bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial variations of 31P metabolites within the liver measured with 3D 31P MRSI at 7T
Authors: van den Wildenberg Lieke , Gursan Ayhan , Seelen Leonard , van der Velden Tijl , Gosselink Mark , Froeling Martijn , van der Kemp Wybe , Klomp Dennis , Prompers Jeanine
Published: August 2024

31P MRS can be used in liver disease diagnosis and treatment monitoring. However, it is unclear whether 31P metabolite concentrations differ across the healthy liver, which would be important to take into account. Using an integrated 31P whole-body transmit coil for a 7T MRI scanner in combination with a 16-channel body receive array, we aimed to assess spatial variations of 31P metabolites within the liver in healthy subjects. We showed that there is significant spatial heterogeneity of various 31P metabolites levels within the liver, with marked differences for the PME and PDE metabolites between the left and right lobe.
Multiple Sclerosis (MS): High Contrast Visualisation of Abnormalities in Normal Appearing White Matter Using MASDIR Sequences
Authors: Condron Paul , Kumar Haribalan , Holdsworth Samantha , Cornfeld Daniel , Bydder Graeme
Published: August 2024

Keywords; Neuroinflammation, Multiple Sclerosis, Neuro, Drugs. MASDIR sequences can show up to 15 times the contrast of T1-weighted MP-RAGE sequences. This is a consequence of using changes in T1 synergistically 3-4 times in the same sequence to detect subtle changes due to neuroinflammation and lesions. Extensive high contrast focal and diffuse abnormalities in white matter were demonstrated in areas that showed no abnormality with state-of-the-art T2-weighted spin echo and T2-FLAIR sequences in patients with multiple sclerosis. This demonstrated good correlation with advanced sequences such as T1 and myelin maps.
Positron emission tomography with [ 18F]-DPA-714 unveils a smoldering component in most multiple sclerosis lesions driving disease progression
Authors: Hamzaoui Mariem , Garcia Jeanne , Boffa Giacomo , Lazzarotto Andrea , Ricigliano Vito A G , Panah Arya Yazdan , Soulier Théodore , Louapre Celine , Bodini Benedetta , Stankoff Bruno
Published: August 2024

Positron emission tomography with18kDa-translocator (TSPO) tracers opens the perspective to image innate immune cells underlying the smoldering component of multiple sclerosis (MS), that currently mostly escape from MRI evaluation. Using [18F]-DPA-714-PET, we developed a novel lesion TSPO based classification of MS lesions and showed that an unexpectedly high proportion have a persistent neuroinflammatory content. A longitudinal follow up of subjects unraveled that this lesional smoldering component predicted atrophy and clinical progression. Following the acute phase, most lesions may therefore develop a chronic inflammatory component which can persist for several years, subsequently promoting neurodegeneration and clinical progression in MS.
Regional Changes in Brain Viscoelasticity in Multiple Sclerosis Assessed with Three-Dimensional MR Elastography
Authors: Fang Ling , Murphy Matthew , Tan Sha , Luo Qiuxia , Chen Jingbiao , He Bingjun , Chen Jun , Scott Jonathan , Glaser Kevin , Murphy Richard , Qiu Wei , Wang Jin
Published: August 2024

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. MR Elastography (MRE) can quantitatively assess biomechanical tissue properties in vivo noninvasively. We investigated the potential value of MRE to reveal changes in tissue viscoelasticity in regions and the whole brain in MS patients and to analyze the relevance to clinical manifestations. Our results suggest that the damping ratio and loss modulus are promising quantitative biomarkers for evaluating tissue damage in MS.
Elevated free-water volume in the brains of HIV+ alcohol drinkers compared to HIV- drinkers as an indication of neuro-inflammation
Authors: Salan Teddy , Govind Varan , Gullett Joseph , Porges Eric , Li Zhigang , Cohen Ronald , Cook Robert
Published: August 2024

Chronic alcohol use and HIV infection can have synergistic effects that negatively impact the brain leading to abnormalities such as neuro-inflammation. Free-water eliminated DTI (FWE-DTI) has been suggested as a biomarker of neuro-inflammation. This study compare DTI and FWE-DTI derived metrics in the brains of HIV+/HIV- chronic drinkers to determine whether HIV infection or drinking behavior is a more significant factor contributing to brain microstructural abnormalities and neuro-inflammation. Our results suggest that HIV is a more significant factor than drinking level contributing to elevated free water in the brain as a sign of neuro-inflammation.
Motion robust MR Fingerprinting scans for non-sedated infant imaging
Authors: Badve Chaitra , Sun Jessie , Nayate Ameya , Wien Michael , Martin Douglas , Durieux Jared , Flask Chris , Costello Deanne , Ma Dan
Published: August 2024

The 5 min high resolution MRF scans coupled with low-rank iterative reconstruction successfully generated perfectly co-registered T1, T2 maps, synthetic MR contrast images, R1R2 maps, and myelin water fraction maps. Image Quality Assessment analysis with three pediatric neuroradiologists found that MRF based synthetic T1w and T2w images quality were superior in quality to MRI T1w and T2w (p<.0001) with lower image artifacts in the MRF synthetic images as compared to standard of care MRI. MRF T1w images demonstrated better myelin visualization compared to clinical T1w, and MRF T2w demonstrated improved tissue structure visualization as compared to clinical T2w images.
Altered neurovascular coupling in children with idiopathic generalized epilepsy
Authors: Ran HaiFeng , Hu Jie , Chen GuiQin , He YuLun , Liu Heng , Zhang TiJiang
Published: August 2024

This study investigated the neurovascular coupling of children with idiopathic epilepsy using resting-state functional Magnetic Resonance Imaging and arterial spin labeling. Children with IGE present altered global neurovascular coupling, and higher regional neurovascular coupling in in the right medial frontal gyrus associated with lower performance intelligence quotient scores. The study shed a new insight into the pathophysiology of epilepsy and provided the potential imaging biomarkers of cognitive performances in children with IGE.
Brain Ventricular and Microstructural Correlates of Executive Dysfunction in Congenital Heart Disease Using Explainable Machine Learning
Authors: Lee Vincent , Reynolds William , Meyers Benjamin , Wallace Julia , Badaly Daryaneh , Lo Cecilia , Panigrahy Ashok , Ceschin Rafael
Published: August 2024

This study examined cerebrospinal fluid volumes as neuroimaging features and their role in predicting specific executive function impairments among adolescents with congenital heart disease using explainable machine learning models. The findings showed CSF volumes were among the most important predictors of executive function inhibition domain with 3 CSF volumes ranked amongst the top 20, and 4 more CSF volumes among the top 20% of all features. Selective increased lateral ventricular volume in the frontal regions in CHD patients may be secondary to loss of white matter integrity in the uncinate fasciculus (emotional regulation) and subsequently lead to inhibitory dysfunction.
Non-invasive evaluation of anti-integrin αvβ6 treatment of liver fibrosis by collagen-targeted MRI
Authors: Ning Yingying , Zhou Iris , Rotile Nicholas , Boice Avery , Schaub Johanna , Turner Scott , Caravan Peter
Published: August 2024

A collagen-binding molecular MR probe CM-101 was employed to non-invasively assess liver fibrosis and the anti-fibrotic effects of a novel αvβ6/αvβ1 integrin antagonist treatment in bile duct-ligated rats. Reduction of fibrosis was detected by collagen imaging and correlated with morphometric assessment of fibrosis from histology. CM-101 enhanced MR is a useful tool to monitor drug treatment response in chronic liver disease.
Analyzing the Spatially-Resolved Performance of mpMRI for Detection of Prostate Cancer using a Prostate Sector Map
Authors: Zabihollahy Fatemeh , Raman Steven , Wibulpolprasert Pornphan , Vangala Sitaram , Wu Holden , Chien Aichi , Thomas Albert , Reiter Robert , Sung Kyunghyun
Published: August 2024

Multiparametric MRI (mpMRI) has shown a marked impact on prostate cancer (PCa) diagnosis, but the understanding of the spatial distribution of tumors and the correlation between tumor location and mpMRI performance is still limited. The purpose of this study was to determine the performance of mpMRI for PCa detection and visualize the results on a prostate sector map described by Prostate Imaging Reporting and Data System (PI-RADS) v2.1. Also, this study aimed to investigate the association between mpMRI performance and tumor location in the prostate.
A Novel Accelerated 3D Phase-Unwrapping Method Based on Subdivided Arrays and Polynomial Modeling with Application: Dixon Water-Fat Separation
Authors: Cheng Junying , Zheng Qian , Xu Man , Liu Liang , Cui Yan , Liu Biaoshui , Zhang Yong , Feng Yanqiu , Cheng Jingliang
Published: August 2024

In this work, a novel robust and accelerated phase-unwrapping method is presented. The proposed method firstly introduces an artificial volume compartmentalization to break down the large-scale unwrapping problems, and then uses the phase partition method to cluster the phase into blocks to be paralleled unwrapped first, and residual-voxel to be unwrapped later. The simulated and in vivo datasets experiments have demonstrated that the proposed method allows for a reduction of the unwrapping problem size, a speed-up for handling large datasets, and obtains the accurate phase results under different SNRs and phase-change levels.
Optimized 7 T Cortical Magnetization Transfer Saturation Imaging: Application to Cortical Myelin Imaging in Multiple Sclerosis
Authors: Thevakumaran Risavarshni , Couch Marcus , Narayanan Sridar , Arnold Douglas , Rudko David
Published: August 2024

We designed an MRI protocol for rapid, high-resolution human cortical MTsat (csMTsat) imaging at 7 T. Our approach leveraged the PTx capability of the 7 T Siemens Terra MRI system. Further, we developed a post-processing scheme that reduces residual B1+ field bias and noise in csMTsat maps for imaging cortical myelin in the human cortex at high-resolution, which can be applied to study cortical demyelination in Multiple Sclerosis.
TORTOISE V4: ReImagining the NIH Diffusion MRI Processing Pipeline
Authors: Irfanoglu M. Okan , Nayak Amritha , Taylor Paul , Pierpaoli Carlo
Published: August 2024

The processing needs for diffusion MRI data have evolved over the years with data sizes getting larger, diffusion sensitization going higher. Large multi-site studies, especially on "uncooperative subjects" such as young children or patients with movement disorders increased the necessity for dMRI processing pipelines that are fast, robustly capable of handling a variety of artifacts/distortions, and that have summary reporting capabilities that can pinpoint problematic data. The NIH Diffusion MRI processing pipeline, TORTOISE, has been reimagined, redesigned and and significantly enriched to satisfy these processing needs.
Repeatability of in vivo T2 Relaxation Times Regional and Cluster Analysis in the Loaded Knee
Authors: Sofko Kaitlin , Elebute Ibukunoluwa , Cui Lumeng , Black Marianne , Bzowey Natasha , McWalter Emily
Published: August 2024

T2 relaxation time mapping of articular cartilage is most often assessed in relaxed knees; however, it’s primary function is resisting and distributing forces. Further, most work has focused on regional analysis rather than local changes. The aim of this work was to assess the repeatability of T2 relaxation time in the loaded knees of five healthy participants using both regional and local (cluster-based) approaches. We show that regional and local assessments are sufficiently repeatable for in vivo studies.
Repeatability and Sensitivity of qDESS T2 Mapping of Cartilage
Authors: Williams Ashley , Asay Jessica , Asare Daniella , Desai Arjun , Mahtani Gordhan , He Jade , Wadsworth Adam , Bansal Sachi , Gold Garry , Hargreaves Brian , Chaudhari Akshay , Chu Constance
Published: August 2024

Intra- and inter-day repeatabilities of qDESS T2 in knee cartilage, assessed by fully-automatic segmentation using a deep-learning, open-source framework for musculoskeletal MRI analysis (DOSMA) and also by manual segmentation of tread mark regions of known tibiofemoral contact areas, were assessed and compared in 10 uninjured participants. qDESS T2 RMSA-CVs were less than 6% for all ROIs examined and showed good to excellent ICCs for the majority of ROIs assessed. A preliminary sensitivity analysis found that both segmentation schemes detected significant T2 changes over time in lateral tibial cartilage while only DOSMA segmentation detected T2 change to medial tibial cartilage.
Contraction characteristics of the triceps surae in muscular diseases assessed by 3D dynamic imaging with synchronized electrical stimulation
Authors: Santini Francesco , Deligianni Xeni , Paoletti Matteo , Ravaglia Sabrina , Faggioli Arianna , Jin Ning , Pichiecchio Anna
Published: August 2024

Accelerated three-dimensional. three-directional dynamic acquisition of muscle contraction during electrical muscle stimulation was applied on a cohort of 10 patients with metabolic diseases affecting the muscles and 14 healthy controls. Maximum strain and contraction rates were calculated on the three muscles of the triceps surae. The strain and the buildup rate (rate to reach maximum strain) showed a clear trend for the differentiation of patients and volunteers, especially in the Soleus muscle. In conclusion, dynamic muscle MRI during electrical stimulation is a promising marker for muscle health in muscular diseases.
Sensitivity and Reproducibility of MRI Detection of Hourglass-Like Constrictions in Parsonage-Turner Syndrome
Authors: Nimura Clare , Sneag Darryl , Colucci Philip , Urban Casey , Li Tim , Pedrick Emily , Feinberg Joseph , Milani Carlo , Tan Ek Tsoon
Published: August 2024

A retrospective analysis of 123 patients diagnosed with Parsonage-Turner Syndrome (PTS; neuralgic amyotrophy) found that magnetic resonance neurography (MRN)-based detection of hourglass-like constrictions (HGCs) in affected nerves was 91.2-92.0% sensitive to electromyography-confirmed PTS. Post-hoc inter-rater reliability analysis revealed an inter-reliability of 91.3-94.3% for detection of HGCs. This retrospective study confirmed that MRN detection of HGCs is sensitive and reliable for diagnosing PTS and may be used as an objective diagnostic tool for the syndrome.
A 3D dual-echo spiral sequence for dynamic susceptibility contrast imaging
Authors: Li Zhiqiang , Choudhary Poonam , Wang Dinghui , Ragunathan Sudarshan , Ooi Melvyn , Karis John , Pipe James , Stokes Ashley , Quarles C
Published: August 2024

Dynamic susceptibility contrast (DSC)-MRI is an important tool to assess brain tumor status for diagnosis, surgical planning, and surveillance. Dual-echo EPI based DSC-MRI enables accurate perfusion measurements using a single-dose of contrast agent, simultaneous DSC- and dynamic contrast enhanced (DCE)-MRI measures and greater parameter flexibility. However, EPI-related distortion artifacts impair its clinical utility. In this work, we proposed a 3D dual-echo spiral acquisition to mitigate EPI-related artifacts, and improve the fidelity of DCE-MRI derived parameters and arterial input function estimation. Preliminary data from volunteers and a glioma tumor patient showed reduced geometric distortion, increased temporal SNR, and accurate perfusion measurements.
Multimodal serial assessment of neoadjuvant therapy response and recurrence-free survival in locally advanced breast cancer
Authors: Kazerouni Anum , Peterson Lanell , Jenkins Isaac , Novakova Alena , Linden Hannah , Hockenbery David , Mankoff David , Specht Jennifer , Partridge Savannah
Published: August 2024

We investigated the combination of DCE-MRI and 18F-FDG PET for assessing metabolism/perfusion mismatch and predicting pathological response and recurrence-free survival (RFS) in women undergoing neoadjuvant chemotherapy (NAC) for breast cancer. Thirty-five patients with localized breast cancer were imaged with both modalities at 3 timepoints over the course of NAC. Greater mid-treatment decreases in imaging measures were predictive of pathological response and associated with improved long-term outcome. Furthermore, mid-treatment decreases in metabolism/perfusion ratios were predictive of RFS. These results indicate a complementary relationship between DCE-MRI and 18F-FDG PET metrics and potential value of metabolism/perfusion mismatch as a marker of response.
Multi-Parametric Quantitative MRI Assessment of Soft Tissue Sarcoma Response to Preoperative Therapy
Authors: Huang Wei , Kaempf Andy , Beckett Brooke , Tudorica Alina , Lim Jeong Youn , Ryan Christopher
Published: August 2024

Thirty patients with lower extremity soft tissue sarcoma were treated with preoperative chemoradiotherapy and underwent MRI exams including DCE- and DW-MRI pre-therapy, after the first cycle of therapy regimen, and after completion of therapy but before surgery. Ten patients had optimal and the other 20 had sub-optimal pathologic responses based on necrosis percentage of the surgical tumor specimens. Quantitative DCE-MRI markers and apparent diffusion coefficient (ADC) were superior to radiographic tumor size measurement in early prediction and evaluation of therapy response. Multi-parametric approach of combining DCE- and DW-MRI markers further improved early prediction of optimal vs. sub-optimal response.
Detection and Assessment of Treatment Response in Multiple Myeloma using Whole-body DETECT: Quantitative Biomarkers of MRI and FDG-PET
Authors: Lin Sheng Qing , Fonseca Sebastian , Udayakumar Durga , de Leon Alberto Diaz , Oz Orhan , Kaur Gurbakhash , Afrough Aimaz , Anderson Larry , Madhuranthakam Ananth
Published: August 2024

WBMRI-DETECT has been previously shown to have improved lesion conspicuity and shorter scan times compared to WBMRI-STIR and WBMRI-DWIBS in multiple myeloma. In this work, we demonstrate that quantitative biomarkers measured through WBMRI, fat fraction (FF) and apparent diffusion coefficient (ADC), have weak correlation suggesting both biomarkers to provide complementary information. Additionally, both ADC and FF showed negative correlation with the semiquantitative SUVmax from FDG-PET, demonstrating potential use of quantitative MRI biomarkers for the assessment of therapy response.
Hyperpolarized [1-13C] Gluconolactone Can Visualize TERT Silencing Directly or via the Upstream Transcriptional Factor GABPB1 in Glioblastoma
Authors: Minami Noriaki , Hong Donghyun , Taglang Celine , Batsios Georgios , Gillespie Anne , Viswanath Pavithra , Stevers Nicholas , Costello Joseph , Ronen Sabrina
Published: August 2024

TERT promoter mutation is a genetic hallmark of glioblastoma, and targeting TERT or its upstream transcriptional factor GABPB1 are considered ideal therapeutic targets. Accordingly, establishing reliable imaging modalities that will enable monitoring of TERT silencing are needed as early indicators of target engagement and response to these molecular targeting therapies. Here, we demonstrate that using 13C MRS to monitor the metabolism of hyperpolarized δ-[1-13C] gluconolactone via the pentose phosphate pathway to 6-phosopho-[1-13C]gluconate (6PG) provides such a noninvasive imaging readout of TERT or GABPB1 silencing in glioblastoma.
AMIDE PROTON TRANSFER IMAGING-ARTERIAL SPIN LABELING MISMATCH – A NEW IMAGING BIOMARKER FOR PILOCYTIC ASTROCYTOMA
Authors: Rajendran Adhithyan , Natesan Chidambaranathan , Yegnaraman Lavanya , Jalali Rakesh , Rao Rashmi , Mariyapillai Manikandan , Jawahar Prashant , Kumar Roopesh , Chilukuri Srinivas , Patil Sushma
Published: August 2024

Atypical features of Pilocytic astrocytoma (PA) on conventional MR imaging are often challenging and can be mistaken as High-grade glioma. Advanced Novel techniques of Amide Proton Transfer (APT) and Arterial spin labelling (ASL) have shown promising results in the grading of gliomas. This study to explore the added value and utility in characterizing the atypical form of PA, if these two non-contrast techniques are combined in the clinical practice. Mismatch between APT and ASL signals, was seen in all the cases of PA and this unique imaging appearance of APT ASL imaging mismatch could be a biomarker for pilocytic astrocytoma.
Tumor Blood Volume Measurement in Brain Gliomas Using Velocity-Selective Arterial Spin Labeling
Authors: Qu Yaoming , Qin Qin , Wen Zhibo
Published: August 2024

Velocity selective arterial spin labeling (VSASL) has shown comparable CBF measurements in brain gliomas with DSC-PWI. As CBV derived from DSC-PWI is the most widely adopted perfusion marker of brain tumor angiogenesis, the clinical utility for neurooncology imaging of VSASL based CBV quantification worth investigation. This study on preoperative patients with brain gliomas demonstrated that VSASL provided highly correlated quantifications of relative tumor blood volume (R2=0.83) compared to DSC-PWI, and further improved diagnostic performance than VSASL derived relative tumor blood flow measurements (ROC AUC=0.94 vs. 0.89), indicating its potential as a viable non-contrast alternative to DSC-PWI for brain tumor applications.
Improved diagnostic performance of APTw MRI to multiparametric non-contrast-enhanced MRIs in patients with post-treatment high-grade gliomas
Authors: Huang Qianqi , Wu Jingpu , Shen Yiqing , Le Nhat , Guo Pengfei , Schreck Karisa , Kamson David , Blair Lindsay , Heo Hye Young , Li Xu , Li Wenbo , Sair Haris , Blakeley Jaishri , Laterra John , Holdhoff Matthias , Grossman Stuart , Mukherjee Debraj , Bettegowda Chetan , van Zijl Peter , Zhou Jinyuan , Jiang Shanshan
Published: August 2024

We explored non-contrast-enhanced MRI performances of APTw, DWI, SWI, and pCASL at 3 Tesla in glioma patients post-treatment. APTw, ADC, QSM, and CBF histogram parameters from volumetric ROIs were recorded. Multivariable logistics regression with principal component analysis (PCA) was built for differentiating treatment effect from tumor recurrence. Results showed that the regression model trained on the combination of APTw, CBF, and QSM achieved the highest classification performance, with an AUC of 0.90.
Tumour virtual histology with Magnetic Resonance Elastography
Authors: Annio Giacomo , Bugge Robin , Svensson Siri , Darwish Omar , Seano Giorgio , Biernat Donata , Skogen Karoline , Ramm-Pettersen Jon , Vik-Mo Einar , Schregel Katharina , Emblem Kyrre , Sinkus Ralph
Published: August 2024

The reciprocal interaction between cancer cells and the surrounding creates a tumorigenic feedback loop capable of shifting the anti-neoplastic feature of the microenvironment towards a tumour growth-promoting one. Unfortunately infiltrating tumours, like GBMs, do not have discrete boundaries and intra-axial metastases are not visible on conventional MR images. However they are expected to change the tissue biomechanics. Here we explored tumour microenvironment biomechanics non-invasively using MRE in a cohort of 23 patients with brain tumours - 13 meningiomas, 10 glioblastomas. We show how MRE provides a comprehensive characterization of the tumour microenvironment, explaining histological features and tumour invasive features.
Avoiding shortcut-learning by mutual information minimization in deep learning-based MR image processing
Authors: Fay Louisa , Yang Bin , Gatidis Sergios , Kuestner Thomas
Published: August 2024

Deep Learning methods can detect patterns in data such as MR images but are incapable of determining causal relationships. However, causal understanding is crucial in medical applications, since the presence of confounders (e.g. scan conditions) obscure the causal relationship and create spurious-correlations. State-of-the-art models purely rely on correlated patterns which can result in wrong conclusions or diagnoses when spurious-correlations change (e.g. new scanner). We propose a deep learning framework that is robust in the presence of spurious-correlations by decreasing mutual information between learned features of MR images and leads to improved performance under distribution shifts.
Multi-Contrast 3D Fast Spin-Echo T2 Shuffling Reconstruction with Score-Based Deep Generative Priors
Authors: Kumar Sidharth , Aali Asad , Tamir Jonathan
Published: August 2024

Score-based generative modeling has emerged as a powerful tool for modeling image priors and has recently been used to solve ill-posed inverse problems in various domains including MRI reconstruction. Here we extend the framework to reconstruct multi-contrast 3D fast spin-echo (FSE), i.e. T2 Shuffling data. This is achieved by constraining the posterior sampling reconstruction to a low-dimensional subspace and training a score model on images from this subspace. We demonstrate a proof-of-principal reconstruction of data with no model mismatch, i.e. generated from the forward model.
Myocardial T2ρ Mapping in Small Animals: Comparison of Balanced Spin-Lock and Malcolm-Levitt Preparations
Authors: Gram Maximilian , Albertova Petra , Gutjahr Fabian Tobias , Jakob Peter Michael , Bauer Wolfgang Rudolf , Nordbeck Peter , Christa Martin
Published: August 2024

In this work, we propose myocardial T2ρ mapping as a potential and more robust alternative to conventional T2 quantification. Our new approach for T2ρ imaging, which is based on Malcolm-Levitt preparations with zero inter-pulse delays, was compared with established pulse sequences for T2, T1ρ and T2ρ in both phantom and in vivo experiments. In summary, the new preparatory pulse sequence was shown to meet the demanding requirements of myocardial T2ρ mapping at high magnetic field strength and to outperform conventional T2ρ preparations using balanced spin-locking.
Quantitative Perfusion with Rate-Pressure Product Corrections in Heart Transplant Patients with Cardiac Allograft Vasculopathy
Authors: Bisen Jay , Quinn Sandra , Kilinc Ozden , Pedamallu Havisha , Chow Kelvin , Davids Rachel , Lee Daniel , Kim Daniel , Weinberg Richard , Carr James , Markl Michael , Allen Bradley , Avery Ryan
Published: August 2024

Cardiac Allograft Vasculopathy (CAV) is a form of accelerated intimal hyperplasia in heart transplant patients that limits long-term survival. Quantitative perfusion is a novel MR imaging technique that is useful in determining myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) in CAV patients. After Rate-Pressure Product MBF corrections, Quantitative perfusion has shown that vessels with severe CAV (>70% stenosis) have significantly decreased MPR driven primarily by increased resting MBF. Quantitative perfusion may improve non-invasive monitoring of CAV status in heart transplant patients.
T2 and ADC correlated mapping of breast cancer lesions: A spatiotemporal encoding 3T MRI analysis
Authors: Otikovs Martins , Nissan Noam , Furman-Haran Edna , Anaby Debbie , Agassi Ravit , Sklair-Levy Miri , Frydman Lucio
Published: August 2024

The possibility to improve the MRI contrast on cancerous breast lesions was explored by correlating quantitative T2 and ADC values. To this end, T2 maps of patients were measured at more than one b-value and ADC maps at more than one TE value –in all cases using spatiotemporal encoding (SPEN) MRI. SPEN delivered quality, artifact-free TE-weighted DW images, from which ADC and T2 maps could be correlated despite relatively long acquisitions and heavy signal weighting. Data suggest there may be potential value in combining T2 and ADC mappings, as these low-correlated variables can provide complementary information about breast lesions.
Validation and Application of SLfRank RF Pulse Design
Authors: zhong zheng , Liao Congyu , Singhal Janhavi , Ong Frank , Vasanawala Shreyas , Pauly John
Published: August 2024

SLfRank is a novel RF pulse design framework proposed to improve upon the well-established Shinnar Le-Roux (SLR) design algorithm. Numerical experiments demonstrated promising effectiveness of SLfRank, prompting a need to validate its experimental feasibility. An experimental comparison of SLR and SLfRank is achieved by measuring slice profiles, multiband excitation, and spin-echo pulses on phantom and human brain. SLfRank produced images of comparable quality to the SLR algorithm, but with reduced RF energy and greater control over RF pulse phase. SLfRank’s numerical feasibility aligned closely with its effectiveness experimentally thus proving its technical feasibility for applications in this work and beyond.
Online gradient optimisation for spokes parallel transmit – the BOGAT method
Authors: Zhang Minghao , Rodgers Christopher
Published: August 2024

Spokes parallel transmit pulses improve the homogeneity of ultra-high field imaging. Typically the gradient trajectory (i.e. spoke kt-space positions) is determined using the iterative Fourier transform approach (FTA). We introduce “BOGAT” (Bayesian Optimisation of GrAdient Trajectory) to efficiently determine globally optimal gradient trajectories. We evaluated BOGAT in phantoms for single-band and multi-band excitation, and retrospectively in 9 volunteers using existing B0 and B1+ maps. BOGAT improves flip angle homogeneity (by 12.8% vs FTA, P<0.001) and reduces SAR (17.2%, P<0.001). Calculations take ~10s extra for a set of multiband pulses, making it feasible to use for online per-subject optimisation.
A Metamaterial Liner Body Coil for Wide-bore 3T MRI
Authors: Rémillard Leo , Maunder Adam , Robb Fraser , Iyer Ashwin , De Zanche Nicola
Published: August 2024

The transmit field suffers from standing wave inhomogeneities at field strengths ≥3T, which degrade image quality and create specific absorption rate (SAR) hotspots. We present the first experimental demonstration of a whole-body metamaterial liner (metaliner) that enables traveling wave excitation at a lower frequency than achievable otherwise. The simulated transmit efficiencies for a comparable birdcage and metaliner were 2.43μT⁄√kW±23.8% and 1.80μT⁄√kW±25.5% respectively, and the maximum 10g local SAR was reduced by 18% with the metaliner. This shows that the metaliner is an attractive alternative to the BC with greater safety thanks to the lower localized SAR.
Investigating the endfolial pathway of the human hippocampus using ex vivo dMRI at high spatio-angular resolution
Authors: Nielsen Jonathan , Aggarwal Manisha
Published: August 2024

The endfolial pathway is a collection of fibers within the hilus of the human hippocampus that forms part of the complex intra-hippocampal circuitry. We investigate this pathway using high-field (11.7 T), high spatio-angular resolution diffusion MRI (dMRI) of 3 intact, excised hippocampi. Using probabilistic tractography and computational unfolding of the hippocampal strata, we demonstrate a unique sensitivity of dMRI to the 3D trajectory of the intra-hippocampal fibers. Keywords: Ex vivo high spatio-angular resolution diffusion MRI; hippocampus internal circuitry; probabilistic tractography.
Distinct subcortical and cortical functional gradient dysfunction in schizophrenia and the treatment effects after antipsychotics
Authors: Yang Chengmin , Zhang Wenjing , Liu Jiajun , Yang Zhipeng , Lui Su
Published: August 2024

By characterizing the connectome gradient changes of subcortex and cortex in drug-naive first-episode schizophrenia and the treatment effect after antipsychotics, we found that the distinct fundamental functional segregation of subcortex and functional integration in cortex in patients at baseline when compared to healthy controls, and the longitudinal analyses indicated that the treatment would normalize the altered gradients. The improved subcortical gradient changes were associated with significant improvement of symptoms. This study provided the new perspective on the abnormal subcortical and cortical hierarchy organization in schizophrenia and its longitudinal subcortical gradient changes could be sensitive to reflect the antipsychotic treatment effect.
Topological Disruption of High-Order Functional Networks in Cognitively Preserved Parkinson’s Disease
Authors: Shang Song'an , Dou Weiqiang , Jing Ye
Published: August 2024

Parkinson’s disease (PD) is not solely a disruption of motor-related networks but a consequence of impaired high-level cognitive processes, indicating that high-order information exchange in cognitively preserved patients with PD could be sensitively revealed in the high-order-functional connection (HOFC) networks. We thus attempted to characterize the topological alterations and classification performance of HOFC networks in normally cognitive patients with PD. Our findings identified the disrupted topology of functional interactions at high-level with extensive alterations of topological properties and improved differentiating ability in patients with PD prior to clinical symptoms of cognitive impairment, providing complementary insights into complex neurodegeneration in PD.
Longitudinal Changes of Functional Connectivity Dynamism Are Relevant for Disability Worsening in Multiple Sclerosis: A 2.5-Year Study
Authors: Valsasina Paola , d'Amore Giulia , Preziosa Paolo , Margoni Monica , Filippi Massimo , Rocca Maria Assunta
Published: August 2024

Here, we investigated changes in time-varying functional connectivity over 2.5 years of follow-up in 129 multiple sclerosis patients and their association with disability progression. At follow-up, 25/129 (19.3%) patients worsened clinically. At baseline, multiple sclerosis patients showed reduced time-varying functional connectivity vs controls in orbitofrontal, cerebellar, precuneal and thalamic regions. At 2.5-year follow-up, patients exhibited widespread reduction of time-varying functional connectivity over time. Such a pattern was confirmed when looking at clinically stable patients. Conversely, clinically worsened patients presented peculiar reductions of time-varying functional connectivity in default-mode network areas and in basal ganglia, this latter significant at time-by-group interaction analysis.
MRI-based deep learning radiomics can predict HER2 expression and disease-free survival in breast cancer
Authors: Tang Wenjie , Guo Yuan , Chen Siyi , Huang Bingsheng , Xie Xiaotong , Wang Mingyu , Xu Yongzhou , Jiang Kuiming , Wei Xinhua
Published: August 2024

To the best of our knowledge, our study is the first to non-invasively assess human epidermal growth factor receptor 2 (HER2) status, especially HER2-low-positive status in breast cancer. In this study, a deep learning radiomics (DLR) model based on contrast-enhanced MRI was constructed and showed high and stable performance in predicting HER2 status in both the training and validation cohorts, and the predicted status was an independently significant predictor of disease-free survival (DFS) in HER2-low-positive/HER2-zero breast cancers. The DLR model showed prospects as a computer-aided diagnostic tool to help more accurately identify HER2-low-positive breast cancers, thereby guiding patient treatment strategies.
Acceleration of Multi-Echo MP2RAGE using Interleaved Undersampling and Joint-Contrast Reconstruction
Authors: Yao Jingwen , Liu Jing , Burns Brian , Henry Roland , Larson Peder
Published: August 2024

In this study, we evaluated the use of interleaved undersampling and joint-contrast reconstruction to accelerate multi-echo MP2RAGE. We compared three sampling patterns (GRAPPA, interleaved GRAPPA, and CIRCUS) and five reconstruction algorithms (GRAPPA, ESPIRIT, LORAKS, Joint-GRAPPA, and Joint-LORAKS) using retrospective undersampling experiments. The results demonstrated better performance achieved using joint-contrast compared to single-contrast reconstruction, and CIRCUS sampling compared to GRAPPA. With the combination of CIRCUS undersampling and Joint-LORAKS reconstruction, we obtained quantitative measurements of T1, R2*, QSM, and volumes at R=6.8 highly consistent with the fully sampled data, demonstrating the potential of using the proposed strategy to accelerate ME-MP2RAGE acquisition.
High-resolution whole-brain multi-parameter mapping at 7 Tesla with interleaved fly-back 3D-EPI and universal pTX pulses
Authors: Stirnberg Rüdiger , Völzke Yannik , Löwen Daniel , Pracht Eberhard , Gras Vincent , Boulant Nicolas , Sherif Siya , Wang Difei , Ferreira Mónica , Faber Jennifer , Stöcker Tony
Published: August 2024

We present a versatile high-resolution whole-brain multiparametric/susceptibility mapping protocol at 7T, introducing interleaved fly-back skipped-CAIPI 3D-EPI. To overcome the impeding limitations of B1+ inhomogeneity, universal pTX pulses for excitation and magnetization transfer saturation are employed. Within 17 minutes scan time, 0.6mm isotropic whole-brain MT-/PD-/T1-weighted magnitude and phase images at four echo times and corresponding quantitative parameter maps are obtained. Supplementary output, like SWI and MPRAGE-like images can be generated as well. Scan efficiency is high and geometric distortions are negligible. Optionally, the interleaved fly-back acquisition allows a separate analysis of two monopolar readout images.
A normative cortical T1 atlas for single-subject pathology detection at 7T
Authors: Caneschi Samuele , Hilbert Tom , Bonanno Gabriele , Hoepner Robert , Wiest Roland , Radojewski Piotr , Maréchal Bénédicte , Thiran Jean-Philippe , Kober Tobias , Piredda Gian Franco
Published: August 2024

Quantitative MRI allows establishing normative atlases of relaxometry parameters which enable single-subject comparisons for anomaly detection. The large anatomical inter-subject variability of the brain cortex and its convoluted shape, however, complicate such comparison in this region. In this study, a method to align inter-subject brain cortices is proposed and a voxel-wise normative T1 atlas in the cortex is built from a cohort of 133 healthy subjects scanned at 7T. The atlas is used to detect and characterize T1 alterations in two multiple sclerosis patients on a single-subject basis.
Effects of hypertension and type 2 diabetes on cerebrovascular reactivity in older adults
Authors: Nanayakkara Nuwan , Meusel Liesel-Ann , Anderson Nicole , Chen J. Jean
Published: August 2024

Differences in CVR amplitude and time delay were assessed among patients with hypertension (HT), hypertension-plus-type-2 diabetes (HT+DM), and age-matched controls (CTL) using a pipeline for adaptive capturing of the BH response directly from BOLD data, ensuring greater robustness. The lowest CVR amplitude and the longest delay were found in the HT+DM group. CTL had the highest CVR amplitude, and the HT group had the shortest time delays. CVR delay was more sensitive to group differences than amplitude.
Systematic assessment of published QSM inversion algorithms for detecting longitudinal changes in brain susceptibility
Authors: Salman Fahad , Ramesh Abhisri , Jochmann Thomas , Prayer Mirjam , Bergsland Niels , Dwyer Michael , Jakimovski Dejan , Zivadinov Robert , Schweser Ferdinand
Published: August 2024

Quantitative susceptibility mapping (QSM) calculates the tissue magnetic susceptibility from gradient-echo phase images. Tissue magnetic susceptibility is of high clinical interest because it reflects tissue iron, myelin, and calcium. However, the clinical significance of these findings remains unclear. In particular, it is unknown if algorithms differ in their ability to detect group differences and longitudinal changes in susceptibility. The present work compared a large number of published algorithms with respect to their ability to detect aging-related changes over time.
A novel method to calculate standardized quantitative maps from a single T2-weighted image: A feasibility study.
Authors: Elsaid Nahla , Tagare Hemant , Galiana Gigi
Published: August 2024

T2w imaging could assist in the early diagnosis of multiple sclerosis (MS). However, these scans are inherently qualitative, and variable intensities in the images depend on hardware and acquisition parameters. On the other hand, standardized quantitative T2 maps can serve as a sensitive biomarker of MS and the longitudinal assessment of the disease progression. In this abstract, we present the first results demonstrating that calculating T2 maps from vendor T2w sequence is feasible, which could allow for an earlier diagnosis of MS disease.
Full-scale imaging system for brain MRI and magnetoencephalography
Authors: Zevenhoven Koos , Havu Marko , Lehto Iiro , Mäkinen Antti , Luomahaara Juho , Laine Petteri , Kiviranta Mikko , Ilmoniemi Risto
Published: August 2024

We have built the first full-scale brain scanner performing both MRI and neuromagnetic measurements. Many improvements have been made compared to previous-generation systems. Parts of the system include a helmet-shaped array of 120 superconducting sensors and a pulsed superconducting polarizing coil. An open-geometry coil system provides unobstructed access, and MRI signal acquisition is performed at ultra-low field. The first MEG and MRI data have been successfully obtained with the device. The new prototype is an important milestone on the way towards a commercial implementation.
Four-fold acceleration of in vivo T1 mapping at 0.1 T using heavily-undersampled Look-Locker data and matrix completion
Authors: Fiorito Marco , Spreiter Mauro , Sarracanie Mathieu , Salameh Najat
Published: August 2024

Quantitative T1 mapping has proven useful in several clinical applications, nevertheless it is not widely deployed as it generally suffers from long acquisition times. This problem is exacerbated at low magnetic fields, due to inherent lower sensitivity. In spite of more favourable magnetisation properties (e.g., shorter recovery times, higher dispersion), exotic acquisition strategies and reconstruction pipelines are key to make quantitative MRI at low field fast, and compatible with clinical routines. Here, we present a low-rank matrix completion-based reconstruction method applied to heavily undersampled Look-Locker data for accelerated T1 mapping at 0.1 T.
Compact and Lightweight Single-sided Inward-outward (IO)-ring permanent magnet array for back imaging
Authors: Liang Ting-Ou , Li Erping , Yu Wenwei , Huang Shao Ying
Published: August 2024

A compact and lightweight single-sided Inward-outward (IO)-ring permanent magnet array is proposed for back imaging. Its size is 1396×528×1080mm3 and it weighs 924 kg. Within a field-of-view (FoV) of 300×80×20mm3, it has an axial magnetic field with an average strength of 129.8mT, a built-in gradient (averaged at 158mT/m) that corresponds to a radiofrequency (RF) bandwidth of 9.7% and a good linearity with a R2-coefficient of 0.952. It has a compact 5-Gauss zone of 400×320×460mm3.
Prostate cancer characterization with a data-driven analysis of multi-center 3D 1H-MRSI data using Multivariate Curve Resolution
Authors: Stamatelatou Angeliki , Bertinetto‬ ‪Carlo , Jansen Jeroen , Postma Geert , Selnæs Kirsten , Bathen Tone , Heerschap Arend , Scheenen Tom
Published: August 2024

Location and aggressiveness of cancer lesions in the prostate were assessed with a Multivariate Curve Resolution (MCR) approach. This data-driven method was trained on 3D 1H MRSI data from 63 patients from 6 institutions to extract common spectroscopic components without needing prior knowledge. MCR identified 5 components related to known prostate metabolites, residual lipid and water signals. The relative amounts of these components robustly separated cancer from benign tissue in a test set of 43 other subjects from 8 centers, and showed a strong correlation with cancer aggressiveness. This approach facilitates automatic analysis of prostate MRSI, avoiding subjective human intervention.
Diffusion dispersion mapping of ischemic lesions in the ex vivo porcine heart
Authors: Michael Eric , Dick Claire , Hennel Franciszek , Stoeck Christian , Pruessmann Klaas
Published: August 2024

Diffusion dispersion mapping is a recently proposed method for probing tissue microstructure and quantifying microstructural disorder based on differences in the impact of diffusion restrictions over different length scales. In this work, this method was employed in the ex vivo heart to investigate the utility of diffusion dispersion in identifying and characterizing ischemic tissue. Our results show that ischemic cardiac lesions exhibit reduced diffusion dispersion rates, in agreement with known microstructural changes, and can be differentiated with respect to surrounding tissue. These findings demonstrate that microstructure-sensitive contrast offers a novel avenue for probing and characterizing cardiac pathologies.
Referenceless Nyquist Ghost Correction Outperforms Standard Navigator Based Method for DT-CMR
Authors: Huo Zimu , Wen Ke , Luo Yaqing , Ferreira Pedro F , Neji Radhouene , Pennell Dudley , Scott Andrew , Nielles-Vallespin Sonia
Published: August 2024

Nyquist ghosting is a common artefact in echo planar imaging (EPI), typically corrected using separately acquired reference data. Here we demonstrate that reference free Nyquist ghost correction algorithms based on entropy and Ghost/Object ratio minimization can outperform navigator based methods and improve imaging efficiency for in vivo diffusion tensor cardiovascular magnetic resonance.
Highly-Accelerated High-Frame-Rate Cine for Exercise Cardiac MRI
Authors: Morales Manuel , Morales Manuel , Yoon Siyeop , Rodriguez Jennifer , Manning Warren , Nezafat Reza
Published: August 2024

Combined cardiac MRI with exercise (Ex-CMR) is a stress test with promising applications. However, standard ECG-segmented cine imaging during exercise is challenging. Free-breathing ECG-free real time cine can be achieved with compressed sensing. Yet tradeoff remains between temporal and spatial temporal resolution. Thus, we sought to develop a highly accelerated high-frame-rate cine for Ex-CMR by accelerating spatial resolution using Resolution Enhancement Generative Adversarial Inline Network (REGAIN), followed by synthesizing new frames using Deformation ENcoding Transformer (DENT). REGAIN enabled 14-fold scan acceleration, DENT enabled 2-fold improvement in temporal resolution. We achieved spatiotemporal resolution of 1.9 × 1.9 mm2 and 16 ms.
Automatic segmentation of the interscapular BAT in rats by the dynamic magnetic resonance fat fraction images
Authors: Cheng Chuanli , Zhang Lei , Peng Hao , Zheng Hairong , Liu Xin , Zhang Huimao , Zou Chao
Published: August 2024

The noninvasive assessment of BAT volume is fundamental for characterizing the longitudinal effects in rodents. In this work, dynamic fat fraction images of 34 rats fed under different conditions were acquired before and after noradrenaline injection for 2.5 hours. The iBAT regions were recognized and labelled automatically by identifying the regions with significant changes in FF images. Then a deep learning network was built up by training the FF images and the automatically identified mask images in all rats. The dice similarity coefficient, precision rate and recall rate of the network were found to be 0.897±0.061, 0.901±0.068 and 0.889±0.086, respectively.
Simultaneous imaging of cerebral perfusion and blood-CSF exchange using dual-TE split echo train Fast-Spin-Echo Arterial Spin Labeling
Authors: Taso Manuel , Alsop David
Published: August 2024

The recent years have seen a growing interest in the study of brain waste clearance mechanisms, also referred to as glymphatics. Recently, ASL has been used to image choroid plexus perfusion but also the exchange between blood and CSF by taking advantage of the long CSF T2 compared to blood and brain tissue. We evaluate the possibility to measure this using reduced flip-angles FSE with variable-density k-space sampling, using a split echo-train strategy to collect in the same echo-train a short-TE PD-weighted as well as long-TE T2-weighted ASL datasets. We evaluate in a pilot group potential age-related differences.