bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary study of amide proton transfer-weighted with intravoxel incoherent motion imaging in predicting bone metastasis of prostate cancer
Authors: Hu Wenjun , Chen Lihua , Lin Liangjie , Dai Xu , Wang Jiazheng , Liu Ailian
Published: August 2023

Bone metastasis is an important issue in the management of prostate cancer, and can drastically alter the treatment strategy. PET/CT has been widely used in the diagnosis of bone metastasis; however, the high cost and radiation exposure limit its extensive clinical applications. APT-weighted imaging and IVIM, recent developed function-oriented MRI sequences, allow for a non-invasive visualization of tissue composition and microscopic information without the need for contrast agents. Results of this study indicate the APT value and IVIM parameters can effectively predict bone metastases in prostate cancer. A combination of APT and D* mono can further improve the prediction performance.
NOE imaging in tumors using asymmetric analysis of 2pi-CEST signals
Authors: Cui Jing , Zu Zhongliang
Published: August 2023

Nuclear overhauser enhancement (NOE) mediated chemical exchange saturation transfer (CEST) effect at -3.5 ppm has shown clinical interests in diagnosing tumors. Asymmetric analysis is a fast and simple method to measure and quantify the NOE effect, but has contamination from the downfield amide proton transfer (APT) effect at 3.5 ppm. In this abstract, we provide a new NOE quantification method using asymmetric analysis of CEST signals acquired with 2pi saturation pulses (2pi-CEST) which is also fast but has reduced contamination from the APT effect.
SLOW-EPSI for the Whole Brain Detection of Phosphorylethanolamine (PE) at 7T
Authors: Weng Guodong , Radojewski Piotr , Schucht Philippe , Wiest Roland , Slotboom Johannes
Published: August 2023

Purpose: to detect phosphoethanolamine (PEtn or PE) in vivo for whole-brain MRSI, overcoming challenges of B1+-inhomogeneities and CSDE at 7T.

Methods: An EPSI-based B1+ robust SLOW-editing was applied to three healthy subjects. TE = 90 ms, TR = 1500 ms, and TA = 9:04 mins.

Results: the editing PE signal at 3.22 ppm was clearly present, and the B1+-homogenous result/map was obtained.

Conclusions: whole-brain in vivo PE-editing can be performed in around 9 minutes measurement time and is therefore clinically applicable.
Reproducibility of multi-slice MR spectroscopic imaging of GABA at 3 T
Authors: Zöllner Helge , Özdemir Ipek , Senapati Dillip , Považan Michal , Oeltzschner Georg , Chan Kimberly , Lin Doris , Barker Peter
Published: August 2023

Reproducibility of multi-slice GABA-edited MRSI of the human brain recorded at 3T was investigated in 6 healthy adult volunteers, with and without a retrospective motion compensation scheme applied (MoCo). Overall reproducibility was good with improved performance when MoCo was applied (relative GABA+/tCr difference between visits: 20.8% no Moco, 10.0% with MoCo). Retrospective MoCo is a viable alternative for edited-MRSI when prospective motion correction is unavailable, at least in relatively compliant subject groups.
GABA-edited MEGA-PRESS at 3T: Does a measured MM background improve linear-combination modeling?
Authors: Zöllner Helge , Song Yulu , Hui Steve , Barker Peter , Edden Richard , Oeltzschner Georg
Published: August 2023

Recent work identified a 'best practice' linear-combination modeling (LCM) strategy for GABA-edited spectra using parameterized basis functions for co-edited macromolecules. Here we introduce a measured macromolecular basis function to evaluate possible improvements in the modeling.
Why is 7T fMRI in the entorhinal cortex so difficult and what can we do about it?
Authors: Graedel Nadine , Warrington Oliver , Dymerska Barbara , Malekian Vahid , Josephs Oliver , Kok Peter , Callaghan Martina
Published: August 2023

Functional MRI in the entorhinal cortex is very challenging due to large and geometrically complex B0 field inhomogeneity. As a result, a quarter of voxels are lost due to T2*-driven dephasing and/or because the echo is pushed outside of the acquisition window. Additionally, off-resonant voxels suffer from poor excitation efficiency with frequency-selective binomial pulse excitation, which are preferred for fat suppression for SAR and time efficiency. We empirically demonstrate substantial signal, and consequently tSNR, gains in off-resonance regions by reducing binomial pulse order (from 1-3-3-1 to 1-2-1 or 1-1) that match numerical predictions.
SpinalCompCor: PCA-based denoising for spinal cord fMRI
Authors: Hemmerling Kimberly , Hoggarth Mark , Parrish Todd , Barry Robert , Bright Molly
Published: August 2023

SpinalCompCor is a denoising technique in which principal component (PC) analysis is performed in a region outside of the spinal cord to define nuisance regressors. Temporal SNR was greater when PC regressors were included in the general linear model, compared to when they were regressed out of the data prior to motion correction. In comparing models that vary the number of PC regressors, models with multiple PCs generally performed better than those with single PCs. SpinalCompCor is a promising technique for spinal cord fMRI denoising.
Deep Learning Based Mask Generation Tools for QSM
Authors: Lee Gawon , Son Ji Wan , SaKaie Ken , Jung Woojin , Oh Se-hong
Published: August 2023

Even subtle differences in masks can generate systematic but avoidable errors in QSM calculations. We believe these errors propagate through the calculation of the background phase. In this work, we assessed the effect of the mask on the QSM, selected optimal mask generation method and Deep Learning-based efficient mask generation method for in-vivo has been presented. This study represents the first step towards a fully-automated and optimal workflow for QSM calculation.
Preservation of Brain Oxygen Metabolism in Emerging Young Adult Survivors of Fontan Palliation for Single Ventricle.
Authors: Shen Jian , Suriany Silvie , Gonzalez-Zaccarias Clio , Xu Botian , Panigraphy Ashok , Detterich Jon , Wood John
Published: August 2023

Surgical palliation of single ventricular heart disease (Fontan procedure) leads to poor cardiac output, high central venous pressures, and long-term multiorgan morbidity. We report cerebral blood flow, brain oxygen delivery, and cerebral metabolic rate in 20 Fontan survivors and 9 control subjects. Fontan patients had lower cerebral blood flow and oxygen saturation but maintained cerebral oxygen delivery and cerebral metabolic rate of oxygen (CMRO2) because of polycythemia. Scattergram between CMRO2 and O2 delivery suggests similar oxygen extraction at the microvascular level in both groups. Taken together, these data suggest adequate cerebrovascular compensation to low cardiac output in Fontan patients.
GRASPNET: Spatiotemporal deep learning reconstruction of golden-angle radial data for free-breathing dynamic contrast-enhanced MRI
Authors: Jafari Ramin , Do Richard , Fung Maggie , Bayram Ersin , Otazo Ricardo
Published: August 2023

GRASP is a valuable tool to perform free-breathing dynamic contrast-enhanced (DCE) MRI with high spatial and temporal resolution. However, the 4D reconstruction algorithm is iterative and relatively long for clinical studies. In this work, we present a spatiotemporal deep learning approach to significantly reduce the reconstruction time without affecting image quality.
Intrinsic reproducibility issues in deep learning-based MR reconstruction
Authors: Oh Chungseok , Jung Woojin , Lee Jongho
Published: August 2023

Deep learning requires a large number of parameter settings, which can be prone to reproducibility issues, undermining the reliability and validity of the outcomes. In this study, we list the common sources that may induce the reproducibility issues in deep learning-based MR reconstruction. The effect size of each source on the network performance was investigated. From the results of this study, we recommend to share a trained network.
Hyperpolarized 129Xe MRI and spectroscopy in healthy control subjects reveals age-related changes in measurements of pulmonary gas exchange
Authors: Mummy David , Swaminathan Aparna , Bier Elianna , Yarnall Kevin , Bechtel Aryil , Lu Junlan , Leewiwatwong Suphachart , Kabir Sakib , Korzekwinski Jennifer , Driehuys Bastiaan
Published: August 2023

Age-related changes in 129Xe gas exchange MRI and spectroscopy are not well understood. We assessed a suite of common 129Xe-derived measures of gas exchange function in a population of healthy control subjects age 19-87. Increased age was associated with reduced red blood cell (RBC) to barrier ratio and with greater levels of ventilation defects and RBC transfer defects. These effects must be accounted for when evaluating 129Xe-derived metrics as markers of disease in individual patients. Notably, high barrier uptake remained largely minimal across age groups, and does not appear to be a feature of healthy aging.
Establishing a hemoglobin correction for 129Xe gas exchange MRI
Authors: Bechtel Aryil , Bier Elianna , Lu Junlan , Church Alexander , Korzekwinski Jennifer , Mummy David , Driehuys Bastiaan
Published: August 2023

Hyperpolarized 129Xe gas MRI provides a spatially resolved method of monitoring gas exchange function in the lungs via 3D reconstruction of RBC/gas and barrier/gas signals. However, the strength of these signals is affected by patient hemoglobin concentration (Hgb). Thus, correcting for Hgb is important for establishing normative healthy reference distributions and accurately assessing the degree of gas exchange impairment. Here, we use a 1D physical diffusion model to establish Hgb-dependent correction factors to standardize gas exchange MRI relative to a fixed Hgb value. This correction can result in substantial changes in the visualization and quantification of gas exchange MRI.
Simultaneous fMRI and metabolic MRS of hyperpolarized [1-13C]pyruvate during nicotine stimulus in rat
Authors: Hyppönen Viivi , Rosa Jessica , Kettunen Mikko
Published: August 2023

fMRI is widely used to study cerebral metabolism to stimulus through combination of BOLD and hemodynamic changes. Hyperpolarized carbon can also be used to study cerebral metabolism, but it is currently poorly understood. Here we performed simultaneous 1H fMRI and 13C MRS experiments to compare their response to nicotine stimulus. Cortical BOLD signal increase was accompanied by increased bicarbonate labelling. Combined 1H fMRI and 13C MRS may therefore offer complementary information on brain response to stimulus.
15N-enriched NAD+/ NADH Analogs as Redox-Responsive MRI Sensors
Authors: Buchanan Emily , Ratnakar James , Suh Eul Hyun , Chen Jun , Dimitrov Ivan , Park Jae Mo , Sherry A. Dean , Kovacs Zoltan
Published: August 2023

In this study, we prepared a 15N-enriched analog of NAD+ (N-methyl nicotinamide = MNA+) and demonstrated that it undergoes reduction by sodium dithionate to form MNAH. The 15N chemical shifts of the oxidized and reduced forms differ by 124.2ppm. DNP of MNA+ followed by dissolution and 15N NMR showed a favorable T1 relaxation time of 130s at 1T and 50s at 3T. Deuteration of the methyl protons only increased the T1 of 15N by ~10s. The long T1 of 15N in these NAD+/NADH mimetics and the large chemical shift difference offer the exciting potential for their use as redox sensors.
Passive Real-Time Needle Tracking and Needle Tip Estimation
Authors: Reichert Andreas , Hickey Samantha , Fischer Johannes , Vogele Michael , Reiss Simon , Bock Michael
Published: August 2023

A real-time sequence is presented with automatic adjustment of the imaging plane parallel to a needle. The sequence utilizes the phase-only cross correlation (POCC) algorithm to detect the orientation of an end-effector and to visualize the planned needle pathway. Additionally, it detects a passive marker at the distal end of the needle to calculate the position of the needle tip for real-time display during needle insertion. The sequence is evaluated in a phantom experiment, and both lateral and longitudinal needle insertion accuracies are determined.
Simulating the effects of off-resonance effects from a CHORUS pulse sequence in a single sided, low-field MRI system.
Authors: Selvaganesan Kartiga , Gomes Muller , Grissom Will , Nacev Alek
Published: August 2023

Moving towards single-sided, low-field MRI systems can increase the portability and access to this invaluable clinical tool. However, the B0-fields generated by these systems are highly inhomogeneous, and severe artifacts arise when the RF pulse does not cover the full bandwidth of spin resonances. In this study, we have developed a simulation algorithm that will allow us to better simulate the phase variations induced by B1 and B0 inhomogeneities and help us design RF schemes to remove unwanted phase to produce higher quality images.
Comparing Single and Multiple Delays methods for ASL Perfusion Quantification on Pediatric Neuroimaging
Authors: Zhao Moss , Yeom Kristen , Tong Elizabeth , Duarte Rui Miguel , Moseley Michael , Zaharchuk Greg
Published: August 2023

This study compared the CBF measurements using single and multiple delay ASL on 28 children without neurological or cerebrovascular disorders. Results showed that CBF of multiple delay ASL was significantly higher than the values of single delay ASL by a mean of 18%. CBF of both ASL techniques increased with age.
Dynamic resting state connectivity of the default mode, salience and central executive networks in adolescents with concussion
Authors: Ho Rachelle , Shaw Saurabh , Bock Nicholas , DeMatteo Carol , Noseworthy Michael , Hall Geoffrey
Published: August 2023

Our study evaluated the dynamic functional connectivity of adolescents with concussion in comparison to healthy controls using (1) sliding window ROI-to-ROI and (2) sliding window graph theory analyses. Adolescents with concussion exhibited higher between-network connectivity between the salience network and central executive network, but reduced between-network connectivity between the default mode network to both the salience and executive networks. This suggests lower default mode network integration and engagement during rest following concussion in adolescents.
Whole brain 3D radial T2 mapping with retrospective motion correction capabilities.
Authors: Corbin Nadège , Trotier Aurélien , Miraux Sylvain , Ribot Emeline
Published: August 2023

T2 mapping is usually very time consuming and long acquisition time often result in high sensitivity to intra-scan motion. Here we propose a T2 mapping method relying on 3D radial sampling and advanced iterative reconstruction to retrospectively correct for motion and/or reduce the acquisition. First, in-vivo experiments at 3T showed the capability of the technique to correct for intra-scan motion and therefore improve the quality of resulting T2 maps. Second, acquisitions varying from 7 to 33 min of whole-brain single and multi-compartment T2 maps were obtained, showing the potential of the method to accelerate and therefore reduce sensitivity to motion.
Sodium 23Na-MRI relaxometry and tissue sodium content at 15.2T in a murine model of lymphangiogenesis
Authors: Taylor Shannon , Harkins Kevin , Colvin Daniel , Rutkowski Joseph , Does Mark , Gore John , Crescenzi Rachelle
Published: August 2023

To investigate questions regarding the physiology of salt storage in skin and muscle and its relationship with lymphangiogenesis, we are developing sodium 23Na-MRI protocols for a mouse model of controllable lymphangiogenesis in adipose tissue. We acquired images at 15.2T from a UTE center-out sequence and quantified sodium longitudinal and bi-exponential transverse relaxation times and tissue sodium content (TSC) in the skin and muscle. Baseline TSC was reduced in animals undergoing lymphangiogenesis compared to littermates, while 23Na-relaxometry was similar. These results will be used for protocol development in this animal model to study sodium and lymphatic physiology.
A multi-organ assessment of the acute effects of haemodialysis using intradialytic multiparametric magnetic resonance imaging
Authors: Cox Eleanor , Gullapudi Venkata Rukmini Latha , Buchanan Charlotte , White Kelly , Coleman Sebastian , Cocking Daniel , Kazmi Isma , Köhler Katrin , Canaud Bernard , Taal Maarten , Selby Nicholas , Francis Susan
Published: August 2023

Twelve patients underwent serial cardiac, cerebral and renal multiparametric 3T MRI scans before, during and after haemodialysis. During dialysis, there was a significant decline in cardiac and stroke index and myocardial strain, with increased diastolic dysfunction. This was accompanied by a reduction in blood flow to both the heart and brain. White matter T1 increased during dialysis suggesting fluid shifts increasing water content resulting in local oedema. Total kidney volume, renal cortex T1 and T2* all reduced during dialysis likely reflecting reduced renal blood volume and change in renal tissue water. These results highlight the acute multi-organ effects of dialysis.
Structural and functional brain imaging in a rat model of fetal growth restriction
Authors: van de Looij Yohan , Mairesse Jérôme , Pansiot Julien , Zinni Manuela , Sizonenko Stéphane , Baud Olivier
Published: August 2023

Brain injuries and subsequent neurodevelopmental impairments observed following Fetal Growth Restriction (FGR) were shown to be associated with an exacerbated neonatal neuro-inflammation. The aim of this work was to characterize a rat model of FGR by advanced diffusion MRI (DTI and NODDI) and functional ultrasounds (fUS). We show in this study that neonatal inflammation lead to transient microstructural damages and subsequent behavioral and functional disabilities at long term. This model mimics very closely clinical reality in babies born following FGR. Innovative neuroimaging tools associated with this neuro-inflammatory model pave the way for their translational use in human neonates.
Validation of fast in vivo T1 and T2* mapping of tissues in the knee using 3D UTE
Authors: Rothe Maik , Deistung Andreas , Brill Richard , Wohlgemuth Walter , Gussew Alexander
Published: August 2023

In this study we present a 3D high resolution method for fast in vivo T1 and T2* mapping of fast relaxating tissues of the knee. All experiments were performed using a prototypical 3D spoiled gradient echo ultrashort echo time sequence with stack of spirals readout. T1 and T2* values of the mapping technique were validated by reference methods and literature values and showed good agreement for fast T1 and T2* values. The mapping technique enables T1 and T2* quantitation of fast relaxating tissues in a clinically appropriate measurement time of 9 minutes with a submillimeter spatial resolution (0.8mmx0.8mmx0.8mm).
Deuterium Metabolic Imaging for 3D Mapping of Human Brain Metabolism at 3T
Authors: Adamson Philip , Datta Keshav , Watkins Ron , Recht Lawrence , Hurd Ralph , Spielman Daniel
Published: August 2023

Deuterium metabolic imaging (DMI) is an emerging modality for investigating glucose metabolism with particular application for assessing the Warburg effect in tumors. Although high field systems, e.g., 7T, provide maximal signal-to-noise ratio (SNR), implementation on widely available 3T scanners could have immediate clinical impact. Using a birdcage 2H RF coil, modified gradient filter, and spherical k-space sampling, we demonstrate high-quality 3T whole-brain DMI of healthy adults following the oral ingestion of deuterated glucose. Results from these experiments provide critical data needed to explore DMI SNR, spatial resolution, and imaging time tradeoffs.
3D high-resolution Contrast-enhanced MR neurography of lumbosacral plexus with precise fat-suppression: A pilot image quality evaluation
Authors: Kong Xiangchuang , Sun Peng , Gu QingPing , Liao Tian , Liu XiaoMing , Liu DingXi
Published: August 2023

The objective of this study was to investigate the values of precise fat-suppression for the robust visualization of 3D high-resolution contrast-enhanced MR neurography of lumbosacral plexus by inversion time (TI) scout technique. The precise TI of individuals could be calculated from several fast different TI experiments by measuring the fat signals recovery on the real and imaginary images. CNR (precise fat-suppression) (13.26±5.47) was about 425.4% higher than CNR (traditional TI) (2.39±0.55). Accurate fat suppression in MRN of lumbosacral plexus can help visual the branch of lumbosacral plexus nerves distinctly and improve the accuracy of diagnosis in diseases of lumbosacral plexus.
Field Strength and Gadolinium Dose Dependency of Dynamic Time-Resolved 4D MRA of the Brain Using Golden-Angle Radial Sparse Parallel (GRASP) MRI
Authors: Goldman-Yassen Adam , Patel Vishal , Borja Maria , Derman Anna , Chen Duan , Dogra Siddhant , Wiggins Roy , Block Kai Tobias , Dehkharghani Seena
Published: August 2023

GRASP MRI obtained as part of routine clinical care, without specific angiographic parameters, can be reconstructed post-hoc into dynamic 4D MR images and can be displayed with high spatial and temporal resolution. Additionally, contrast dose and magnet strength appear to have minimal effect on the diagnostic quality of angiographic images. Further exploration into diagnostic accuracy and the tolerance of varying field strength and dosing to further increasing degrees of acceleration is warranted.
Joint effusion contrast differences in 2D fat-saturated T2-weighted pulse sequences in 3T and 7T MRI
Authors: Tafti Sina , Damon Bruce , Hoffmeister Dean
Published: August 2023

7T MRI provides excellent resolution of the structures in the knee. Fat-saturated T2-weighted imaging at 7T has been used clinically for assessing knee joint effusion, but may provide different contrast than 3T MRI in cases of acute injury involving suspected blood products in the fluid. Here, we show three cases in which joint effusion due to acute injury had dark contrast in T2-weighted images acquired at 7T. For one case, T2-weighted 3T MRI was acquired in which the effusion appeared bright. These differences illustrate the potential for high field MRI to elucidate pathological components not observable at lower field strength.
Three-Dimensional real-time dynamic knee MRI using 3D cones with a multiscale low-rank reconstruction
Authors: Hales Laurel , Sandino Chris , Mazzoli Valentina , Kogan Feliks
Published: August 2023

3D real-time imaging of joints in motion can help us gain valuable insight into joint disorders. The combination of 3D golden-ratio re-ordered cones and multiscale low-rank reconstruction allow for continuous acquisition and high accelerations making 3D real time dynamic imaging of knees possible. We demonstrated the feasibility of this approach to capture patellar motion caused by a quadriceps flexion in 16 slices and with a temporal resolution of ~500ms. Although the resulting images are blurred, this method shows promise.
Intravoxel Incoherent Motion (IVIM) to study synovitis in Osteoarthritis: a feasibility study
Authors: Mazzoli Valentina , Kogan Feliks
Published: August 2023

Synovial inflammation (synovitis) is present in the majority of people with Osteoarthritis(OA) and has been linked with pain, disease severity and progression of knee OA. However, synovitis is not widely studied due to challenges differentiating synovial inflammation from adjacent fluid on conventional MRI and contraindications and time, cost and complexity of gadolinium-based contrast-enhanced methods. In this work, we evaluate the feasibility of the intravoxel incoherent motion(IVIM) imaging model for characterization of synovitis activity. By characterizing the diffusion from synovial fluid effusions, we showed that the intravoxel signal from effusions can be removed allowing isolation of diffusion effects from the synovium.
Simultaneous morphologic and quantitative imaging of the knee joint using pseudo-3D MIXTURE sequences: from deliberation to implementation
Authors: Nolte Teresa , Zhang Shuo , Pridöhl Nicola , Ciba Malin , Yoneyama Masami , Kuhl Christiane , Nebelung Sven
Published: August 2023

This work aimed to propose a clinical sequence platform for simultaneous morphologic and quantitative imaging of joints and identified TSE-based MIXTURE (Multi-Interleaved X-prepared Turbo-Spin Echo with Intuitive Relaxometry) sequences in terms of PDFS-T2 and T1-T1ρFS combinations for clinical implementation. Even though capable of isotropic resolution, MIXTURE sequences were acquired as pseudo-3D (thicker slices, higher in-plane resolution) to match standard-clinical 2D TSE sequences. After identification of clinical demands, MIXTURE sequences were systematically optimized, while maintaining clinically feasible acquisition times of 5:00 min (PDFS-T2 for T2-mapping) and 6:40 min (T1-T1ρFS for T1ρ-mapping), and evaluated in a cadaveric human knee cartilage defect model.
MRI based Radiomics for Distinguishing IDH-mutant from IDH wild-type Grade-4 Astrocytomas
Authors: Hosseini Seyyed Ali , Shiri Isaac , Hajianfar Ghasem , Bagley Stephen , Nasrallah MacLean , O’Rourke Donald , Mohan Suyash , CHAWLA SANJEEV
Published: August 2023

To distinguish IDH-mutant from IDH wild-type grade-4 astrocytomas, conventional MR imaging (post-contrast T1-weighted and T2-Flair images) was acquired from 57 patients [IDH-mutant (n=23) and IDH-wild-type (n=34) grade-4 astrocytomas]. Post-contrast T1-weighted and T2-FLAIR images were resliced, resampled and co-registered. Neoplasms were segmented into whole tumor, enhancing region, central necrotic region, edema region, and core tumor (contrast enhancing + necrotic region). A total of 105 first-, second-, higher-order and shape based radiomics features were extracted from each ROI. Readily interpretable and quantitative features from different sub-regions of neoplasms were observed with high diagnostic performances in distinguishing IDH-mutant from IDH wild-type grade-4 astrocytomas.
Enhancement of the Lymphatic System Following Intravenous Administration of Ferumoxytol
Authors: Young Daniel , Reddy Surendranath , Divekar Abhay , Pimpalwar Sheena , Hussain Tarique , Greer Joshua
Published: August 2023

Lymphatic Imaging is increasingly important in the management of patients with Congenital Heart Disease. It is not known how the intravenous contrast agent ferumoxytol influences this imaging. This retrospective review of 120 patients suggests that intravenously given ferumoxytol rapidly enters the lymphatic system. The resultant shortening of T2 relaxation causes a degradation in T-2 weighted lymphangiography. Conversely, T1-weighted angiography shows clear depiction of the thoracic lymphatic duct immediately after ferumoxytol infusion. This enhancement depends on fasting status of the patient. The classic mechanism of macrophage uptake of iron oxide for MR lymphangiography does not explain the timing of these findings.
Shielded-coaxial-cable (SCC) coils - the array configuration for maximized central SNR at 7T MRI
Authors: Guler Sadri , Costa Giovanni , Boer Vincent , Paulides Maarten , Baltus Peter , Petersen Esben , Zivkovic Irena
Published: August 2023

The shielded-coaxial-cable (SCC) coils have been proposed recently as highly decoupled elements per se. The SCC coils are not very sensitive to bending, elongation and various degrees of overlapping. We experimentally investigated the central SNR when the SCC coils are placed in three different arrangements on a cylindrical object. The highest central SNR (more than 30% higher than in the other two arrangements) was obtained when the coils were elongated and adjacent to each other. This arrangement is important when the ROI is located deep inside the field of view, such in c-spine spinal cord or deep brain imaging.
SNR Evaluation with High Input Impedance Preamplifier Decoupling Performance for a 2-Layer and 32-Channel Receive Array for Brain Imaging at 7T
Authors: Gapais Paul-François , Almokdad Saadou , Luong Michel , Giacomini Eric , Georget Elodie , Amadon Alexis
Published: August 2023

With the increasing number of elements in receive arrays, the need to accurately predict coil performance is crucial. Decoupling is usually performed with low-input impedance preamplifier decoupling. Recently, new schematics have been proposed that rely on high-input impedance preamplifiers. A simulation method is proposed here to evaluate preamplifier decoupling performance in this context on a 2-layer array at 7T. Results show a strong influence on the thermal SNR according to the impedance presented by the preamplifier to the coil output. The higher this impedance the higher the SNR, but practical implementation need a trade-off between high impedance and noise-matching.
Early aging, iron accumulation and demyelination in cervical spinal cord and brain as long-term effects of rugby practice?
Authors: Forodighasemabadi Arash , Baucher Guillaume , Soustelle Lucas , Troalen Thomas , Girard Olivier , Duhamel Guillaume , Ranjeva Jean-Philippe , Guye Maxime , Grisoli Jean-Baptiste , Callot Virginie
Published: August 2023

Brain alterations due to cumulative effects of impacts have been reported in rugby players. However, literature on long-term effects is scarce, and no study has been conducted to characterize potential spinal cord impairments.

In this study using a multiparametric MR protocol dedicated to both brain and cord, and combining state-of-the-art T1 relaxometry and ihMT imaging, we observed diffuse T1 increase in the cervical spinal cord, together with increased T1 and decreased ihMTsat in specific brain WM tracts in retired players.

These preliminary results also suggest early aging, tissue degeneration, iron accumulation, and different aging processes in retired players.
Dark Blood, Susceptibility-Insensitive 3D Unbalanced Steady-State Free Precession: A Potential New Approach for Lung Cancer Screening
Authors: Edelman Robert , Allen Bradley , Leloudas Nondas , Pang Jianing , Koktzoglou Ioannis
Published: August 2023

We recently described the feasibility of using a prototype 3D unbalanced steady-state free precession (3D uSSFP) pulse sequence for dark blood imaging. We sought to determine whether this technique could be adapted for dark blood, susceptibility-insensitive imaging of the lungs. A breath-hold, ECG-gated version of 3D uSSFP was implemented for a pilot study of healthy volunteers and patients. Initial results suggest that 3D uSSFP allows efficient volumetric imaging of the lungs and can demonstrate even small lung nodules without artifacts. With further development, the technique could provide a radiation-free alternative to low-dose CT for lung cancer screening.
Imaging biomarkers of ventilation in Interstitial Lung Disease from 129Xe and Oxygen Enhanced 1H MRI
Authors: Tibiletti Marta , Eaden James , Naish Jo , Hughes Paul , Waterton John , Heaton Matthew , Chaudhuri Nazia , Skeoch Sarah , Bruce Ian , Bianchi Stephen , Wild Jim , Parker Geoff
Published: August 2023

Interstitial lung diseases (ILD) are a heterogeneous group of conditions exhibiting inflammation and scarring of the lung parenchyma. Here, we compare imaging biomarkers from hyperpolarised 129Xe ventilation MRI and oxygen-enhanced MRI (OE-MRI) with standard pulmonary function tests in cohorts of ILD patients with mixed origins. We also evaluated whether disease resolution or progression could be detected over two visits. None of the imaging biomarkers considered completely differentiated ILD subtypes. OE-MRI biomarkers are feasible in ILD patients and do not correlate strongly with PFT. Both OE-MRI and 129Xe MRI revealed spatially heterogeneous ventilation in patients with DI-ILD and IPF.
T2-weighted Free-breathing 3D Abdominal Imaging Using Magnetization Prepared SPGR
Authors: Zhong Zheng , Cao Xiaozhi , Liao Congyu , Li Zhitao , Syed Ali , Setsompop Kawin , Vasanawala Shreyas
Published: August 2023

T2-weighted imaging is conventionally obtained using multi-slice 2D or 3D fast spin-echo (FSE) sequences. However, FSE suffers from severe specific absorption rate (SAR) issue and motion artifact particularly in the abdomen. A potential approach to address these challenges is using T2-prepared 3D SPGR sequence with a non-Cartesian trajectory such as cones. In this study, we proposed a T2-prepared 3D-cones sequence to achieve T2-weighted abdominal imaging with free breathing. The feasibility of the technique was tested on both healthy subjects and patients.
Nested Geometrically Decoupled Triple-Tuned Volume Coil for 1H, 23Na and 31P at 4.7T
Authors: Busher Joseph , Valle Edith , Wright Steven , McDougall Mary
Published: August 2023

The use of traps as well as the use of switching circuitry to develop multinuclear coils is well established. However, it is well known that the use of traps introduces undesired losses to one or more nuclei in the structure while switching eliminates applications requiring true simultaneous imaging. As a result, our group developed a triple-tuned volume coil that solely uses geometric decoupling using only two structures. The coil demonstrated homogeneous fields with sufficient decoupling between the structures to acquire multinuclear NMR data.
Development of 8-Channel 1H-2H Dual-Frequency loop coil array with LC tanks for 1H MRI and 2H MRS imaging of human brain at 7 Tesla
Authors: Soon Soo Han , Waks Matt , Wiesner Hannes , Li Xin , Zhu Xiao-Hong , Chen Wei
Published: August 2023

Deuterium (2H) MRS imaging (DMRSI) enables us to measure both the cerebral metabolic rate of glucose and TCA cycle rate and to image brain tumor with an excellent contrast. It is common to apply two sets of 2H and 1H RF coils for performing DMRSI, resulting in coil complexity and RF interference. We introduce an 8-channel 2H-1H dual-frequency loop coil array with LC tanks, enabling each loop coil being tuned to 2H and 1H resonant frequencies simultaneously. We have constructed a prototype head coil for human brain applications at 7 Tesla and validated the coil via benchtop and imaging tests.
Comparison of arterial input functions obtained through back-to-back acquisition of DCE and DSC MRI
Authors: Tseng Chih-Hsien , Jaspers Jaap , Romero Alejandra Mendez , Wielopolski Piotr , van Osch Matthias , Vos Frans
Published: August 2023

We aimed to compare the AIF determined from DCE-MRI with the AIF from DSC-MRI in back-to-back imaging, using the same dose of Gadobutrol. The DCE-driven AIFs showed the same ‘pattern’ as the DSC-driven AIFs, but had smaller variance of the shape and peak value. A linear relation was found between the contrast agent concentration from DCE and ΔR2*, but the linear coefficients showed large variation across regions and subjects. Our findings show that the DCE-driven AIF has the potential to serve as an alternative for the DSC-driven AIFs for quantitative perfusion assessment.
Texture analysis using chemical shift imaging improves differentiation between patients with and without osteoporotic vertebral fractures
Authors: Sollmann Nico , Becherucci Edoardo , Boehm Christof , El Husseini Malek , Ruschke Stefan , Burian Egon , Kirschke Jan , Link Thomas , Subburaj Karupppasamy , Karampinos Dimitrios , Krug Roland , Baum Thomas , Dieckmeyer Michael
Published: August 2023

Osteoporosis is characterized by increased skeletal fragility with vertebral fractures (VFs). Areal bone mineral density (BMD) from dual-energy X-ray absorptiometry (DXA) is the reference standard but has well-known limitations. Texture analysis (TA) can provide parameters of tissue microstructure using spine chemical shift encoding-based water-fat MRI (CSE-MRI) and computed tomography (CT), thus potentially improving fracture risk estimation. This study found that a model including volumetric BMD (vBMD) and several texture features (TFs) from CSE-MRI and CT predicts 81% of the variance regarding osteoporotic VF status, compared to 47% when based on vBMD and the proton density fat fraction (PDFF) only.
A vendor-neutral 3D MP-RAGE implementation in Pulseq for reduced inter-site variability
Authors: Rathi Yogesh , Nielsen Jon-Fredrik , Zaitsev Maxim , Ning Lipeng , Kim Tae , Grissom William , Gagoski Borjan , Bilgic Berkin
Published: August 2023

Inter-scanner variability can reduce the statistical power of neuroimaging studies due to the increased variance in the data. While existing efforts employ consistent high level parameters to acquire data across scanners, we hypothesize that differences due to sequence implementation and reconstruction algorithms contribute substantially to variability in multi-center settings. We propose a unified vendor-neutral MP-RAGE protocol based on the Pulseq sequence development platform that can be used consistently across sites and vendors for reducing inter-scanner variability. Preliminary results show increased consistency of cortical thickness across sites using Pulseq protocol compared to vendor-provided sequences.
Feasibility of 3D Adiabatic T1ρ-prepared Fast Spin Echo (3D Adiab-T1ρ-FSE) Imaging
Authors: Jang Hyungseok , Ma Yajun , Moazamian Dina , Carl Michael , Jerban Saeed , Lombardi Alecio , Chung Christine , Chang Eric , Du Jiang
Published: August 2023

T1ρ has been investigated as a quantitative biomarker sensitive to changes in macromolecules such as proteoglycan and collagen in musculoskeletal systems. More recently, adiabatic T1ρ (Adiab-T1ρ) has emerged as an alternative to conventional continuous wave T1ρ to reduce the magic angle effect, which is a major confounding factor in accurate T1ρ estimation. In this study, we investigated a new pulse sequence combining adiabatic T1ρ preparation and efficient 3D fast spin echo (FSE) for more robust adiab-T1ρ mapping in the human knee. The efficacies of RF cycling and magnetization reset were also demonstrated.
Head-tilting in diffusion weighted imaging to reduce susceptibility-induced signal dropout in the frontal cortex: feasibility study.
Authors: Ryu Jae-Kyun , Otgonbaatar Chuluunbaatar , Yeo Seok-Jin , Song Jeonghak , Jang Eunseok , Lee Jaebin , Shim Hackjoon
Published: August 2023

Diffusion-weighted MRI is a highly sensitive to alteration in the movement of water molecules and allows the assessment of various pathologies. Interpretation of the changes can be obscured by signal-dropout due to tissue-air susceptibility difference at the boundaries of nasal cavities, especially in the prefrontal region. The head tilting (chin-up) method during the brain scan could be considered as an accessible way without additional hardware- or sequence to prevent those susceptibility-induced signal-dropout. We demonstrated DWI with head-tilting (up to 20°) resulted in had less severe signal dropout and improved image quality than normal scan in the prefrontal cortex.
Characterizing Heterogeneity of Gliomas with a Fractional-order Calculus Diffusion Model
Authors: Sun Wenbo , Xu Dan , Zhang Yunfei , Dai Yongming , Xu Haibo
Published: August 2023

This study aimed to investigate whether the FROC diffusion model could help predict molecular biomarkers in gliomas. It was found that FROC has the potential in comprehensively characterizing heterogeneity of gliomas, not only in glioma grading, but also in predicting tumor cell proliferation rate and isocitrate dehydrogenase-1 (IDH-1) gene mutation status.
Sample Extraction of ex vivo Myocardial Tissue: Combination of High Resolution MRI with 3D-printed Guides
Authors: Reiss Simon , Fischer Johannes , Thielmann Julien , Lottner Thomas , Heidt Timo , von zur Mühlen Constantin , Bock Michael
Published: August 2023

Magnetic resonance provides a multitude of imaging techniques to detect and characterize myocardial infarction (MI). Terminal animal studies are often performed in which CMR findings after MI are correlated to histology. However, precise manual extraction of tissue samples from a specific myocardial region defined by CMR is difficult. Here, we propose the use of 3D-printed guides for extraction of tissue samples from myocardial regions pre-defined on high resolution ex vivo CMR. Using the presented technique, histology findings can be correlated to the exact position within the MRI data set with a precision of < 1 mm.
Effects of warm ischemia on myocardial metabolism: a normothermic perfused heart MRS study
Authors: Ding Belinda , Young Liam , Huang Margaret , Page Aravinda , Messer Simon , Murphy Mike , Perkins Justin , Tunnicliffe Elizabeth , Large Stephen , Rodgers Christopher , Weir-McCall Jonathan
Published: August 2023

Ischaemia-reperfusion injury is a key pathophysiological process driving cardiac injury in myocardial infarction, heart surgery and transplants. Succinate accumulation is a specific marker of ischaemic injury, and a potential therapeutic target to reduce reperfusion injury.Single-voxel proton spectra were acquired during normal perfusion and during ischaemia in three machine-perfused porcine hearts. During ischaemia, a peak was evident in the expected region of succinate, which was absent during normal perfusion. This was further examined in a phantom model which confirmed the peak location with concentration-signal correlation of R>0.999. MRS detection of succinate holds potential for the detection of ischaemia.
Theoretical Considerations on Joint Inference of Cardiac Diffusion and Strain Tensors from second-order motion compensated cDTI Data
Authors: Weine Jonathan , Buoso Stefano , Kozerke Sebastian
Published: August 2023

Cardiac diffusion tensor imaging (cDTI) as well as cardiac strain imaging both offer invaluable information on the functional state of the heart. Acquiring both, takes too long to be clinically feasible. Free breathing, cDTI acquisition with second-order motion compensated diffusion encoding waveforms display residual phase variations, that encode higher orders of contractile motion during the diffusion encoding process. This work presents a theoretical framework on how to jointly infer strain and diffusion tensors from complex-valued cDTI data with varying trigger delays.
Breast DTI: A Prospective Study in Individuals Referred for Biopsy of Indeterminate Breast Lesions
Authors: Ecanow Jacob , Ecanow David , Leloudas Nondas , Hack Bradley , Prasad Pottumarthi
Published: August 2023

We present preliminary data from an ongoing study in individuals referred for biopsy of BIRADS 3, 4, and 5 breast lesions based on mammography, ultrasound, and/or screening MRI. DTI data was acquired using single shot EPI with 30 different directions and 2 mm isotropic resolution. MRI data was analyzed using BIT-Motion software. All cancers showed low ADC and λ1 values compared to control regions. FA, consistent with prior reports showed minimal difference and so did (λ1-λ3).
A Fourier representation of the diffusion MRI signal
Authors: Fang Chengran , Wassermann Demian , Li Jing-Rebecca
Published: August 2023

The diffusion MRI community lacks a spectral perspective to investigate the intricate relationship between the diffusion MRI signals and cellular structures. Our study proposes a new simulation method that can provide a Fourier representation of the signal. Common spectral methods suffer from the singularity of the heat kernel, which requires infinite Fourier modes. We overcome the singularity by formulating the solution in a convolutional form and splitting the heat kernel into a singular part and a smooth part. Numerical experiments are performed to demonstrate the convergence of our method.
Model-based reconstruction of IVIM-DTI in skeletal muscle: Improving IVIM-DTI parameter map quality in low-perfused tissues
Authors: Rauh Susanne , Maier Oliver , Gurney-Champion Oliver , Hooijmans Melissa , Stollberger Rudolf , Nederveen Aart , Strijkers Gustav
Published: August 2023

IVIM and DTI techniques are both sensitive to a variety of muscle disorders. Their combination can give a more complete description of ordered diffusion processes and perfusion. Model-based reconstruction can overcome many short-comings of image-based fitting such as Rician noise bias or low SNR. In this study we investigate the feasibility of model-based IVIM-DTI reconstruction in skeletal muscle, a low-perfused tissue. Results were compared to image-based least-square fitting. The parameter maps show more anatomical detail with model-based reconstruction. The mean parameter values are comparable to image-based fitting. Model-based reconstruction is sensitive to subtle changes after exercise in the underlying parameters.
Diagnosis and Follow-up of cervical vascular dissection using 3D MR vessel wall imaging: A Single Centre Experience of 65 Cases
Authors: Zhang Jin , Sun Beibei , Ding Shenghao , Tian Jiaqi , Wan Jieqing , Zhang Jilei , Chen Weibo , Zhao Xihai , Chun Yuan , Xu Jianrong , Zhao Huilin
Published: August 2023

Cervical artery dissection (CAD) is one of the important causes of ischemic stroke in young and middle-aged people[1; 2]. DSA remains the gold standard for identifying and characterizing carotid vascular dissections[3]. However, this imaging approach is known to have certain limitations, including invasiveness, ionizing radiation exposure, uneconomic, and inconvenience in follow-up. Recently, rapid three-dimensional MR vessel wall imaging (3D MR-VWI) techniques have been developed to visualize arterial lumen and outer wall boundaries non-invasively and without contrast administration. Non-invasive 3D MR-VWI has the potential to be a powerful tool for follow-up of cervical artery dissection.
Self-calibrated through-time spiral GRAPPA for real-time, free-breathing evaluation of left ventricular function
Authors: Franson Dominique , Ahad James , Liu Yuchi , Fyrdahl Alexander , Seiberlich Nicole
Published: August 2023

Through-time non-Cartesian GRAPPA enables real-time, free-breathing evaluation of the left ventricle, but it requires extra calibration data. This work proposes a self-calibrated spiral GRAPPA method that uses an interleaved acquisition to eliminate the calibration scan. A long spiral trajectory is used to improve robustness to motion. Data were acquired at 12 LV slices with spatiotemporal resolutions of 2.08x2.08 mm2 and 32.72 ms/phase in 71 seconds. In a preliminary study of 6 volunteers comparing the proposed method to a gold-standard, functional values are within the limits of agreement in Bland-Altman analyses and are not statistically significantly different in paired t-tests (p<0.05).
Real-Time Spiral bSSFP Functional Cardiac MRI on a 0.55T Scanner Using a Deep Image Prior Reconstruction with GROG
Authors: Hamilton Jesse , Seiberlich Nicole
Published: August 2023

This work introduces a physics-based deep learning reconstruction that can enable real-time (free-breathing and ungated) spiral 2D bSSFP functional cardiac MRI on a 0.55T scanner. The proposed method extends the concept of a deep image prior and does not require prior training on reference data. In addition, GROG is used to reduce the computational complexity of the forward model calculation by shifting spiral k-space data to their nearest Cartesian grid points, allowing use of FFT rather than NUFFT operations. Results are demonstrated in healthy subjects with functional measurements compared to gold standard acquisitions at 1.5T.
Multi-Scale Evaluation of Uncertainty Quantification Techniques for Deep Learning based MRI Segmentation
Authors: Lambert Benjamin , Forbes Florence , Tucholka Alan , Doyle Senan , Dojat Michel
Published: August 2023

Efforts are required to design Deep Learning models that are not only powerful, but also capable of expressing the certainty of their predictions.

We evaluate 3 state-of-the-art techniques for uncertainty quantification : Monte-Carlo Dropout, Deep Ensemble, and Heteroscedastic models. Evaluation is illustrated on a task of automatic segmentation of White-Matter Hyperintensities in T2-weighted FLAIR MRI sequences of Multiple-Sclerosis patients. Analysis is performed at 3 different scales : the voxel, the lesion, and the whole image. Results indicate the superiority of the Heteroscedastic approach, which ranked first in both the uncertainty and segmentation tasks.
Multi-voxel PRESS for fast and sensitive static MRS of hyperpolarized nuclei
Authors: Gottwald Wolfgang , Nagel Luca , Topping Geoffrey , Schilling Franz
Published: August 2023

A multi-voxel point resolved spectroscopy (MV-PRESS) sequence was developed for measuring hyperpolarized 13C-labelled compounds, on a 7T preclinical small animal scanner. MV-PRESS allows to excite selected imaging voxels within a 3D volume with high sensitivity (i.e. 90° excitation angle). This method was compared to both single-voxel PRESS of a thermal 1H phantom and CSI with a hyperpolarized [1-13C]pyruvate phantom. MV-PRESS was then used to detect both pyruvate and lactate in healthy mouse kidneys after hyperpolarized [1-13C]pyruvate injection, using 2x2x2 mm3 voxels for a total of 4 voxels.