). 10%PEG-Ioh-Lipo showed a 20%higher mucus-retention than 1%PEG-Ioh-Lipo. This was also observed in-vivo with significant CEST-contrast difference in the OB between 3groups of mice at 4.3 and 3.5ppm. Moreover, liposomes were mainly found in the ONL, EPL, and MCL of the OB in histology.
Estimating Cerebrovascular Compliance from Normocapnia and Hypercapnia BOLD Pulsatility Mapping
Authors: Valsamis Jake , Luciw Nicholas , Swardfager Walter , Lim Andrew , Ramirez Joel , Black Sandra , MacIntosh Bradley
Published: August 2023

Measuring intracranial vascular compliance (VC) may help characterize a patient’s resilience to Alzheimer’s disease and dementia. In this study, we estimate VC from a BOLD MRI cerebrovascular reactivity (CVR) protocol by measuring cardiac-related BOLD pulsatility and end-tidal CO2 during periods of hypercapnia and normocapnia. We measured high VC in regions proximal to major cerebral arteries like the thalamus and insula, and low VC in the parietal lobe. This study demonstrates the feasibility of extracting additional information from BOLD-CVR experiments and suggests regional differences in VC. Future work will include a second cohort to estimate VC in different patient populations.
Inter-Rater Reliability of Fetal Lung Segmentation in High-Resolution Fetal Body Reconstructions
Authors: Payette Kelly , Geiger Julia , Zellner Michael , Kellenberger Christian , Tuura Ruth , Kottke Raimund , Jakab Andras
Published: August 2023

Reliable measurements of the fetal lung volume are important for the prenatal assessment of various pathologies impacting fetal lung development. Here we compare the inter-rater reliability of fetal lung volume measurements segmented from native ssFSE scans to those from high-resolution fetal body reconstructions to determine if the high-resolution reconstructions provide a clinical benefit. We find that there is increased reliability in the volumes segmented from the high-resolution reconstructions, suggesting that high resolution reconstruction of the fetal lungs may enable more precise assessments of fetal lung volume.
Assessment of Lung Ventilation and Perfusion of Premature Infants at 1.5 Tesla Using Phase-Resolved Functional Lung (PREFUL) MRI in the NICU
Authors: Dyke Jonathan , Voskrebenzev Andreas , Blatt Lauren , Vogel-Claussen Jens , Grimm Robert , Perlman Jeffrey , Kovanlikaya Arzu
Published: August 2023

The purpose of this study was to evaluate quantitative measures of lung function in premature newborns using (PREFUL) MRI on a 1.5 Tesla scanner located within the neonatal intensive care unit (NICU). MRI can non-invasively assess ventilation and perfusion defects in the infant lung without sedation, ionizing radiation or contrast administration. We performed (PREFUL) MRI in 6 neonates [5 preterm/1 term] without respiratory distress to assess lung function in this normal population. Continuation of this work may allow clinicians to quantitatively assess response to treatment in this vulnerable population with respiratory distress.
The spatiotemporal organization of cortical microstructural development in children and adolescents with diffusion MRI
Authors: Lynch Kirsten , Cabeen Ryan , Toga Arthur
Published: August 2023

Neocortical maturation is a dynamic process that proceeds in a hierarchical manner; however, the spatiotemporal organization of cortical microstructure with diffusion MRI has yet to be fully defined. This study characterized cortical microstructural maturation using fwe-DTI and NODDI in a cohort of 637 children and adolescents between 8 and 21 years of age. We found heterogeneous developmental patterns broadly demarcated into frontal, temporal and occipitoparietal domains where NODDI metrics increased and fwe-DTI metrics decreased with age. Our findings corroborate previous histological and neuroimaging studies that show spatially-varying patterns of cortical maturation that may reflect unique developmental processes of cytoarchitectonically-determined regions.
NLINV-Net: Self-Supervised End-2-End Learning for Reconstructing Undersampled Radial Cardiac Real-Time Data
Authors: Blumenthal Moritz , Luo Guanxiong , Schilling Martin , Haltmeier Markus , Uecker Martin
Published: August 2023

In this work, we propose NLINV-Net, a neural network architecture for jointly estimating the image and coil sensitivity maps of radial cardiac real-time data. NLINV-Net is inspired by NLINV and solves the non-linear formulation of the SENSE inverse problem by unrolling the iteratively regularized Gauss-Newton method, which is improved by adding neural network based regularization terms. NLINV-Net is trained in a self-supervised fashion, which is crucial for cardiac real-time data which lack any ground truth reference. NLINV-Net significantly reduces noise and streaking artifacts compared to reconstructions using plain NLINV.
Estimating Noise Propagation of Neural Network Based Image Reconstructio Using Automated Differentiation
Authors: Wang Xiaoke , Ludwig Danial , Rawson Michael , Balan Radu , Ernst Thomas
Published: August 2023

Image reconstructions involving neural networks (NNs) are generally non-iterative and computationally efficient. However, without analytical expression describing the reconstruction process, the compuation of noise propagation becomes difficult. Automated differentiation allows rapid computation of derivatives without an analytical expression. In this work, the feasibility of computing noise propagation with automated differentiation was investigated. The noise propagation of image reconstruction by End-to-end variational-neural-network was estimated using automated differentiation and compared with Monte-Carlo simulation. The root-mean-square error (RMSE) map showed great agreement between automated differentiation and Monte-Carlo simulation over a wide range of SNRs.
Nonlinear encoding scheme design for gradient-free projection imaging in an inhomogeneous Bo at low-field
Authors: Selvaganesan Kartiga , Ha Yonghyun , Galiana Gigi , Constable Todd
Published: August 2023

Gradient-free imaging at low-fields can significantly reduce the cost of and increase access to MRI devices. Here we propose to exploit the Bloch-Siegert shift effect to perform gradient-free, RF spatial encoding at 24mT. We have developed a simulation algorithm that designs various nonlinear encoding schemes and evaluates their performance through image reconstruction. Our results indicate that this technique is tolerant to noise and B0 inhomogeneities; this is an important step towards demonstrating the feasibility of performing low-field imaging with nonlinear RF spatial encoding using the Bloch-Siegert shift.
Design and Analysis of Field-of-View Independent k-space Trajectories for Magnetic Resonance Imaging
Authors: Speidel Tobias , Metze Patrick , Stumpf Kilian , Hüfken Thomas , Rasche Volker
Published: August 2023

The calculation of k-space trajectories in MRI usually involves prior knowledge of the FOV, since the desired FOV defines a minimum k-space sampling density. The reconstruction of a FOV, which is larger than what is represented by the primary sampling density, is equal to undersampling in k-space. Arising artefacts are strictly dependent on the underlying k-space trajectory which leads to advantages for k-space trajectories with low-coherent aliasing properties also for the combination with non-linear reconstruction techniques.Based on a generalised form of the Seiffert Spirals, this abstract describes a k-space trajectory that does not require prior commitment to an imaging FOV.
Correlation Tensor MRI reveals dynamic changes in diffusion kurtosis sources along stroke progression
Authors: Alves Rita , Henriques Rafael , Jespersen Sune , Shemesh Noam
Published: August 2023

Correlation Tensor Imaging is emerging as a novel methodology for resolving diffusional kurtosis sources. Here, we decouple the anisotropic (Kaniso), isotropic (Kiso), and microscopic kurtosis (μK) sources and map them along the progression of experimental ischemia. Our results indicate that μK and Kaniso, associated with cross sectional variance (tentatively associated with neurite beading) and Kiso, likely reflecting edema formation, are pivotal markers for pathology. Our findings are promising for more specific characterizations of stroke lesions and a better understanding of tissue injury.
Tractography protocols for the neonatal brain, standardised against the adult human and macaque
Authors: Warrington Shaun , Thompson Elinor , Dubois Jessica , Baxter Luke , Slater Rebeccah , Mars Rogier , Jbabdi Saad , Bastiani Matteo , Sotiropoulos Stamatios
Published: August 2023

The neonatal brain undergoes rapid development in the months after birth. Diffusion tractography is a unique method for probing developing white matter connections. We present a novel and comprehensive library of tractography protocols for the neonatal brain, whilst ensuring correspondence with previously developed protocols for the adult and macaque brain. We demonstrate protocol robustness across data quality and show that the resultant tracts capture a-priori known trends in white matter microstructure. We show that these protocols open avenues for quantitative comparisons across the lifespan, but also species, which we exemplify by revealing developmental trends in connectivity patterns.
Longitudinal associations between blood biomarkers and white-matter MRI in sport-related concussion: A study of the NCAA-DoD CARE Consortium
Authors: Wu Yu-Chien , Wen Qiuting , Gill Jessica , Thukral Rhea , Gao Sujuan , Lane Kathleen , Meier Timothy , Riggen Larry , Harezlak Jaroslaw , Giza Christopher , Goldman Joshua , Guskiewicz Kevin , Mihalik Jason , LaConte Stephen , Duma Stefan , Broglio Steven , Saykin Andrew , McAllister Thomas , McCrea Michael
Published: August 2023

White matter structural changes occur when an athlete experiences a concussion. To determine if serum biomarkers are a good concussion diagnosis, it seems prudent to associate white matter structural changes to longitudinal biomarker samples. Longitudinal blood biomarkers and DTI scanning from 77 collegiate athletes were collected across 3 timepoints and tested for associations. Tau was found to have the most significant associations. It was concluded that tau is the most sensitive for white-matter micro-structures.
Tracking rapid stimulus-driven BOLD oscillations in the human primary motor cortex and somatosensory cortex
Authors: Hodono Shota , Polimeni Jonathan , Reutens David , Cloos Martijn
Published: August 2023

We investigated the observable frequency range of stimulus-driven BOLD oscillations in human M1 and S1. Experimental results showed that BOLD response oscillations up to 0.50 Hz can be measured in individual subjects. The responses were substantially higher than predicted using the canonical HRF model. Despite their angio-architectural differences, M1 and S1 showed similar nonlinearities in their response. Viewed across cortical depths, M1 and S1 showed different behaviors in terms of response amplitude and especially phase as a function of stimulus frequency.
Geometric and clinical evaluation of deep learning-based segmentation of individual lower limb muscles from patients with neuropathies
Authors: Hostin Marc-Adrien , Ogier Augustin , Michel Constance , Le Fur Yann , Guye Maxime , Attarian Shahram , Bellemare Marc-Emmanuel , Bendahan David
Published: August 2023

Quantification of Fat Fraction (FF) in individual lower limb muscles of patients with neuromuscular disorders relies on segmentation. Few studies have indicated that Fully Convolutional Networks (FCNs) can provide reliable automatic segmentations to replace manual tasks. However, their sensitivity to fat infiltration has never been accurately assessed. Four FCN were benchmarked for the segmentation of 114 thigh and 108 calf images (1788 muscles) with FF up to 60%. HRNet was the only network that didn't show any segmentation failures. DSC obtained was comparable to other networks. The FF values calculated from the automatic (FFa) and manual (FFm) segmentations were consistent.
On the robustness of single UTE-Dixon for simultaneous short T2*, water and fat imaging across skeletal anatomies
Authors: Kronthaler Sophia , Feuerriegel Georg , Boehm Christof , Gersing Alexandra , Schwaiger Benedikt , Makowski Marcus , Weiss Kilian , Karampinos Dimitrios
Published: August 2023

In patients with vertebral fractures or degenerative changes often CT and MR imaging are performed, with CT aiming at the characterization of osseous changes and the MR focusing on soft tissue components. Previous work presented a single UTE-Dixon (sUTE-Dixon) approach which enabled the simultaneous assessment of vertebral fractures and edema of the thoracolumbar spine from a single ultrashort-echo time (UTE) image. This work investigates the robustness of the sUTE-Dixon methodology in various skeletal anatomies.
Increasing-load leg extensions in supine position using a novel pneumatic ergometer for dynamic 1H and 31P NMR muscle evaluations at 3T
Authors: Kolkovsky Alfredo Lopez , Matot Beatrice , Fromes Yves , Giacomini Eric , Carlier Pierre , Reyngoudt Harmen , Marty Benjamin
Published: August 2023

Evaluating quadriceps function is key in the context of sarcopenia. A pneumatic ergometer was built to allow performing knee extensions in supine position. An increasing-load, 13-min-long, isotonic exercise was successfully performed by volunteers during interleaved 1H MRI/1H MRS/31P MRS acquisitions in the quadriceps. Work, pedal displacement and velocity values per stroke and the maximum voluntary torque were measured with the ergometer. End-of-exercise [PCr] decreased (69±10%) and T2* increased (up to 10.5±7.2% in Rectus Femoris) relative to baseline. Simultaneous vascular, metabolic and physical effort evaluations during an incremental physical test could be a powerful method to investigate muscle quality in aging.
Normative Baseline Analysis of Carpal Bone Kinematic Profiles Using 4D MRI
Authors: Koch Kevin , Zarenia Mohammad , Arpinar V. , Mannem Rajeev
Published: August 2023

4D-dynamic MRI were collected and utilized to track unconstrained movement of individual wrist carpal bones in 31 asymptomatic volunteer subjects. Rotational and translational trajectories of the scaphoid, lunate, and capitate bones were collected and processed using a novel multi-subject profile registration and analysis engine. Morphological images were analyzed by an expert radiologist to identify asymptomatic abnormalities within the cohort. Statistical parametric mapping of each profile was performed to identify normative variances of each profile metric and correlation with identified abnormalities. The study presents methodological approaches and normative baseline profile metrics of value to future studies of symptomatic wrists.
Assessing muscle T2 in elderly men with osteosarcopenia
Authors: Gast Lena , Chaudry Oliver , Kemmler Wolfgang , Uder Michael , Nagel Armin , Engelke Klaus
Published: August 2023

In addition to fat fraction (FF), muscular T2 could provide information on disease progression and potential training effects in osteosarcopenia, a combination of osteoporosis and sarcopenia. However, muscular T2 is highly dependent on the amount of muscle fat infiltration, which is usually increased in these patients. Thus, we aimed to assess T2 in thigh muscle tissue of elderly men with osteosarcopenia, comparing vendor-provided T2 maps with custom-fitted approaches also considering fat infiltration. We found highly elevated T2 values in the vendor-provided T2 maps compared to tri-exponentially fitted T2, which might lead to misinterpretation of muscle T2.
1H-14N quadrupolar relaxation of protein backbones: a potential intracellular biomarker of glioma invasion
Authors: Lahrech Hana , Petit Manuel , Pierre Sandra , Leclercq Maxime , Broche Lionel , Berger François
Published: August 2023

In FFC-NMR, R1-dispersion curves of biological systems frequently show quadrupolar peaks (QP) between 1.5 and 3.5 MHz that correspond to the cross relaxation of water 1H and protein 14N. QP of glioma invasion tissues (Glio6 and Glio96 mouse models) and of high glioma proliferation (U87 model) were acquired ex vivo and compared to cell pellets in vitro, showing significant differences. This result suggests that QP signals are intracellular, a result which was confirmed by measurements of cells after trypsin treatment which showed unchanged QP amplitude. This result highlights the potential of the QPs as an intracellular biomarker of glioma invasion.
VERDICT MRI estimates match histopathology features in brain tumours
Authors: Figini Matteo , Castellano Antonella , Bailo Michele , Callea Marcella , Pieri Valentina , Cadioli Marcello , Palombo Marco , Mortini Pietro , Falini Andrea , Alexander Daniel , Cercignani Mara , Panagiotaki Eleftheria
Published: August 2023

We recently adapted the VERDICT framework to characterize both the core and peritumoural areas of brain tumours. We report here its first clinical application in the differentiation of brain tumour histotypes. Comparing groups of lesions with increasing aggressiveness (from lower to higher grades to metastases) we observed a significant increase in the intracellular and vascular fraction in the lesion core. VERDICT maps matched the features showed by histopathology in lower grades and in metastases; in the most heterogeneous higher grades, VERDICT maps showed differences between subregions compatible with histopathology results in multiple biopsy samples.
APTw imaging outperforms relaxation-compensated CEST-MRI at 3T in assessing glioma progression after radiotherapy - a preliminary analysis
Authors: von Knebel Doeberitz Nikolaus , Kroh Florian , Breitling Johannes , Maksimovic Srdjan , Koenig Laila , Debus Juergen , Bachert Peter , Schlemmer Heinz-Peter , Ladd Mark , Goerke Steffen , Paech Daniel
Published: August 2023

In this interim analysis we compared in patients with gliomas the ability of asymmetry-based amide proton transfer weighted (APTw) imaging with Lorentzian-fit-based relaxation-compensated CEST-MRI (MTRRex) of the APT, rNOE and MT signal to differentiate disease progression from treatment induced changes six weeks after completion of radiotherapy. In progressive gliomas, APTw displayed significantly higher signal intensities in contrast enhancing tissue compared to non-progressive gliomas with an AUC of 0.77 in receiver operator characteristic analyses (p 0.03). MTMTRrex showed a trend towards higher signal intensities in progressive tumors. All CEST metrics displayed significant differences in white and gray brain matter signal intensities.
MR Molecular Imaging of Extradomain-B Fibronectin for Non-invasive Active Surveillance of Prostate Cancer
Authors: Vaidya Amita , Shankardass Aman , Buford Megan , Hall Ryan , Lu Zheng-Rong
Published: August 2023

C-X-C motif chemokine receptor 2 (CXCR2) expression is associated with high-grade and advanced prostate cancer. LNCaP-CXCR2+ prostate cancer cells with stable expression of CXCR2 exhibited mesenchymal features and became more aggressive with elevated expression of an ECM oncoprotein EDB-FN as compared to the slow-growing parental cell line, LNCaP. MRMI of EDB-FN with a targeted contrast agent MT218 resulted in significant increase of T1-weighted contrast enhancement in LNCaP-CXCR2+ prostate tumors as compared to the LNCaP tumors in mice. The results suggest that MRMI of EDB-FN has the potential to provide non-invasive active surveillance of low-grade prostate cancer.
Investigating the contribution of hyaluronan (HA) to the breast tumour microenvironment using multiparametric MRI and histology
Authors: Reeves Emma , Li Jin , Zormpas-Petridis Konstantinos , Sullivan James , Cummings Craig , Blouw Barbara , Kang David , Sinkus Ralph , Bamber Jeffrey , Jamin Yann , Robinson Simon
Published: August 2023

The impact of HA on tumour characteristics measured by MRI/E is not fully understood. We evaluated relationships between MRI biomarkers and histology in saline (HA present) and PEGPH20 treated (HA absent) breast tumours. ADC had the strongest association with HA, reaffirming that ADC is the most sensitive biomarker of tumour response to PEGPH20. MTR negatively correlated with HA, likely due to a HA-mediated dilution of MT-inducing components including collagen. MRE-derived elasticity (Gd) did not directly correlate with HA, however, HA degradation reduced the contribution of collagen to tumour viscoelasticity and may shift the sensitivity of Gd to the cellular compartment.
Automated Adipose Tissue Segmentation using 3D Attention-Based Competitive Dense Networks and Volumetric Multi-Contrast MRI
Authors: Kafali Sevgi , Shih Shu-Fu , Li Xinzhou , Chowdhury Shilpy , Loong Spencer , Barnes Samuel , Li Zhaoping , Wu Holden
Published: August 2023

Subcutaneous and visceral adipose tissue (SAT/VAT) are potential biomarkers to detect future risks of metabolic diseases. However, the current standard for analysis relies on manual annotations that require expert knowledge and are time-consuming. Previous neural networks for automatically segmenting adipose tissue had suboptimal performance for VAT. This work developed a new 3D attention-based competitive dense network to rapidly (84 ms/slice) and accurately segment SAT/VAT in adults with obesity by leveraging multi-contrast MRI inputs and considering the complex VAT features. The new network achieved high Dice scores (>0.96) and accurate volume measurements (difference<1.6%) for SAT/VAT with respect to manual annotations.
Improving Radiomics Reproducibility Using MR Fingerprinting and Physics-Informed Quantization
Authors: Zhao Walter , Hu Zheyuan , Kazerooni Anahita , Körzdörfer Gregor , Nittka Matthias , Davatzikos Christos , Viswanath Satish , Wang Xiaofeng , Badve Chaitra , Ma Dan
Published: August 2023

MR fingerprinting (MRF) is a rapid, quantitative imaging approach with significant potential for use in clinical studies, including radiomic applications. Due to its quantitative nature, robustness to system imperfections, and requiring fewer image preprocessing steps, we believe MRF radiomics is uniquely positioned to offer improved reproducibility and generalizability compared to conventional MRI. Here we report reproducibility results of MRF T1 and T2 radiomic features in the healthy human brain, and introduce a novel physics-informed quantization approach for improved reproducibility of quantitative image texture features.
MR fingerprinting and complex-valued neural network for quantification of brain amyloid burden
Authors: Fujita Shohei , Otsuka Yujiro , Murata Katsutoshi , Koerzdoerfer Gregor , Nittka Mathias , Motoi Yumiko , Nakajima Madoka , Murakami Koji , Fukunaga Issei , Kamagata Koji , Abe Osamu , Aoki Shigeki
Published: August 2023

We developed a framework utilizing MR fingerprinting and a complex-valued neural network to detect brain amyloid burden. The tailored neural network was trained on real amyloid-PET imaging data and MR fingerprinting acquisitions to estimate PET-derived amyloid deposition from the MR fingerprinting signal evolutions. This complex-valued neural network architecture, designed to increase sensitivity to amyloid-related signals, showed a subject-level amyloid positivity classification with AUC = 0.87 in patients with cognitive decline. The proposed method enables non-invasive amyloid burden mapping, T1 and T2 mapping in a single scan, and is suitable not only for diagnosis but also for monitoring amyloid-reducing treatments.
Sequence optimisation mitigating undersampling errors in Magnetic Resonance Fingerprinting
Authors: Heesterbeek David , van Gijzen Martin , Vos Frans , Nagtegaal Martijn
Published: August 2023

In MR Fingerprinting acquisitions, the choice of flip angle sequence has a strong effect on the accuracy of the estimated parameter maps. Undersampling artefacts in time-series images are a dominant source of error for standard MRF estimations. We propose to use an undersampling-error model leveraging on perturbation theory, to optimise flip angle patterns taking into account the k-space readout, a realistic ground truth and signal phase. In vivo scans show strong visible reduction in error. Root-mean-square errors in $$$T_1$$$ and $$$T_2$$$ were reduced with at least 6.4%-points and 9%-points respectively, compared to a Cramér-Rao bound optimised and a conventional pattern.
Fast CEST MR Fingerprinting with Increased Volumetric Coverage using Slice Permuted Acquisition and Deep Learning Reconstruction
Authors: Cohen Ouri , Young Robert , Farrar Christian , Otazo Ricardo
Published: August 2023

CEST imaging is a promising tool for diagnosis and evaluation of treatment response in tumors. However, conventional CEST is not quantitative and requires long acquisition times. A recently developed technique, CEST MR fingerprinting (CEST-MRF), overcomes many of the technical limitations of conventional CEST but still suffers from limited volumetric coverage. In this work, we propose a novel multi-slice CEST-MRF pulse sequence and deep learning reconstruction method to enable volumetric coverage without the need for additional scan time. Numerical simulations and in vivo experiments in a healthy subject are performed to demonstrate feasibility and utility of the proposed multi-slice CEST-MRF technique.
Towards quantification of semisolid tissue properties at 7T using multiband-MRF methods.
Authors: West Daniel , Tomi-Tricot Raphael , Cordero-Grande Lucilio , Bridgen Pip , Wilkinson Tom , Giles Sharon , Hajnal Joseph , Malik Shaihan
Published: August 2023

Since semisolid tissue components are strong determinants of relaxation parameters, estimation of semisolid properties may lead to more robust and direct characterization of tissues than relaxation measurement. We have used multiband MR fingerprinting at ultra-high field in an exploratory study towards high resolution quantitative imaging with efficient parameter encoding. To achieve this, two variants of a steady-state sequence are proposed that employ different cycling of nonselective multiband RF pulses: one to highlight dipolar order effects apparent in lipid bilayer-like materials such as myelin, and the other to measure semisolid T2. Initial phantom results and preliminary in vivo investigation are presented.
On the Feasibility of Hybrid-State based Quantitative MRI at 0.55T
Authors: Flassbeck Sebastian , Assländer Jakob
Published: August 2023

Low field magnetic resonance systems have potential as powerful diagnostic tools at comparably low cost. However, the inherently lower signal requires the use of SNR-efficient pulse sequences and reconstruction schemes. In this work, we present initial results with a hybrid-state free precession sequence, used to quantify T1 and T2 in 12min with an isotropic resolution of 1mm3. Visually, these quantitative maps show low noise levels, which allows for compelling synthetic MP-RAGE contrast generation.
In vivo pH imaging in rats using [1,5-13C2]Z-OMPD
Authors: Wodtke Pascal , Grashei Martin , van Heijster Frits , Sühnel Sandra , Setzer Nadine , Schilling Franz
Published: August 2023

We introduce hyperpolarized [1,5-13C2]Z-OMPD as a novel in vivo pH sensor. Upon synthesis from ethyl pyruvate, the molecule appears to be non-toxic and shows good hyperpolarization properties, as indicated by high polarization levels and long T1 relaxation times for both 13C-labels. 13C-chemical shifts show good pH sensitivity in the physiological range, which enables pH imaging in vitro of human blood phantoms of different pH. In vivo pH imaging upon injection in rats reveals previously reported pH compartments in kidneys. It is further demonstrated, that the OMPD1 peak can be used as internal reference, further facilitating the process.
Quantifying regional pulmonary ventilation changes in hyperpolarized 3He MRI of asthma subjects following bronchodilator at three timepoints
Authors: Shammi Ummul AFIA , Blasco Lucia , Altes Talissa , Mugler John , Meyer Craig , Mata Jaime , Qing Kun , Miller Wilson , Thomen Robert
Published: August 2023

Quantification of reginal pulmonary ventilation changes in a longitudinal study with hyperpolarized gas MRI would be beneficial for clinicians evaluating treatment responses. While VDP is a sensitive measure of global lung ventilation, regional ventilation information inherent in imaging is lost. In this work, we present a method of performing voxel-wise comparisons in 3He MRI and producing regional ventilation change maps in asthma patients following bronchodilation with either short-acting or long-acting beta agonists at three timepoints. Regional change maps were congruous with visual assessment of regional ventilation changes and showed the temporal effects of bronchodilator action in patients with severe asthma.
A web-accessible tool for Temperature Estimation from SAR Simulations (TESS)
Authors: Montin Eros , Carluccio Giuseppe , Collins Christopher , Lattanzi Riccardo
Published: August 2023

TESS, Temperature Estimation from Sar Simulation, is a web-based application that performs safety assessments of MRI exams. It numerically solves modified versions of the bioheat equation that include parameters such as temporal variation of core body temperature and various physiological parameters. A web-based graphical user interface, accessible via the Cloud MR framework, enables users to set up simulations and display results.
MRI-based measurement of the transfer function of elongated metallic implants without transceive phase approximation.
Authors: Eijbersen Michael , Steensma Bart , van den Berg Cornelis , Raaijmakers Alexander
Published: August 2023

A new computational method is presented for determining a transfer function of implants using a MRI only paradigm. By relaxing the transciever phase approximation better results are obtained for longer implants, however an optimization for both B1+ and B1- based on magnitude only maps is required.