bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Sampling Schemes of Spin-locking Times to Improve Reproducibility of Quantitative 3D T1rho Mapping
Authors: Jogi Sandeep , Peng Qi , Jafari Ramin , Otazo Ricardo , Wu Can
Published: November 2024

Motivation: Reproducibility of T1rho measurements is crucial for longitudinal studies, as highly reproducible measurements are needed to detect treatment-induced changes in tissue properties. Goal(s): To evaluate two novel sampling schemes of spin-locking times (TSLs) to improve the reproducibility of T1rho quantification in inhomogeneous fields (B1/B0) compared to previously reported TSL-sampling schemes. Approach: T1rho sequences with three different T1rho preparation modules and four TSL-sampling schemes were used for repeated scans of phantom and volunteers to evaluate reproducibility in each case. Results: The proposed TSL-sampling schemes produced significantly better reproducibility (i.e., lower coefficient of variation) than the previously reported TSL-sampling schemes. Impact: The proposed novel TSL-sampling schemes may enable T1rho relaxation parameter as a robust biomarker of imaging tissues with a slow-motional process despite B1/B0 inhomogeneities.
High-Accuracy Ultra-short Inner-Volume Saturation Pulse for 3D Steady-State Imaging
Authors: He Yongli , Fung Rex , Nielsen Jon-Fredrik
Published: November 2024

Motivation: Spatially-tailored excitation is often favorable in MR applications where the region-of-interest only occupies a small portion of the whole FOV. Goal(s): In this study, we sought to design an inner-volume saturation pulse for steady-state imaging. Approach: We propose an extension to the AutoDiff tool by Luo et al. Here we use steady-state magnetization error as the design objective instead of one-time excitation error in the original design. Results: Our proposed pulse design can excite spatially-selective patterns with ultra-short duration(~1.2ms) and high accuracy (error reduced by 50% compared to the original design). Impact: Our pulse design tool enables highly accurate multi-dimensional spatially-tailored excitations with ultra-short pulses. Such pulses can be plugged into functional MRI sequences, and be played in clinical scenarios where ROI-specific excitations can mitigate motion artifacts and reduce image encoding time.
Can Quadruple Quantum Filtering Enhance Lactate Detection?
Authors: Repnin Kostiantyn , Santos Vasco dos , Kemp Graham J. , Meyerspeer Martin
Published: November 2024

Motivation: Metabolites exhibiting J-coupling (like lactate) can be selectively detected against overlapping signals using multi-quantum filtering (MQF). Accurate modelling of such spin systems under realistic RF and gradient pulses is crucial for optimizing signal yield, background suppression and quantification. Goal(s): Improve MQF sequences to mitigate the inherent 50 % signal loss of double-quantum filters. Approach: The effect of realistic RF-pulses (hard/selective, various phases) and gradients on an AX3 system’s higher-order coherences was investigated. Semi-LASER-based spin-echo sequences were simulated in pyGAMMA and tested on a 7T scanner. Results: Quadruple-quantum coherences maintain near-100 % signal, outperforming traditional DQF. Simulations and phantom experiments agreed within 6 %. Impact: Quadruple-quantum filtering of lactate can retain its full signal, promising faster and more precise lactate quantification in human tissues. This could significantly improve the monitoring of glycolytic and oxidative metabolism and thus the understanding of underlying mechanisms in disease.
MRI Acceleration with Frequency Encoding Subsampling using Double Lobe Gradient (DOGE) Readout Waveform
Authors: Hong Haotian , Liu Wenjian , Ren Yuyang , Shang Wenlei , Yang Wenchao , Jiang Tianhao , Xie Zhuocheng , Zhu Jiayu , Qi Haikun , Hu Peng
Published: November 2024

Motivation: The current practice of MRI acceleration commonly subsamples K-space along the Phase Encoding (PE) direction, but this approach does not fully address the need for further reduction in scan time. Goal(s): Our goal was to develop a Frequency Encoding (FE) subsampling technique that reduces scan time while maintaining image quality. Approach: We introduced the Double Lobe Gradient (DOGE) readout approach, which manipulates the readout gradient waveform to subsample along the FE direction. Results: The verification of DOGE readout on b-SSFP resulted in a significant reduction of 40% in readout time and 20% reduction in repetition time (TR), while maintaining comparable image quality. Impact: Our approach exhibits compatibility with existing MRI acceleration techniques, thereby enhancing scan efficiency. Moreover, its potential applicability to other pulse sequences to reduce scan duration could bear substantial implications for clinical practice, potentially revolutionizing patient experience and diagnostic accuracy.
A new technique for automatic removal of local errors in shear modulus estimation from measurement area in liver MR elastography
Authors: Ito Daiki , Numano Tomokazu , Habe Tetsushi , Nozaki Taiki , Jinzaki Masahiro
Published: November 2024

Motivation: The stiffness value in two-dimensional liver MR elastography (MRE) is measured manually to avoid local errors in the stiffness estimation (dark/hot spots). Observer variability with this manual measurement is one of the obstacles to the clinical usage of MRE. Goal(s): Our goal was to automatically remove dark/hot spots from the measurement area. Approach: We introduced a new automated technique (coherent-wave auto-selection: CHASE) for measuring the stiffness value and tested it for the liver of five healthy volunteers. Results: CHASE automatically generated a measurement area scarcely including dark/hot spots, resulting in high uniformity within that area. Impact: The combination of our new technique and confidence mapping (clinical method) can reduce the process of manual measurement of stiffness value in liver MR elastography, resulting in improved variability and diagnostic performance for fibrosis staging.
Introducing a task design independent customized cost function for DNN to denoise task-based fMRI data.
Authors: Van Schuerbeek Peter , Raeymaekers Hubert
Published: November 2024

Motivation: We expected that using a fMRI denoising neural network (DNN) that requires the denoised signal to correlate with a task design matrix in combination with a GLM analysis, can lead to biased results. Goal(s): To find a DNN cost function that is independent of the task design. Approach: We suggested a cost function that is based on the preserved frequency content and the correlation with motion regressors, with non-brain signals and with the non-denoised signal. Results: We found that the DNN with the proposed cost function performed best in reducing the noise while preserving the BOLD signal. Impact: Our intension with this abstract is to make researchers to think more carefully about the conditions included in their customized cost function in DNN-like denoising models and to check critically the denoised output.
Grasping the noise – applying brain vasculature as a priori for sLFO reduction in the BOLD-fMRI signal and the impact on subject identifiability
Authors: Xie Andrew , Dagenais Rémi , Miedema Mary , Askarinejad Emad , Mitsis Georgios
Published: November 2024

Motivation: Denoising systemic low-frequency oscillations (sLFOs) using global signal regression (GSR) can possibly impact the neural component of the BOLD fMRI signal. Goal(s): Our goal was to use the spatial relationship between the sLFO component of the BOLD signal and brain vasculature to perform a less aggressive form of GSR. Approach: We collected structural and functional images at 3T in ten subjects. We then used to temporal and spatial characteristics of the sLFOs to denoise the BOLD signal. Results: The spatial correlation between the sLFOs and venograms confirmed their underlying vascular origin. The performance of our novel denoising technique still needs to be evaluated. Impact: We propose a novel sLFO denoising method that uses the temporal and spatial patterns of physiological noise to preserve a larger fraction of the neural activity.
Machine Learning-based Estimation of Respiratory Fluctuations in a Healthy Adult Population using BOLD fMRI and Head Motion Parameters
Authors: Addeh Abdoljalil , Vega Fernando , Williams Rebecca J. , Pike G. Bruce , MacDonald M. Ethan
Published: November 2024

Motivation: In many fMRI studies, respiratory signals are often missing or of poor quality. Therefore, it could be highly beneficial to have a tool to extract respiratory variation (RV) waveforms directly from fMRI data without the need for peripheral recording devices. Goal(s): Investigate the hypothesis that head motion parameters contain valuable information regarding respiratory patter, which can help machine learning algorithms estimate the RV waveform. Approach: This study proposes a CNN model for reconstruction of RV waveforms using head motion parameters and BOLD signals. Results: This study showed that combining head motion parameters with BOLD signals enhances RV waveform estimation. Impact: It is expected that application of the proposed method will lower the cost of fMRI studies, reduce complexity, and decrease the burden on participants as they will not be required to wear a respiratory bellows.
Automatic Detection of BOLD Activations using a Semi-supervised Bidirectional LSTM Neural Network
Authors: Schmidt Tim , Nagy Zoltan
Published: November 2024

Motivation: Because there is significant variability in the hemodynamic response of individuals, fitting a simple function may lead to false negatives (i.e., a bad fit leads to larger residuals than the noise level would dictate). Goal(s): Develop a robust data-driven based approach for detecting BOLD. Approach: A semi-supervised automatic detection (SAD) method based on a bidirectional long/short-term memory neural network to find BOLD responses in the entire brain and assess classification performance on simulated fMRI data. Results: The proposed detection method exhibits robustness across various HRF shapes at realistic contrast-to-noise ratios. Impact: We proposed a method for detecting BOLD responses in high temporal resolution fMRI data that is based on a Bidirectional long/short-term memory neural network. Classification performance was excellent as tested using simulated data with different HRFs and contrast-to-noise ratios.
M(RF)2 – Improving MRF encoding speed with tailored spatiotemporal excitation patterns
Authors: Urman Yonatan , Abraham Daniel , Setsompop Kawin
Published: November 2024

Motivation: Current Magnetic Resonance Fingerprinting techniques have shown promising results but have room for improvement in terms of acquisition speed and resolution. Goal(s): Explore the potential of a new spatiotemporal encoding dimension unique to MRF, leveraging tailored spatiotemporal excitation patterns. Approach: Employ spatially and temporally varying excitation patterns to create distinct signal evolution dictionaries at different spatial locations and reconstruct using multiple subspaces. To address computational challenges, we introduce a clustering method that reduces the number of subspaces, making the problem tractable. Results: 2D reconstruction experiments demonstrate the approach's potential and show enhanced accuracy, particularly in T2 reconstruction. Impact: We propose tailored spatiotemporal excitation encoding for Magnetic Resonance Fingerprinting. By leveraging controlled excitation patterns, we create spatially varying dictionaries that enhance the encoding capabilities, allowing for faster and higher-resolution imaging.
Holocene Sampling: Where CAIPIRINHA meets T-Hex
Authors: Engel Maria , Kasper Lars , Jones Derek
Published: November 2024

Motivation: For Multiband and 3D EPI (and spirals), k-space sampling patterns used to date, were either optimized heuristically (blipped-CAIPIRINHA) or only available for a discrete subset of imaging parameters (T-Hex). Goal(s): To find the optimum sampling pattern for arbitrary imaging parameters. Approach: We propose the packing density of the k-space grid in the phase-encoding plane as a metric to assess the quality of a sampling pattern, since it minimizes the noise amplification for spherical objects. Furthermore, we choose L’s and Δ’s (blipped-CAIPIRINHA nomenclature) as real-valued numbers. Results: The novel sampling patterns achieve more homogeneous k-space coverage (up to 30% higher packing density) than blipped-CAIPIRINHA. Impact: The proposed method generates k-space sampling patterns that have potential to maximize the SNR yield per unit time in Multiband and 3D imaging by providing the most homogeneous k-space sampling for an arbitrary given set of imaging parameters.
Open SPEN using Pulseq
Authors: Holl Andreas , Zijlstra Frank , Zaitsev Maxim , Groebner Jens , Littin Sebastian
Published: November 2024

Motivation: SPEN is an alternative encoding method with various advantages. However, SPEN sequences are not easily accessible. Goal(s): The aim of this project is to make SPEN in the open-source framework Pulseq openly available. This enables reproducibility and availability of SPEN. Approach: The SPEN sequence was developed in MATLAB using the Pulseq framework and is openly accessible via a GitHub repository. In addition, a sequence example is developed as a guide for the use of SPEN. Results: A SPEN sequence is openly available for the vendor-independent execution on different platforms. Impact: The implementation in Pulseq significantly increases the accessibility of SPEN. This hopefully leads to more SPEN-related studies and to a more widespread use in clinical applications.
Rapid gradient-recalled echo line scanning with crisp line profiles for human MRI at 7 Tesla
Authors: Cloos Martijn , Hodono Shota , Balasubramanian Mukund , Polimeni Jonathan
Published: November 2024

Motivation: Line-scanning trades coverage for speed and resolution in a single direction, suitable for the study of mesoscale structure and functional dynamics across cortical depth. However, at ultra high-field strength, the sampling rate is constrained by the specific absorption rate. Goal(s): Facilitate Rapid gradient-recalled echo line scanning with crisp line profiles for human MRI at 7 Tesla. Approach: A new line-scan Tip-Down Tip-Up based preparation module. Results: Using the proposed preparation module, it is possible to perform gradient-recalled echo line scanning experiments with short TR and crisp line profiles. Impact: Using the proposed preparation module, it is possible to perform gradient-recalled echo line scanning experiments with short TR and crisp line profiles. Such advances can be used to study functional dynamics across cortical depth with high sampling rates.
Silent resting-state fMRI using Looping Star Multi-echo acquisition in a 3T high-performance gradient (300 mT/m & 750 T/m/s) MRI system (MAGNUS)
Authors: Abad Nastaren , Solana Ana Beatriz , Jansen Isabelle , Fernandez Brice , Wiesinger Florian , Ajala Afis , Foo Thomas , Pollatou Angeliki , DeMarco J Kevin , Kohls Gail , Morris H Doug , Hood Maureen , Ho Vincent , Werner J Kent , Marinelli Luca
Published: November 2024

Motivation: To leverage the intrinsic multi-echo capabilities of Looping Star (ME-LS) for fMRI applications to minimize susceptibility-related signal loss to enhance sensitivity to underlying neurovascular changes. Goal(s): Our objective is to demonstrate feasibility of detecting resting state networks using a silent multi-echo fMRI approach enabled by Looping StarApproach: Resting-state Multi-echo Looping Star fMRI was implemented on MAGNUS and scanned in healthy volunteers. Results: This feasibility study shows established resting-state networks and connectome matrixes for multi-echo Looping Star fMRI and highlights the impact of the broad parameter space accessible with MAGNUS for Looping Star. Impact: Silent ME-fMRI has a multitude of advantages, ranging from increased sensitivity to neuro-correlates of sleep dysregulation, auditory-sensory studies, neurological disorders and to provide a more immersive experience by combining sound with visual stimuli in the MR environment.
Characterizing Zero Echo Time fMRI in a Mouse Model
Authors: Daley Lauren , Pan WenJu , Keilholz Shella
Published: November 2024

Motivation: Zero-TE fMRI offers researchers a valuable tool for enabling more efficient and effective awake animal imaging. However, this has yet to be tested and validated in mice, a popular species in fMRI studies. Goal(s): The goal of this study is to validate using zero-TE fMRI in a mouse model, through signal analysis and characterization, and later connectivity comparisons/analyses. Approach: 10 anesthetized (1.1%iso) mice were scanned for resting-state and stimulation-based fMRI at 9.4T, acquired using EPI and ZTE; the reconstructed data were then characterized. Results: This study presents evidence that though ZTE signal differs from EPI signal, there is still sufficient overlap in connectivity. Impact: This study presents evidence that ZTE is an effective alternative to EPI in fMRI studies. If employed, this will address several issues researchers currently face (motion artifacts, signal loss, etc.), while still ensuring functional contrast is produced.
Gradient Echo Sampling of a Spin Echo (GESSE) linescans for human laminar fMRI at 7T: combining echoes to vary functional contrast and sensitivity
Authors: Balasubramanian Mukund , Mulkern Robert , Choi Sangcheon , Rodriguez Nadira Yusif , Berman Avery , Grissom William , Cloos Martijn , Wang Fuyixue , Wald Lawrence , Yu Xin , Polimeni Jonathan
Published: November 2024

Motivation: Resolving distinct functional activation and connectivity within cerebral cortical layers requires high imaging resolutions and microvascular specificity along with sufficient sensitivity—a major challenge for current fMRI methodologies. Goal(s): To measure capillary-weighted spin-echo-BOLD fMRI signals in human cerebral cortex, with 500-micron resolution in the radial direction (i.e., perpendicular to the cortical surface). Approach: We used a novel “linescan” technique that samples a single spin echo with multiple gradient echoes. Results: We provide the first demonstration of T2-weighted BOLD activation via linescan fMRI in humans and show that the multiple gradient echoes can be combined in various ways to manipulate functional contrast and sensitivity. Impact: Our novel LS-GESSE technique allows for controlled trade-offs between sensitivity and specificity and should help enable the measurement of microvascular fMRI signals at spatial resolutions approaching the thickness of individual cortical layers, facilitating noninvasive studies of cortical dynamics and circuitry.
Investigate the correlation between resting-state functional connectivity and EEG spikes with drug-induced epilepsy
Authors: Juan Yi-Jing , Chu Po-Chun , Ruan Wei-Hong , Liu Hao-Li , Chen Jyh-Horng
Published: November 2024

Motivation: Electroencephalography (EEG) and resting-state functional MRI (rs-fMRI) are both critical tools for investigating epilepsy, and their combination will further reveal meaningful insights. Goal(s): This study investigates the correlation between EEG spikes and functional connectivity in a drug-induced epileptic small-animal model. Approach: An epileptic animal model was employed by injecting pentylenetetrazol (PTZ) through intraperitoneal to trigger acute epileptic-like abnormal neuron discharges, and EEG and rs-fMRI data were acquired seperately. Results: This study integrated longitudinal rs-fMRI monitoring and EEG recordings in the same epilepsy animal model to assess drug-induced epileptic signals, showing and increase of both EEG spike numbers and C.C. after inducing epilepsy drug. Impact: This study demonstrate the potential of brain region-to-region connectivity becoming a new bio marker of epilepsy diagnosis. However, greater precision and repeatablility of fMRI measurements is required for future studies to accurately align fMRI data with the electrophysiological data.
Altered Functional Connectivity Density between Obesity and Type 2 Diabetes Mellitus in Rat brain.
Authors: He Zhongyi , Zhu Xinyi , Zhou Jiaqiang , Cai Chunli , Zhao Yuchen , Wang Min
Published: November 2024

Motivation: Obesity and hyperglycemia would both affect brain function, while the longitudinal evolution of brain connectivity from obesity to diabetes is unknow. Goal(s): Obesity and diabetes rat brain were evaluated to find the regions that were mostly affected by the diabetic incidence. Approach: Rats were scanned at baseline and 10 days after streptozotocin injection (for diabetes model). Functional connectivity density (FCD) was applied to detect affected brain regions. Results: Visual cortex’s FCD was increased in both obesity and diabetes. Diabetic rats show increased FCD in insular cortex and decreased FCD in ventral pallidum after streptozotocin injection, and these changes are correlated with fasting glycemia. Impact: Obesity and diabetes show a progressive effect on cortex including visual and insular region. Acute changes are found in diabetic brain after streptozotocin injection for ventral pallidum, which suggested an impaired reward system in the development of T2DM.
Advanced Prostate Cancer Characterization: Enhanced Tissue Compartment Estimation with Extended Grid Sampling and HM-MRI
Authors: Campos Abel Lorente , Chatterjee Aritrick , Karczmar Gregory , Gundogdu Batuhan , Guo Xiaodong , Oto Aytekin , Antic Tatjana , Medved Milica
Published: November 2024

Motivation: Introduction of Extended Grid Sampling (EGS) to overcome the limitations of Hybrid Multidimensional MRI (HM-MRI) in prostate cancer (PCa) detection. Goal(s): Our primary goal is to assess the effectiveness of EGS in improving the accuracy of PCa detection and lesion extension using HM-MRI. Approach: Integrate EGS data with standard HM-MRI, utilizing biexponential fits for short and long T2 component estimation, followed by joint analysis, and risk map generation to enhance the precision of prostate cancer detection and characterization. Results: EGS integrated with HM-MRI can provide more accurate delineation of prostate tissue compartments, notably improving the detection of prostate cancer lesions. Impact: By enhancing prostate cancer (PCa) detection accuracy with Extended Grid Sampling (EGS) integrated into Hybrid Multidimensional MRI (HM-MRI), we empower clinicians to make more precise diagnoses and treatment decisions, directly benefiting patients.
Accuracy of PIRADS 2.1 scoring system to Screen Prostate Cancer in a Ugandan population
Authors: Kawooya Michael , Malumba Richard
Published: November 2024

Motivation: Prostate cancer is highly incident in Africa. Early screening and detection is recommended to lower this rate. BpMRI and PIRADS are used to detect, stage prostate cancer. The accuracy of PIRADS in an African population hasn’t been determinedGoal(s): Determine the accuracy of PIRADs to screen Prostate cancer in an African populationApproach: We assessed the accuracy of PIRADS alone, PIRADS and PSAD, PIRADS and ADC, PIRADS, PSAD and ADC using the AUC to discriminate a positive histological prostate caseResults: PIRADS had AUC 0.70, combination of PIRADS V2.1 and PSAD had AUC 0.73, combination of PIRADS, PSAD and ADC had AUC 0.72Impact: PIRADS accurately predicts PCa satisfactorily AUC 70%. It may be used in an African population in combination with clinical information and history. This is because they were some cases graded as PIRADS 2 and yet had a high gleason score.
Magnetic Resonance Fingerprinting and ADC mapping to optimize Biopsy Decision-Making in patients with a Negative Prostate MRI
Authors: de Oliveira Correia Eduardo Thadeu , Sun Jessie , Griswold Mark , Tirumani Sree , Sun Yilun , Ma Dan , Chen Yong , Bittencourt Leonardo Kayat
Published: November 2024

Motivation: Prostate MRI alone cannot avoid all unnecessary biopsies in MRI-negative patients. This results in overdiagnosis, added morbidity and overtreatment. Goal(s): Investigate if MRF-derived T1 and T2 maps alone or in combination with conventional ADC mapping can reduce unnecessary biopsies while maintaining optimal significant prostate cancer detection. Approach: Regions of interest encompassing the right and left lobes of the peripheral zone were used to compute the mean T1, T2, and ADC values. Results: With a linear regression of mean T1 and T2 values, 63% of all biopsies could be avoided, at the cost of missing one significant prostate cancer. Impact: The use of MR Fingerprinting in prostate biopsy decision-making pathways could reduce unnecessary biopsies while maintaining optimal detection of significant prostate cancer in MRI-negative patients with clinically indicated biopsies. The prospective validation of these findings is crucial for patient outcomes.
Prostate Specific Antigen Density Normalized by Volume Fractions from Hybrid Multi-dimensional MRI Can Improve Prostate Cancer Diagnosis
Authors: Chatterjee Aritrick , Yousuf Ambereen , Campos Abel Lorente , Antic Tatjana , Oto Aytekin , Karczmar Gregory
Published: November 2024

Motivation: Prostate specific antigen(PSA) and PSA density (PSAD) are inadequate for PCa screening. Goal(s): Our goal was to combine PSA and MRI measures from Hybrid Multi-dimensional MRI (HM-MRI) to improved PCa diagnosis. Approach: Blood PSA level, prostate volume from mpMRI and tissue volumes (epithelium, lumen) from HM-MRI were used to measure PSAD and PSAD normalized by tissue type (nPSAD). Results: nPSADepithelium is significantly lower and nPSADlumen is significantly higher in cancer patients compared to benign subjects. The diagnostic accuracy of nPSAD to detect subjects with PCa, was significantly higher than conventional PSAD, and further improved by combining nPSAD with tissue composition measures from HM-MRI. Impact: We introduce a new cancer biomarker that combines PSA (blood-based biomarker) with tissue composition from HM-MRI. nPSADlumen and nPSADepithelium improve PCa diagnosis. These new biomarkers may signal effects of PCa on normal prostate and may indicate cancer aggressiveness.
Preoperative clinical and imaging characteristics associated with aneurysm recurrence after stent-assisted coil embolization
Authors: tian bing , Hou Yuxi , Tian Xia , Lu Jianping
Published: November 2024

Motivation: In this retrospective observational cohort study, we found that both CAWE pattern and aspect ratio were independent predictors of aneurysm recurrence after stent-assisted coil embolization. Goal(s): To explore the baseline clinical and imaging characteristics which can predict aneurysm recurrence after stent-assisted coil embolization. Approach: 3D high-resolution MRI vessel wall imagingResults: Among the 155 patients, 26 patients (16.7%) got aneurysm recurrence after stent-assisted coil embolization during the 2-year follow-up. Multivariate logistic regression analysis revealed that the CAWE pattern (OR 3.87, 95% CI 1.2–10.4, p=0.02) and aspect ratio (OR 2.1, 95% CI 0.6-4.2, p=0.03) were independently associated with aneurysm recurrence after stent-assisted coil embolization. Impact: If validated in future larger-scale studies, preoperative imaging characteristics, especially vessel wall enhancement patterns on 3D HR-VWI could be a potential tool for identifying patients at elevated risk of recurrence after stent-assisted coil embolization.
Enhancing reliability in TOF-MRA: minimizing spin-dephasing effects and improving fat suppression
Authors: Wen Yue , Jiang Xianwang , Xu Qin , Zhang Xingxing
Published: November 2024

Motivation: Clinicians express concerns about false-positive findings, leading to uncertainties in the reliable interpretation of TOF-MRA. Goal(s): This study focuses on improving the reliability of TOF-MRA for cerebrovascular imaging. Approach: By incorporating a small flip-angle spatially-selective fat-suppression and utilizing the shortest echo-time, signal loss is minimized, and uniform fat-suppression is achieved. Results: The results, compared to conventional protocols, demonstrate superior quality and reliability by reducing spin-dephasing and achieving uniform fat-suppression without compromising blood signal quality or requiring extensive post-processing. This approach effectively mitigates the risk of false-positive findings and overestimation of stenosis, potentially establishing it as a more effective routine clinical examination for MRA. Impact: By improving the reliability of TOF-MRA through optimized fat-suppression and echo-time reduction, it enhances the accuracy of evaluating cerebrovascular abnormalities. This advancement enables clinicians to have greater confidence in interpreting TOF-MRA images and reduces the risk of false-positive findings.
Assessment of Intracranial Curved and Distal Small Arteries by Using zTE-MRA: Comparison with TOF-MRA
Authors: Li Xiao , Zhang Jianjian , Zheng Feng , Wu Hangyu , Zhang Yong , Zhao Huilin
Published: November 2024

Motivation: Time-of-flight MRA (TOF-MRA) is sensitive to abnormal blood flow and result in susceptibility artifact signal and signal loss in distal small artery. Goal(s): To investigate whether zero echo time MRA (zTE-MRA) could improve the image quality in intracranial artery with the same scan time. Approach: Recruiting healthy subjects and taking zTE-MRA and TOF-MRA scanning. Results: Compared with TOF-MRA using the same scan time, zTE-MRA could reduce susceptibility artifact signal in intracranial curved artery and suppress tissue signal intensity surrounding artery to better show ophthalmic artery. Impact: Providing a non-invasive method to better reduce susceptibility artifact signal in intracranial curved artery and suppress tissue signal intensity surrounding artery to better show distal small artery.
A Hybrid Deep Learning and Graphics method for Vessel Centerline Extraction and Vessel Segment Labeling to Assist Plaque Detection and Evaluation
Authors: Yang Long , Yang Xiong , Mao Yufei , Cheng Guanxun , Li Ye , Liang Dong , Liu Xin , Zheng Hairong , Zhang Na
Published: November 2024

Motivation: Manual centerline Extraction based on black-blood Magnetic resonance vessel wall imaging is a difficult and time-consuming but important step for further analysis of plaques. Goal(s): To propose a method for quickly, automatically and accurately extracting the centerline and label the segments of the target arteries. Approach: This study proposes a method that combines deep learning and traditional graphics method for the automatic and accurate centerline extraction and even segments labeling, which is applicable to flexible MR sequences (only black-blood images, only bright-blood images, or both). Results: Compared with the ground truth, the proposed method achieved excellent completeness and accuracy in a short time. Impact: This study introduces a flexible (MRVWI or/and TOF-MRI), swift, and precise approach for extracting and labeling the centerline of target vessel. With this method, radiologists can more conveniently and efficiently observe potential abnormal areas around vessel and diagnose vessel-related diseases.
Investigating Brain Health in Coronary Artery Disease: Vascular and Metabolic Biomarkers, Cognition, and Implications
Authors: Sanami Safa , Tremblay Stefanie , Sabra Dalia , Rezaei Ali , Potvin-Jutras Zacharie , Intzandt Brittany , Huck Julia , Gagnon Christine , Mainville-Berthiaume Amelie , Wright Linsay , Vuckovic Dajana , Iglesies-Grau Josep , Vincent Thomas , Gayda Mathieu , Nigam Anil , Bherer Louis , Gauthier Claudine
Published: November 2024

Motivation: There is limited understanding regarding the physiological mechanisms underlying the impact of coronary artery disease (CAD) on brain health. Goal(s): In this study, we sought to explore the influence of CAD on vascular and metabolic biomarkers. Approach: Specifically examining Cerebrovascular Reactivity (CVR), Cerebral Blood Flow (CBF), and Oxygen Extraction Fraction (OEF) in the brain, and how these factors relate to cognitive performance. Results: Our initial findings, based on a preliminary dataset, indicate that individuals with CAD exhibit reduced CBF and CVR, with increased OEF across several brain regions. Low CVR and high OEF are also associated with poorer executive function in these regions. Impact: The influence of coronary artery disease (CAD) on brain health remains unclear. We show that CAD is associated with elevated OEF and reduced CVR and CBF. High OEF and low CVR are linked to poorer cognition, especially executive functions.
Comparison of iNAV-based Free-Breathing Non-Contrast Coronary Magnetic Resonance Angiography Acquired at 0.7mm3 and 0.9mm3 Resolution
Authors: Littlewood Simon , Wood Gregory , Kunze Karl , Crabb Michael , Kim Won Yong , Prieto Claudia , Botnar René
Published: November 2024

Motivation: Coronary artery disease remains a significant problem worldwide and current methods for anatomical assessment involve ionising radiation and iodinated contrast agents. Goal(s): To develop a novel free-breathing, 3D whole-heart, coronary magnetic resonance angiography sequence with high spatial resolution for the assessment of coronary anatomy and coronary artery disease. Approach: Nine patients referred for assessment of suspected coronary artery disease were scanned using the proposed sequence at 1.5T. Acquisitions at 0.9mm3 and 0.7mm3 were compared. Results: The 0.7mm3 acquisition demonstrated improved qualitative and semi-quantitative vessel visualisation and coronary stenosis detection compared with 0.9mm3 acquisition in an average scan time of <14 minutes. Impact: This work demonstrates improved coronary artery lumen visualisation and stenosis detection compared to 0.9mm3 acquisitions, providing a further step forward towards clinical adoption as a contrast- and radiation-free alternative to CTCA.
Efficient native MRA at 0.55T using motion-correction
Authors: Stoll Robert , Nickel Dominik , Kolbitsch Christoph , Giese Daniel
Published: November 2024

Motivation: MRI at 0.55T with an 80cm bore has allowed improved access to CMR for patients. The application of robust native whole-thorax MRA at low-field remains limited especially due to the challenge of respiratory motion. Goal(s): To develop a large field-of-view, whole-thorax, self-gated and breathing-motion corrected native MRA with a predictable scan time and efficient data usage at 0.55T. Approach: An optimized sampling pattern is used with T2-prep, dual-echo Dixon and non-rigid motion correction is developed. Results: The approach was successfully applied in-vivo and shows successful mitigation of motion artefacts and blurring and good separation of water and fat in the entire thoracic region. Impact: Proof of the viability of self-gated MOCO MRA at 0.55T.
A clinical strategy of 3.0-T non-contrast coronary MRA: a combination of diastole and systole imaging
Authors: Lu Hongfei , Jin Hang , Zeng Mengsu , Yue Xiuzheng , Chen Weibo
Published: November 2024

Motivation: Coronary magnetic resonance angiography (MRA) has not been widely used due to lower diagnostic accuracy. The combination of diastole and systole imaging may enhance its clinical applications. Goal(s): Designing a coronary MRA protocol combining diastole and systole imaging and evaluating its diagnostic performance for detecting significant coronary artery disease (CAD). Approach: 3.0-T non-contrast coronary MRA was carried out twice at diastole and systole. Significant CAD was evaluated by coronary MRA as follows:1) by diastole mode, 2) by systole mode, and 3) by combined mode. Results: Combined coronary MRA showed equally high sensitivity but improved specificity than single diastolic mode. Impact: This study demonstrated that 1) 3.0-T non-contrast coronary MRA using combinational diastole and systole imaging can noninvasively detect CAD with high sensitivity and moderate specificity; 2) Combining diastole and systole imaging improved the diagnostic accuracy of coronary MRA, especially specificity.
The impact of nonlinear blood behavior on hemodynamic parameters in large vessels: more than expected
Authors: Mella Hernán , Galarce Felipe , Sotelo Julio , Castillo Ernesto
Published: November 2024

Motivation: It has not been exhaustively studied how the nonlinear behavior of the blood impacts the estimation of hemodynamic parametersGoal(s): To demonstrate the impact of nonlinear viscosities produced by diseases such as anemia and polycythemia on the estimation of hemodynamic parametersApproach: Hemodynamic parameters were estimated from synthetically generated 4D Flow images obtained from CFD simulations of the aorta using a nonlinear model for the viscosity and different levels of nonlinearityResults: Important differences were observed in WSS, OSI, and energy loss estimated using a nonlinear model for the viscosity compared to results obtained using constant viscosities. Comparisons were made for several casesImpact: This investigation could impact how the MR community estimate hemodynamic parameters from 4D MR images.
The Staging of Lower Limb Venous Thrombosis using DANTE-MP2RAGE Sequence: A Comparative Analysis
Authors: Tan Mingxia , Huang Lanbin , Liu Zeping , Liao Liping , Huang Zehe , Chen Song , Ruan Qizeng , Li Qingchun , Wang Mengzhu Wang , ZHAO Chen
Published: November 2024

Motivation: The aim of this work was to investigate fast T1-mapping for the characterization of deep vein thrombosis (DVT). Goal(s): Discuss the research value of Dante-MP2RAGE technology in venous thrombosis of the lower extremitiesApproach: Select 15 patients with venous thrombosis in the lower extremities and analyze the correlation between the T1 value formed by Dante-MP2RAGE and the stage of venous thrombosis in the lower extremities. Results: DANTE-MP2RAGE is related to venous thrombosis in the lower extremities and provides an accurate T1 value。Impact: Without injecting contrast agents, it provides an effective quantitative indicator for the staging of venous thrombosis in the lower extremities.
Paeoniflorin's Cardioprotective Role in High-Altitude MI: A CMR Study
Authors: Fang Xin , Gao Fabao
Published: November 2024

Motivation: To investigate the cardioprotective effects of paeoniflorin on myocardial infarction-induced ventricular remodeling in high-altitude hypobaric hypoxia environments. Goal(s): To evaluate the potential protective role of paeoniflorin in a rat model of myocardial infarction-induced ventricular remodeling under high-altitude hypobaric hypoxia using cardiovascular magnetic resonance strain analysis. Approach: Rats were allocated to plain sham operation control, high-altitude sham operation control, high-altitude myocardial infarction operation, and paeoniflorin treatment groups. CMR assessed cardiac function. Results: Paeoniflorin treatment groups demonstrated enhanced left ventricular function and regional strains compared to the myocardial infarction group. Histological analyses also showed reduced myocardial injury and fibrosis with paeoniflorin treatment. Impact: The study's outcomes have implications for managing patients at risk of MI, especially those in high-altitude environments or exposed to hypobaric hypoxia.
Analysis of postural effect on cardiac function using multiposture MRI
Authors: Ohno Naoki , Miyati Tosiaki , Imao Shoki , Nakagawa Seiya
Published: November 2024

Motivation: Cardiac function is affected by body posture. However, MRI measurements have been limited to the supine posture. Goal(s): Our goal was to evaluate the effect of body posture on cardiac function using multiposture MRI. Approach: We assessed cardiac function in supine and standing postures in seven healthy males using a 0.4T multiposture MRI. Results: Significant reductions in left ventricular end-diastolic volume, end-systolic volume, and stroke volume were observed in the standing posture, with increased heart rate, while cardiac output and ejection fraction remained consistent across postures. Impact: Multiposture MRI enables the assessment of the postural effect on cardiac function and potentially provides new diagnostic insights into regulatory response to postural change.
Feasibility of a 2D Radial Simultaneous Multi-Slice Phase Contrast MRI sequence for Aortic Pulse Wave Velocity Measurements
Authors: Naren Tarun , Roberts Grant , Johnson Kevin , Breidenbach Bri , Jarchow Mackenzie , Lose Sarah , Pandos Alyssa , Okonkwo Ozioma , Wieben Oliver
Published: November 2024

Motivation: Pulse wave velocity (PWV) is an important biomarker for cardiovascular risk that can be measured non-invasively with phase contrast MRI. Sequential scans at different planes can lead to inaccurate measurements so an alternate approach is needed. Goal(s): We aim to develop a 2D simultaneous multi-slice (SMS) radial phase contrast sequence to image multiple planes concurrently, reduce timing inconsistencies, and measure PWV more accurately. Approach: The radial phase contrast SMS sequence was implemented on a GE scanner and included in an ongoing volunteer study. Results: The SMS scan provided higher quality images in less scan time than sequential and had reduced timing inconsistencies. Impact: Pulse wave velocity (PWV) is a clinically important biomarker for cardiovascular risk. A simultaneous multi-slice radial 2DPC sequence allows for faster, more accurate MR flow measurements with high temporal resolution and reduced timing inconsistency which can improve early detection.
A Spiral, Golden Angle SPGR Sequence for Blood Vessel T1 and T2 Measurement
Authors: Umolac Troy , Portnoy Sharon , Sun Liqun , Seed Mike , Macgowan Christopher
Published: November 2024

Motivation: Current methods for measuring T1 and T2 in fetal blood are inefficient, which limits their applicability to the largest vessels in late gestation. Goal(s): To develop a faster, more motion-robust sequence for blood T1 and T2 measurement, which can be applied in fetal subjects. Approach: A spiral, spoiled gradient echo sequence (sp-SPGR) was developed to jointly estimate blood T1 and T2 from a single, 12 second scan. sp-SPGR accuracy was validated in adult volunteers by comparison with conventional MOLLI and T2p-bSSFP techniques. Results: The sp-SPGR sequence obtained T1 and T2 estimates consistent with conventional methods in approximately one-fifth the acquisition time. Impact: As a faster, more motion robust sequence for estimating blood T1 and T2, sp-SPGR will support oximetry measurements in the fetal great vessels at earlier gestational age, facilitating more accurate and timely evaluation of fetal hypoxia.
Fibrous cap status, plaque surface morphology, and intraplaque hemorrhage volume over two years in patients with carotid plaques: PARISK study
Authors: Kassem Mohamed , Gorissen Tahnee , Albenwan Mohammad , van Dam-Nolen Dianne H.K. , Liem Madieke I , Hofman Paul AM , Wilberger Joachim E , Hendrikse Jeroen , Mess Werner , Nederkoorn Paul J , Bos Daniel , Nelemans Patty , van Oostenbrugge Robert J. , Kooi M Eline
Published: November 2024

Motivation: We explored the relationship between intraplaque hemorrhage (IPH) and thin/ruptured fibrous cap (TRFC) or disrupted plaque surface. Goal(s): We investigated the relationship between a TRFC/disrupted plaque surface and the change in carotid IPH volumeApproach: Longitudinal carotid MR study in 110 symptomatic patients with mild-to-moderate carotid stenosis. Results: Baseline MR images revealed a larger IPH volume in patients with a TRFC/disrupted plaque surface and the IPH volume (tended to) decrease during follow-up. However, part of patients with a TRFC/disrupted plaque surface at baseline had a higher risk of IPH progression. Impact: Identifying patients at higher risk of IPH progression allows for timely monitoring and intervention, potentially reducing the incidence of stroke. This research contributes to improved quality of life for individuals at risk of carotid IPH-related complications
Prognostic value of late gadolinium enhancement in children with dilated cardiomyopathy
Authors: Zhou Zhongqin , Wen Lingyi , Guo Yingkun
Published: November 2024

Motivation: The prognostic value of late gadolinium enhancement (LGE) in adult dilated cardiomyopathy (DCM) has been confirmed, but its prognostic value in children with DCM remains unclear. Goal(s): To evaluate the prognostic value of late LGE in children with DCM. Approach: This retrospective single-center study analyzed 76 children with DCM. The composite endpoint was all-cause mortality, heart transplant, and rehospitalization for heart failure. The risk factors for the composite endpoint were identified with multivariable Cox analysis. Results: Multivariable Cox analysis showed that LGE present was associated with the composite endpoints (hazard ratio [HR], 2.59 [95% CI: 1.05, 6.37], p=0.039). Impact: Late gadolinium enhancement of CMR in children with DCM provides independently prognostic value of all-cause mortality, heart transplant, and rehospitalization for heart failure.
Evaluation of Wideband Cardiac, Real-Time Pulse Sequences in Children with a Cardiac Implantable Electronic Device
Authors: Aboyewa Oluyemi , Shah Dhaivat , Popescu Andrada , Lee Simon , Camarda Joseph , Golestanirad Laleh , Webster Gregory , Kim Daniel
Published: November 2024

Motivation: Cardiac MRI is rarely performed in children with cardiac implantable electronic devices (CIED) due to safety concerns and image artifacts. Goal(s): To determine the clinical utility of wideband cardiac, real-time MRI methods in children with an implantable pulse generator (IPG). Approach: We performed free-breathing real-time cine, wideband late gadolinium enhancement (LGE) and perfusion in 18 healthy children with IPG taped to below the left clavicle and abdomen to mimic endocardial and epicardial systems, respectively. Results: Compared to the standard, wideband sequences effectively suppressed image artifacts, and produced relatively accurate quantification of bi-ventricular functional metrics. Impact: Wideband cardiac, real-time pulse sequences are effective in reducing image artifacts induced by an IPG, thereby increasing the potential benefit of cardiac MRI in children with CIEDs.
Fetal Blood Flow Measurements at Low Field (0.55T) using Metric Optimized Gating
Authors: Cleri Michela , Woodgate Tomas , Zhang Charlie , McElroy Sarah , Giles Sharon , Story Lisa , Pushparajah Kuberan , Lloyd David , Hutter Jana , Payette Kelly
Published: November 2024

Motivation: To allow diagnosis of CHD at low field strengths in order to increase the accessibility of MRI.Goal(s): To demonstrate that acquiring 2D phase contrast sequences in utero at 0.55T is possible. Approach: Acquire 2D Phase contrast sequences, optimize sequences parameters, and perform metric optimized gating and flow measurementsResults: Umbilical vein, descending aorta, and superior vena cava flow in utero measurements were calculated. Impact: Fetal flow measurements provide additional information on the complex hemodynamics in complex CHD cases – potentially enhancing antenatal counselling and postnatal surgery planning. Optimizing these for emerging low field MRI scanners widens their availability.
Augmented hemodynamic quantification of the fetal cardiovascular system using 4D flow MRI and slice to volume 3D black blood imaging
Authors: Fujiwara Takashi , Polak Paul , Englund Erin , Lloyd David , Friesen Richard , Browne Lorna , Moghari Mehdi , Barker Alex
Published: November 2024

Motivation: Small blood vessel size relative to spatial resolution in fetal 4D flow MRI makes segmentation and flow quantification difficult. Goal(s): To quantify blood flow from fetal 4D flow using black blood imaging-based segmentation and to compare hemodynamic results to 4D flow-only approach. We hypothesize black blood will provide better flow delineation for complex anatomies. Approach: The great vessels were segmented from 4D flow and black blood for volunteers and coarctation cases; flow volumes were compared after alignment of segmentations. Results: Black blood underestimated flow volume but captured vessel geometry and flow features 4D flow segmentation missed in several cases of coarctation. Impact: While the combination of black blood imaging and fetal 4D flow did not offer flow quantification comparable to conventional 4D flow approach, its potential of capturing coarctation flow may assist prenatal diagnosis of coarctation, which is challenging solely with ultrasound.