bluuebunny/crossref_metadata_2025 huggingface dataset:
Using sodium (23Na) MRI to measure sodium concentration in the interventricular septum of patients on hemodialysis
Authors: Tan Josephine , Deleaval Patrik , Nagel Armin , Thiessen Jonathan , Scholl Timothy , McIntyre Christopher , Akbari Alireza
Published: November 2024

Motivation: Cardiovascular risk is elevated in chronic kidney disease (CKD) patients on hemodialysis (HD) and may be associated with tissue sodium accumulation in the heart. Goal(s): To compare tissue sodium concentration (TSC) in the interventricular septum of HD patients and healthy controls using sodium (23Na) MRI. Approach: 23Na MRI was performed on 3 HD patients and 6 controls to quantify TSC in the interventricular septum. Results: TSC in the septum was higher in HD patients compared to controls but was not statistically significant. These results may be limited by sample size and age and sex effects, which will be explored in a larger cohort. Impact: For the first time, 23Na MRI was used to directly measure TSC in the heart of CKD patients on HD. These findings may provide insight on the cardiovascular risk associated with sodium accumulation in this group.
Radiomics feature based discrimination between aortic flow profiles in HFpEF and healthy controls using 2D Flow MRI
Authors: Krueger Nina , Huellebrand Markus , Beyer Rebecca , Ivantsits Matthias , Laube Ann , Doeblin Patrick , Hashemi Djawid , Edelmann Frank , Kelle Sebastian , Hennemuth Anja
Published: November 2024

Motivation: HFpEF (heart failure with preserved ejection fraction) patients show similar diagnostic parameter values to healthy subjects in the quantitative evaluation of cardiac magnetic resonance imaging (CMR). Improving the performance of CMR-based HF characterization is desirable. Goal(s): Evaluation of radiomics features from 2D flow MRI of the aorta for the classification into healthy, HFpEF, HFmrEF (mildly reduced) and HFrEF (reduced). Approach: Training and evaluation of a decision tree classifier using 70 CMR datasets with conventional diagnostic parameters and 2D flow radiomics features to find relevant flow descriptors. Results: The classifier achieved excellent results, considering the local flow homogeneity during diastole. Impact: We evaluate adding 2D flow MRI radiomics to standard EF measurements for the classification of heart failure subtypes. This would enable the diagnosis of the subtypes with one imaging modality without the need for stress testing.
Long-Term Outcomes Prediction in Diabetic Heart Failure with Preserved Ejection Fraction: A Cardiac Magnetic Resonance Imaging Study
Authors: Yang Wenjing , Zhu Leyi , Lu Minjie
Published: November 2024

Motivation: While diabetes mellitus has a high prevalence in HFpEF and being associated with poorer outcomes, limited data are available on the cardiac MRI features of diabetic HFpEFGoal(s): We aimed to explore imaging features including tissue characterization and myocardial deformation in diabetic HFpEF patients by MRI, and investigate its prognostic value for adverse outcomesApproach: Feature-tracking derived strain and strain rates parameters and myocardial fibrosis were assessed by cardiac MRI in patients with diabetic HFpEFResults: Diabetic HFpEF patients were characterized by more impaired strains and myocardial fibrosis. Tissue characterization and global longitudinal strain obtained from MRI-FT provided incremental value for risk predictionImpact: Our findings suggested that MRI-derived variables especially GLS played a crucial role in risk stratification and predicting worse prognosis in diabetic HFpEF, which could assist in identifying high-risk patients and guide therapeutic decision making.
Cardiac magnetic resonance in subclinical primary cardiac involvement in systemic sclerosis
Authors: Zhao Yanan , Li Tao , Yue Xiuzheng
Published: November 2024

Motivation: Cardiac involvement is a significant cause of mortality in SSc. There are, however, no effective methods for detecting cardiac involvement in a general, asymptomatic SSc cohort. Goal(s): We aimed to characterize and identify subclinical SSc-pHI by CMR. Approach: 48 Patients underwent CMR, including cine imaging, LGE, T2 mapping, and native and post-contrast T1 mapping for ECV quantification. Results: 56.25% of SSc-pHI patients had LGE, and 79.16% and 54.17% had native T1 and ECV above normal values. In addition, patients with dcSSc had worse contractility than patients with lcSSc, and contractile function is closely related to presence of RP, dcSSc, and ANA positive. Impact: Cardiac magnetic resonance imaging provides a reliable method for detecting sub-clinical cardiac involvement in SSC patients. Patients with dcSSc had worse contractility than patients with lcSSc, and contractile function is closely related to presence of RP, dcSSc, and ANA positive.
Association of pulmonary transit time by CMR with diastolic dysfunction and left ventricle deformation in restrictive cardiomyopathy
Authors: Gao Yue , Li Yuan , Yang Zhi-Gang
Published: November 2024

Motivation: Cardiopulmonary circulation usually present hemodynamic congestion in RCM patients. Pulmonary transit time (PTT) and pulmonary blood volume index (PBVi) are physiological parameters reflective of cardiopulmonary hemodynamics statue. Goal(s): Evaluate the PTT and PBVi in RCM patients, and evaluated the association with LV function and deformation. Approach: The images of first-pass perfusion were acquired to assess PTT which was normalized to heart rate. PBVi was measured by the product of PTT and RVSV and indexed to BSA. Results: PTT showed independent association with LVEF and LVMVR, as well as with LV GCPS and GLPS; PBVi was an independent association of LVMI and LV GRPS. Impact: PTTc and PBVi as the non-invasive marker of cardiopulmonary hemodynamics in patients with RCM, and reflects progression of diastolic dysfunction, and impaired LV global deformation. PTT and PBVI may provide additional information for prognostic management and clinical decision making.
Impact of Epicardial Adipose Tissue Assessed by CMR on Atrial Fibrillation in Heart Failure with Preserved Ejection Fraction
Authors: Li Yunling , Liu Shengliang , Li Ye , Wang Guokun , Gu Xia , Zhao Yanming , Lian Jianxiu , Lian Jianxiu , Sun Yong
Published: November 2024

Motivation: Heart failure with preserved ejection fraction (HFpEF) frequently presents with atrial fibrillation (AF). But the mechanism of AF in HFpEF are incompletely understood. Epicardial adipose tissue (EAT) is linked with left atrial volume and function changes.Goal(s): This study aims to evaluate the relationships between EAT volumes and AF in patients with HFpEF. Approach: All subjects were imaged with a 3.0T Philips scanner. CMR parameters were quantified with a stack of short axis views perpendicular to the long axis of the left ventricle. Results: EAT was an independent predictor for the presence of AF in patients with HFpEF and demonstrated high prediction power. Impact: EAT plays an important role in the progression of HFpEF and may be a promising therapeutic target.
Cardiac Magnetic Resonance Assessment of Left Atrium Function and Strain in Hemodialysis Patients: A Preliminary Study
Authors: Pu Qian , Zhang Miaoqi , Zhang Bo , Sun Jiayu
Published: November 2024

Motivation: Hemodialysis is a common risk factor for cardiovascular disease. Left atrial function and strain are effective predictors of cardiovascular morbidity and mortality. Goal(s): The aim was to assess the alterations in left atrial function and strain following hemodialysis, with the objective of enabling early diagnosis of cardiac changes and risk stratification in patients with chronic kidney disease (CKD). Approach: Patients with advanced CKD were enrolled, including those who had not started hemodialysis and those who had started regular hemodialysis. Left atrial function and strain parameters were compared between the two groups. Results: Left atrial function and strain deteriorated with increasing hemodialysis age. Impact: Early detection of left atrial function and strain changes and timely intervention are of great significance for the prevention of adverse cardiovascular events in patients with CKD.
Biventricular Remodeling Predicts Adverse Outcomes in Long-Term Follow-up of Chronic Thromboembolic Pulmonary Hypertension: A CMR Study
Authors: Zhang Bowen , Liu Xin , Guo Xiaojuan , Yang Qi
Published: November 2024

Motivation: While cardiovascular magnetic resonance (CMR) is a well-established tool for assessing heart remodeling and predicting outcomes, its application in Chronic thromboembolic pulmonary hypertension (CTEPH) has received limited attention. Goal(s): This study investigated whether biventricular remodeling derived form CMR could predict adverse clinical outcomes during the long-term follow-up of CTEPH patients. Approach: Establish a CMR-only model and compare its predictive value with the model that combines clinical data and invasive RHC. Results: CMR-derived biventricular remodeling have prognostic value in long-term follow-up CTEPH. Risk assessment based on CMR alone is at least as effective as that of clinic combined RHC. Impact: These findings contribute to the optimization of early patient care and timely intervention. it's advisable to add CMR parameters in the management score. And performing noninvasive CMR alone is sufficient, as it also demonstrates excellent predictive efficacy.
Myocardial Microstructural Characterization in Patients with Hypertrophic Cardiomyopathy by In Vivo Cardiac Diffusion Tensor Imaging
Authors: Dong Zhixiang , Yin Gang , Sun Peng , Wu Zhigang , Zhao Shihua
Published: November 2024

Motivation: The non-invasive imaging evaluation of myocyte disarray in hypertrophic cardiomyopathy (HCM) is still challenging. Goal(s): We aimed to explore the myocardial microstructural characteristics of HCM by in-vivo cardiac diffusion tensor imaging (cDTI). Approach: We prospectively enrolled thirty-five HCM patients and fifteen healthy controls for cDTI at 3.0T scanner. Results: Myocardial disarray and abnormal microstructural dynamics of HCM can be characterized by in vivo cDTI. Moreover, cDTI allows early identification of myocardial microstructural changes, even before cardiovascular magnetic resonance (CMR) signs of fibrosis and hypertrophy. Impact: Our findings shed light on the potential of cDTI for the early detection of myocyte disarray, further improving the value of CMR in the non-invasive myocardial tissue characterization of HCM.
3D Cardiac T1p Mapping using XD-GRASP Reconstruction: Initial Evaluation in Patients with Ischemic and Non-ischemic Cardiomyopathy
Authors: Gunasekaran Suvai , Benefield Brandon , Hong KyungPyo , Robinson Joshua , Webster Gregory , Passman Rod , Lee Daniel , Katsaggelos Aggelos , Rigsby Cynthia , Witschey Walter , Kim Daniel
Published: November 2024

Motivation: T1ρ mapping is an emerging non-contrast pulse sequence for measuring cardiac fibrosis, but current techniques suffer from lack of coverage, poor spatial resolution, and long scan time. Goal(s): We aimed to develop an accelerated, free-breathing 3D cardiac T1ρ mapping pulse sequence using XD-GRASP reconstruction extended to include both respiratory and spin-locking time dimensions. Approach: Our 3D T1ρ sequence was tested in 12 patients undergoing clinically indicated cardiac MRI to compare T1ρ with extracellular volume fraction (ECV) and late gadolinium enhancement (LGE). Results: Myocardial T1ρ correlates with ECV of non-ischemic myocardium but not with a mixture of acute and chronic ischemic myocardium. Impact: 3D T1ρ mapping achieves robust image quality and T1ρ values that agree with literature. 3D T1ρ could be used for measuring fibrosis in patients where contrast should be avoided, after further research into the nature of T1ρ in focal scar.
Monitoring Myocardial Alterations in the LGE Grey Zone of Infarction Patients Using T1rho Mapping
Authors: Yang Yanbing , Yue Xiuzheng
Published: November 2024

Motivation: This study employs T1rho imaging to examine myocardial changes in the LGE grey zone of patients with myocardial infarction, presenting a possible non-invasive approach for patients who cannot undergo contrast-enhanced procedures. Goal(s): provide a possible non-invasive approach for patients who are unable to undergo contrast-enhanced surgery. Approach: This study employs T1rho imaging to examine myocardial changes in the LGE gray area in patients with myocardial infarction. Results: T1rho localization provides a viable diagnostic tool for the detection of diffuse myocardial fibrosis in patients with infarction. Impact: This study explores the potential of T1rho in evaluating the tissue characteristics of gray myocardium adjacent to infarcted myocardium to provide a new clinical, non-invasive, accurate, and contrast-free method for monitoring diffuse fibrosis in the myocardium.
First Application of a 3D Radial Trajectory for Free-Breathing ECG-Triggered Cardiac T1ρ Mapping at 1.5 T
Authors: Zhang Jana Huiyue , Bustin Aurélien , Ogier Augustin C. , van Heeswijk Ruud , Roy Christopher W. , Quesada Isabel Montón , Stuber Matthias , Yerly Jérôme
Published: November 2024

Motivation: Most cardiac T1ρ mapping techniques collect data in 2D, while the few existing 3D methods use a Cartesian sampling trajectory. Goal(s): In this study, we report the first use of a 3D radial trajectory for whole-heart T1ρ mapping at 1.5 T. Approach: The proposed technique was validated in a phantom, tested in one volunteer, and compared to a 2D reference method. Results: Our results show that the T1ρ values obtained from our 3D technique are comparable to the 2D reference values for both phantom and volunteer. However, we observed an underestimation of the T1ρ values using the 3D method in the phantom. Impact: 3D radial free-breathing electrocardiogram-triggered cardiac T1ρ mapping at 1.5 T has the potential to serve as a contrast agent-free adjunct to late gadolinium enhancement imaging for the whole-heart motion-robust quantification of tissue properties such as myocardial fibrosis.
Long term cardiac MRI surveillance in patients transplanted for ischemic cardiomyopathy: myocardial ECV and strain variation.
Authors: Zbihley Andrew , Sarnari Roberto , Quinn Sandra , Engel Joshua , Raikar Connor , Pedamallu Havisha , Markl Michael , Carr James
Published: November 2024

Motivation: Ischemic dilated cardiomyopathy (DCM) is associated with low-grade chronic inflammation which may persist after heart transplantation (HTx) and impact graft function and tissue characteristics in the post-HTx period. Goal(s): Our goal was verify whether any difference in graft tissue characteristics or function was evident during long-term follow up by cardiac MRI between patients transplanted for ischemic DCM and those transplanted for non-ischemic indications. Approach: Longitudinal analysis of graft tissue mapping and 2D FTS was performed on patients transplanted for ischemic DCM (n=13) and non-ischemic indications (n=50). Results: In the non-ischemic DCM cohort, tissue mapping and FTS parameters, ECV and GCS, worsened over time. Impact: No effect of pre-HTx low grade inflammation was evident on graft tissue characteristics and function in patients transplanted for ischemic DCM. Cardiac MRI may play an important role in long term monitoring of patients undergoing HTx.
Accelerated and Accurate Myocardial Multi-Parametric Quantitative Mapping using Bloch Equation Simulation-based Fitting
Authors: Tao Yiming , Liu Wenjian , Lv Zhenfeng , Qi Haikun , Hu Peng
Published: November 2024

Motivation: Motivated by the time-consuming process of dictionary matching in quantitative cardiac MRI, this study aims to develop a faster and more accurate method for myocardial multi-parametric quantitative mapping. Goal(s): The goal is to overcome the limitations of discretization errors and incomplete inversion pulses, which lead to inaccurate parameter estimation. Approach: The proposed approach utilizes Bloch equation simulation-based fitting, enabling rapid reconstruction of T1, T2, and T1ρ maps simultaneously. Results: Experimental results demonstrate excellent quality of fit and significant acceleration (100x) compared to the traditional method. Impact: This novel method has the potential to revolutionize myocardial quantitative mapping, offering improved efficiency and precision in clinical applications.
Regional Evaluation of Left Ventricular Cardiac Diffusion Tensor Imaging Metrics in Healthy Volunteers
Authors: Cork Tyler , Hannum Ariel , Perotti Luigi , Ennis Daniel
Published: November 2024

Motivation: cDTI is a useful method for evaluating cardiac microstructure with proven clinical utility. To better enable the use of cDTI in the diagnosis of various cardiomyopathies, establishing quantitative baseline values in healthy subjects is needed. Goal(s): Goal: To quantify healthy baseline cDTI metrics on a regional basis to understand normal regional differences in cDTI metrics. Approach: Healthy volunteers received a cDTI exam covering the entire LV. Regional and global analyses of cDTI metrics were completed using the AHA 16-segment model. Results: Statistically significant regional differences were found across all parametric maps, with the majority of them in basal segments. Impact: Characterizing regional differences in cDTI measures provides data to define healthy baseline values for several cDTI metrics. Defining this baseline regionally provides a normative database for understanding patient-specific changes in these quantitative diffusion metrics.
Correlations between 5-ALA fluorescence and 7T MRSI in gliomas: Preliminary observations
Authors: Huskić Sara , Lazen Philipp , Cadrien Cornelius , Acharya Sagar , Roetzer-Pejrimovsky Thomas , Kiesel Barbara , Furtner Julia , Wadiura Lisa , Preusser Matthias , Bogner Wolfgang , Roessler Karl , Trattnig Siegfried , Widhalm Georg , Hangel Gilbert
Published: November 2024

Motivation: Heterogeneity in gliomas represents a clinical and diagnostic issue. 5-ALA fluorescence used for intraoperative tumor delineation is different depending on the tumor type. Understanding the dysregulations in the heme pathway using 7T MRSI could help understanding metabolic heterogeneity in tumors. Goal(s): Identifying 7T MRSI metabolites useful for investigating mechanisms of 5-ALA fluorescence and preoperative tumor characterization. Approach: We retrospectively correlated 5-ALA fluorescence from clinical reports to metabolic ratios from 7T MRSI scans in a cohort of 23 patients. Results: 5-ALA correlated with the Gln/tCr ratio (r2=0.597), which also correlated with the tumor grade. Impact: Using 7T MRSI and 5-ALA, we improve guidance for neurosurgeons to resect aggressive tumor hotpots. Furthermore, 7T MRSI could be useful for in vivo studies of metabolic disturbances involved in 5-ALA activation.
Investigating redox imbalance in first-episode schizophrenia using 7T functional MRS
Authors: Jeon Peter , Mackinley Michael , Dempster Kara , Ford Sabrina , Palaniyappan Lena , Theberge Jean
Published: November 2024

Motivation: Redox imbalance in schizophrenia may help to explain the full range of observable schizophrenia symptoms. Goal(s): Our goal was to use a more appropriate tool to measure dynamic changes in neurometabolites in schizophrenia compared to traditional MRS techniques. Approach: We used functional MRS with a cognitive Stroop task to investigate glutathione dynamics as well as associated glutamate and glutamine dynamics. Results: Glutathione levels increased during task and stayed elevated for healthy subjects, but not for patients. Impact: By demonstrating abnormal anterior cingulate cortex glutathione response to short-term cognitive battery in first-episode schizophrenia, we offer novel support and added framework behind potential redox imbalances in schizophrenia and their utility in managing symptom treatment.
Metabolic imaging at 14.1T in the rat brain: preliminary results for PRESS-MRSI vs FID-MRSI
Authors: Alves Brayan , Briand Guillaume , Mosso Jessie , Simicic Dunja , Lanz Bernard , Cudalbu Cristina
Published: November 2024

Motivation: Valuable in the preclinical realm, Magnetic Resonance Spectroscopic Imaging encounters issues with long acquisition time and low signal-to-noise ratio. Numerous excitation schemes allow for metabolic mapping. Goal(s): The current study aims at comparing, with relevant quality metrics, preclinical application of two 1H-MRSI localization schemes at 14.1T: FID-MRSI and PRESS-MRSI. Approach: Both FID and PRESS-MRSI datasets were acquired on the rodent brain in identical conditions (n=3) and processed using the same workflow for objective analysis. Results: An increased coverage and SNR per unit of time were observed for FID-MRSI. Both methods reached similar quantitative results for two different brain regions. Impact: Objective assessment of preclinical 1H-FID and 1H-PRESS-MRSI allows for exploration of their respective limitations and optimization of both localization schemes for different case studies found in preclinical research.
Evidence of impaired dACC glutamate modulation under task-specific motor control in obsessive compulsive disorder (OCD) using 1H fMRS
Authors: Stanley Jeffrey , Eichstaedt Jillian , Khatib Dalal , Easter Phil , Neill Rebecca , Rajan Usha , Bellamy Julia , Rosenberg David , Diwadkar Vaibhav
Published: November 2024

Motivation: The neurobiological mechanisms of poor top-down motor control in OCD are not well understood. Goal(s): Our goal was to investigate neurobiological differences in glutamate modulation across different motor/inhibitory control responses in OCD compared to healthy controls. Approach: 1H fMRS was conducted in adolescents with OCD and healthy controls. Results: Task-specific impairments to the dACC glutamate modulation were observed in OCD compared to healthy controls. Impact: These results providing compelling evidence towards characterizing neurosignaling changes in OCD pathophysiology.
Detection of Elevated Succinate in Brain During Circulatory Arrest: A 3T 1H MR Spectroscopy Study
Authors: Spielman Daniel , Gu Meng , Hurd Ralph
Published: November 2024

Motivation: To measure succinate in brain during circulatory arrest in a piglet model of cardiac bypass. Goal(s): Dynamic measurement of succinate using 3T MR spectroscopyApproach: Spectral fits of the archived data were used to create dynamic plots of succinate, to provide statistics, and to generate simulated spectra for validation. Results: Elevation of succinate during circulatory arrest was observed and validated. Fitting bias was evaluated over the linewidths and signal-to-noise S/Ns of the archived data. Succinate increase did not appear to be dependent on bypass temperature. Succinate elevation was not observed with antegrade cerebral perfusion. Impact: Elevated succinate during ischemia has been identified as a source of ischemic-reperfusion injury. The ability to measure increased succinate during ischemia plus the ability to intercede with succinate inhibitors may have important consequence prior to re-perfusion in bypass and stroke.
Metabolic biomarkers of IDH status in gliomas by in vivo Magnetic Resonance Spectroscopy
Authors: Cadin Capucine , Chetouane Thamila , Melkus Gerd , Lejeune François-Xavier , Deelchand Dinesh , Lehericy Stéphane , Marjanska Malgorzata , Nguyen Thanh , Branzoli Francesca
Published: November 2024

Motivation: Reliable noninvasive quantification of D-2-hydroxyglutarate (2HG) for diagnosis of isocitrate dehydrogenase (IDH)-mutant gliomas is challenging. Goal(s): To discriminate between IDH-mutant and wild-type gliomas based on their full metabolic profile. Approach: Partial Least Squares Discriminant Analysis (PLS-DA) was used to discriminate IDH-mutants from wild-types using in vivo 3T MRS data from 47 patients with a newly diagnosed glioma. Results: Higher 2HG and lower glutamate + glutamine, glutamate, glycine, and glutathione were observed in IDH-mutants compared to wild-types. The PLS-DA model showed higher accuracy (AUC = 0.949) compared to 2HG alone (AUC = 0.753), underscoring the superiority of a comprehensive approach over single metabolite analysis.Impact: Exploring in vivo metabolic alterations beyond D-2-hydroxyglutarate is crucial for enhancing diagnostic accuracy in detection of IDH mutations in patients with gliomas, as well as for a deeper understanding of the fundamental biological consequences of this mutation.
Quality Assessment Tool using Deep Learning for GABA-Edited MRS data
Authors: Bugler Hanna , Souza Roberto , Harris Ashley
Published: November 2024

Motivation: GABA-edited MRS suffers from data quality challenges due to its low signal to noise ratio (SNR). Goal(s): We propose an automated labeling algorithm for transient quality and a dual-domain deep learning model for filtering spectra transients based on quality. Approach: We trained our model with simulated data containing commonly occurring artifacts labelled with our continuous automated labelling algorithm which ranges from –1 (poor quality) to +1 (good quality). We subsequently evaluated our model’s performance by removing (filtering) poor quality transients corresponding to quality values less than 0. Results: Our model outperformed qualitatively simple averaging using all collected transients for 70-80% of scans. Impact: Our model can successfully assign a continuous quality score between –1 (poor) and +1 (good) to GABA-edited MRS difference data (i.e., a single ON-OFF edit pair) which when used for filtering, improves MRS quality metrics compared to simple transient averaging.
Simultaneous frequency and phase corrections of single-shot MRS data using cross-correlation
Authors: Deelchand Dinesh
Published: November 2024

Motivation: Preprocessing of MRS data is important in order to improve the spectral quality. Goal(s): Here we propose a novel approach to simultaneously correct for frequency and phase drifts using cross-correlation technique. Approach: Random frequency and phase offsets were added to a previously acquired STEAM human data at 7T at two different noise levels. Results: Results show that the proposed technique can accurately correct for both small and large frequency (<50 Hz) and phase drifts (±40 deg) even at low SNR levels. The technique was successfully demonstrated in a noisy MRS dataset acquired from a small volume-of-interest in the mouse brain. Impact: A fast and robust technique which accurately correct for both small and large frequency and phase shifts in MRS data.
Medium Term Reproducibility of 1H FID-CRT-MRSI at 7 Tesla
Authors: Lazen Philipp , Azgın Ahmet , Spurny-Dworak Benjamin , Hingerl Lukas , Strasser Bernhard , Bogner Wolfgang , Lanzenberger Rupert , Rössler Karl , Trattnig Siegfried , Hangel Gilbert
Published: November 2024

Motivation: 1H FID-CRT-MRSI at 7T is a promising approach for non-invasive quantification of metabolic processes in the brain. Its medium-term reproducibility has never been investigated even though it is a requirement for many potential study setups. Goal(s): To evaluate the intersession reproducibility of 1H FID-CRT-MRSI at 7T. Approach: We calculated metabolite concentration estimates in 55 brain regions for two measurement sessions one week apart, and determined coefficients of variations between them. Results: We found good overall reproducibility, with CVs ranging from 7.5% to 12% for different brain regions, and concentration estimates matching our previous work. Impact: We established good reproducibility of FID-CRT-MRSI at 7T, enabling longitudinal study setups e.g. for disease monitoring. Another potential follow-up of this work may be tracking the intra-day metabolite level variations in the brain in a non-invasive way.
Chemical shift displacement and within-voxel saturation of water signals on MRS data: prospective & retrospective corrections
Authors: Rotaru Diana , Lythgoe David
Published: November 2024

Motivation: Chemical shift displacement error (CSDE) and within-voxel saturation (WVS) lead to significant spatial displacement of the MRS voxel from the prescribed region and to overestimation of metabolite concentrations. Goal(s): To compare prospective and retrospective corrections for severe CSDE+WVS observed in standard 3T GE PRESS data. Approach: Prospective corrections utilize (a) removal of OVS saturation bands and (b) over-prescription of the shifted water voxel at data acquisition. Retrospective correction relies on Gasparovic’s equation and re-scaling of metabolite concentrations by the water vs. metabolite volume ratio. Results: Corrected concentrations agree with literature. Both corrections are applicable in multi-centre studies and laboratories with limited technical support. Impact: Chemical shift displacement error (CSDE) and within-voxel saturation (WVS) observed in standard 3T GE PRESS data can be corrected prospectively and retrospectively relative to data acquisition. These solutions are relevant to multi-centre studies and laboratories with limited pulse-sequence technical support.
Image navigators insensitive to B0 inhomogeneity for optimal prospective motion-corrected MRS
Authors: Deelchand Dinesh , Adanyeguh Isaac , Henry Pierre-Gilles
Published: November 2024

Motivation: Navigator-based prospective motion-corrected MRS is often performed with 2nd order shims optimized in the whole brain to prevent degradation of navigator images, resulting in suboptimal linewidth. Goal(s): Here, we report image-based prospective motion correction with 2nd order shims adjusted in the MRS voxel while maintaining good navigator image quality despite the strong B0 inhomogeneity outside the voxel. Approach: This was achieved by segmenting multislice spiral navigator images to reduce blurring artifacts from inhomogeneous B0 fields. Results: High-quality spectra with optimal linewidth were acquired in the presence of subject motion at 3T and 7T, demonstrating the feasibility of this new approach on clinical scanners. Impact: Image-based prospective motion correction with optimal localized B0 shim (1st and 2nd order) in the MRS voxel is feasible in the human brain at 3T and 7T.
Magnetic Resonance Spectroscopy Data Generation Using Physics-informed Autoencoders
Authors: van de Sande Dennis , Amirrajab Sina , Veta Mitko , Breeuwer Marcel
Published: November 2024

Motivation: MRS data can be accurately simulated in terms of metabolite signals, but contributions from macromolecules, lipids, and scan-related imperfections are more challenging to simulate, leading to realism gaps between in-vivo and simulated spectra. Goal(s): The goal is to bridge the realism gap between in-vivo and simulated MRS spectra for developing downstream deep learning applications. Approach: We propose a physics-informed autoencoder which uses signal-based modules in the encoder and a deep learning-based decoder to generate spectra with in-vivo characteristics. Results: Our physics-informed method effectively narrows the realism gap between in-vivo and simulated spectra with reduced reconstruction scores and increased overlap in spectral feature space. Impact: Our research lays the foundation for a robust hybrid MRS data generation framework which generates realistic MRS data while maintaining the interpretability of physics-based simulations. It will help to generate data for developing downstream deep learning applications for MRS.
A 3/2-channel 1H/13C RF surface coil for localized 13C MRS in the human frontal lobe at 7 T
Authors: Xiao Ying , Lanz Bernard , Wenz Daniel , Pierzchala Katarzyna , Xin Lijing
Published: November 2024

Motivation: Studying cerebral metabolism in the human frontal lobe using 13C MR spectroscopy is of great interest but presents challenges due to the low sensitivity of 13C nuclei and SAR limitations at ultrahigh magnetic fields. Goal(s): Our goal was designed a 3/2-channel 1H/13C RF coil specifically for conducting 13C MRS measurements in the human frontal lobe. Approach: The feasibility and effectiveness of the coil design were demonstrated with bench measurements and the application of adiabatic carbon editing (ACE)-STEAM and ISIS-DEPT sequences. Results: The coil enables the acquisition of naturally abundant 13C metabolite signals in both in vitro and in vivo with high sensitivity. Impact: The 3/2-channel 1H/13C RF coil, designed and optimized for 13C MRS study in the human frontal lobe, benefits high transmit efficiency and provides large FOV in the forehead.
Dynamic imaging of the heart from scattering parameters using deep learning – an MR based feasibility study
Authors: Meliado E.F. , Louka C.A. , van den Berg C.A.T. , Steensma B.R.
Published: November 2024

Motivation: To enable more accessible and less costly monitoring of cardiovascular mechanical function. Goal(s): Perform a feasibility study into the potential of imaging the heart based on scattering parameters of an RF antenna arrayApproach: An MRI inspired reconstruction network was trained based on 150 in silico simulations of MRI segmented heart models. The method predicts 2D-maps of dielectric property changes and was tested in silico and in vivo on a healthy control. Results: In silico validation shows that it is feasible to reconstruct the shape and size of the heart, as well as left and right ventricular volumes, based on RF scattering measurements. Impact: This work shows the feasibility of imaging the heart from differential scattering parameter measurements and by using MRI inspired reconstruction. Preliminary results warrant further investigation into acquiring paired MRI and RF scattering measurements in human subjects.
Dynamic Latent Variable Modeling for Improved Cardiac MRI Reconstruction
Authors: Zhou Shuo , Jia Sen , Cheng Jing , Cui Zhuoxv , Zhu Yanjie , Liang Dong , Wang Haifeng , Zhou Yihang
Published: November 2024

Motivation: The beating of the heart is predictable, and existing methods mainly focus on sparsity and low rank, ignore the predictability. Goal(s): Our goal is to improve the quality of dMRI reconstruction through predictability. Approach: Introduced a method to extract predictability latent vectors and reconstruct images based on it. Results: We used highly undersampled data for reconstruction and compared it with L+S,the experimental results indicate that we have achieved better reconstruction results than L+S. Impact: This work use predictability for dMRI reconstruction without the use of sparsity and low rank.It is possible to introduce a new perspective for the reconstruction of dynamic images.
Parallel MRI accelerator: The MPSoC design for real time image reconstruction
Authors: Basit Abdul , Inam Omair , Omer Hammad
Published: November 2024

Motivation: Real-time MRI requires efficient data acquisition and low latency image reconstruction along high temporal resolution. The pMRI method known as GRAPPA, offers advantage in terms of fast data acquisition. Goal(s): However, large computational requirements of GRAPPA limit its performance in real-time clinical settings. Approach: This paper presents a novel MPSoC based hardware accelerator which combines 32-bit FPGA based accelerator module with multiple DSP engines and on-chip ARM processor, to provide sufficient computational resources for GRAPPA. Results: The results using in-vivo cardiac datasets i.e. 18-receiver coils, show that the proposed accelerator reconstructs cardiac images at ∼35 frames-per-second without degrading the image quality. Impact: The proposed accelerator is capable to reconstruct 35 frames in one second as compared to the CPU-based counterparts which can only reconstruct 2 frames/second for a given GRAPPA reconstruction setting in our experiments.
Plug and play truncated low rank optimization combined iterative soft thresholding (PNPT) for dynamic MRI reconstruction
Authors: Yang Runyu , Sun Haozhong , Li Haokun , Chen Huijun
Published: November 2024

Motivation: Try to obtaining high spatial and temporal resolution image in dynamic MRI. Goal(s): The plug and play truncated low rank optimization combined iterative soft thresholding(PNPT-) embedded method was proposed to reconstructe data and tested to accurately estimate the rank function for dMRI reconstruction. Approach: The PNPT- method uses truncated nuclear norm combined iterative soft thresholding to assign different shrink values to different singular vectors, enabling the preservation of essential image information while effectively eliminating noise. Results: The embedded method was proposed to reconstructe data and tested to accurately estimate the rank function for dMRI reconstruction. Impact: The proposed method demonstrated reduced aliasing artifacts compared to other methods and yielded better reconstruction images in cine and perfusion data. Consequently, it provided more accurate and efficient image information, benefiting the clinical diagnosis of heart-related diseases.
Quantitative in vivo imaging of median and ulnar nerves using ultrashort echo time (UTE) MRI: a feasibility study
Authors: Lo James , Silva Melissa Lou , Moazamian Dina , Athertya Jiyo , Wu Yuanshan , Jang Hyungseok , Ma Yajun , Chang Eric , Jerban Saeed , Shah Sameer
Published: November 2024

Motivation: Improvements in the medical imaging of nerves have broad medical applications in the diagnosis, tracking, and management of peripheral nerve disease, injury, and treatment. Goal(s): We aim to demonstrate the feasibility of quantitative in vivo imaging of median and ulnar nerves using ultrashort echo time (UTE) MRI. Approach: UTE magnetization transfer (MT) prepared Cones (UTE MT-Cones), UTE MT Fat-Sat-Cones, and UTE Multi-echo-T2-FS-Cones sequences were performed in nine healthy adults using a clinical 3T scanner. Results: Cross-sectional area (CSA), T2*, MMF, and all MTR values were lower in the ulnar nerve, but the differences were significant only for CSA, non-fat-sat MTR 800-2k and 500-10k. Impact: This demonstration of high-contrast, quantitative imaging of the wrist nerve has considerable potential in practical applications for managing and monitoring nerve disease, injury, and treatment.
Detection of Type 2 Diabetic Peripheral Neuropathy using Lumbosacral Nerve Root Diffusion Tensor Imaging
Authors: Chen He , Xie Sheng , Yue Xiuzheng
Published: November 2024

Motivation: Electrophysiology is the gold-standard tool to diagnose diabetic peripheral neuropathy (DPN), but it is invasive. We try to find a convenient and reliable technique for diagnosing DPN. Goal(s): The study aimed to reveal whether DTI of the lumbosacral nerve roots could be used to detect DPN. Approach: Using a 3T MRI scanner to get the DTI parameters of lumbosacral nerve roots from 2 diabetic patients with and without DPN, respectively, and analyze data using statistical methods. Results: DTI of lumbosacral nerve roots can detect whether peripheral nerve injury occurs in diabetic patients. Impact: DTI of lumbosacral nerve roots can not only detect whether peripheral nerve injury occurs in diabetic patients but also quantitatively describe the degree of peripheral nerve injury and has the potential to evaluate the nerve changes after treatment in DPN patients.
Super-resolution MRI of Human Olfactory Bulb and Tract at 3T
Authors: Jafari Ramin , Peeters Johannes , Zhao Yansong , Wu Can , Peng Qi
Published: November 2024

Motivation: Olfactory bulb and tract imaging with high resolution is required for patient evaluationGoal(s): Optimized protocol along with super resolution deep learning to improve olfactory bulb and tract imaging Approach: Optimized T2 weighted and DTI imaging along with deep learning reconstruction was performed and results were evaluatedResults: Good agreement between existing and proposed methods were observed while the proposed methods improves resolution with better noise performance. Impact: This work will allow olfactory system high resolution imaging to serve as a diagnostic tool for patient evaluation.
Explicit analytical solution for bSSFP with 3 general phase-cycled acquisitions
Authors: Dong Yiyun , Xiang Qing-San , Hoff Michael
Published: November 2024

Motivation: Unlocking the phase-cycled bSSFP system with high efficiency, accuracy, and flexibility. Goal(s): To find and validate an explicit analytical solution to the bSSFP MRI framework using three general phase-cycled acquisitions. Approach: Using the elliptical signal model and trigonometrical relationships, this study obtains explicit, general, and closed form expressions of an analytical solution to the bSSFP system with only 3 acquisitions. To reduce noise sensitivity, the solution was also linearized using regional optimal weighted averaging. Results: Analytical results showed efficacy via validation by simulated data with noise covering all possible scan parameters. Impact: Phase-cycled bSSFP imaging is becoming prominent, and has recently been analytically unlocked with only 3 acquisitions. This development will allow even more widespread use of the technique due to its associated multi-parametric capability.
31P MRSI multi-channel signal combination using 23Na coil sensitivity profiles at 7T: further evaluations in silico, on phantom, and in vivo
Authors: Dai Jiying , Gosselink Mark , Raaijmakers Alexander , Klomp Dennis
Published: November 2024

Motivation: Multi-channel 31P MRSI signal combination is challenging due to low intrinsic SNR. Goal(s): Improve multi-channel 31P signal combination for a multi-tuned 31P/23Na head coil receiver array. Approach: Combining 15-channel 31P data using the 23Na sensitivity maps received with the same dual-tuned array. The results are evaluated quantitatively and qualitatively in silico, on phantom scans, and in vivo. Results: Simulation shows <5% SNR-decrease by combining 31P signals using 23Na sensitivities. Phantom data shows 25% SNR-decrease but also potential for mitigating point-spreading effect. In vivo data analysis shows 5% SNR increase when the intrinsic SNR is low but 15% decrease after the dataset is denoised. Impact: This study explores an alternative approach for multi-channel 31P MRSI signal combination. The performance is positive when intrinsic SNR is low. This approach can be extended to other X-nuclei with not-too-far Larmor frequencies if multi-tuned receiver antennas are used.
Laminar fMRI-MRS Study: Exploring the Relationship Between Cortical Depth Dependent BOLD Signals and Neurometabolites Concentrations in PCC
Authors: Rajkumar* Ravichandran , Pais-Roldán* Patricia , Yun Seong Dae , Farrher Ezequiel , Palomero-Gallagher Nicola , Collee Maria , Hagen Jana , Ramkiran Shukti , Shah N. Jon , Neuner Irene
Published: November 2024

Motivation: To gain insights into the neurochemical underpinnings of brain function by investigating the association between the cortical depth-dependent BOLD signal and neurometabolite concentrations in the PCC. Goal(s): Examine the relationship between neurometabolites and laminar-fMRI metrics in the PCC to uncover layer-specific functional relationshipsApproach: Laminar fMRI and MRS at 7T and assessment of correlations between cortical depth-dependent fMRI-metrics and neurometabolitesResults: Glutamate positively correlated with the fMRI ECM-metric in the intermediate layers of the PCC, suggesting increased long-range neural excitability. Conversely, lactate concentration negatively correlated with the fMRI ALFF-metric in superficial layers of the PCC, indicating potential layer-specific metabolic and functional differencesImpact: This study exposes the intricate relationship between regional neurometabolite concentrations and laminar fMRI metrics in the posterior cingulate cortex (PCC) that contribute to our understanding of brain activity and functional connectivity at rest
Association between Long Range Temporal Correlations in Functional MRI BOLD signal and the Excitatory / Inhibitory Metabolites Ratio
Authors: Sochan Lydia , Weber Alexander , Giaschi Deborah , Vanderwal Tamara
Published: November 2024

Motivation: Animal and computational studies have been used as a basis to assume a link between excitatory-inhibitory (E/I) ratio and Hurst exponent (H) in the human brain; however, it has yet to be sufficiently demonstrated in healthy human subjects. Goal(s): We seek to test the E/I-Hurst link in the visual cortex during rest and movie-watching. Approach: Multi-echo functional MRI, sLASER, and MEGAPRESS sequences are used in 17 healthy human adults (ages 21-53 years; 13 female, 4 male) with MRS voxel ROI in visual cortex. Results: E/I and Hurst are not significantly correlated in either the MRS voxel ROI or visual network. Impact: Hurst exponent (H) is assumed to correlated with excitatory-inhibitory (E/I) ratio without sufficient human evidence. Given the role of E/I imbalance in neuropsychiatric illness and the technical difficulty to measure it, understanding if H acts as its proxy is critical.
Deuterium labeling kinetics in rat cerebral cortex using ex-vivo 2H NMR spectroscopy
Authors: Ramesh Akila , Patel Anant
Published: November 2024

Motivation: Lower sensitivity of 13C NMR spectroscopy requires longer acquisition time while quantifying brain metabolites. An alternative technique is essential to aid faster detection. Goal(s): To evaluate the kinetics of 2H labeling brain metabolites from [6,6’-2H2]glucose using 2H NMR spectroscopy. Approach: The cortical extracts of rats infused with [6,6’-2H2]glucose were analyzed using 2H NMR spectroscopy. Results: The signals of deuterated GlcC6, GluC4, LacC3, GABAC2and GlnC4 are seen in the 2H NMR spectrum of cortical extract obtained after 90 min of [6,6’-2H2]glucose infusion. The resonances of AspC2, GluC2, and GluC3 are absent suggesting complete loss/dilution of 2H from the TCA cycle intermediates beyond α-ketoglutarate. Impact: Judicious use of 2H NMR together with suitable deuterated substrates may an alternative for neurometabolic analysis in neurological disorders.
CSF Flow Dynamics and Volume Changes in Sigmoid Sinus Wall Dehiscence-Pulsatile Tinnitus with Idiopathic Intracranial Hypertension
Authors: Chen Lanyue , Ma Xiaobo , Qu Xiaoxia , Zheng Dandan , Zhou Mengdi , Wang Xiwen , Liu Zhaohui
Published: November 2024

Motivation: The mechanism of sigmoid sinus dehiscence (SSWD) in pulsatile tinnitus (PT) patients remains unclear. Goal(s): To assess the cerebrospinal fluid (CSF) dynamics and volume of SSWD-PT with intracranial hypertension by phase-contrast magnetic resonance imaging (PC-MRI). Approach: Thirty-five PT patients with SSWD and intracranial hypertension identified on dual-phase contrast-enhanced CT (DP-CECT) and brain magnetic resonance venogram (MRV), respectively. And 35 age-, gender-, and handiness-matched healthy volunteers. All participants underwent T1-weighted volumetric and PC-MRI. Results: The body mass index, regurgitant fraction and CSF volume were significantly higher and the mean velocity, peak velocity and mean flux were significantly slower in SSWD-PT. Impact: We found the CSF dynamics and volume changes in SSWD-PT with intracranial hypertension, which may be related to blood flow dynamics changes in sigmoid sinus and presence of PT. These results suggest treatment for SSWD-PT should be more comprehensive.
Interleaved HYDROPS: towards motion robust imaging of endolymphatic hydrops after intravenous administration of gadolinium
Authors: Yoneyama Masami , Osawa Iichiro , Kondo Atsushi , Namiki Takashi , Hamano Hiroshi , Kozawa Eito , Niitsu Mamoru , Van Cauteren Marc
Published: November 2024

Motivation: HYDROS is useful method for detection of endolymphatic hydrops in patients with Meniere’s disease, but it has a potential risk for motion of patients during the acquisition because of its long scan time, resulting in misalignments of subtraction images. Goal(s): To develop a new sequence, called interleaved HYDROPS, which acquires PPI and PEI images with an interleaved manner in one single scan. Approach: We developed the interleaved 3D IR-prepared TSE with variable inversion delays. Interleaved HYDROPS were compared with conventional HYDROPS for image quality, particularly in the motion simulated situation. Results: Initial findings indicated good feasibility of interleaved HYDROPS, encouraging further clinical evaluation. Impact: Interleaved HYDROPS could provide PPI and PEI images with minimized motion effects during scan, compared with conventional separately acquired sequence. It holds promise for increasing robustness for motion-induced subtraction errors, but further studies are warranted to confirm its full potential.