bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of 4D Flow MRI to Indirectly Predict Cardiac Adverse Events Through Hemodynamic Alterations Induced by Exercise
Authors: Li Jiali , Liu Qian , Chen Meining , Chen Jing
Published: November 2024

Motivation: Cardiovascular-related deaths are increasing in athletes, which necessitates a deeper understanding of hemodynamics. Goal(s): Our goal was to use 4D flow MRI to assess athletes' cardiac and aortic hemodynamics and their links to myocardial fibrosis and cardiac remodeling risks. Approach: Cardiac MRI was performed on 213 athletes and 32 matched controls. Hemodynamic parameters were measured and analyzed against myocardial fibrosis and cardiac remodeling risks. Results: Athletes exhibited increased wall shear stress and energy loss. Hemodynamics differed markedly between groups. Our prediction model reliably displayed the potential of 4D flow in assessing cardiac risks. Impact: Exercise can elevate aortic wall shear stress and energy loss. Four-dimensional flow cardiac MRI may allow predicting myocardial fibrosis or cardiac remodeling risks in athletes, thus informing clinicians of adverse event associations and guiding follow-up adjustments.
Free-running fat-suppressed radial whole-heart 4D flow using OptiPulse
Authors: Ferincz Robin , Sieber Xavier , Akporeha Efena , Falcao Mariana , Yerly Jérôme , Markl Michael , Richiardi Jonas , van Heeswijk Ruud , Stuber Matthias , Roy Christopher
Published: November 2024

Motivation: Free-running radial 4D flow has been shown to enable accurate whole-heart quantification and visualization of hemodynamics. However, unsuppressed fat signal can lead to artifacts, which may compromise image quality and cause errors in flow quantification. Goal(s): Our study therefore aims to reduce fat signal in radial 4D flow MRI. Approach: We integrated a novel b-splines iteratively optimized water-excitation RF pulse generated with a previously described framework (OptiPulse) into a radial 4D flow sequence to suppress the signal from fat. Results: We successfully integrated OptiPulse in radial 4D flow to suppress fat signal and demonstrated comparable quantitative flow assessment to non-fat-suppressed 4D flow. Impact: The integration of b-splines iteratively optimized water-excitation RF pulses (OptiPulse) into a free-running radial whole-heart 4D flow sequence leads to significantly reduced fat-signal in a promising step towards more robust hemodynamic assessment in patients with large amounts of adipose tissue.
Assessment of Pulmonary Arteries Hemodynamics in Athletes with 4D Flow MRI
Authors: Tang Mingsong , Chen Meining , Chen Jing
Published: November 2024

Motivation: Long-term intense training in athletes can lead to pathological cardiac remodeling (CR) and potential myocardial fibrosis (MF), raising cardiovascular risks. Goal(s): Employ 4D flow MRI to study pulmonary arterial hemodynamics in athletes and explore correlations with CR and MF. Approach: Scanned 121 athletes and 21 controls using 3 T MRI scanner; 4D flow data analysis on CVI42; built machine learning models for differentiation based on cardiovascular conditions. Results: Found significant associations between the altered pulmonary arterial hemodynamics parameters and CR and/or MF. Machine learning models identified athletes with cardiac anomalies. Impact: We indicated that exercise can induce remodeling of the pulmonary circulation in athletes. The evaluation of pulmonary arterial 4D flow hemodynamics parameters can be beneficial for clinical follow-up of athletes.
Coronary Artery Wall Contrast Enhancement Imaging Impact on Disease Activity Assessment in IgG4-RD a direct marker of coronary involvement
Authors: Du Yaqi , Wang Guan , Bai Yun , Wang Xinrui , Zhong Ying
Published: November 2024

Motivation: The coronary wall involvement in IgG4-related disease (IgG4-RD) is overlooked in conventional imaging, more sensitive approach is needed. Goal(s): To investigate the feasibility of quantifying contrast enhancement (CE) to detect coronary involvement in IgG4-RD and the influence on disease activity assessment based on the IgG4-RD Responder Index (RI). Approach: The coronary artery wall images of the IgG4-RD, systemic lupus erythematosus (SLE) patients and healthy subjects were analyzed and IgG4-RD-RI scores were collected for correlations analysis. Results: Coronary artery wall CE can be a direct marker of coronary artery injury and may improve disease activity assessment in IgG4-RD. Impact: Coronary artery wall CE can serve as an objective indicator of disease activity. Considering coronary artery wall CE in the IgG4-RD-RI scoring has the potential to enhance the comprehensiveness of disease activity assessment and enable more appropriate treatment decisions.
Associations between atherosclerotic luminal stenosis in the distal internal carotid artery and diffuse wall thickening in its upstream segment
Authors: Zhang Jin , Sun Beibei , Wu Peng , Cheng Yongjun , Chen Weibo , Zhao Huilin
Published: November 2024

Motivation: Significant atherosclerotic stenosis or occlusion in the distal carotid artery may induce diffuse wall thickening (DWT) in the upstream arterial wall. Goal(s): This study aimed to assess the association of atherosclerotic steno-occlusive diseases in the distal internal carotid artery (ICA) with DWT in the upstream ipsilateral ICA. Approach: Individuals with atherosclerotic stenosis in the distal ICA, detected by carotid MR vessel wall imaging, were enrolled. Results: Significant correlations were found between distal ICA stenosis and DWT in the petrous ICA, DWT severity, the longitudinal extent of DWT in the ICA, enhancement in the petrous ICA) and enhancement degree. Impact: Diffuse wall thickening is a common secondary change in atherosclerotic steno-occlusive disease in the intracranial carotid. This phenomenon constitutes a confounding factor in the distinction between atherosclerosis and inflammatory vasculopathies, and could be reversed after alleviated atherosclerotic stenosis.
Joint Estimation of Brain Connectivity and Propagation of Neurodegeneration
Authors: Schroder Anna , Thompson Elinor , He Tiantian , Palombo Marco , Schiavi Simona , Daducci Alessandro , Oxtoby Neil , Alexander Daniel
Published: November 2024

Motivation: Models of propagation of neurodegeneration encode hypotheses on the mechanisms of pathology spread via the brain’s connectome. However, they fail to accurately capture pathology patterns, partly due to errors in tractography-estimated connectomes. Goal(s): We use this link between pathology and connectivity to help resolve errors in connectivity estimation. Specifically, we use disease-related pathology to jointly estimate brain connectivity and pathology propagation. Approach: We introduce a new algorithm to use an estimate of the false-positive potential (FPP) of each connection to constrain the pathology-informed connectome-optimisation. Results: Combining FPP and pathology-informed optimisation yields substantial improvement to both the connectome and the connectome-based prediction of pathology. Impact: By jointly estimating pathology and the connectome, we advance both disease understanding and understanding of structural connectivity. The work is a first demonstration of the general idea of using pathology to inform on brain connectivity.
Distinct longitudinal brain white matter microstructure changes and associated polygenic psychiatric and neurodegenerative disorder risk
Authors: Korbmacher Max , van der Meer Dennis , Beck Dani , Askeland-Gjerde Daniel , Eikefjord Eli , Lundervold Arvid , Andreassen Ole , Westlye Lars , Maximov Ivan
Published: November 2024

Motivation: White matter microstructural (WMM) changes are a crucial feature of ageing and disease development. There is yet no comprehensive mapping of such changes. Goal(s): Providing an overview of WMM changes at different spatial scales, and relationship of these changes to polygenic risk scores (PGRS) of developing psychiatric disorders and Alzheimer's disease. Approach: WMM metrics were estimated using multiple diffusion approaches, associated with age and PGRS, and ageing changes (inter-scan interval:2.44±0.73 years) assessed at different spatial scales. Results: We find spatially distributed WMM-changes and PGRS-associations across the brain (most age-sensitive: central and cerebellar WMM). Brain longitudinal changes reflected disorder PGRS better than cross-sectional measures. Impact: The manuscript details for the first time longitudinal WMM changes in a large longitudinal sample (UK Biobank, N=2,676), and provides the currently most comprehensive overview of PGRS associations with WMM change and WMM (using an additional cross-sectional validation sample, N=31,056).
High-resolution Fluid-suppressed Diffusion Tractography Shows Altered Fornix Volume and Diffusion Metrics in Pediatric Multiple Sclerosis
Authors: Weber Carly , Wilbur Colin , Beaulieu Christian
Published: November 2024

Motivation: It is unknown if the fornix (main output tract of the hippocampus) is affected in pediatric multiple sclerosis (MS), which would suggest its early involvement. Goal(s): Are the volume and diffusion metrics of the fornix affected in pediatric MS as it is in adult MS, and does fornix injury precede damage to the hippocampus?Approach: Fornix diffusion tensor imaging and whole-brain MPRAGE were acquired from pediatric MS patients and controls. The fornix was identified with tractography. Results: Pediatric MS showed a much (29%) smaller fornix with abnormal diffusion metrics indicative of early injury, but had no difference in hippocampus volume, compared to controls. Impact: Diffusion tractography identifies marked injury to the fornix, a small white matter tract important for cognition, in children and adolescents with multiple sclerosis, while the hippocampus volume is unaffected, implicating the fornix as an early brain target in this disease.
Blind spherical deconvolution of multi-shell diffusion MRI to model regional changes in pathology
Authors: Leysen Siebe , Radwan Ahmed , Maes Frederik , Sunaert Stefan , Christiaens Daan
Published: November 2024

Motivation: Diffusion-weighted MRI (dMRI) has significantly enhanced our ability to investigate the brain's microstructure, but analysis in pathology remains difficult. Goal(s): This study introduces a voxelwise approach to concurrently estimate the Orientation Distribution Function (ODF) and response function for fiber orientation analysis and tractography. Approach: The proposed blind deconvolution method models the kernel as a sum of axially-symmetric Gaussian functions, defined in spherical harmonics. It is evaluated through simulations and in-vivo experiments in healthy volunteers and glioma patients, demonstrating its efficacy in ODF estimation and data fitting. Results: This novel approach presents better modeling of pathology and offers promising results for white matter analysis. Impact: We introduce a blind deconvolution method for brain microstructure analysis with DWI that concurrently estimates a voxelwise ODF and kernel. This method can aid tractography and provide new image contrasts in the presence of pathology.
Brain microstructure charts in controls and multiple sclerosis patients using clinical diffusion MRI
Authors: Chen Jenny , Ades-Aron Benjamin , Liao Ying , Pang Michelle , Stepanov Valentin , Shepherd Timothy , Chasen Elizabeth , Veraart Jelle , Novikov Dmitry , Fieremans Els
Published: November 2024

Motivation: Currently, brain charts index gray matter brain volume from T1-weighted MRI, whose sensitivity is limited to millimeter resolution, thereby unable to probe early signs of aging and pathology at the cellular level. Goal(s): To introduce normative data for diffusion MRI (dMRI) and apply it to multiple sclerosis (MS) patients to evaluate sensitivity and accuracy. Approach: We created normative data using diffusion tensor, diffusion kurtosis, and standard model imaging metrics in white matter. Then, assessed MS subjects by comparing to these normative data. Results: dMRI metrics from MS patients deviate from normative data, suggesting brain charts may be used to benchmark brain health. Impact: This study is the first step to achieve a brain-age framework from clinically feasible dMRI scans that provides meaningful insight into microstructural processes underlying brain aging and disease– possibly enabling quantitative assessment of treatment response to future disease-modifying therapies.
Multiple advanced diffusion models for preoperative prediction of macrotrabecular-massive subtype in solitary hepatocellular carcinoma
Authors: Zhu Yongjian , Cai Wei , Jiang Yueluan , Yi Yinqiao , Yang Guang , Zhao Xinming
Published: November 2024

Motivation: Pretherapeutic characterization of the aggressive macrotrabecular-massive (MTM) subtype hepatocellular carcinoma (HCC) may promote the implementation of precision treatment and improvement of prognosis. Goal(s): To investigate the value of multiple advanced diffusion models in identifying the MTM subtype of HCC preoperatively. Approach: DWI of twelve b-values (0-2000 s/mm2) were performed in 70 patients with HCC. Multiple diffusion-derived parameters were extracted and compared between MTM and non-MTM HCC. The predictive efficacy of various diffusion parameters was assessed. Results: CTRW_α exhibited the highest predictive performance with an AUC of 0.861 among individual parameters, a combination of parameters could improve the AUC to 0.912. Impact: MTM is a distinct subtype of HCC and is associated with aggressive biological behavior, but it might be a suitable candidate for immunotherapy. Our result demonstrated that non-Gaussian diffusion parameters could serve as promising biomarkers for predicting MTM preoperatively.
Investigating neural responses using fast, non-selective MRI and simultaneous EEG
Authors: Morgan A , Molfese Peter , Derbyshire J , Huber Renzo , Bandettini Peter
Published: November 2024

Motivation: Recent reports of DIANA responses open the possibility of non-invasively recording neural activity using fMRI. Goal(s): We aim to test fast, non-selective MRI to better evaluate the feasibility of capturing DIANA responses in the human brain. Approach: We develop a fast bSSFP sequence without gradient encoding to record the center of k-space during neural activation with a temporal resolution of 3ms. Results: We observe MRI response dynamics on the order of tens to hundreds of milliseconds, and compare to simultaneously acquired EEG measurements. Impact: We tested a fast, non-selective MRI sequence to provide preliminary evidence for direct measurement of neural responses in the human brain, and compare these responses to simultaneously acquired EEG measurements.
Exploring the sensitivity limits of neuronal current imaging with MRI and MEG in the human brain
Authors: Capiglioni Milena , Tabarelli Davide , Turco Federico , Tambalo Stefano , Wiest Roland , Jovicich Jorge
Published: November 2024

Motivation: In-vivo use of Spin-lock (SL) rotary MR saturation contrast, despite encouraging phantom studies, raises questions about its sensitivity and practicality in neural magnetic field imaging. Goal(s): Determine if SL contrast effectively maps human neuronal activation, evaluating its sensitivity and localization against MEG and 3T BOLD-fMRI. Approach: Thirteen volunteers underwent SL-based scanning during visual stimulation, alongside BOLD and magnetoencephalography, with phantom experiments validating the paradigm and processing pipelines. Results: Preliminary analysis revealed significant activation in the expected visual region for three subjects in SL contrast maps. Low detection was attributed to sensitivity limits estimated in the phantom, falling below MEG-estimated neural fields. Impact: We assess Spin-lock 3T MR contrast for human neuronal activation mapping. Promising initial results highlight the need for refinement due to sensitivity limitations in neural field detection, supported by phantom MRI and MEG measures.
Neurovascular & experimental confounds when probing neuronal activity with fast fMRI: exploring evasive DIANA & DW-fMRI.
Authors: Zamboni Elisa , Watson Isaac , Torkelsen Frida , McStravick James , Kennerley Aneurin
Published: November 2024

Motivation: Exploring the cerebrum's functional organisation and processing is challenging. Functional Magnetic Resonance Imaging (fMRI) measures neuronal activity (NA) noninvasively, but relies on indirect signals related to cerebral haemodynamics. Goal(s): We rigorously investigate if NA in the human brain can be measured using diffusion-weighted fMRI and Direct Imaging of Neuronal Activity (DIANA). Approach: We utilise DW-fMRI and DIANA at 3 Tesla to record the responses in the somatosensory cortex following electric stimulation of the digits. Results: We confirm BOLD responses in somatosensory cortex. Both DW-fMRI and DIANA also show stimulus-locked responses. However, we express concerns regarding electrical stimulation noise artefacts and neuronal inhibition. Impact: This study advances our understanding of neuronal activity measurement using innovative fMRI techniques. It sheds light on the challenges, potential artefacts, and optimal strategies for precise human brain mapping, which is crucial for both basic research and clinical applications.
No observation of DIANA signals in rats at 7.0 and 17.2 Tesla
Authors: Cloos Martijn , Selingue Erwan , Hodono Shota , Ciobanu Luisa
Published: November 2024

Motivation: Direct Imaging of Neuronal Activity (DIANA) was proposed by Toi et al. in Science 2022. Before DIANA can be adopted, key findings must be reproduced. Goal(s): Independent reproduction of the results shown in supplemental Figure 26 of Toi et al. Approach: Rats were scanned at 7.0T and 17.2T using a visual paradigm consisting of a 10ms blue flash every 200ms. Results: No DIANA signal was detected, even though the temporal signal to noise ratio was sufficient to detect signal changes of 0.1%. However, a slow hemodynamic signal, much larger than the expected DIANA signal, was observed between measurements with and without stimulus. Impact: Our failure to detect a DIANA signal in rat at 7.0T and 17.2T, echo's findings by Hodono et al. (Imaging Neuroscience) and Choi et al. (bioRxiv), indicating DIANA is not ready for use in neuroscientific studies.
A different interpretation of the DIANA fMRI signal
Authors: van Valerie Phi , Sen Sajal , Jasanoff Alan
Published: November 2024

Motivation: A recent study argued that it is possible to detect neuroelectrical potentials using an fMRI scanning approach called DIANA. Although DIANA signals coincide with electrophysiological measurements, no mechanism for the effect was reportedGoal(s): We sought to implement DIANA in order to understand the origins of the reported results. Approach: We applied variants of the DIANA pulse sequence under test and control conditions, comparing results with simulations. Results: We observed DIANA signals but show that neural activity is neither necessary nor sufficient for this. Instead, the DIANA signal appears to result largely from nonideal aspects of pulse sequence timing. Impact: Our study suggests that the DIANA signal arises from an artifact in the line scan pulse sequence. This indicates possible pitfalls in implementing such sequence designs and emphasizes the continuing need for fMRI-based direct readouts of neural activity.
Structural connectome shapes the maturation of cortical morphology from childhood to adolescence
Authors: Liang Xinyuan , Sun Lianglong , Liao Xuhong , Lei Tianyuan , Xia Mingrui , Duan Dingna , Zeng Zilong , Li Qiongling , Xu Zhilei , Men Weiwei , Wang Yanpei , Tan Shuping , Gao Jia-Hong , Qin Shaozheng , Tao Sha , Dong Qi , Zhao Tengda , He Yong
Published: November 2024

Motivation: Cortical thinning is an important hallmark of the maturation of brain morphology during childhood and adolescence. However, the connectome-based wiring mechanism that underlies cortical maturation remains unclear. Goal(s): We aim to model how the maturational pattern of cortical morphology is shaped by white matter connectome architecture. Approach: We integrated neuroimaging, connectome, transcriptome analyses and computational modeling. Results: We found that the maturational patterns of cortical morphology are constrained by the white matter connectome and are particularly represented using a network-based diffusion model. Such constraints are predominantly located in frontoparietal nodes and are linked with the expression of genes associated with microstructural developmental processes. Impact: Our results highlight the importance of white matter network structure in shaping the coordinated maturation of regional cortical morphology, which demonstrates the feasibility of using a network model to reveal the maturational principle of cortical morphology from childhood to adolescence.
Age-related differences in macromolecular resonances observed in ultra-short-TE STEAM MR spectra at 7 T
Authors: Genovese Guglielmo , Terpstra Melissa , Filip Pavel , Mangia Silvia , McCarten J. Riley , Hemmy Laura S. , Marjańska Małgorzata
Published: November 2024

Motivation: Macromolecular signals mainly originate from amino-acids within flexible cytosolic proteins, contributing to 1H-MR spectra. Previous studies have yielded inconsistent results regarding age-related differences in macromolecular resonances. Goal(s): To investigate the macromolecular content across a wide age range in a large cohort of healthy participants. Approach: Spectroscopy data were acquired at 7 T. The macromolecular content was investigated in 134 datasets from a cohort ranging in age from 19 to 89 years. Results: Age-related effects were observed for macromolecular peaks. Some macromolecular resonances had significantly higher content at 30-40 years of age while others at 60-70 years of age. Impact: Our findings strengthen the necessity of using age-matched measured macromolecules during quantification of metabolite concentrations. The ability to detect differences in macromolecular content may be helpful for understanding the neurodegenerative processes associated with aging.
Quantitating Neuroanatomic Volumetry and White Matter Hyperintensity Lesion wrapped in AI Model in Aging Cohorts as a determinant of Brain Age
Authors: Yadav Neha , Gupta Niraj , Tiwari Vivek
Published: November 2024

Motivation: In an aging population, a subset of individuals at any age group present with low white matter hyperintensity (WMH) volume in the brain, while another subset has intermediate to high WMH load. Goal(s): To establish a Brain Age Estimation model involving WMH lesion quantification as a clinical indicator of Brain Health. Approach: We have investigated the ‘Brain Health’ in terms of Brain Age using neuroanatomic volume, thickness together with WMH load across cognitively normal, impaired and Alzheimer’s Disease subjects. Results: An increased Brain Age gap is observed for the subjects with elevated WMH load compared to the brains with low WMH. Impact: Brain health is a composite representation of structural, fiber and vascular health. For the first time, a MR based quantitative platform with WMH load and comprehensive neuroanatomic volumetry is established, which estimates ‘Brain Age’ as an indicator of Brain Health.
Black blood cine vessel wall imaging based dynamic quantitative mapping of carotid artery vessel wall
Authors: Xu Ning , Chen Shuo , Qiao Huiyu , Li Zhongsen , Xu Ziming , Yu Shuwan , Liu Jiachen , Shen Rui , Tong Xinyu , Zhao Xihai
Published: November 2024

Motivation: Dynamic quantitative carotid artery vessel wall imaging can effectively reduce the blurring effect caused by vascular pulsation. Goal(s): This study aims to develop a black blood cine sequence based dynamic quantitative carotid artery vessel wall imaging method. Approach: A VFA and ViMSDE duration-based BB cine quantitative sequence was proposed to acquire dynamic multi-contrast images. Dictionary matching method was introduced to estimate quantitative parameters from complicate signal equation. Results: The proposed protocol was in excellent agreement with standard mapping sequence in both phantom and volunteer experiment. Dynamic T1 and T2 maps has shown its potential in eliminating pulsation resulting blurringImpact: Dynamic T1 and T2 maps can be acquired with less pulsation related blurring. Dynamic and accurate quantitative information is expected to better assist clinical decision-making.
Finding common ground: Subject grounding to reduce electromagnetic interference at 46 mT
Authors: Lena Beatrice , de Vos Bart , Webb Andrew
Published: November 2024

Motivation: Electromagnetic interference (EMI) reduction is essential to utilize low-field point-of-care MRI devices in different environments with different noise conditions. Goal(s): Improving EMI reduction by subject groundingApproach: Noise scans and brain images were acquired with and without subject grounding. This is done with normal imaging conditions and when adding broadband noise or single frequency EMI. Results: The SNR of the images was improved by a factor of ~4 when grounding the subject and adding broadband EMI to the experiment. A factor ~2 improvement in SNR was observed for the single frequency EMI and a factor of 1.5 improvement for the normal imaging conditions. Impact: Subject grounding effectively reduced EMI interference. It may be relevant to investigate whether this setup would be able to reduce EMI from medical equipment, or general environmental EM noise in typically challenging POC settings (ICU, emergency room, in remote locations)
OPM-MEG/ULF-MRI Hybrid System: towards acquisition of both MR image and neural magnetic field
Authors: Ueda Hiroyuki , Oida Takenori , Moriya Takahiro , Saito Akinori , Ito Yosuke , Suyama Motohiro
Published: November 2024

Motivation: To overcome the limitations of signal co-registration in MEG, we constructed MEG/MRI hybrid system. Goal(s): To demonstrate feasibility of this system. High-sensitivity OPMs in a reasonable magnetic shield with MRI system. Approach: Phantom experiments. Phantom includes triangle coil and MEG measures its magnetic field. MRI scanned this phantom with 3D-SE sequence. Results: We recognized signal peak generated by 100 nAm current dipole moment in amplitude spectrum density visually. We also confirmed the structure of the phantom in 3D MR images. Impact: We made MEG/MRI hybrid system for the purpose of accurate signal co-registration between them. MEG employed scalar-mode OPM, and its noise level was 367 fT/rHz. We scanned phantom using 7-mT MRI scanner and confirmed its structure.
Sustained Tumour Response to Repeated STING Activation Assessed by Diffusion Weighted MRI
Authors: Roy Upasana , Box Carol , Pedersen Malin , Boult Jessica , Rullan Antonio , Schmohl Michael , Amend Mario , Carotta Sebastian , Vogt Anne , Harrington Kevin , Robinson Simon
Published: November 2024

Motivation: Cancer immunotherapy with cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) agonists aims to generate an immune response by T cell priming, activation and infiltration into the tumour microenvironment leading to cell death. Goal(s): The clinical development of STING agonists would benefit from imaging biomarkers that inform on intratumoural pharmacodynamics and potentially anti-tumour response. Approach: Longitudinal diffusion-weighted MRI in a thyroid xenograft model indicated sustained increase in ADC as an imaging biomarker of tumour microenvironment changes following treatment with a STING agonist. Results: The potential use of MRI as an indicator of early STING pathway related pharmacodynamic effects in situ is demonstrated. Impact: Increased ADC is a sensitive, clinically-translatable imaging biomarker of tumour response to a STING agonist.
Hyperpolarized 129Xe MRI of the Irradiated Lung using a Chemical Shift Imaging – Chemical Shift Saturation Recovery (CSI-CSSR) Technique
Authors: Loza Luis , Ruppert Kai , Taylor Yohn , Chen Jiawei , Amzajerdian Faraz , Ismail Mostafa , Hamedani Hooman , Profka Harrilla , Duncan Ian , Rizi Rahim
Published: November 2024

Motivation: Chemical shift saturation recovery (CSSR) measurements are incredibly useful for quantifying pulmonary gas exchange and uptake; because CSSR is a spectroscopic technique, however, such measures are only global in nature. Goal(s): Our goal was to develop an imaging-based technique for spatially-resolving CSSR measurements. Approach: We demonstrated our technique’s utility in a rodent model of radiation-induced lung injury. Results: Images of hyperpolarized-129Xe dissolved in the pulmonary membrane (Mem) and red blood cells (RBC) showed higher Mem signal and reduced RBC signal in radiated vs non-radiated lungs. Septal wall thickness (SWT) measurements derived on a quadrant level also revealed elevated SWT in the irradiated region. Impact: We demonstrated a new imaging technique for regionally quantifying radiation-induced alterations in pulmonary gas exchange and uptake. This study lays the groundwork for future investigations aimed at improving radiotherapy strategies, mitigating radiotoxicity, and treating radiation-associated illness.
Acidic Tumor Microenvironment-Activated MRI Nanoprobes for Modulation and Visualization of Anti-PD-L1 Immunotherapy
Authors: Fan Kai , Ju Shenghong
Published: November 2024

Motivation: Molecular imaging holds revolutionary significance in the diagnosis and treatment of tumors. Goal(s): Clinical trials targeting immune checkpoint receptors with immune checkpoint blockade (ICB) therapies has encountered limited efficacy in pancreatic cancer. Approach: MRI-guide ICB therapy (MRGIT) strategy for enhancing and guiding anti-PD-L1 therapy was proposed. Results: The successful inhibition of tumor growth via MRGIT strategy in pancreatic tumor models demonstrates that it may be efficiently reverse the immunosuppressive PDAC and improve the ICB therapy with the employment of MRI technology. Impact: The MRGIT strategy bridging the antitumor immune response with the MRI technique, which devised a potent tool that holds great promise for improving cancer diagnosis and facilitating the development of personalized treatment strategies tailored to individual patients.
Magnetic resonance imaging-based radiomic for predicting infiltration levels of CD68+ tumor-associated macrophages in Glioblastomas
Authors: Zhou Qing , Zhou Junlin
Published: November 2024

Motivation: Predicting Tumor-Associated Macrophages (TAMs) levels using preoperative non-invasive imaging can influence patients with Glioblastoma (Gb) treatment decision-making and evaluate prognosis. Goal(s): This study aimed to combine imaging and radiomics features of preoperative for predicting CD68 + macrophage infiltration. Approach: Retrospective collection 143 patients with Gb. Divided patients into high CD68+TAMs（≥14.8%）and low CD68+TAMs (<14.8%) groups. The radiomics features extraction were based on CE-T1WI and T2WI. Multi-parameter stepwise regression was used to create the models. Results: The combined model, with ADCmin and radiomics features, had the best performance revealing AUCs of 0.865 and 0.825 for the training and testing sets, respectively. Impact: To provide imaging biomarkers for the evaluation of the TAMs infiltration of Gb by using machine learning combined with MR imaging parameters, reveal the relationship between images features and TAMs, and construct an evaluation model to predict macrophage before surgery.
Longitudinal Trends and Effects in Placenta Multiparametric MRI (mpMRI) in Early Gestation
Authors: Ramirez Raymi , Janzen Carla , Kim Jennifer , Lee Brian , Devaskar Sherin , Sung Kyung
Published: November 2024

Motivation: This study is motivated by the clinical need to understand and monitor early gestational placenta development. Goal(s): The goal is to show that multi-parametric placenta imaging during early gestation is a clinical tool to flag possible pregnancies in danger of multiple adverse effects. Approach: This study includes data from a previous perspective study where MRI was taken at two separate timepoints during early gestation. Information on volume, perfusion, and oxygenation were evaluated for longitudinal trends as well as changes driven by obesity and fetal sex outcomes. Results: We show statistically significant differences of longitudinal trends in most of the parameters between study cohorts. Impact: The results in this study could allow for clinicians to gain insight on pregnancy development within the early second trimester currently unavailable with the current imaging with Doppler ultrasound. This will allow for overall life improvement for mother and fetus.
Quantitative Placental R2* Mapping on Rhesus Macaques with Thrombotic and Inflammatory Injury Model
Authors: Liu Ruo-Yu , Keding Logan , Vazquez Jessica , Starekova Jitka , Zhu Ante , Chen Ruiming , Simmons Heather , Basu Puja , Mejia Andres , Stanic Aleksandar , Shah Dinesh , Johnson Kevin , Hernando Diego , Golos Thaddeus , Wieben Oliver
Published: November 2024

Motivation: Pregnancy complications are often associated with placenta dysfunction, which lacks non-invasive assessment in early pregnancy. Goal(s): Evaluating placental R2* as a non-invasive and quantitative biomarker to identify and monitor pregnancy complications. Approach: We introduce a novel thrombotic and inflammatory placental injury model of rhesus macaques and report mean values, histograms, and spatial distribution of placental R2* based on blood oxygenation level dependent (BOLD) MR imaging at different gestational ages before and after iron nanoparticle (ferumoxytol) administration. Results: Higher overtime and post-contrast increase in mean values and more heterogeneous spatial patterns of R2* are observed in placentas with induced injury. Impact: A refined nonhuman primate model for thrombosis and inflammation is introduced for investigating placental pathology. Larger R2* increases over time and immediately after ferumoxytol injections suggest the potential for R2* to be an indicator of pathology with or without contrast.
Simplified Anisotropic IVIM using Spherical Means and an Application in the Placenta
Authors: Slator Paddy , Pleva Luke , Higgins Lucy , Johnstone Edward , Heazell Alexander , Alexander Daniel , Naish Josephine , Duhig Kate
Published: November 2024

Motivation: The intravoxel incoherent motion (IVIM) model can separately assess diffusion in tissue and perfusion in vasculature. However, anisotropic extensions to IVIM that model coherently orientated vasculature are complex and difficult to fit. Goal(s): Enhance the IVIM model to account for macroscopic anisotropy in vascular structures, while minimizing the increase in model complexity. Approach: We model perfusion and diffusion compartments using constrained tensors and estimate the tensor parameters via the spherical mean. Results: Our spherical mean anisotropic IVIM approach quantifies and maps anisotropy in perfusion and diffusion compartments and captures microstructural and microcirculatory alterations in the placenta during pregnancy. Impact: Existing anisotropic IVIM models are complex and clinically impractical. We demonstrate a spherical mean approach that simplifies the disentanglement of perfusion- and diffusion-related anisotropy. This can enable rapid quantification of biomarkers for detecting microcirculatory and microstructural changes in anisotropic tissue.
A combined T2* weighted gradient echo and 1D quantitative flow sequence for investigating placental function
Authors: Hutchinson George , Turnbull Amy , Dewick Louise , Bradley Chris , Peters Andrew , Jones Nia , Walker Kate , Gowland Penny
Published: November 2024

Motivation: Both oxygenation and blood flow are key measures of placental function; if we could dynamically, and simultaneously measure T2* and flow we could investigate placental function over time. Goal(s): To Implement and test a gradient echo, quantitative flow sequence with EPI readout in the placenta. Approach: 4 participants were scanned at 3T using the sequence, and the T2* and velocity maps produced were investigated. Results: The T2* weighted image retained sufficient contrast, and the quantitative flow was repeatable across subjects, measuring similar velocities in the placenta (<0.1cm/s) that has previously been measured with MRI. Impact: This sequence has promise for dynamically investigating placental function, simultaneously providing information about oxygenation and blood flow. This will allow us to evaluate placental function in compromised pregnancies over time, and investigate the role of placental contractions.
A Radiogenomics Model for Classifying Molecular Subtypes of Endometrial Cancer: A Two-Center Retrospective Study
Authors: Yue Wenyi , Han Ruxue , Wang Haijie , Zhang Chen , Song Yang , Liang Xiaoyun , Zhang He , Li Hua , Yang Qi
Published: November 2024

Motivation: To explore genetically based molecular profiling of endometrial cancer (EC) patients to delineate prognostic risk groups. Goal(s): To demonstrate the potential of radiogenomics for classification of EC molecular subtypes, 254 EC patients with histologically and genetically proven EC from two-center were enrolled. Approach: A radiomics model based on four sequences was combined with genomics features to form the final diagnosed model. Results: Our results showed a medium-to-high diagnostic performance to distinguish molecular subtypes with AUC of 0.849 and 0.673 in internal and external test sets, respectively. The radiogenomics model could guide clinicians in administering individual treatments for EC patients. Impact: Our results demonstrate that the predictive model derived from MRI imaging features holds significant promise in identifying molecular subtypes in endometrial cancer. This model has the potential to guide clinicians in tailoring individualized treatments for EC patients.
Rapid High Resolution Integrated Structural and Functional Susceptibility and Conductivity Mapping in the Human Brain
Authors: Kiersnowski Oliver , Fuchs Patrick , Nassar Jannette , Arsenov Oriana , Luo Jierong , Karsa Anita , Wastling Stephen , Shmueli Karin
Published: November 2024

Motivation: Quantitative susceptibility mapping (QSM), electrical conductivity mapping (EPT) and fMRI show promise in characterising neurodegenerative diseases but each currently needs a separate time-consuming acquisition. Goal(s): To develop a single, rapid acquisition for simultaneous structural and functional QSM and EPT, providing multi-modal contrasts to facilitate development of biomarkers for neurological diseases. Approach: We developed a multi-echo 2D EPI sequence with 1.3 mm isotropic resolution and 4.02 s TR enabling acquisition of 70 timepoints in 6 min 15 s. We optimised QSM, EPT and fQSM reconstruction pipelines. Results: We obtained high-quality structural QSM and EPT, alongside fMRI and fQSM activations from a visual stimulus. Impact: Demonstrating that this efficient multi-echo EPI acquisition rapidly produces high-quality simultaneous QSM, fQSM and EPT reconstructions alongside conventional T2*-weighted, SWI and fMRI contrasts in 6 min 15 s will allow it to be incorporated into clinical studies of neurodegenerative diseases.
Potential of phase-based electrical conductivity in evaluating lumbar intervertebral disc degeneration
Authors: Tha Khin , Kitagawa Maho , Sakamoto Daiki , Hamaguchi Hiroyuki , Katscher Ulrich
Published: November 2024

Motivation: Visual assessment of T2-weighted image constitutes the mainstay in evaluating the severity of intervertebral disc degeneration (IVD) degeneration. Quantitative MRI indices that strongly correlate with the degree of degeneration are lacking. Goal(s): This study aimed to evaluate if electrical conductivity (σ) derived from phase-based EPT was sensitive to the degenerative changes of lumbar IVD. Approach: EPT was conducted, along with DWI, T1ρ, and T2* imaging, in 54 patients with lumbar IVD degeneration. The diagnostic performance of σ was compared with that of ADC, T1rho, and T2*. Results: σ can compliment the other quantitative MRI indices in evaluating lumbar IVD degeneration. Impact: This is the first study which evaluated the potential clinical usefulness of σ derived from phase-based EPT in evaluating the severity of degeneration of lumbar IVD.
Baseline virtual MR elastography and extracellular volume fraction in the prediction of response to neoadjuvant chemotherapy in gastric cancer
Authors: Zhu Yongjian , Cai Wei , Jiang Yueluan , Jiang Liming
Published: November 2024

Motivation: Although neoadjuvant chemotherapy (NAC) was recommended for gastric cancer (GC), only about 40% patients could achieve pathological response. Accurate prediction of the NAC response is crucial for patients’ benefits. Goal(s): To evaluate the predictive performance of virtual MR elastography (vMRE) and extracellular volume (ECV) for predicting the response to of NAC in GC patients. Approach: Patients underwent DWI-based elastography, pre- and post-contrast T1 mapping before treatment. DWI-based virtual shear modulus (μDiff) and ECV were calculated from DWI and T1 mapping. Results: Both μDiff (AUC: 0.833) and ECV (AUC: 0.794) were independent predictors for NAC response, their combination could improve the AUC to 0.968. Impact: Our result revealed that DWI-based virtual shear modulus (μDiff) and ECV exhibited a promising predictive ability for predicting response to NAC. This would aid in identifying responders before treatment, reducing unnecessary toxicity and side effects, and guiding individualized treatment.
Apparent diffusion coefficient as a non-contrast marker of residual disease after breast neoadjuvant treatment
Authors: Bolan Patrick , Li Wen , Joe Bonnie , Le Nu , Price Elissa , Gibbs Jessica , Wilmes Lisa , Biswas Debsmita , Kazerouni Anum , Church An , McDonald Elizabeth , Loubrie Stephane , Rakow-Penner Rebecca , Yu Hon , Malyarenko Dariya , Chenervert Thomas , Reig Beatriu , Hylton Nola , Partridge Savannah
Published: November 2024

Motivation: Accurate imaging markers to establish pathologic complete response (pCR) during neoadjuvant chemotherapy (NACT) could enable therapy de-escalation to avoid excessive systemic treatmentsGoal(s): To determine if quantitative diffusion-weighted MRI (DWI) can accurately detect pCR following NACT. Approach: In the ACRIN 6698/I-SPY 2 multicenter trial dataset, tumor region apparent diffusion coefficient (ADC) from DWI was measured on post-NACT/presurgical MRIs. The accuracy of ADC for predicting pCR, alone and in combination with functional tumor volume (FTV) from contrast-enhanced MRI, was assessed. Results: In multivariate models ADC accurately predicts pCR, and is influenced by field strength, spatial resolution, and lesion morphology. Impact: Apparent diffusion coefficient measured by DWI shows promise for determining absence of residual disease following chemotherapy and may provide a non-contrast option for tailoring therapies and enabling patients to avoid unnecessary prolongation of treatment.
Effects of multi-vendor gradient non-linearity correction on breast tumor ADC measurements in the ACRIN 6698 trial
Authors: Wilmes Lisa , Li Wen , Zimmermann Judith , Newitt David , Malyarenko Dariya , Liang Jiachao , Bolan Patrick , Partridge Savannah ,   I-SPY 2 Investigator Network, Chenevert Thomas , Hylton Nola
Published: November 2024

Motivation: MRI scanner gradient non-linearity (GNL) is a known source of variability and spatially-dependent bias in quantitative ADC measurements derived from diffusion-weighted imaging (DWI). Goal(s): Evaluate the effects of GNL correction on DWI from the ACRIN 6698 multi-center trial, which investigated ADC as a marker breast cancer response in patients receiving neoadjuvant therapy. Approach: Retrospective GNL correction was performed on the ACRIN 6698 DWI dataResults: Percent decrease in mean tumor ADC post-GNC ranged from 0.5%-11% for different MRI gradient sets, illustrating that GNL can confer significant bias to ADC measurements and should be corrected in multi-center clinical DWI trials.Impact: Implementation of gradient non-linearity correction to reduce bias and variability of tumor ADC measurements from DWI data acquired in multi-center, multi-platform oncology trials may improve the quantitative utility of ADC for characterizing response to treatment.
The diagnostic performance of time-dependent diffusion MRI in differentiating benign and malignant breast tumors
Authors: Lu Jie , Li Xue , Li Haotian , Liu Kuiyuan , Li Chunmei , Chen Min , Wu Dan
Published: November 2024

Motivation: Diffusion-time-dependent diffusion MRI (td-dMRI) has potential in noninvasive mapping of breast tumor microstructure. However, its diagnostic value in differentiating benign and malignant tumors remains unclear, especially including transcytolemmal water exchange. Goal(s): To investigate the clinical value of td-dMRI-based microstructural mapping for discriminating benign and malignant breast tumors. Approach: Time-dependent dMRI data acquired with OGSE and PGSE sequences were estimated with the JOINT models. Results: The td-dMRI-based fin, cellularity and τin showed significant group differences between benign and malignant breast tumors. The combination of cellularity and τin indices achieved the highest diagnostic performance, with an accuracy of 94% and AUC of 0.958. Impact: The diagnostic performance of cellularity-τin obtained from td-dMRI was comparable with or superior to previous studies. The 7.5-minute protocol is translatable to clinical diagnostics.
Pre-treatment multiparametric MRI for prediction of chemo‑immunotherapy response in advanced non-small cell lung cancer
Authors: Zheng Yu , Zhang Jing
Published: November 2024

Motivation: Early detection in poor responders to chemo‑immunotherapy for non-small cell lung cancer (NSCLC) facilitates timely adjustment of treatment strategies. Goal(s): To explore the value of histogram analysis based on intravoxel incoherent motion (IVIM) and difusion kurtosis imaging (DKI) in predicting chemo‑immunotherapy response in advanced NSCLC. Approach: 72 NSCLC patients underwent pre-treatment MRI examination. Histogram parameters of IVIM and DKI were calculated and compared. Results: Compared with non-responders, ADC, D, Dapp were significantly lower and f was higher in responders (all p <0.05). The multivariate logistic regression model performed the best with an AUC of 0.954. Impact: IVIM and DKI imaging would predict chemo-immunotherapy response in advanced NSCLC at initial state, which could help make clinical individualized treatment strategies.
In vivo detection and imaging of aminopeptidase activities related to renin-angiotensin system using newly designed hyperpolarized MR probes
Authors: Yatabe Hiroyuki , Saito Yutaro , Takakusagi Yoichi , Saito Keita , Yamamoto Kazutoshi , Krishna Murali , Sando Shinsuke
Published: November 2024

Motivation: Detection of aminopeptidase (AP) activities related to renin-angiotensin system (RAS) can lead to diagnosis of various diseases. Magnetic resonance imaging utilizing suitable hyperpolarized molecular probes can non-invasively detect in vivo AP activities. However, there have been no hyperpolarized molecular probes for APA, APB, and leucine AP. Goal(s): We aimed to design and develop new hyperpolarized molecular probes for the detection and imaging of RAS related AP activities in vivo. Approach: Based on the previously reported APN probe scaffold, three new hyperpolarized probes were designed. Results: Using the developed probes, target AP activities were successfully detected and visualized in vivo. Impact: This study exhibits a framework that artificially designed hyperpolarized molecular probes can detect in vivo aminopeptidase activities, which is assumed impossible with isotope labeled natural substrates and broadens the possibility of hyperpolarized MR diagnosis based on AP activities.