bluuebunny/crossref_metadata_2025 huggingface dataset:
Noninvasive assessment of renal function and pathology of CKD using amide proton transfer weighted imaging and diffusion kurtosis imaging
Authors: Yuan Guanjie , Liao Zhouyan , Liang Ping , Yin Ting , Chen Wei , Xu Chuou , Li Zhen
Published: November 2024

Motivation: To explore a noninvasive and sensitive method for detecting the renal insufficiency and pathological abnormality of chronic kidney disease (CKD). Goal(s): To investigate the potential of amide proton transfer-weighted imaging (APTWI) and diffusion kurtosis imaging (DKI) as viable tools for assessing renal function and pathology of CKD. Approach: To analyze the differences and diagnostic performances of MRI metrics between different renal dysfunction and pathological injury groups. Results: Both APTWI and DKI can be feasible tools for the noninvasive assessment of renal functional and pathological changes associated with CKD. APT exhibits superior diagnostic efficacy than MD in detecting early renal dysfunction and pathological abnormalities. Impact: The study suggests that APTWI and DKI provide valuable information regarding the renal function and pathology, which has great significance in guiding risk stratification and longitudinal follow-up of CKD.
Monitoring diabetic kidney disease progression with DTI and tractography
Authors: Periquito Joao , Sharma Kanishka , Soe Kywe , Alhummiany Bashair , Fulford Jonathan , Shelley David , Gilchrist Mark , Shore Angela , Gooding Kim , Mansfield Michael , Gomez Maria , Sourbron Steven
Published: November 2024

Motivation: Previous studies have shown that DTI and tractography may act as early indicator of DKD. Goal(s): The aim of this study was to identify DTI biomarkers that may be sensitive to changes over a relatively short 2-year time frame in early-stage DKD. Approach: Thirteen type-2 diabetic patients were scanned two times during a two-year period on a 3T MRI scanner using a free-breathing diffusion protocol. 180 biomarkers from DTI and tractography were calculated with DIPY. Results: 46 biomarkers showed a significant change over the 2 years, with mean changes that reach over ½ of a standard-deviation and cohen-d effect-sizes up to 0.6Impact: DTI biomarkers show strong changes in early-stage diabetic kidney disease over 2-years, a time frame where clinical biomarkers are typically stable. This finding may have significant implications for clinical practice if confirmed in the larger population.
Repeatability of DTI and tractography biomarkers in healthy kidneys
Authors: Periquito Joao , Sharma Kanishka , Soe Kywe , Alhummiany Bashair , Fulford Jonathan , Shelley David , Gilchrist Mark , Gooding Kim , Shore Angela , Gomez Maria , Sourbron Steven
Published: November 2024

Motivation: For clinical application uncertainty of DTI and tractography biomarkers is critical to avoid that management decisions are made based on changes that are due to measurement error. Goal(s): Provide a comprehensive reference guide of estimated uncertainties for DTI and tractography renal biomarkers and use the data to screen these biomarkers based measurement precision. Approach: Five healthy-volunteers were scanned 4 times on 3T MRI scanner using a diffusion free-breathing protocol. DTI and tractography parameters were calculated using DIPY. Results: Tractography markers are less precise than DTI, sphericity is the most reliable of all DTI metrics, and histogram metrics kurtosis and skewness are inherently imprecise. Impact: This study presents comprehensive reference values for error ranges in renal DTI that will help to identify real (patho)physiological changes in future clinical results
From Low-Field to High Risk: Analyzing RF Heating of Neuromodulation and Cardiac Devices during MRI at 0.55T relative to 1.5T
Authors: Bhusal Bhumi , Sanpitak Pia , Jiang Fuchang , Vu Jasmine , Richardson Jacob , Seiberlich Nicole , Golestanirad Laleh
Published: November 2024

Motivation: Radiofrequency-induced heating of elongated medical implants during MR imaging on newly introduced commercial 0.55T systems has not been thoroughly investigated. Goal(s): We aim to evaluate and compare the RF heating of elongated medical implants during MRI at 0.55T and 1.5T scanners. Approach: Neurological and cardiac implant leads were routed along different trajectories inside a tissue mimicking gel phantom, and the temperature increase during MRI at 0.55T and 1.5T was measured at the lead tip. Results: For certain implant configurations, RF heating at 0.55T MRI can be an order of magnitude higher than that at 1.5T. Impact: Our findings show that unsafe levels of RF heating, exceeding those at higher field strengths, are possible on commercial 0.55T MRI systems for certain implant configurations. Therefore, extra caution should be taken during low-field MRI of patients with long implants.
Modeling of cardiac stimulation limits by MRI gradient coils in a population of body models
Authors: Klein Valerie , Davids Mathias , Ferris Natalie , Wald Lawrence , Guerin Bastien
Published: November 2024

Motivation: Our previous modeling of gradient-induced cardiac stimulation (CS) in two body models indicated that the regulatory IEC 60601-2-33 CS limit overestimated CS thresholds by 9- to 46-fold. Goal(s): To investigate the expected variance of CS thresholds across a healthy population. Approach: We deploy our validated cardiac magnetostimulation modeling approach in six body models with varying shape/BMI/age and a commercial gradient system. Results: Predicted CS thresholds vary up to 2-fold across body models. Worst-case CS thresholds are 7X greater than the IEC CS limit and 4X greater than experimental PNS limits. Impact: Our modeling allows investigation of the variability of CS thresholds across the population, which is not accessible experimentally. This knowledge is critical to obtain a robust estimate of safe, but not overly restrictive cardiac safety limits for MRI gradients.
Deep Learning Based Local SAR Prediction for Head imaging at 7T: applicability and accuracy for unknown head coils
Authors: Meliado E.F. , van den Berg C.A.T. , Raaijmakers A.J.E.
Published: November 2024

Motivation: The methods presented for on-line local SAR evaluation require access to geometric design details of the transmit coil which are not always available. Goal(s): Evaluate the generalization capabilities of deep learning-based methods when they are used to assess the local SAR distribution for coils not included in the training data. Approach: We built a diverse synthetic dataset four different coils and trained a neural network: using only samples from each coil, and using samples from all coils except one. Results: Including a reasonably wide variety of coils in the training process enables local SAR assessment without knowing the design details of the coil. Impact: The lack of access to design details of the coil makes it challenging to transition the more advanced local SAR assessment methods into clinical practice. Training with a diverse set of coils could enable local SAR assessment without coil information.
Brain Clearance Assessment Using the DTI-ALPS Index and Intrathecal Contrast Enhanced Magnetic Resonance Imaging
Authors: Mossige Ingrid , Storås Tryggve , Emblem Kyrre , Eide Per Kristian , Ringstad Geir
Published: November 2024

Motivation: To investigate if DTI-ALPS as a non-invasive method compared to intrathecal contrast enhanced magnetic resonance (gMRI) imaging can be used for evaluating human brain clearance function. Goal(s): To investigate whether or not DTI-ALPS can be used as a non-invasive alternative to gMRI. Approach: This study compared the ALPS index with brain clearance parameters derived from gMRI in a reference group (REF). Results: No significant relationships were found between the ALPS index and change in normalized T1w signal intensity from the gMRI data in both the distribution phase and clearance phase. Impact: The proposed DTI-ALPS index may not be a valid marker of glymphatic function.
Locus Coeruleus Influence on Cognitive Function via the Glymphatic System in Parkinson's Disease
Authors: Wang Xinhui , Haacke Ewart , He Naying , Liu Yu , Wu Peng , Yan Fuhua
Published: November 2024

Motivation: The underlying mechanism of locus coeruleus (LC) in cognitive function of Parkinson’s disease (PD) has not been clearly elucidated. Goal(s): To investigate the relationship among LC degeneration, cognitive function, and the glymphatic system in PD. Approach: All participants underwent neuromelanin-sensitive magnetic resonance imaging (NM-MRI) and diffusion tensor image scanning. The whole brain glymphatic activity was measured using diffusion along the perivascular space (ALPS) index, while LC degeneration was estimated using the NM contrast-to-noise ratio of LC (CNRLC). Results: Mediation analysis demonstrated that the ALPS index acted as a significant mediator between CNRLC and the MoCA score in PD subjects. Impact: These findings enhance our grasp of how the LC noradrenergic system influences cognitive function through the glymphatic system. This research offers a promising starting point for exploring potential therapies and further research into cognitive impairment in Parkinson's disease.
EX VIVO 11,7T MR MESOSCOPIC MULTIMODAL IMAGING OF FETAL BRAIN DEVELOPMENT
Authors: Arcamone Lucas , Poupon Cyril , Khung Suonavy , Alison Marianne , Adle-Biassette Homa , Hertz-Pannier Lucie , Leprince Yann
Published: November 2024

Motivation: White matter injuries are common in very premature babies and carry a significant risk of lifelong motor/cognitive disabilities. Goal(s): Create mesoscopic resolution anatomical imaging, relaxometries, and diffusion MRI data to collect full 3D coverage of multiparametric information on tissue composition and connectivity, and compare to co-registered histology. Approach: Each brain is imaged in situ at 3T shortly after death for registration purposes. After sample preparation, brains are imaged at 7T, then at 11.7T. Results: We develop a unique multimodal mesoscopic (~100µm isotropic) post-mortem MRI atlas of brain development during the prenatal period (from 20 to 41 gestational weeks -GW) using 11,7T MRI. Impact: The premature Human Connectome Project (p-HCP) provides the first mesoscopic multimodal quantitative MRI data at 11.7T of the anatomy, connectivity, cytoarchitecture, and microstructure of normal prenatal neurodevelopment during the second and third trimester of pregnancy.
Using TE-Dependent Analysis for Multi-Echo fMRI Analysis of the Fetal Brain
Authors: Schellenberg Janina , Hall Megan , Story Lisa , Wohlschläger Afra , Hutter Jana
Published: November 2024

Motivation: fMRI of the fetus in the womb must overcome the challenges of fetal motion and heterogeneous tissue boundaries. Multi-Echo fMRI reduces signal dropout and thermal noise, improving contrast-to-noise ratio of the BOLD signal. This can produce higher quality fetal MRI and allow adequate functional assessment of fetal brain development. Goal(s): This study aims to denoise ME-fMRI of the fetal brain with TE-dependent analysis (tedana) in a subset of 10 cases (gestational age >35weeks). Approach: Multi-echo gradient echo EPI scans were acquired in 80 fetuses. The fetal brain is segmented and passed to the analysis. Results: Credible BOLD components are successfully identified using tedana. Impact: TE-dependent analysis denoises ME-fMRI data of fetuses which undergo motion during scanning and contain heterogeneous tissue boundaries. This study assesses capabilities of ME-fMRI analysis to determine BOLD components in the fetal brain,paving the way for future research and clinical usage.
Inhomogeneous Magnetization Transfer Imaging in Extremely Preterm Neonates at 7T.
Authors: van Ooijen Inge , van den Wildenberg Lieke , Bhogal Alex , Ercan Ece , Dudink Jeroen , Tataranno Maria Luisa , Nijman Maaike , Benders Manon , Visser Fredy , Klomp Dennis , Wijnen Jannie , Wiegers Evita
Published: November 2024

Motivation: Extremely preterm neonates often show myelination delay in the brain, which is associated with long-term neurodevelopmental outcome impairments. Traditional imaging lacks myelin specificity, therefore, we implemented inhomogeneous magnetization transfer (ihMT). Goal(s): This study explores the use of ihMT at 7 Tesla for myelin assessment in extremely preterm neonates. Approach: The ihMT data was acquired from a phantom, demonstrating its specificity for myelin content. Six neonates and five adults were scanned with ihMT, and an ROI-based analysis was performed. Results: Phantom and human data confirm ihMT's potential for myelin evaluation. As expected, neonates exhibit lower ihMTR values in key brain regions compared to adults. Impact: This study is an important first step in discovering myelin development in the extremely preterm neonatal brain. Differences in myelin development across the extremely preterm population could be used to predict long-term neurodevelopmental outcome in the future.
Differential myelination maturation across cortical regions and white matter tracts during infancy
Authors: Li Ruolin , Wu Wentao , Mohapatra Sovesh , Sindabizera Kay L. , Zhang Ziqin , Lee Cheng En , Ouyang Minhui , Huang Hao
Published: November 2024

Motivation: While myelination is known to progress rapidly in the infant brain, the specific myelination progression in finer cortical regions and white matter (WM) tracts remain elusive. The precise effects of environmental impacts on infant brain myelination maturation require further investigation. Goal(s): Our goal was to delineate differential myelination maturation trajectories across cortical and WM regions during infancy and explore their associations with environmental factors. Approach: T1-weighted and T2-weighted images were used to map myelin content and analyzed with generalized additive models.Results: Differential myelination processes were found across cortical and white matter regions, with significant correlations to socioeconomic status and parental stress.Impact: This research advances understanding of complicated yet organized patterns in the early developing brain, informing pediatric care strategies. It enables targeted interventions for at-risk groups based on environmental impacts, potentially improving long-term cognitive outcomes. Further studies could investigate intervention efficacy.
Liver T1 Mapping in a Large Cohort of Healthy Subjects: Normal Ranges and Correlation with Age and Sex
Authors: Meloni Antonella , Carnevale Aldo , Gaio Paolo , Positano Vincenzo , Pepe Alessia , Barison Andrea , Todiere Giancarlo , Grigoratos Chrysanthos , Pistoia Laura , Keilberg Petra , Giganti Melchiore , Cademartiri Filippo , Cossu Alberto
Published: November 2024

Motivation: To fully exploit the clinical potential of T1 mapping in liver disease detection, normal values should be established. Goal(s): We defined normal ranges for native hepatic T1 values using a 1.5T General Electric scanner. Approach: MOLLI sequences were acquired in 100 healthy volunteers and native T1 values were quantified in the visible hepatic segments. Results: Segmental and global liver T1 values exhibited a good intra- and inter-observer reproducibility. A significant difference in the segmental T1 values was detected. Segmental and global T1 values were not associated with age and were comparable between males and females. Impact: Liver T1 mapping is feasible and reproducible and the provided normal ranges may help to establish diagnosis and progression of various liver diseases.
Enhanced Non-invasive Characterisation of Renal Tumour Microstructure with VERDICT-MRI
Authors: Sen Snigdha , Smith Lorna , Caselton Lucy , Clemente Joey , Tran Maxine , Punwani Shonit , Atkinson David , Hesketh Richard , Panagiotaki Eleftheria
Published: November 2024

Motivation: Diffusion-weighted (DW)-MRI may characterise renal cell carcinoma (RCC) by reflecting cellularity, but results using the apparent diffusion coefficient (ADC) model are inconclusive. Goal(s): Use advanced modelling with VERDICT-MRI to characterise renal tissue in two different grades and subtypes of RCC, and compare performance to ADC. Approach: Fit VERDICT and ADC models to DW-MRI data from two patients and compare performance in terms of accuracy of fitted signal and parameter estimates. Results: The VERDICT model captures the DW-MRI signal more accurately than ADC. It discriminates between tissue types, and shows high cellularity and low vasculature in the grade 3 tumour, agreeing with independent CT. Impact: We show that VERDICT-MRI can be used to accurately characterise tumour and benign tissue microstructure in two patients with RCC of different grade and subtype, improving performance over ADC and reflecting histological tissue properties such as cellularity and vasculature.
In-vitro evaluation of the performance of PDFF against classification-based algorithms in calculation of breast density
Authors: Gordon Isobel , Ralli George , Fernandes Carolina , Herlihy Amy , Collins Sally , Brady Michael
Published: November 2024

Motivation: Operator-independent quantification of breast density with proton density fat fraction (PDFF) may be more accurate than conventional T1-weighted imaging-based methods, which are limited by the partial volume effect (PVE) and require significant user input. Goal(s): We aimed to assess the accuracy of PDFF against fuzzy clustering (FCM) of T1-weighted images. Approach: Five phantoms representative of different breast compositions were imaged and the breast density calculated with both methods was compared to the known density. Results: PDFF demonstrated improved accuracy compared to FCM of T1-weighted images. FCM-derived density was more sensitive to the partial volume effect and dependent on the bias correction algorithm. Impact: The improved accuracy and comparative robustness of proton density fat fraction (PDFF) suggests it is a more reliable and operator-independent approach to breast density calculation than fuzzy clustering. This is particularly important when assessing longitudinal changes to breast structure.
T2-weighted imaging and water-fat-silicone separation in breast MRI.
Authors: Nurdinova Aizada , Lee Philip , Zhou Xuetong , Moran Catherine , Daniel Bruce , Hargreaves Brian
Published: November 2024

Motivation: Breast MRI is increasingly used for diagnosis and high-risk screening in patients with silicone breast implants, a common aesthetic procedure, but silicone-specific sequences lengthen and complicate protocols. Goal(s): We aim to demonstrate simultaneous water-fat-silicone separation with T2-weighting, and improved contrast between fat and silicone. Approach: We propose Dual-Interval Echo-Time (DIET) preparation to provide T2-weighting with reduced fat signal, and multi-point species separation with 5 gradient echoes at each spin-echo. Results: We demonstrate robust water-fat-silicone separation (WFSS) and improved control of T2-weighting in water, and the contrast between fat and silicone. Impact: We have combined DIET Fast Spin Echo with multi-echo water-fat-silicone separation to enable T2-weighted imaging for subjects with silicone breast implants. This may allow improved evaluation of breast tissue, as well as assessment of complications with implants.
Investigation of Metabolic Heterogeneity in von Hippel Lindau (VHL) Patient Derived Renal Tumor cells using NMR Stable Isotope Tracing
Authors: Asampille Gitanjali , Crooks Daniel , Yang Youfeng , Linehan William
Published: November 2024

Motivation: To develop targeted therapies for Clear Cell Renal Cell Carcinoma (ccRCC). Goal(s): Investigation of metabolic activity in von Hippel-Lindau (VHL) patient derived renal tumor cells using NMR based stable isotope tracing to develop targeted tumor therapies. Approach: Cultured VHL patient derived renal tumor cells (UOK270 and UOK 366) were harvested and extracted upon 24 h of [U-13C] Glucose tracing and analyzed using NMR based stable isotope Resolved Metabolomics (SIRM). Results: After 24 h of [U-13C] Glucose tracing, we determined the relative levels of 13C incorporation in Glycolysis and (Tri Carboxylic Acid) TCA cycle intermediates in UOK 270 and UOK366 using NMR based SIRM. Impact: This is the first-time investigation of metabolic activity in VHL patient derived renal tumor cells generated in house (UOK270 and UOK366) impacting on ccRCC treatment development.
Integrating radiomics, pathomics, and biopsy-adapted immunoscore for predicting distant metastasis in locally advanced rectal cancer
Authors: Zhao Rui , Shen Wenjuan , Wang Sicong , Zou Shuangmei , Zhang Hongmei
Published: November 2024

Motivation: Identifying high-risk patients for distant metastasis (DM) before treatment can facilitate the development of personalized neoadjuvant treatment and improve the prognosis of patients with locally advanced rectal cancer (LARC). Goal(s): This study aimed to construct a predictive model that integrates radiological information at the macroscale and pathological information at the microscale to estimate the probability of DM in LARC patients after neoadjuvant chemoradiotherapy, using radiomics, pathomics, and biopsy-adapted immunoscore. Approach: Feature selection and signature construction were performed using the least absolute shrinkage and selection operator (LASSO)-Cox analysis. Results: The results demonstrated the effectiveness of the nomogram in identifying high-risk DM patients. Impact: Incorporating multiscale information, including radiomics, pathomics, and the immune microenvironment, enhances the characterization of tumors and provides a robust model for identifying high-risk DM patients in LARC. This approach aids in the development of personalized neoadjuvant treatment strategies.
Deep learning enabled MRI general denoising at 0.55T
Authors: Zhu Zheren , Rehman Azaan , Ohliger Michael , Lee Yoo Jin , Xue Hui , Yang Yang
Published: November 2024

Motivation: Recent advancements in 0.55T MRI systems present promising opportunities for affordable and accessible MRI. Enhancing SNR to mitigate the inherent limitations of mid field strength is a crucial step in advancing this technology. Goal(s): In this study, we aim to advance 0.55T MRI for speed and quality through a deep-learning-driven general denoise method processing low-SNR scans of various body parts and sequences. Approach: We constructed a model with a spatial-temporal attention mechanism and employed massive complex image data for training. Results: The proposed method significantly improves low SNR single-repetition images at 0.55T, making the results comparable or superior to the averages of multi-repetitions. Impact: With robust denoising on mid-field systems, enhanced image quality and quicker scans can be expected for more accurate diagnoses and improved patient experience. New sequences can be developed and paired to further advance the system.
Multi-Atlas Segmentation of MR Brain Images with Lesions Using Subspace-Assisted-GAN Based Image Recovery
Authors: Ding Yi , Zhuang Huixiang , Guan Yue , Zhang Yunpeng , Meng Ziyu , Liang Zhi-Pei , Li Yao
Published: November 2024

Motivation: Multi-atlas segmentation (MAS) of MR brain images with lesions is of great clinical significance but remains challenging due to registration inaccuracy caused by pathologies. Goal(s): Our goal was to improve the MAS performance of pathological brain images by restoring more accurate normal images form lesion data. Approach: We integrate a novel subspace-assisted generative model into the MAS framework for estimation of subject-specific posterior normative distribution, which can effectively extract a “hypothetical” normal image from the lesion data, thus enhancing the accuracy of lesion segmentation. Results: Our method produced significantly improved results in normal recovery and MAS compared to the state-of-the-art methods. Impact: The proposed method significantly improves the performance of segmentation of MR brain images with lesions, which may provide a useful tool for tissue segmentation in pathological brain images.
Human fMRI at 10.5T: new regimes of high resolutions
Authors: Vizioli Luca , Dowdle Logan , Moeller Steen , Grant Andrea , Yacoub Essa , Ugurbil Kamil
Published: November 2024

Motivation: Submillimeter fMRI allows imaging the human brain noninvasively at the mesoscopic scale, targeting layers and columns. Standard submillimeter resolution however may be inadequate to fully capture these ensembles. Consequently, the Brain Initiative challenged the MR community to achieve 0.1µL, and subsequently, 0.01µL voxel resolutionGoal(s): Achieve and surpass the goal of human functional mapping at 0.1µL, towards the goal of 0.01µL using a 10.5T scanner. Approach: We recorded human functional BOLD responses at 10.5T, during visual experiments, at different spatial resolutions. Results: Using 10.5T and NORDIC denoising we demonstrate functional imaging the human brain with <0.1µL resolution. Impact: We demonstrate functional mapping at 10.5 T with unprecedented spatial resolutions, moving towards the 0.01µL voxel volume goal (Brain Initiative 2.0). At these resolutions single voxels contain a few thousand neurons, heralding major new opportunities in human neuroscience.
Dynamic MRI in vivo investigation of abdominal hernia repair during standardized exercises
Authors: Joppin Victoria , Bège Thierry , Masson Catherine , Bendahan David
Published: November 2024

Motivation: The incidence of abdominal hernia recurrence is reaching up to 45%; so the integration of biomechanical concepts into management could be helpful. Goal(s): Few tools are currently available to assess the behaviour of the abdominal wall in vivo under physiological conditions. Approach: Dynamic MRI was employed to obtain motion of the abdominal wall of patients before and after hernia surgery during a range of exercises. The areas of interest were segmented. Results: Quantification of displacements and deformations in the abdominal muscles, hernia sac area, and inter-muscular distance demonstrate anatomical and functional changes in the abdominal wall post-hernia surgery. Impact: A better understanding of the biomechanical behaviour of pathologic abdominal wall could be helpful to understand the mechanisms involved in the appearance and recurrence of hernias, thereby opening the way to more effective interventions for hernia patients.
Leveraging unprecedented ultra-high strength gradients in commercially available MRI for in-vivo diffusion tensor CMR
Authors: Scott Andrew , Kunze Karl , Ferreira Pedro , Speier Peter , Geppert Christian , Pennell Dudley , Nielles-Vallespin Sonia
Published: November 2024

Motivation: Spin echo diffusion tensor cardiovascular magnetic resonance (DT-CMR) suffers from low SNR and resolution due to the time-consuming motion-compensated encoding gradients required. Goal(s): Shorten TEs for motion compensated spin echo (MCSE) DT-CMR techniques to improve SNR and allow higher spatial resolution using ultra-high strength whole body gradients (200mT/m) newly available in commercially available scanners. Approach: We implemented second order MCSE and acquired data in healthy subjects at peak systole and end diastole with maximum gradient strength of 146mT/m. Results: We demonstrate high quality MCSE DT-CMR data with reduced TEs and higher spatial resolution than on previously available scanners using similar protocols. Impact: Increases in imaging efficiency in DT-CMR enabled by the use of ultra-high strength gradients on commercial MRI systems will deliver shorter scans and improvements in spatial resolution which are vital steps on the road to clinical translation of DT-CMR.
Safe Diffusion Lobes for Diminished Gradient Vibration
Authors: McCready Matthew , Pauly John , Kerr Adam
Published: November 2024

Motivation: Gradient coil vibrations are a source of loud acoustics, persistent field distortions, potential system damage, and in some cases signal dropout in diffusion MRI. Vibrations are particularly strong at mechanical resonant frequencies. Goal(s): To design “safe” time-optimal diffusion gradients which avoid mechanical resonant frequencies. Approach: A convex optimization problem is formed which seeks to maximize b-value for a given duration while constraining the discrete cosine transform of the diffusion lobe. A bisection search is applied to duration to find the shortest feasible solution with the target b-value. Results: Safe diffusion lobes greatly diminished coil vibration and minimized oscillations in the gradient fields. Impact: Safe diffusion lobes were shown to avoid specified gradient mechanical resonant frequencies reducing vibrations and persistent k-space oscillations. These waveforms have clinical and research potential to improve auditory comfort, prevent DWI signal dropout and image artifacts, and prevent system damage.
Quantitative parameters obtained from gadobenate dimeglumine-enhanced MRI can predict proliferative subtype of hepatocellular carcinoma.
Authors: Ding Feier , Zhang Chao , Qi Xu , Wang Lianbang , Liang Changhu , Zhao Xinya
Published: November 2024

Motivation: Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and the third leading cause of cancer-related death. Goal(s): This study investigated the value of gadobenate dimeglumine-enhanced quantitative parameters for predicting the proliferative subtype of HCC and patients’ prognosis. Approach: All HCC lesions were resected and pathologically confirmed. The lesion-to-liver contrast enhancement ratio (LLCER) was measured in the hepatobiliary phase. Results: LLCER was identified as an independent predictor of proliferative HCC. Patients with LLCER < -4.59% had a significantly higher incidence of proliferative HCC. In addition, patients with LLCER < -4.61% showed poorer overall survival than those with LLCER ≥ -4.61%. Impact: Quantitative information from gadobenate dimeglumine–enhanced MRI can provide crucial information on hepatocellular carcinoma subtypes. It might be valuable to design novel therapeutic strategies, such as targeted therapies or immunotherapy.
3D Seiffert spiral k-space trajectories for a functional sodium (23Na) MRI protocol at 3T
Authors: Rot Samuel , Clemence Matthew , Solanky Bhavana , Wheeler-Kingshott Claudia Gandini
Published: November 2024

Motivation: With advancing hardware, scan durations of 23Na-MRI have decreased, enabling novel applications that probe dynamic or functional processes; existing sequences, though, may not fully exploit the possible acceleration. Goal(s): Implement and demonstrate a highly efficient ultrashort echo time non-Cartesian sequence based on 3D Seiffert spirals, for temporally-resolved applications of 23Na-MRI. Approach: A possible acquisition protocol for functional brain 23Na-MRI at a temporal resolution of 47s was tested on a healthy volunteer at rest, at 3T. Results: Image quality and SNR are high considering the temporal resolution, with compressed sensing successfully reducing noise. Further work will optimise the sequence analytically, ensuring homogeneous k-space sampling. Impact: Dynamic 23Na-MRI at 3T is possible at sub-minute temporal resolution with a 3D Seiffert spiral k-space trajectory. Unlike for other sequences, efficient k-space coverage is achieved without downsides of unpleasant acoustic noise, or exciting mechanical resonances of scanner hardware.
Using NORDIC with 23Na MRI to study dynamic changes in tissue sodium concentration
Authors: Prestwich Ben , Francis Susan , Nicholas Rosemary , Marsh Daniel
Published: November 2024

Motivation: To perform 23Na MRI to study dynamic studies of changes in tissue sodium concentration in-vivo. Goal(s): To demonstrate the application of NOise Reduction with DIstribution Corrected (NORDIC) PCA denoising to 23Na MRI data. Approach: Dynamic timeseries of 23Na GRE data and NORDIC denoising to validate measurement of a known change in sodium concentration in a phantom, and dynamic changes in calf muscle in response to exercise. Results: NORDIC PCA denoising allows detection of the temporal change in sodium in a phantom with good spatial resolution. This is applied to study the dynamics of sodium changes in muscle in response to exercise. Impact: NOise Reduction with DIstribution Corrected (NORDIC) PCA denoising provides the potential to improve low SNR 23Na MRI measures to study dynamic changes in sodium on a spatially resolved level. Here, applied to study 23Na changes in calf muscle on exercise.
Wideband joint black- and bright-blood late gadolinium enhancement imaging in patients with cardiac implantable devices
Authors: Gut Pauline , Cochet Hubert , Caluori Guido , El-Hamrani Dounia , Constantin Marion , Valchos Konstantinos , Sridi Soumaya , Sacher Frederic , Jaïs Pierre , Stuber Matthias , Bustin Aurélien
Published: November 2024

Motivation: Wideband bright-blood late gadolinium enhancement (LGE) enables artifact-free imaging of myocardial scars in patients with implantable cardioverter defibrillators (ICDs). Unfortunately, the poor scar-blood contrast makes it difficult to depict subendocardial scars. Goal(s): To improve myocardial scar visualization and localization in ICD patients. Approach: We propose a 2D breath-hold single-shot ECG-triggered gradient echo wideband joint black- and bright-blood (wideband SPOT) LGE sequence to improve scar visualization and localization, while limiting ICD-artifacts. Wideband was implemented in an adiabatic inversion pulse and in an adiabatic T2 preparation. Results: Wideband SPOT successfully suppressed ICD-artifacts while improving scar detection, and provided same image quality than reference wideband bright-blood. Impact: This new technology will enable radiologists and cardiologists to detect and localize myocardial scars more accurately in ICD patients by eliminating ICD hyperintensity artifacts and enhancing scar tissue with unprecedented contrast.
Visual deficits in a late-stage Parkinson’s Disease mouse model revealed by functional MRI and validated by C-FOS expression and CBF measurements
Authors: Baião Ruxanda , Fernandes Francisca , Monteiro Sara , Figueiredo Patricia , Outeiro Tiago , Shemesh Noam
Published: November 2024

Motivation: The involvement of the brain’s sensory systems in PD is poorly understood and visual deficits are often a complex and underappreciated aspect of the disease. Goal(s): The goal of this study is to study the visual deficits in the PD mouse line by using fMRI, C-FOS expression and CBF. Approach: Here we report aberrations in BOLD-fMRI responses along the visual pathway in mouse model of PD and validate via C-FOS protein expression and ASL. Results: Our findings revealed decreased activity in the visual areas, decreased C-FOS confirmed the neural origin, and the ASL excluded any vascular differences that could alter the fMRI signals. Impact: Many individuals with PD experience a decline in visual acuity. Thus, understanding and addressing visual deficits in Parkinson's disease is crucial for improving the overall well-being and daily functioning of individuals living with this condition.
Neuronal activity can drive cerebrospinal fluid flux via brain blood volume
Authors: Zott Benedikt , Zimmermann Juliana , Boudriot Clara , Eipert Christiane , Hoffmann Gabriel , Nuttall Rachel , Schneider Sebastian , Schmitzer Lena , Kufer Jan , Kaczmarz Stefan , Hedderich Dennis , Ranft Andreas , Golkowski Daniel , Ilg Rüdiger , Schneider Gerhard , Priller Josef , Zimmer Claus , Preibisch Christine , Sorg Christian
Published: November 2024

Motivation: A driver of macroscopic CSF flux across ventricles and basal cisternae is hypothesized to be global cerebral blood volume, possibly induced by changes in brain-wide neuronal activity. Goal(s): We intended to test this hypothesis experimentally in healthy human subjects. Approach: We performed two experiments: (1) electro-encephalography and functional MRI (fMRI) during burst-suppression anesthesia, and (2) arterial spin labeling and fMRI during transient hypercapnic challenges in wakefulness. Results: Changes in brain blood volume, induced by neuronal activity switches during burst-suppression or brain blood flow during hyper-normocapnia transitions, cause fMRI signal changes in the basal cisternae which represent CSF flux from or into the brain. Impact: Two distinct experiments revealed a consistent and direct coupling between macroscopic CSF flux and brain blood volume, which can be induced by changes in global neuronal activity. This may contribute to perivascular CSF flow and facilitate brain waste clearance.
Artery-pulsation dependence of the paravascular cerebrospinal fluid flow measured by dynamic diffusion tensor imaging in human brain
Authors: Han Guangxu , Jia Yinhang , Hsu Yi-Cheng , Bai Ruiliang
Published: November 2024

Motivation: There is still lack non-invasive methods to quantitative measure the paravascular cerebrospinal fluid (pCSF) flow speed and directions pulsations of arterial vessel . Goal(s): To explore whether dynamic DTIlow-b could capture the artery-pulsation dependence of pCSF flow in human and how DTIlow-b metrics are modulated by artery pulsation. Approach: Six-direction dynamic DTIlow-b was acquired simultaneously with finger pulse oximeter recording on eight subjects. Results: Both the axial and radial diffusivity of pCSF and whole-brain white matter is increased by artery dilation. DTIlow-b signal of pCSF at b = 0 mm2/s also shows artery-pulsation dependence but lags from diffusivity changes. Impact: The proposed dynamic DTIlow-b with ultra-long TE could potentially capture the volume and flow dynamics of MRI-visible and -invisible pCSF in artery pulsation.
Extracellular Volume Change in Human Brains during Sleep: A Simultaneous Sodium (23Na) MRI and EEG Study
Authors: Chen Xingye , Lin Ying-Chia , Kumbella Nahbila-Malikha , Henin Simon , Rockowitz Zena , Liu Anli , Masurkar Arjun , Babb James , Ge Yulin , Lui Yvonne , Qian Yongxian
Published: November 2024

Motivation: Alzheimer's disease is associated with neurotoxic amyloid-beta(Aβ) plaques. Studies in mice demonstrate that impaired cerebrospinal fluid(CSF) clearance reduces Aβ clearance by 70%. Sleep enhances CSF clearance by expanding extracellular space. Goal(s): However, the impact of sleep on extracellular volume change remains unclear in human brains due to a lack of non-invasive technology. Approach: To address this gap, we use sodium(23Na) MRI to measure the extracellular volume fraction in 16 healthy human brains. We monitor the sleep stage with MRI-compatible Electroencephalography(EEG). Results: On average, a decrease in extracellular volume fraction was observed in the gray matter significantly, but not significant in the white matter. Impact: Our research may shed light on how sleep may facilitate Aβ clearance in humans, bridging the gap between animal and human studies.
Altered perivascular CSF mobility in human cerebral amyloid angiopathy
Authors: Deike-Hofmann Katerina , Scheyhing Paul , Nordsiek Julia , Decker Andreas , Radbruch Alexander , Petzold Gabor
Published: November 2024

Motivation: Perivascular spaces (PVS) are mediating brain clearance, i.e. cerebrospinal fluid (CSF) - interstitial fluid exchange, and dilated PVS are a hallmark of cerebral amyloid angiopathy (CAA). However, until now, brain clearance function could not be assessed in humans in vivo. Goal(s): Goal of this study was to assess perivascular cerebrospinal fluid (CSF) mobility in CAA patients. Approach: A CSF mobility-specific 7-Tesla MRI sequence was applied for the first time in patients with CAA and healthy control (HC) subjects. Results: The study revealed perturbed CSF mobility in enlarged perivascular spaces in CAA compared to HC subjects, suggesting impaired perivascular clearance in CAA. Impact: With the finding of a perturbed CSF mobility in enlarged PVS in CAA patients, the study provides proof-of-principal for in vivo measurements of perivascular CSF mobility as a crucial component of the brain clearance pathway in health and disease.
The effect of low frequency visual stimulation on CSF flow in the fourth ventricle measured with BOLD-fMRI
Authors: Munting Leon , Hirschler Lydiane , Roefs Emiel , Keller Jasmin , van Harten Thijs , van Osch Thijs , van der Weerd Louise , van Veluw Susanne
Published: November 2024

Motivation: Glymphatic clearance is impaired in neurodegenerative disease. Vasomotion has been suggested to drive CSF flow and influence clearance. Furthermore, low frequency sensory stimulation can enhance vasomotion. Whether low frequency visual stimulation can drive CSF flow in humans is still unclear. Goal(s): To study the effect of different visual stimulation frequencies on BOLD signal and CSF flow. Approach: 7T BOLD-fMRI scans were acquired in healthy volunteers watching a checkerboard flashing at 0.025, 0.05, or 0.1 Hz. Results: Visual cortex BOLD responses clearly oscillated at the stimulation frequencies, with increased power at lower frequencies. CSF flow responses observed in the fourth ventricle, however, were modest. Impact: This preliminary study confirms that BOLD responses can be evoked locally in the brain with low frequency visual stimulation, but that there is only modest effect on ventricular CSF flow.
High-field contrast-enhanced magnetic resonance imaging demonstrates cerebrospinal fluid nasal efflux dynamics in vivo
Authors: Swanberg Kelley , Kritsilis Marios , Shanbhag Nagesh , Johansson Emily , Jukkola Jari , Zandt René In 't , Lundgaard Iben
Published: November 2024

Motivation: The astroglia-mediated circulation of metabolites and waste between cerebrospinal fluid (CSF) and blood or lymph, recently termed the glymphatic system, is implicated in processes from autoimmunity to neurodegeneration. Goal(s): Many details of CSF dynamics, particularly efflux routes from brain to periphery including nasal pathways as we examine here, remain to be clarified. Approach: Here we investigate CSF efflux in living mice using 9.4-T in vivo dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Results: We show that gadolinium-based contrast agent injected into the cisterna magna (CM) of live mice dose-rate-dependently effluxes into the nasal mucosa in a manner affected by olfactory neuronal integrity. Impact: Controversy surrounds the current model of CSF efflux from brain ventricles to periphery. We show with high-field DCE-MRI in live mice that nasal efflux of CSF from cisterna magna adapts to both a flow rate challenge and olfactory neuronal damage.
Brain structure-function interaction network via graph convolution network for Parkinson’s disease classification
Authors: Xia Jing , Chan Yi Hao , Girish Deepank , Rajapakse Jagath
Published: November 2024

Motivation: Brain functional connectivity (FC) and structural connectivity (SC) have distinct neural mechanisms for Parkinson’s disease (PD). Furthermore, the interactions between SC and FC could reveal underlying mechanisms and enhance classification performance. Goal(s): We aim to utilize structure-function interactions for PD classification. Approach: We propose a brain structure-function interaction model via graph convolution network to incorporate both modality-specific embeddings and structure-function interactions. Results: Results on 72 PD patients and 69 normal controls demonstrate that our method outperforms other state-of-the-art methods. We identify strong structure-function couplings in the precentral gyrus, prefrontal, superior temporal, cingulate cortices, and cerebellum that are associated with PD. Impact: We proposed a novel brain structure-function interaction network based on GCN to utilize modality-specific features and interactions of SC and FC for PD classification. Our method identified the coupling strengths between SC and FC associated with PD.
Robust Multi-Shot Diffusion Weighted Imaging of the Abdomen with Region-Based Shot Rejection
Authors: Lee Philip , Zhou Xuetong , Hargreaves Brian
Published: November 2024

Motivation: To improve the motion robustness of multi-shot DWI in the abdomen and reduce signal dropouts and ADC overestimation caused by unresolved shot-to-shot phase. Goal(s): Demonstrate that region-based weighting of different shots improves diffusion contrast in rapidly moving abdominal organs. Approach: Shot rejection was evaluated in the pancreas. Multiple shot rejection formulations were tested, and compared using conventional monopolar, and motion-compensated diffusion encodings. Results: Shot rejection allows conventional monopolar encoding to achieve diffusion weighting and ADCs similar to the motion-compensated encoding in the pancreas. The reconstruction is linear, requires no modifications to the sequence, and is applicable to many encoding trajectories. Impact: Shot rejection may improve the consistency and robustness of multi-shot abdominal DWI in the clinic, as well as its ability to differentiate pathologies. This will improve repeatability of DWI studies of rapidly moving organs, such as the pancreas and heart.
Low-distortion Spine DWI with Ultra-high Shot and Navigator-free Reconstruction
Authors: Qian Chen , Han Mingyang , Guan Feiqiang , Guo Yucheng , Wu Zhigang , Wang Jiangzheng , Jiang Boyu , Tao Ran , Zhu Liuhong , Guo Di , Zhou Jianjun , Qu Xiaobo
Published: November 2024

Motivation: State-of-the-art low-rank methods recover multi-shot DWI with 2D structured matrix completion, but are hindered by long computation time (tens of minutes per image) and unsatisfactory ultra-high shot reconstruction (no more than 8-shot). Goal(s): Fast and reliable ultra-high (above 8-shot) DWI reconstruction. Approach: ODLRS: A 1D low-rank Hankel reconstruction method with self-adaptive subspace. Results: ODLRS is a novel 1D low-rank framework for multi-shot DWI reconstruction. Compared to conventional low-rank methods, ODLRS achieves 109 times accelerated reconstruction, and low-distortion spine DWI with 12 shots.SImpact: This work achieves fast (109 times acceleration) and reliable ultra-high (10 and 12 shots) DWI reconstruction, reducing the deformation of conventional spinal cord DWI significantly.
Slice-POCS-ICE: a navigator-free reconstruction for SMS-accelerated multi-shot spiral-based diffusion-weighted imaging
Authors: Li Guangqi , Jiang Yuancheng , Zhang Yajing , Guo Hua
Published: November 2024

Motivation: Simultaneous multi-slice (SMS) technique can further enhance the acquisition efficiency of spiral-based diffusion imaging. Goal(s): Our goal was to achieve SMS-accelerated navigator-free multi-shot spiral-based diffusion imaging. Approach: RF pulse phase encoding strategy was optimized to introduce the CAIPI phase modulation. Furthermore, we proposed the slice-POCS-ICE algorithm to simultaneously perform CAIPI phase demodulation, inter-shot phase error correction, and diffusion image reconstruction. The proposed algorithm was tested on simulated and in-vivo data. Results: Our proposed slice-POCS-ICE algorithm can simultaneously accomplish CAIPI phase demodulation and remove the shot-to-shot phase variations, for SMS-accelerated multi-shot navigator-free spiral-based DWI. The proposed slice-POCS-ICE has a stable convergence behavior. Impact: The proposed slice-POCS-ICE reconstruction algorithm can successfully reconstruct multi-shot diffusion images from SMS-accelerated navigator-free spiral acquisitions with optimized CAIPI phase modulation, which may be valuable for speeding up multi-shot spiral-based DWI acquisitions, to facilitate both neuroscience research and clinical diagnosis.
MRF-SEG: Accelerated Brain MRI Acquisition and Segmentation
Authors: Kumar Ashwin , Zhou Zihan , Chen Quan , Cao Xiaozhi , Billot Benjamin , Fischl Bruce , Chaudhari Akshay , Setsompop Kawin
Published: November 2024

Motivation: Despite the availability of rapid high-resolution MRF sequences that can be used to synthesize MPRAGE, acquiring MPRAGE scans remains necessary for accurate downstream segmentation. Goal(s): The aim is to perform accurate-segmentation directly on MRF time-resolved data, eliminating the need for a lengthy MPRAGE scan, resulting in significant time savings, and providing quantitative tissue parameter maps. Approach: We used deep learning to directly segment MRF time-resolved data and generate multi-tissue brain segmentation maps. Results: Our findings indicate that deep learning segmentation methods trained directly on MRF data, both quantitatively and qualitatively perform better than segmentation on synthesized MPRAGE. Impact: Applying deep learning directly on MRF data improves MRF segmentation compared to synthesizing MPRAGE and performing segmentation on it. This strengthens the validation of MRF and enhances its clinical potential by rapidly acquiring and segmenting brain images.