bluuebunny/crossref_metadata_2025 huggingface dataset:
Detecting tract-specific abnormalities in individual patients with epilepsy using fixel-based analysis
Authors: Mito Remika , Pedersen Mangor , Smith Robert , Parker Donna , Churilov Leonid , Vaughan David , Jackson Graeme
Published: August 2023

Fibre tract-specific abnormalities have been identified in various neurological disorders and conditions using fixel-based analysis. However, for this technique to be useful in clinical practice, such abnormalities should be detectable in individual patients. In this work, we apply the fixel-based analysis framework to detect fibre density and cross-sectional changes in individual patients with varying epilepsy diagnoses. Abnormalities could be detected in individual epilepsy patients, both at the tract level, and at the fixel-level, with different patterns of tract-based abnormality observed across the different epilepsy syndromes. This information could be clinically valuable when examining individual patients.
T2*-weighted dual-polarity skipped-CAIPI 3D-EPI: 400 microns isotropic whole-brain QSM at 7 Tesla in 6 minutes
Authors: Stirnberg Rüdiger , Deistung Andreas , Stöcker Tony
Published: August 2023

We propose a dual-polarity readout technique to eliminate residual segmentation artifacts in interleaved multi-shot EPI despite established echo time shifting. The method only requires retrospective averaging of two or more complex-valued images acquired with alternating EPI readout polarity across measurements. The approach has been integrated into a custom skipped-CAIPI 3D-EPI sequence, combining highly segmented EPI with CAIPIRINHA parallel imaging. We present dual-polarity skipped-CAIPI 3D-EPI for ultrahigh-resolution, rapid, motion-robust whole-brain T2*-weighted imaging and quantitative susceptibility mapping at 7 Tesla. We demonstrate its capability to acquire exquisite imaging contrast at 0.7mm and 0.4mm isotropic resolution in only 1:15 and 6:14 [min:s], respectively.
Investigating the relationship between cortical myelin and functional brain activity
Authors: Patitucci Eleonora , Germuska Michael , Tomassini Valentina , Wise Richard
Published: August 2023

The role of cortical myelin for cortical function is still under debate. Here we investigate the relationship between cortical myelination (represented by R1) and functional activation (represented by BOLD-fMRI and arterial spin labelling CBF signals) during the execution of a motor task. We demonstrate associations between cortical myelination and functional activity in a subset of task-responding regions. We observe a decrease of the significance of these relationships in the deeper cortical layers.
Dependence of liver R2* on the fat spectral model.
Authors: Hamilton Gavin , Schlein Alexandra , Henderson Walter , Batakis Danielle , Ceriani Lael , Louie Ashley , Middleton Michael , Covarrubias Yesenia , Fowler Kathryn , Sirlin Claude
Published: August 2023

Using MRS, we examined whether the assumed fat spectral model (6-, or 9-peak) altered liver R2* estimation in vivo. We found that liver R2* estimation was model-independent, and liver R2*was not significantly different from water R2* (p = 0.07). However, fat R2* values estimated for these models were different (p < 0.0001), suggesting that fat R2* estimation in high-fat tissues may be model dependent.
Free-Breathing, 3D Phase Sensitive Inversion Recovery T1-Weighted MRI of the Liver
Authors: Muslu Yavuz , Cashen Ty , Mandava Sagar , Reeder Scott
Published: August 2023

Gadoxetic acid (GA)-enhanced hepatobiliary phase T1-weighted (HBP-T1w)-MRI is widely used in the clinical setting for detection of focal liver lesions (FLLs). However, complete characterization of liver lesions also requires T2w, diffusion weighted (DWI) and dynamic contrast enhanced (DCE) imaging. These methods often have inferior image spatial resolution compared to GA-enhanced HBP-T1w and may be unable to resolve small (<1cm) lesions visible only on HBP-T1w. In this work, we propose a novel phase sensitive inversion recovery (PSIR) T1w-MRI in combination with 3D radial stack-of-stars imaging and model-based water/fat separation for improved detection and characterization of small FLLs.
Dynamics of insulin secretion and pancreatic blood-flow: a simultaneous ASL perfusion imaging / hyperglycemic clamp study
Authors: Taso Manuel , Simonson Donald , Phung Lauren , McGrath Colleen , Waldman Stephanie , Papadopoulou Fotini , Alsop David
Published: August 2023

Loss of β-cell function and mass are hallmarks of type-1 and type-2 diabetes. Non-invasive imaging of endocrine pancreatic function would provide valuable insights into the degree and temporal patterns of endocrine dysfunction. For this purpose, Arterial Spin Labeling (ASL) is a uniquely suited non-invasive technique. We therefore conducted a dynamic ASL study during a hyperglycemic clamp to explore the dynamics of insulin secretion and pancreatic blood-flow.

This study showed that hyperglycemia and arginine-stimulated insulin secretion causes an increase in pancreatic perfusion and that the rate of insulin concentration change seems to be driving perfusion changes rather than absolute concentration.
Risk Factors for Perioperative Brain Lesions on MRI in Infants with Severe Congenital Heart Disease: A European Collaboration
Authors: Bonthrone Alexandra , Stegeman Raymond , Feldmann Maria , Claessens Nathalie , Nijman Maaike , Jansen Nicolaas , Nijman Joppe , Groenendaal Floris , de Vries Linda , Benders Manon , Haas Felix , Bekker Mireille , Logeswaran Thushiha , Reich Bettina , Kottke Raimund , Hagmann Cornelia , Latal Bea , Dave Hitendu , Simpson John , Pushparajah Kuberan , Austin Conal , Kelly Christopher , Arulkumaran Sophie , Rutherford Mary , Counsell Serena , Knirsch Walter , Breur Johannes
Published: August 2023

Infants with Congenital Heart Disease (CHD) are at risk of neurodevelopmental impairments. MRI studies have identified brain injury in infants with CHD both before and after cardiac surgery. We characterized risk factors for preoperative and new postoperative arterial ischaemic stroke (AIS), white matter injury (WMI) and cerebral sinovenous thrombosis (CSVT) in a cohort of infants with severe CHD. Balloon atrial septostomy was associated with increased risk of preoperative brain injury. Induced vaginal delivery was associated with preoperative WMI. Cardiac physiology and perioperative factors were associated with increased risk of new postoperative brain injury.
Early Postnatal Multi-modal MRI Structural Trajectory of Brain Dysmaturation Predicts Early Childhood Language Outcomes in Complex CHD
Authors: Lee Vincent , Ceschin Rafael , Reynolds William , Meyers Benjamin , Wallace Julia , Landsittel Douglas , Badaly Daryaneh , Gaynor J , Licht Daniel , Greene Nathaniel , Brady Ken , Hunter Jill , Chu Zili , Wilde Elisabeth , Easley R , Andropoulos Dean , Panigrahy Ashok
Published: August 2023

This study examined trajectories of early postnatal brain structure (macrostructural brain volumes and microstructural white matter tractography) relationship with early childhood neurodevelopmental deficits (NDD) in complex congenital heart disease patients. This analysis included development of predictive multi-variable models incorporating other known risk factors of poor NDD in CHD. A multi-modal dysmaturation phenotype of reduced subcortical volume and cerebral white matter volume/connectivity predicted poor early childhood language outcomes, despite high relative contribution of genetic and socio-demographic factors (maternal IQ). Favorable socio-demographic factors, despite the high incidence of focal WMI and presence of genetic abnormalities, predicted better neurodevelopmental outcomes.
Hyperperfusion on arterial spin labelling is associated with cognitive impairment in infants with neonatal hypoxic ischemic encephalopathy
Authors: Tuura Ruth O'Gorman , Kottke Raimund , Brotschi Barbara , Sabandal Carola , Hagmann Cornelia , Latal Beatrice
Published: August 2023

Neonatal hypoxic ischemic encephalopathy (HIE) is a serious neurological condition, representing a primary cause of neonatal death and developmental impairment. In newborns with HIE, hyperperfusion is related to severe adverse outcomes, but less is known about the link between perfusion and mild to moderate developmental impairments. Using a voxelwise correlation analysis, we investigated the link between ASL perfusion in newborns with HIE and developmental outcome at 2 years. A more adverse outcome was associated with hyperperfusion across the whole brain. A better cognitive outcome was associated with lower perfusion in the bilateral basal ganglia, thalamus, hippocampus and cerebellum.
Impacts of prenatal COVID-19 pandemic-related distress on brain functional connectivity in 3-month infants
Authors: Jaffer Aliza , Manning Kathryn , Giesbrecht Gerald , Tomfohr-Madsen Lianne , Lebel Catherine
Published: August 2023

Prenatal psychological distress has been substantially higher during the COVID-19 pandemic, but its impacts on infant brain development remain unclear. We investigated the relationship between prenatal pandemic-related distress and functional connectivity within the default mode (DMN), auditory, and left frontoparietal brain networks in 3-month old infants. Resting-state functional MRI scans were analysed using FSL. Higher prenatal anxiety was associated with increased infant functional connectivity within the DMN. These connectivity changes may predispose these infants to later mental health challenges, and highlight the need to screen for prenatal anxiety and provide support for pregnant individuals and infants born during the pandemic.
Evaluation of precision of multi-compartment model on relaxation properties in breast cancer on 3T using numerical simulation
Authors: Senthilkumar Roshni , Cheung Sai Man , Chan Kwok-Shing , He Jiabao
Published: August 2023

MR relaxation properties of T1 and T2 are well known to alter in cancer, reflecting diseased tissue micro-environment. Multiple compartment models have been developed to better approximate tissue classes within an imaging voxel, allowing more accurate estimation of disease load for more precise treatment planning and monitoring. However, multiple compartment models is more sensitive to noise and suffers from potential overfitting, due to from significantly increased number of variables for fitting exponential functions and consequently more complex cost function. We therefore conducted numerical simulation to establish, the first in the literature, applicability condition of multiple compartment model in breast cancer.
Comparison of Image Normalization Techniques for Rectal Cancer Segmentation in Multi-Center Data: Initial results
Authors: Albert Steffen , Wichtmann Barbara , Zhao Wenzhao , Hesser Jürgen , Attenberger Ulrike , Schad Lothar , Zöllner Frank
Published: August 2023

We evaluated the influence of normalization (setting mean and standard deviation, histogram matching and percentiles) on the segmentation of rectal cancer on multimodal images when operating on multicenter data as part of a Radiomics pipeline. We used two different networks for segmentation. When training and evaluating on all data or data from a single center, normalization did not play a significant role. In contrast, when training on one center and evaluating on all others, it did play a major role. Best results are obtained by normalization using percentiles. Fixing the mean and standard deviation did not work well.
DCE-MRI with free-breathing compressed sensing VIBE for predicting chemotherapy response and patient outcome in pancreatic adenocarcinoma
Authors: Fukukura Yoshihiko , Ejima Fumitaka , Ayukawa Takuro , Kamimura Kiyohisa , Nakajo Masanori , Nagano Hiroaki , Takumi Koji , Nickel Marcel , Imai Hiroshi , Yoshiura Takashi
Published: August 2023

This study focused on the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) with motion-resolved compressed sensing T1-weighted volumetric interpolated breath-hold examination (CS-VIBE) for prediction of treatment response to chemotherapy and patient outcome in pancreatic ductal adenocarcinoma (PDAC). Our results showed tumor ve was significantly higher in the response group than in the non-response group and was an independent predictor of progression-free survival in patients with PDAC treated with chemotherapy. These results suggest that DCE-MRI obtained with CS-VIBE may be useful for predicting treatment response to chemotherapy and patient outcome in PDAC.
Bias-free T1 Mapping via Simultaneously Estimating Bloch-Siegert and Magnetization Transfer Effects
Authors: Jang Albert , Han Paul , Ma Chao , El Fakhri Georges , Liu Fang
Published: August 2023

T1 maps obtained using fast steady-state sequences are usually sensitive to B1+ inhomogeneity and MT effects. We propose a novel method to achieve simultaneously B1+- and MT-corrected T1 quantification by introducing off-resonance RF pulses that create two effects: 1) direct saturation of macromolecules and 2) B1+ dependent Bloch-Siegert phase shift. This method, termed BTS (Bloch-Siegert and magnetization transfer simultaneously), is presented and validated in both simulations and experiments, correcting for T1 bias induced from B1+ inhomogeneity and MT effects.
Efficient Time-dependent Diffusion MRI Using Multiple Stimulated Echoes
Authors: Dan Guangyu , Sun Kaibao , Luo Qingfei , Zhou Xiaohong Joe
Published: August 2023

Studies on temporal diffusion characteristics can reveal a wealth of tissue microstructural information for disease evaluation, but typically require a long scan time because multiple diffusion times are need with each requiring a separate acquisition acquire. We herein report a time-efficient pulse sequence that acquires multiple diffusion-weighted images with different diffusion times in a single shot by utilizing multiple stimulated echoes with variable flip angles. This technique has been implemented on a 3T human scanner and successfully demonstrated in a quantitative diffusion phantom, the human brain gray and white matters, and the prostate peripheral zone and central grand.
Increasing the T2 sensitivity of MR-STAT sequences by small quadratic RF phase increments
Authors: Liu Hongyan , Bruijnen Tom , van Haandel Maaike , van den Heide Oscar , Fuderer Miha , van den Berg Cornelis , Sbrizzi Alessandro
Published: August 2023

We propose a new method to increase the T2 encoding ability of MR-STAT sequences, according to a recently developed strategy for T2 mapping. Recent work has shown that RF phase modulated GRE sequences with small quadratic phase increments can effectively encode T2 information into the phase of the signal. In this abstract, we show that by incorporating a simple and similar RF modulation strategy in 2D MR-STAT sequences, T2 sensitivity of transient-state gradient-spoiled sequences is improved, and therefore T2 maps as well as the proton density maps (PD) can be reconstructed with higher accuracy.
Real-time observation of postprandial hepatic glucose metabolism with interleaved 2H Metabolic Imaging and 13C-MRS at 7 T
Authors: Poli Simone , Emara Ahmed , Ballabani Edona , Buser Angeline , Schiavon Michele , Herzig David , Man Chiara Dalla , Tappy Luc , Kreis Roland , Bally Lia
Published: August 2023

The liver takes a central role in the regulation of glucose homeostasis by storing glucose in the fed state and releasing it during food abstinence. As a consequence, the liver is critically involved in glucose homeostasis disorders. We propose a novel non-invasive approach combining Deuterium Metabolic Imaging (DMI) with 13C-MRS at 7 T to dynamically map hepatic glucose metabolism. Preliminary results support technical feasibility and provide first insights into distinct hepatic glucose profiles in patients with dysregulated glucose homeostasis. The proposed approach may open new avenues for a better understanding of pathophysiology of glucose dysregulation and development of targeted treatments.
Deuterium labeling enables non-invasive 3D proton MR imaging of glucose and neurotransmitter metabolism in the human brain
Authors: Bednarik Petr , Goranovic Dario , Svatkova Alena , Niess Fabian , Hingerl Lukas , Strasser Bernhard , Deelchand Dinesh , Spurny-Dworak Benjamin , Trattnig Siegfried , Hangel Gilbert , Scherer Thomas , Lanzenberger Rupert , Bogner Wolfgang
Published: August 2023

Recent studies have proposed deuterium (2H)-Magnetic Resonance Spectroscopic Imaging (MRSI) as a reliable, non-invasive, and safe method to quantify the human metabolism of 2H-labeled substrates such as glucose and their downstream metabolism and address the major drawbacks of positron emission tomography or carbon (13C)-MRS. Here, we pioneered a dynamic proton 3D (1H)-MRSI for indirect 2H-measurements in humans. In contrast to 2H-MRS(I), the method provides higher sensitivity and chemical specificity to differentiate glutamate, glutamine, and gamma-aminobutyric acid deuterated at specific molecular positions while simultaneously mapping both labeled and unlabeled metabolites without specialized hardware after peroral ingestion of 2H-labeled glucose.
Adaptive Feedforward Control of Gradient Currents Using Gradient Heating Prediction
Authors: Babaloo Reza , Aydin Ege , Atalar Ergin
Published: August 2023

The MRI gradient system heating changes its characteristics, and without a feedback system, the gradient waveform distorts resulting image artifacts. The primary effect of temperature rise in the gradient coil winding is the increase in the coil resistance. Feedforward based controllers, preferable in gradient array systems and multi-coil designs, use a linear time-invariant model. However, the gradient heating makes the system time-variant. To address this issue, we propose predicting gradient coil thermal variation using the thermal differential equation and updating feedforward controller parameters continuously.
Construction and Validation of Multi-Coil Technology for Accessible Head-Only Scanner
Authors: Theilenberg Sebastian , Shang Yun , Kumaragamage Chathura , McIntyre Scott , Nixon Terence , de Graaf Robin , Juchem Christoph
Published: August 2023

As part of a multi-center effort to design and build an accessible 1.5 T head-only MRI scanner (NIH U01EB025153, PI M. Garwood), we designed and constructed a prototype multi-coil array fitting the limited available space and capable of generating linear and non-linear image encoding fields as well as strong concomitant localized B0 shim fields. Here, we describe the construction process, and present system characteristics as well as experimental validation of its field generation capabilities utilizing a conventional 4 T MRI scanner.
A multiclass deep-learning model with realistic data augmentation for improved 7T gray matter/spinal cord segmentation on patients and controls
Authors: Medina Nilser Laines , Gros Charley , Cohen-Adad Julien , Le Troter Arnaud , Callot Virginie
Published: August 2023

Automated methods for WM/GM segmentation in the spinal cord are now largely available. However, these techniques were mostly developed for conventional systems (≤3T) and do not necessarily perform well on 7T MRI data that feature finer details, contrasts, but also different artifacts or signal dropout.

The primary goal of this study was thus to propose a new deep-learning model allowing robust SC/GM multi-class segmentation based on high-resolution 7T T2*-w MR images. The second objective was to highlight the relevance of implementing a realistic hybrid data augmentation strategy to provide better model generalization.
Length-dependent spatial distribution of short fiber bundles revealed with the mesoscopic Chenonceau dataset
Authors: Popov Alexandros , Uszynski Ivy , Herlin Bastien , Chauvel Maelig , Maldonado Igor , Destrieux Christophe , Poupon Cyril
Published: August 2023

Mesoscopic diffusion datasets allow to study the superficial tracts of the human brain. We exploit the new Chenonceau Dataset, an ultra-high resolution diffusion-weighted dataset, to investigate the organization of short fibers ( between 10 and 60 mm ) in the whole brain.

To achieve this goal, we process the dense Chenonceau connectogram with a hierarchical clustering algorithm to obtain coherent fiber bundles, sorted over a centimetric range. It leads to the first density mapping of short fibers across the whole human brain. This mapping displays important inter-hemispheric variations, supporting the functional lateralization of various functional networks.
Functional 3D-UTE MRI of the Lungs for Monitoring Ventilation Inhomogeneity in Patients with Cystic Fibrosis on Treatment with CFTR Modulators
Authors: Heidenreich Julius , Kuhl Philipp , Metz Corona , Weng Andreas , Grunz Jan-Peter , Benkert Thomas , Hebestreit Helge , Bley Thorsten , Köstler Herbert , Veldhoen Simon
Published: August 2023

Single breath-hold 3D-UTE-MRI was proposed for simultaneous evaluation of lung morphology and function. Sixteen patients with cystic fibrosis (CF) underwent initial and follow-up 3D-UTE-MRI in 2019 and 2021. In line with a previous study, referenced voxelwise fractional ventilation (FV) provided a marker that correlates strongly with the lung clearance index (LCI), reflecting ventilation inhomogeneity. Seven patients received a new drug-combination (ivacaftor/elexacaftor/tezacaftor) with significantly improved lung function during clinical follow-up. Similarly, significantly decreased ventilation inhomogeneity was derived from functional MRI. Thus, single breath-hold 3D-UTE MRI is a valuable tool for monitoring ventilation inhomogeneity in patients with CF during drug treatment.
Whole-body fasciculation detection in Amyotrophic Lateral Sclerosis (ALS) using motor unit MRI (MUMRI)
Authors: Heskamp Linda , Birkbeck Matthew , Hall Julie , Schofield Ian , de Oliveira Hugo , Williams Timothy , Whittaker Roger , Blamire Andrew
Published: August 2023

The spontaneous contraction of motor units in muscle, i.e. fasciculation, has been recognised as an important diagnostic marker in amyotrophic lateral sclerosis (ALS). Fasciculation can be imaged with a novel MRI technique called motor unit MRI. This technique uses a diffusion weighted sequence on which fasciculation presents as short-living signal voids. We demonstrated an increased fasciculation rate in ALS patients compared to healthy controls by assessing the four body regions relevant in the diagnosis of ALS. The affected body regions differed between patients. This is in line with the heterogeneous disease onset and supports our proposed whole-body approach.
Evaluating correlations of quantitative muscle MRI of leg muscles and clinical outcome measurements in patients with LGMD2A
Authors: Schlaffke Lara , Rohm Marlena , Rehmann Robert , Güttsches Anne-Katrin , Froeling Martijn , Vorgerd Matthias , Forsting Johannes
Published: August 2023

Quantitative MRI (qMRI) techniques like Dixon fat-fraction (FF) and quantitative water-T2 relaxation time (T2) are promising non-invasive tools in the evaluation of neuromuscular diseases like LGMD2A. In this study, we were able to show moderate to strong correlations between quantitative MRI values, especially FF, with clinical outcome measures and daily life activities. Analysis of T2 relaxation time in non-fat-infiltrated leg muscles of LGMD2A patients showed a significantly higher water T2 values compared to healthy controls. Therefore, T2 relaxation times may offer an earlier detection of disease-related change of muscular tissue in limb girdle muscular dystrophy compared to irreversible fat-fractions.
Strain rates along the fiber are heterogeneously distributed over the length of lower leg muscles during dynamic exercise
Authors: Hooijmans Melissa , Veeger Thom , Mazzoli Valentina , van Assen Hans , Gottwald Lukas , Nederveen Aart , de Groot Jurriaan , Strijkers Gustav , Kan Hermien
Published: August 2023

In this study we assessed strain rates along and close to perpendicular to the fiber in the lower-leg muscles, by combining 3D phase contrast with DTI-derived fiber orientations, during dynamic exercise with and without load. Our data revealed spatially heterogeneous strain rate patterns along the fiber within lower-leg muscles, with smallest and largest strain rates in the most proximal and distal segments of the Gastrocnemii muscles, respectively, and opposed (expansion and contraction) strain rate patterns between some of the Tibialis Anterior (TA) muscle compartments. Additional loading resulted in higher strain rates in TA compartments but lower in the Gastrocnemii muscles.
Deuterium magnetic resonance spectroscopy using 2H-pyruvate allows in vivo imaging of tumor burden and response to therapy
Authors: Batsios Georgios , Taglang Celine , Tran Meryssa , Gillespie Anne Marie , Ronen Sabrina , Costello Joseph , Viswanath Pavithra
Published: August 2023

Telomerase reverse transcriptase (TERT) is essential for tumor proliferation and is an attractive therapeutic target. Non-invasive methods of imaging TERT can report on tumor proliferation and response to therapy. Here, we show that 2H-MRS following administration of [U-2H]pyruvate non-invasively monitors TERT expression in clinically relevant patient-derived glioma models. Importantly, imaging TERT using [U-2H]pyruvate provides a readout of response to targeted TERT inhibitors and standard of care chemotherapy in vivo, at early timepoints that precedes MRI-detectable anatomical alterations. Clinical translation of our results can enable non-invasive assessment of TERT expression in vivo and, thereby, aid in imaging response to anti-cancer therapies.
Proton and hyperpolarized 13C MRS based biomarkers response to the BAY-1436032 IDH inhibitor in cell and in vivo glioma models
Authors: Hong Donghyun , Radoul Marina , Minami Noriaki , Gillespie Anne Marie , Pieper Russell O. , Costello Joseph , Viswanath Pavithra , Ronen Sabrina M.
Published: August 2023

Mutant IDH1 inhibitor treatment is currently in clinical trials for glioma patients. Therefore, in vivo biomarkers are needed to assess early therapeutic responses. Here we treated mutant IDH1-expressing cells and animals with patient-derived mutant IDH1 brain tumors with the emerging inhibitor BAY-1436032. Using 1H MRS we found a significant decrease in 2HG that was accompanied by an increase in glutamate and phosphocholine, and using 13C MRS we detected a significant decrease in 2HG and a significant increase in glutamate produced from hyperpolarized [1-13C] α-ketoglutarate in cell and animal models.
Advanced Vessel- and Cell-Size MRI to Assess Chemo-Radiation Treatment Response in Pediatric Ependymoma Models
Authors: Serkova Natalie , Manalo Jane , Steiner Jenna , Griesinger Andrea , Pierce Angela , Brown Mark , Foreman Nicholas
Published: August 2023

We report on an advanced mpMRI protocol for characterizing the cellular and vascular phenotype in an orthotopic mouse model of pediatric ependymoma (EPN). Using diffusion-weighted based cell-size imaging, iron-oxide based vessel-size imaging and quantitative T2-maps, we report on an EPN-specific phenotype, characterized by an increased cell size (S=14 microns), increased vessel density index (Q=0.54), and low ADC values (0.63x10-3). Radiation treatment (10 Gy) in combination with 5-fluorouracil chemotherapy resulted in a decrease of gross tumor volumes, tumor necrosis with decreased cell sizes and increased ADC values, as well as a dramatic vascular-inflammatory response (highly decreased Q and DT2 values).
Assessing tumour haemodynamic heterogeneity and response to choline kinase inhibition using DCE-MRI in rodent models of glioblastoma
Authors: Bhaduri Sourav , Sharkey Jack , Lesbats Clémentine , Kelly Claire L. , Mukherjee Soham , Delikatny Edward J , Kim Sungheon G , Poptani Harish
Published: August 2023

This study was designed to monitor changes in DCE-MRI based parameters Ktrans, ve, τi and Fp in pre-clinical GBM models in response to choline kinase inhibition using a cluster analysis approach. The study demonstrates that region-based clustered pharmacokinetic parameters obtained using DCE-MRI can be used for detecting and assessing tumour heterogeneities which may be useful in assessing therapeutic response.
Uncertainty estimation via ensembling for deep learning-based MR image reconstruction
Authors: Hepp Tobias , Gatidis Sergios , Hammernik Kerstin , Küstner Thomas
Published: August 2023

Deep learning-based MR image reconstruction from undersampled data bears the risk of inducing reconstruction errors like in-painting of non-anatomical structures, or missing pathologies. These errors may be obscured by the deep learning process and thus remain undiscovered. Furthermore, most methods are task-specialized and not well calibrated to domain shifts. Thus, integrated uncertainty prediction would be desirable. We propose a deep ensembling strategy that allows us to assess potential algorithm failures and better adapt to changing scenarios. The proposed approach can be paired with any DL reconstruction, enabling investigations of their predictive uncertainties on a voxel-level.
Comparing Diffusion MRI Metrics with 3D Nissl Staining of Whole Mouse Brain at Microscopic Resolution
Authors: Wang Nian , Maharjan Surendra
Published: August 2023

Magnetic resonance imaging (MRI) offers a noninvasive method for characterizing brain neuroanatomy and provides insights into various disease processes. Diffusion MRI (dMRI) has been used for assessment of tissue microstructure due to its exquisite sensitivity to finer scales far above imaging resolution. The recently developed Allen Mouse Brain Common Coordinate Framework (CCFv3) has opened the opportunities to integrate multimodal and multiscale datasets of whole mouse brain in 3D, and thus, this approach can be used to compare quantitative MRI parameters with conventional histology features throughout the whole brain.
High-resolution MAP-MRI reveals cortical area specific laminar patterns observed with histological staining
Authors: Avram Alexandru , Saleem Kadharbatcha , Komlosh Michal , Basser Peter
Published: August 2023

We investigate the sensitivity of high-resolution MAP-MRI to distinguish cortical architectonic features by directly comparing laminar patterns in whole-brain volumes of MAP-derived parameters to the corresponding histological sections in the same macaque monkey brain. MAP parameters, in particular PA, NG, RTAP, DEC, and fODF maps, show cortical area-specific lamination patterns with excellent conspicuity in the mid-cortical layers, matching, and sometimes complementing, the contrast observed in the immuno- or histochemically stained sections. Delineating cortical areas with distinct cytoarchitectonic features non-invasively based on diffusion propagators could transform our ability to study brain networks and diagnose subtle microstructural changes in many clinical applications.
Quantitative validation of MRI mapping of cerebral venous oxygenation with direct blood sampling: a graded-O2 study in piglets
Authors: Jiang Dengrong , Koehler Raymond , Liu Xiuyun , Kulikowicz Ewa , Lee Jennifer , Lu Hanzhang , Liu Peiying
Published: August 2023

The neonatal brain relies primarily on oxygen metabolism to meet its enormous energy demands. Cerebral venous oxygenation (Yv) is an important parameter of the brain’s oxygen utilization, and has been demonstrated to be a potential biomarker in various neonatal diseases. We previously developed two non-invasive MRI techniques, TRUPC and accelerated-TRUPC, to measure Yv in the neonatal brain. In this work, we validated the accuracy of these two techniques by comparing their Yv measurements with gold-standard blood gas oximetry on a piglet model, and demonstrated that TRUPC and accelerated-TRUPC can provide accurate quantifications of Yv.
Novel non-invasive determination of parasagittal dural volume and cerebrospinal fluid flux: assessment of glymphatic clearance mechanisms
Authors: Hett Kilian , McKnight Colin , Eisma Jarrod , Elenberger Jason , Considine Ciaran , Claassen Daniel , Donahue Manus
Published: August 2023

Despite prior assumptions that the brain is devoid of lymphatic vessels, emerging evidence indicates that lymphatic vessels are present in the region alongside the superior sagittal sinus, the parasagittal dural (PSD) space, and could play a critical role in waste clearance or glymphatic physiology. However, limited methods are available for interrogating this space non-invasively in vivo. Here, in 62 healthy participants we apply novel deep learning algorithms in sequence with anatomical and phase contrast cerebrospinal fluid (CSF) flow assessments to test fundamental hypotheses regarding how PSD volume evolves across the lifespan and relates to measures of CSF flux and volume.
Measuring RF field-induced temperature variations in brain MRI exams with motion compensated MRT and field monitoring.
Authors: Le Ster Caroline , Mauconduit Franck , Mirkes Christian , Vignaud Alexandre , Boulant Nicoal
Published: August 2023

Sub-degree brain temperature rise occurring through RF power deposition during the MR exam was measured with MR thermometry at 7T using a multi-slice EPI sequence and concurrent field monitoring. This sequence was first tested in vitro with field perturbations, an optical probe being used for ground truth measurements, and the accuracy of the method reached 0.02°C. In vivo, this methodology was complemented by a motion compensation step and precision reached 0.05°C. After 20-min of scanning at maximal SAR, temperature rise induced by RF power deposition throughout the inner brain reached 0-0.2°C, well below the values predicted by thermal models.
Design and Optimization of Transmit Arrays for MRI at 11.7T
Authors: Chu Son , Gras Vincent , McElhinney Paul , Boulant Nicolas , Gunamony Shajan
Published: August 2023

The promise of supra-linear boost in signal-to-noise-ratio is driving the development of MRI at extremely high static field strengths, such as 10.5T and beyond. The shorter wavelengths in tissues at high Larmor frequency causes destructive interference of the electromagnetic field, resulting in image inhomogeneity and increased local specific absorption rate (SAR). An efficient transmit array is vital in this regime to optimally use the available RF power, achieve efficient excitation and operate within SAR constraints. This work presents the design and optimization of an 8-channel transmit array for MRI at 11.7T and its performance evaluation using RF pulse design simulations.
A Compact 16Tx-32Rx Geometrically Decoupled Phased Array for 11.7T MRI
Authors: Luong Michel , Ferrand Guillaume , Chazel Edouard , Gapais Paul-François , Gras Vincent , Boulant Nicolas , Amadon Alexis
Published: August 2023

A geometrically decoupled 16Tx-32Rx RF coil has been designed for the Iseult 11.7T project. It has 16 transceive resonators and 16 receive-only loops. This peculiar architecture satisfied three major concerns: compactness-made compatibility with a local B0 shim insert, easy tuning and performance prediction. Simulations show high flip angle homogeneity in the whole brain (NRMSE<6%) with kT-points, accounting for all constraints (pulse length, SAR, power budget). Predicted global SNR in phantom with SoS reconstruction is 2.47±0.2 times higher as compared to 7T (with the commercial 8Tx-32Rx Nova coil) or equivalently, the SNR scales as B0 to the power of 1.74±0.16.
Generalized approach of quadruple or quintuple-tuned RF coil setups for metabolic MRI throughout the body at 7 Tesla
Authors: Dai Jiying , Meliadò Ettore , Gosselink Mark , Arteaga Catalina , Raaijmakers Alexander , Klomp Dennis
Published: August 2023

The 7T operating frequency of 1H and 19F RF transceivers is in far field regime, while for remaining nuclei these are in near-field regime. Consequently, the optimal setup for far field is based on antennas, while for near field these are based on loop coils. Owing to their intrinsic field orthogonality, these setups can be merged with low RF coupling and thus low penalty in efficiency as we demonstrated for a quintuple tuned head coil. Here we show that the design is generalized and can in principle be used for any body part, as demonstrated in brain, breast and extremity.
An integrated 64-channel receive array design for 7 Tesla head and torso MRI of young infants
Authors: Clément Jérémie , Hajnal Joseph , Ipek Özlem
Published: August 2023

7T MRI has potential for adding value in studies of infant brain and heart. In this study we introduce the first integrated high channel count receive array designed to enable both head and torso imaging of young infants at 7T. The array performance was evaluated in terms of noise correlation matrix, signal-to-noise ratio, and spatial coverage. The initial results are promising with the array providing a large coverage of the targeted regions in phantom. After further safety checking, the next step will be to conduct in-vivo studies, paving the way for future high performance infant examinations at 7T.
Increased structural connectivity in high schizotypy: a possible protective mechanism against schizophrenia.
Authors: Messaritaki Eirini , Foley Sonya , Barawi Kali , Jones Derek
Published: August 2023

This work explores the link between brain structural connectivity and schizotypy in healthy participants. We found evidence of higher structural connectivity in the sensorimotor network of high-schizotypy participants compared to those with low schizotypy. Weaker evidence was also found for alterations in the auditory, default-mode and visual networks. In contrast, no significant differences were found in the structural connectivity of the whole-brain or limbic networks. The higher connectivity possibly shields these participants from schizophrenia. Our results agree with the results of works proposing that deficiencies in the sensorimotor brain network should be investigated as possible causes for schizophrenia.
Unravelling the serotonergic contribution to citalopram-induced changes in functional connectivity
Authors: Schrantee Anouk , Dispasquale Ottavia
Published: August 2023

While citalopram pharmacology has been extensively investigated and defined, the molecular mechanisms underlying brain functional response to this antidepressant are less well characterised. Therefore, we explored the functional response of the healthy brain to an acute citalopram challenge by enriching resting-state fMRI with molecular templates of serotonin neurotransmitters. We found that a high oral dose of citalopram induces significant alterations in 5-HT1A-enriched functional connectivity, and that serotonin transporter occupancy is linked with the interindividual functional response to citalopram in the SERT-related network. These findings set a new basis for a mechanistic understanding of the functional effects of citalopram in depression.
Frontal and Temporal Cortical Myelination Associations with Cognition Revealed by a Novel T1w/T2w-based Marker in Subjective Cognitive Decline
Authors: Sui Yu Veronica , Masurkar Arjun , Marsh Karyn , Reisberg Barry , Wisniewski Thomas , Rusinek Henry , Lazar Mariana
Published: August 2023

Identifying early changes associated with Alzheimer’s Disease (AD) and separating pathological from normal brain aging is a key step in AD treatment development. It has been proposed that a neuropathological retrogenesis heralded by cortical demyelination underlies the behavioral retrogenesis characterizing AD. As one of the earliest behavioral manifestations of AD, subjective cognitive decline (SCD) is a major research target, however, few studies have discovered reliable neural correlates at this stage. Here, using a novel cortical profile approach, we examined the cortical gradient of T1w/T2w, a putative myelin marker, in SCD and healthy control participants and its association with cognition.
Development of MRI-based 3D Radiomics Signatures for Preoperative Risk Stratification of Patients with Histology-proven Endometrial Cancer
Authors: Lefebvre Thierry , Ueno Yoshiko , Dohan Anthony , Chatterjee Avishek , Vallières Martin , Winter-Reinhold Eric , Saif Sameh , Levesque Ives , Zeng Xing , Forghani Reza , Seuntjens Jan , Soyer Philippe , Savadjiev Peter , Reinhold Caroline
Published: August 2023

Radiomics analysis on standard MRI prior to surgery holds potential to help identifying high-risk histopathological features of endometrial carcinoma, including FIGO stage, deep myometrial invasion, lymphovascular space invasion and tumor grade, thus supporting preoperative risk stratification for optimal patient management. This dual-center retrospective study evaluated the role of radiomics to assess high-risk phenotypes of endometrial cancer in women who underwent 1.5-T MRI before hysterectomy. Radiomics-based machine learning models provided consistent clinically acceptable performance for differentiating early from advanced FIGO stage endometrial carcinoma and for differentiating low- from high-risk histopathological markers in two independent datasets from different institutions on preoperative MRI.
Automatic Segmentation of Twin Regions in Mo-Di Placentae Based on Geometric Analysis of Spatiotemporal BOLD MRI Signals
Authors: Shnitzer Tal , Abulnaga S. Mazdak , Bibbo Carolina , Grant P. Ellen , Golland Polina , Solomon Justin , Turk Esra Abaci
Published: August 2023

We propose an automatic segmentation method for delineating functional regions of the placenta responsible for each twin in Mo-Di placentae. The study of differences in MRI biomarkers between identical twins promises to elucidate placental function and fetal development. We combine temporal information from BOLD MRI time series and spatial information from the umbilical cord insertion in a flattened placenta representation. We demonstrate alignment of the automatic segmentation results with expert manual delineations and subsequent agreement of dynamic MRI signals in the identified regions with those derived from expert segmentations. Our method enables automatic localized analysis of the placenta.
Abnormal Brain Activation in Post-acute Sequelae of COVID-19
Authors: Chang Linda , Ryan Meghann , Liang Huajun , Zhang Xin , Cunningham Eric , Wilson Eleanor , Levine Andrea , Kottilil Shyamasundaran , Ernst Thomas
Published: August 2023

Post-acute sequelae of COVID-19 is highly prevalent after the acute infection. Neuropsychiatric symptoms are particularly common; however, the pathophysiology of how the brain is affected remains unclear. This study aimed to evaluate whether convalescent COVID-19 participants have abnormal brain activation that is related to quantitative neurobehavioral measures. 21 COVID-19 participants and 20 healthy controls were evaluated with the NIH-Toolbox® and blood-oxygenation level dependent-functional MRI (BOLD-fMRI), using the N-back tasks. Despite similar performance on the NIH-Toolbox-cognitive battery, COVID-19 participants had greater brain activation than controls in the precuneus and dorsal anterior cingulate cortex, which also predicted poorer dexterity, endurance, and locomotion.
Multinuclear lung MRI assessment of COVID-19 patients at 6 and 12 weeks after hospital admission
Authors: Saunders Laura , Collier Guilhem , Chan Ho-Fung , Hughes Paul , Smith Laurie , Marshall Helen , Eaden James , Bray Jody , Capener David , Armstrong Leanne , Rodgers Jennifer , Brook Martin , Biancardi Alberto , Watson James , Gabriel Zoë , Rao Madhwesha , Norquay Graham , Rodgers Oliver , Wilson Fred , Cahn Tony , Swift Andy , Rajaram Smitha , Gleeson Fergus , Grist James , Mills Gary , Meiring James , Watson Lisa , Collini Paul , Lawson Rod , Thompson Roger , Wild Jim
Published: August 2023

This work uses a multinuclear 1H and 129Xe protocol to assess pathophysiological changes in patients with COVID-19 pneumonia, without signs of interstitial lung disease, at 6 and 12 weeks after hospital admission. 1H and 129Xe protocol: ultra-short echo time, dynamic contrast enhanced lung perfusion, 129Xe lung ventilation, 129Xe diffusion weighted MRI, 129Xe 3D spectroscopic imaging. Though significant improvements in lung ventilation homogeneity (decreased low ventilation percentage and ventilation coefficient of variation), gas transfer (increased RBC:TP, decreased TP T2*) and perfusion (increased pulmonary blood volume and flow) were seen between 6 and 12 weeks, low RBC:TP ratio persisted for some patients.
Vital Signs, Temperature and COMFORT Scale Scores in Infants During Ultra-High-Field MR Imaging.
Authors: van Ooijen Inge , Annink Kim , Dudink Jeroen , Alderliesten Thomas , Groenendaal Floris , Tataranno Maria Luisa , Lequin Maarten , Hoogduin Hans , Visser Frederik , Raaijmakers Alexander , Klomp Dennis , Wiegers Evita , Benders Manon , Wijnen Jannie , van der Aa Niek
Published: August 2023

7T MRI in infants could improve cerebral diagnostic quality, but safety should be evaluated before standard use. In this study, twenty infants without respiratory support between term-equivalent age and 3 months corrected age, were scanned on 7T directly after 3T MRI. Vital signs (heart rate, oxygen saturation and respiratory rate), temperature (rectal, body and brain), COMFORT scale scores and adverse events were monitored throughout the process. None of these parameters changed around 7T MRI. Also, heart rate and temperature were not significantly different during 7T, when compared to 3T MRI. Therefore scanning infants at 7T appears to be safe.
The effects of preterm birth on GABA+, Glx and GSH in the neonatal brain
Authors: Lopez Maria Yanez , Price Anthony N , Puts Nicolaas AJ , Hughes Emer J , Edden Richard AE , McAlonan Grainne M , Arichi Tomoki , De Vita Enrico
Published: August 2023

We have performed the first simultaneous measurement of GABA+, Glx and GSH in the preterm brain. Our main findings show that GABA+ and Glx significantly increased with postmenstrual age in preterm neonates during the 31-45 week period. We additionally found that metabolites underpinning glutamate and GABA neurotransmission levels in preterm babies were significantly lower than normative neonatal values, even when measured at the term time equivalent timepoint. We also identified higher GABA+ and Glx in the thalamus compared with the cortex. Our findings provide further support for the application of edited MRS in neurodevelopment.
A biphasic pattern of cerebral blood flow increases during infancy revealed with 3D multi-shot, stack-of-spirals pCASL and phase-contrast MRI
Authors: Ouyang Minhui , Detre John , Hyland Jessica , Sindabizera Kay , Peng Yun , Edgar J. Christopher , Huang Hao
Published: August 2023

Infancy is one of the most prominent times of daily energy expenditure across the lifespan. Here, using cutting-edge pCASL with high-resolution at isotropic 2.5mm and phase-contrast MRI, we delineated the developmental trajectory of the infant’s global and regional cerebral blood flow (rCBF) supporting the metabolic needs for brain development in 0-28months. Significant age-related CBF increases during infancy were better modeled with biphasic linear models, with break-point ages observed earlier in sensorimotor and auditory cortices and later in association cortices. The established population-averaged rCBF maps across infancy can serve as normative rCBF atlases for neuroscientific research or clinical care.
What do children need to learn for an MRI-scan? Gamification of learning goals into the cosmo@home app
Authors: Geuens Sam , Nauts Sanne , Abdelrazeq Anas , Aertsen Michael , Buyse Gunnar , Demaerel Philippe , Lemiere Jurgen , Nijs Jessica , Pauwels Greet , Potoms Marlies , Privender Saini , Sauer Kate , Sjölinger Marie , Ståhl Olov , Treunen Marlies , Van Cauter Sofie , Wouters Leen , Weyn Barbara
Published: August 2023

Undergoing an awake MRI-scan can be very stressful for young children and bears the risk that image quality is poor due to motion artefacts. Behavioral training by an experienced trainer has shown success in preparing children before a scan, however, this approach is costly and trainer dependent. We have designed a mobile app to prepare children for an upcoming MRI-scan at home. This app was tested by 52 children in four different hospitals. First data show that children and parents appreciate the app very much and that learning goals can be reached with a digital application at home.