bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying early haemodynamic treatment effects in carotid stenosis using arterial transit artifacts and spatial CoV on ASL-MRI
Authors: Lin Zhiyuan , Muthukumarasamy Mary , Cheng Suk , Gregson John , Brown Martin , Jäger H Rolf , Sokolska Magdalena
Published: November 2024

Motivation: There is little understanding of how arterial transit artefacts (ATA) on ASL-MRI, which indicate regions of haemodynamic compromise, change in patients with carotid artery stenosis following optimised medical therapy versus surgical revascularisation. Goal(s): To assess treatment effects using visually rated ATA severity and a spatial coefficient of variance before and after optimised medical therapy versus additional surgical revascularisation. Approach: We visually rated ATAs using an established four-point grading system and computed the spatial coefficient of variance in corresponding regions. Results: Both methods demonstrated only surgical revascularisation led to significant improvements in haemodynamics 1-month post-treatment, solely within the ipsilateral middle cerebral artery cortical territory. Impact: A robust method of quantifying early haemodynamic treatment effects could be used to identify who truly benefits from surgical revascularisation in the long-term. Future work will correlate these measures to long-term clinical outcomes.
The value of NODDI in detecting the changes of brain microstructure in rabbit models with early cerebral ischemia
Authors: Sun Jiali , Chen Yue , Lv Min , Wang Wei , Lian Jianxiu , Huang Sicong , Ma Yuefei
Published: November 2024

Motivation: It is currently unclear whether neurite orientation dispersion and density imaging (NODDI) can reflect the microstructure in early cerebral hypoperfusion. Goal(s): Therefore, this study aims to detect the cerebral microstructure using NODDI in rabbits’ cerebral ischemia model. Approach: The orientation dispersion index (ODI) and intracellular volume fraction (Vic) were calculated for comparing among groups, including pre-operative and post-operative of rabbit models, and control group. Results: The results showed that Vic of bilateral cerebral hemispheres in post-operative state was higher than that of pre-operative and control groups (all P < 0.05). NODDI could be used to reflect the mild injury in early cerebral ischemia. Impact: Early recognition of injury in brain tissue microstructure in patients with cerebral ischemia is helpful to guide clinical treatment, and NODDI will be able to identify early brain injury.
Both hypoperfusion and structural impairment associates with cognitive decline in HR-NICE patients
Authors: Shang Meiling , Dun Wanghuan , Yan Gezhi , Liu Fude , Wang Wenyang , Ma Ling , Quan Lu , Liu Huiping , Wei Xiaocheng , Zhang Ming
Published: November 2024

Motivation: Patients with high-risk non-disabling ischemic cerebrovascular events (HR-NICE) are recommended as the key population for stroke prevention. However, the functional impairment and underlying neural mechanisms are rarely investigated in this cohort. Goal(s): We attempt to confirm the neural and cognitive impairment and explain the mechanism of cognitive impairment in aspects of both hypoperfusion and cortical abnormality in HR-NICE patients. Approach: Cerebral blood flow, grey matter volume and asymmetry were calculated based on MR perfusion and anatomical data. Results: Hypoperfusion and cortical abnormality are significant in HR-NICE patients, these neural impairments are robustly correlated with cognitive decline. Impact: Our study confirmed the existence of early neural damage in HR-NICE patients, which is reflected in multiple aspects of hypoperfusion, grey matter atrophy and decreased asymmetry. These abnormalities collectively contribute to cognitive decline, especially in patients with left involvement.
MRI Grading Scores Significantly Improve the Prognostic Performance of Standalone Clinical Model for Guillain-Barré Syndrome
Authors: Fang Qiang , Wu Danyang , He Jingzhen
Published: November 2024

Motivation: Guillain-Barré syndrome (GBS) has an unpredictable outcome, and it's vital to find ways to forecast its progression, as some patients may face severe disability or even death. Goal(s): The study aimed to assess the value of MRI grading scores for muscle denervation edema in predicting the course of GBS. Approach: We conducted a retrospective analysis on 354 GBS patients, employing a 5-point MRI grading scale. We compared the predictive capabilities of models using only clinical data against those that combined clinical information with MRI findings. Results: The results clearly demonstrated that including MRI data significantly enhanced the accuracy of predictions for patient outcomes. Impact: MRI grading scores may improve GBS prognosis, enable personalized treatment, and potentially reduce morbidity. This method paves the way for incorporating imaging biomarkers in neurological disorders to improve clinical strategies.
Magnetization Transfer Ratio Shows Selective Spinal Tracts Damage in Patients with Degenerative Cervical Myelopathy
Authors: Filimonova Elena , Abdaev Mars , Prokhorov Oleg , Kubetsky Yulij , Rzaev Jamil
Published: November 2024

Motivation: Quantitative spinal cord imaging is essentially helpful in various pathological conditions, such as degenerative cervical myelopathy (DCM). However, the role of myelin-sensitive techniques in DCM seems to be underestimated. Goal(s): Assess demyelination within different spinal tracts in patients with DCM. Approach: Spinal cord 3T MRI with magnetization transfer ratio (MTR) technique was performed with subsequent post-processing in Spinal Cord Toolbox (v5.5). Results: We revealed structural impairment of the spinocerebellar, rubrospinal, and reticulospinal tracts, as well as fasciculus cuneatus, in patients with DCM compared to the control group. The associations between JOA score and MTR values within spinal cord white matter were also found. Impact: Our results could help to better understand the pathophysiology of DCM. Further studies in this field could be dedicated toassociations of MTR values with surgical recovery, links with supraspinal structural changes, or comparisons with other quantitative techniques.
Hemodynamic quantification for modelling functional outcome in stroke population using 4D Flow Imaging – a pilot study
Authors: Singh Himanshu , VY Vishnu , Kumaran S. Senthil , Karthikeyan G. , Chopra Neha , Mehta Bhairav , Sharma Yatin
Published: November 2024

Motivation: Recurrent stroke is associated to hemodynamic abnormalities in ischemic stroke population, and MRI may play a major role in routine clinical setting. Goal(s): Our goal was to assess hemodynamic variation in aortic region in stroke population (especially in subacute phase) undergoing routine treatment. Approach: we used 4D flow imaging method which employs a non-contrast method with respiratory motion compensation method to acquire flow dynamics in stroke population to assess the aortic flow quantification. Results: Flow abnormalities are significantly differing across subacute phase suggesting changes in hemodynamic. Impact: Understanding cardiac flow dynamics in subacute phase of stroke population (undergoing clinical treatment) can help in understanding the functional recovery pattern to stratify recovery from recurrent stroke condition in future.
T1-Weighted MP2RAGE Optimisation for Neonates at 7T
Authors: Dokumaci Ayse Sila , Uus Alena , Bridgen Philippa , Bonse Beya , Tomazinho Ines , Tomi-Tricot Raphael , Di Cio Pierluigi , Mahmoud Aiman , Hajnal Joseph V. , Deprez Maria , Arichi Tomoki , Carmichael David W. , Malik Shaihan J.
Published: November 2024

Motivation: There is currently no high contrast structural T1-weighted protocol available for neonatal imaging at ultrahigh field (7T), as the longer T1 relaxation times make existing protocols optimized for older subjects unsuitable. Goal(s): To produce submillimeter T1-weighted images for neonates at 7T in a clinically feasible scan time. Approach: We optimised a T1-weighted MP2RAGE protocol using the genetic algorithm for constrained optimisation while accounting for transmit field inhomogeneities. Results: 3D whole-brain images with 0.65-0.8mm isotropic resolution were acquired in under 6-7 minutes from 3 infants. Quantitative T1 maps were produced using an in-house fitting algorithm. Impact: We describe the first neonatal optimised MP2RAGE protocol for acquiring high-contrast submillimeter-resolution images with full-brain coverage that are relatively insensitive to transmit field inhomogeneities.
Spatiotemporal development of structure-function coupling during the perinatal period
Authors: Zhao Ruoke , Li Mingyang , Chen Ruike , Zhao Zhiyong , Wu Dan
Published: November 2024

Motivation: Structure-function coupling (SFC) has been proposed to decode the relationship between anatomical structure and neural activity, but how SFC develops in the perinatal period remains largely unknown. Goal(s): To establish typical SFC map at birth and portray its development during the perinatal period. Approach: SFC of neonatal brains from 26 to 45 postmenstrual weeks were characterized using the dHCP data, and compared to that of adults. The developmental trajectories were depicted by GLM. Results: SFC at birth already demonstrated a sensorimotor-to-association pattern but were immature in somatomotor and frontoparietal networks compared to adults. SFC increased extensively and fastest in visual and limbic networks. Impact: This study fills a gap in the SFC research during early development. Our findings characterized the brain connectome in term- and preterm-born neonates, revealing that visual regions developed earlier than somatomotor regions.
Brain Metabolite Concentrations in Neonates with Congenital Heart Disease Before and After Cardiac Surgery
Authors: Hui Steve , Andescavage Nickie , Ngwa Julius , Kapse Kushal , Kasper Merrick , Saulino Patricia , Limperopoulos Catherine
Published: November 2024

Motivation: Alterations in brain metabolism before and after surgical repair of congenital heart disease is not well studied. Goal(s): To investigate changes in key brain metabolites and primary neurotransmitters before and after cardiac surgery using 1H-MRS. Approach: Data were acquired in the cerebellum, right basal ganglia and right frontal lobe using MEGA-PRESS in 3T. Results: Measurements of myo-inositol (mI) in the cerebellum were significantly higher in the preoperative CHD group compared to the healthy controls. γ-Aminobutyric acid (GABA) measurements were significantly higher in the right basal ganglia in the postoperative CHD group compared to the preoperative group. Impact: Expanded investigation of brain biochemistry in neonates with congenital heart disease has revealed dynamic changes in key metabolites before and after cardiac repair, especially in key neurotransmitters GABA and mI which are known to play important roles in neurodevelopmental disabilities.
MRI-based Cerebral Palsy Early Diagnosis in Infants with Periventricular White Matter Injury aged 6 to 24 months: A Multireader Multicase Study
Authors: Huang Ting
Published: November 2024

Motivation: Early diagnosis of cerebral palsy in infants with periventricular white matter injury is crucial for rehabilitation. Goal(s): To develop and externally validate a MRI-based model to predict CP in infants with PWMI aged 6 to 24 months, and evaluate the diagnostic performance of the model using the MRMC analysis. Approach: In this study, A MRI-based multivariable logistic regression model was develop at one center , and was validated at the three centers, and to evaluate the diagnostic performance of the model using the MRMC analysis. Results: The model showed both excellent predictive performance in the multicenter cohorts and high diagnostic performance in MRMC analysis. Impact: Our model is a reliable and reproducible tool for diagnosis of CP in infants with PWMI aged 6 to 24 months.
MRI-Guided Transcranial Magnetic Stimulation in the Treatment of Pediatric Cases with Spastic Cerebral Palsy
Authors: Bian Yitong , Wu Liang , Jia Zhen , Bai Lu , Han Yangyang , Huang Tingting , Liu Congcong , Wang Miaomiao , Yang Jian , Li Xianjun
Published: November 2024

Motivation: Transcranial magnetic stimulation (TMS)-assisted rehabilitation therapy has demonstrated the potential to enhance prognoses in spastic cerebral palsy (SCP). However, there are still great differences in the efficacy among individuals. Goal(s): We employed personalized MRI-guided TMS to precisely target symptomatic neural circuits in children with SCP. Approach: We used DSI Studio software to track symptom-related fibre bundles within the cortex for targeting and analysed MRI structural and functional differences before and after treatment. Results: Our findings revealed post-treatment improvements in the quantity, maximum length, and mean length of fiber bundles. Additionally, enhanced neural activity and improved consistency of neural signals were observed after treatment. Impact: Individualized MRI-guided TMS interventions have shown promise in ameliorating neurological symptoms in individuals with SCP.
Altered association of cortical thickness with cognitive abilities in very preterm children at 6 years of age
Authors: Jeong Hyejin , Choi Uk-Su , Shim So Yeon
Published: November 2024

Motivation: Very preterm children have a risk of impaired cognitive function mediated by several risk factors. The association between structural alteration and high-order cognitive function remains unclear. Goal(s): Very preterm children at 6 years old showed significant differences in cortical thickness associated with cognitive abilities compared with term infants. Approach: Cortical thickness was assessed in 41 very preterm and 24 full-term children at 6 years of age. The cortical thickness analysis of structural T1-weighted images was performed using Advanced Normalization Tools. Results: Perceptual reasoning indices, high-order cognitive function, were found to be broadly correlated with cortical thickness in both very preterm and term children Impact: This study explores the between brain structure changes and cognitive abilities in very preterm and full-term children, providing insights for neurodevelopmental diagnosis.
Amide proton transfer MRI-based radiomic signatures for molecular subgrouping of pediatric medulloblastoma
Authors: Wen Junjie , Zhang Hongxi , Ma Xiaohui , Chen Xinchun , Chen Weibo , Zhao Feng , Chan Kannie W. Y. , Shen Zhipeng , Zhang Yi
Published: November 2024

Motivation: Medulloblastoma (MB) is classified into different molecular (WNT, SHH, Group 3, and Group 4) subgroups. Accurate identification of molecular subgroups provides clinical value to the diagnosis of MB. Goal(s): We aim to combine APT MRI and radiomic analysis to establish signatures for distinguishing molecular subgroups of pediatric medulloblastoma. Approach: Fifty newly diagnosed pediatric patients with medulloblastoma were enrolled in this study. Radiomic features were extracted from APT-related metrics to differentiate MB subgroups. Results: APT MRI-based radiomic signatures exhibited favorable performance in identifying WNT, SHH, Group 3, and Group 4 subgroups with AUCs ≥ 0.91. Impact: Our research findings demonstrate that amide proton transfer MRI-based radiomic analysis offers a noninvasive and cost-effective method to distinguish molecular subgroups and holds great potential in providing valuable clinical insights for the diagnosis of pediatric medulloblastoma patients.
Utilizing a 3D deep learning reconstruction to improve pediatric abdominal 3D LAVA-Flex image quality
Authors: Milshteyn Eugene , Roberts Nathan , Tsai Leo , Guidon Arnaud , Gee Michael
Published: November 2024

Motivation: Fat suppressed T1 images, such as LAVA-FLEX, are routinely used in pediatric abdominal imaging, but can suffer for SNR and IQ issues. Goal(s): Our goal was to validate application of 3D deep learning to 3D LAVA-FLEX via image quality assessment and noise characterization. Approach: DL and conventionally reconstructed images were assessed by two radiologists and noise characteristics were evaluated by calculation of total variation and number of detected edges. Results: The radiologists preferred DL in a majority of cases (>80%), with noticeably lower noise and improved sharpness in DL images. Impact: The application of DL to routine pediatric 3D LAVA-FLEX imaging provides enhanced diagnostic quality, and has the potential to improve pediatric patient care.
Investigating the influence of post-mortem interval on diffusion anisotropy of whole human brains
Authors: Lüthi Nina , Fritz Francisco , Fricke Björn , Streubel Tobias , Ohana Ora , Sauvigny Thomas , Mushumba Herbert , Püschel Klaus , Mohammadi Siawoosh
Published: November 2024

Motivation: The ISMRM-Diffusion-Study-Group recommends a post-mortem interval (PMI) under six hours to avoid degeneration in ex-vivo tissue for validation of microstructure parameters estimated using preclinical MRI. Fractional anisotropy (FA) deviation from the in-vivo value serves as a quality indicator.[1]Goal(s): Investigating the influence of PMI and tissue size on FA. Approach: Five human whole-brains (PMI 15-24h) and a temporal-lobe (TL) specimen (PMI 2h) were examined with diffusion MRI (dMRI) before and after fixation. Results: The FA of the unfixed whole-brain samples didn’t show differences to the in-vivo values, but between unfixed and fixed states. The FA of the TL specimen was unaffected during fixation. Impact: For the PMIs examined here, myelin decomposition may not significantly affect FA from dMRI of unfixed post-mortem specimens. However, it can affect whole-brain samples during immersion fixation - an effect that may be mitigated by using smaller samples.
Pre-Excitation Gradients for Eddy Current Nulled Convex Optimized Diffusion Encoding (Pre-ENCODE)
Authors: Middione Matthew , Loecher Michael , Cao Xiaozhi , Setsompop Kawin , Ennis Daniel
Published: November 2024

Motivation: Eddy current-induced image distortions in DWI require either tedious image-based corrections or time inefficient pulse sequence acquisitions that increase the minimum echo time (TEmin) and limit SNR. Goal(s): Pre-excitation gradients for eddy current-nulled convex optimized diffusion encoding (Pre-ENCODE) was used to mitigate eddy current-induced image distortions without increasing TEmin. Approach: Simulations, phantoms, and volunteer DWI with monopolar (MONO), eddy current-nulled convex optimized diffusion (ENCODE), and Pre-ENCODE were used to evaluate TEmin, eddy current-induced image distortions, and ADC. Results: Pre-ENCODE offers shorter TEmin compared to MONO and ENCODE as well as reduced eddy current-induced image distortions and more accurate ADC values compared to MONO. Impact: Pre-ENCODE reduces eddy current-induced image distortions by incorporating an additional pre-excitation gradient. Pre-ENCODE provides a shorter TEmin, increased SNR, improved image registration, and more accurate ADC quantification compared with conventional DWI encoding techniques.
Navigator-free, high-resolution prostate diffusion imaging: Multi-Shot EPI with Multi-Scale Low-Rank Reconstruction
Authors: Dong Yiming , Koolstra Kirsten , Atkinson David , van Osch Matthias , Börnert Peter
Published: November 2024

Motivation: Prostate DWI is an important contrast for the diagnosis of prostate cancer. Goal(s): The aim is to achieve prostate DW images and ADC maps with less-geometric-distortion, high-resolution and high signal-to-noise ratio (SNR). Approach: A novel multi-scale low-rank reconstruction approach is introduced to improve multi-shot EPI diffusion-weighted imaging of the prostate. It addresses the ability to jointly reconstruct images over all b-value/diffusion directions at multiple different spatial scales without loss of contrast/structure information. Results: Applied to healthy volunteers using different resolution protocols, the method demonstrates significant improvements in image resolution and SNR compared to a state-of-the-art reference method in a clinically acceptable scan time. Impact: This multi-scale, low-rank reconstruction approach for prostate DWI can significantly improve the quality of diagnostic images, benefiting clinicians and patients by enabling more accurate prostate cancer diagnoses within short scan times.
Whole-Brain Mesoscale 0.7 millimeter-Isotropic-Resolution Diffusion MRI at Ultra-High Fields: The JETS-NAViEPI Approach.
Authors: Hofmann Annika , Tan Zhengguo , Liebig Patrick , Laun Frederik , Knoll Florian
Published: November 2024

Motivation: Diffusion weighted MRI (DWI) may blur structures due to limited resolution. Increasing to submillimeter resolution reduces partial volume effects but sacrifices SNR. Goal(s): We seek to demonstrate submillimeter isotropic DWI at 7T in 3 minutes, and enhanced high-resolution DTI maps. Approach: Data acquisition is done via NAViEPI, enforcing consistent echo spacing between the imaging and the navigator echo, rendering minimal distortion mismatch. Image reconstruction is done using JETS, benefiting from complementary k-q-space sampling and regularization. Results: We show a 3-scan trace acquisition with a scan time of 3:19 minutes, and offer high-resolution DTI measurement leading to Mean Diffusivity and colored Fractional Anisotropy maps. Impact: This work demonstrates submillimeter isotropic diffusion MRI at ultra-high field 7T with improved image quality and reduced scan duration. The JETS-NAViEPI method has the potential to advance high-resolution diffusion MRI, enhancing both spatial and temporal resolution.
Efficient High-Resolution Cardiac DTI with Spiral Keyhole Sampling (SPIK) and Joint Spatial-Angular Sparse Representation
Authors: Golshani Shokoufeh , Teh Irvin , Ravikumar Nishant , Schneider Jurgen , Frangi Alejandro
Published: November 2024

Motivation: In cardiac diffusion MRI, spatial resolution is often limited by the available SNR and scan time. However, reducing voxel size enables precise microstructure characterisation. Goal(s): To develop and evaluate the feasibility of a new sampling/reconstruction scheme that takes advantage of similarities between diffusion-weighted images in (k,q) space in order to provide high spatial resolution with significantly reduced scan times. Approach: A new spiral-based sampling scheme is proposed and its benefits when combined with an efficient reconstruction is demonstrated through simulations. Results: Evaluations showed that the proposed technique provides high-quality diffusion parameter maps comparable to fully sampled reference data with RMSEs less than 4%. Impact: We introduce a novel sampling technique for accelerating high-resolution cardiac diffusion tensor imaging (cDTI). Harnessing the improved spatial resolution and scan time reduction has the potential to make significant contributions to practicability of more complex diffusion models in the heart.
Achievable Flow-Compensation Parameters on a Clinical 33 mT/m Wide-Bore Scanner for Intravoxel Incoherent Motion Imaging
Authors: Rashid Ivan , Ljungberg Emil , Nilsson Markus , Gunnlaugsson Adalsteinn , Olsson Lars , Brynolfsson Patrik
Published: November 2024

Motivation: Can flow-compensated intravoxel incoherent motion be performed on a wide-bore scanner with a 33 mT/m gradient system?Goal(s): To find the shortest feasible diffusion encoding time for double diffusion encoding waveforms. Approach: Phantom measurements with various diffusion encoding times, with application of the optimal encoding times on in-vivo brain and prostate scans. Results: The shortest achievable encoding time was found to be 80 ms, with artefacts being the limiting factor. This encoding time was found to not be sufficiently short for brain imaging. For prostate imaging, it was found to be sufficient for imaging the transitional zone, but not the peripheral zone. Impact: Due to ghosting artefacts associated with higher gradient amplitudes, we found a diffusion encoding time of 80 ms to be the shortest practically feasible. This encoding time was shown to be insufficient for brain IVIM, and partially so for prostate.
Multi-dimensional denoising of diffusion MRI using low rank tensor dictionary learning
Authors: Yan Kang , Dou Quan , Meyer Craig
Published: November 2024

Motivation: Joint denoising diffusion-weighted images in high b-valuesGoal(s): to achieve a better joint denoising of diffusion-weighted image at high b-values. Approach: A low-rank tensor dictionary learning model was introduced to joint denoising diffusion-weighted images at b-values of 1000/2000 s/mm2 for both simulations and in vivo datasets. Three state-of-the-art methods, MPPCA, WNNM, and a pre-trained complex-valued DnCNN were compared. Results: In the simulation, the proposed method achieved the smallest RMSE. In vivo, the proposed method demonstrated a promising denoising ability while better preserving the image structures. Impact: We proposed a low-rank tensor dictionary learning method to better exploit non-local spatial redundancies and image correlations across different b-values with learned dictionaries and low-rank tensor approximation, providing a promising performance in denoising and preserving the image structures.
Mitigation of Peripheral-Nerve Stimulation with Arbitrary Gradient Waveform Design for Diffusion-Weighted MRI
Authors: Hannum Ariel , Loecher Michael , Setsompop Kawin , Ennis Daniel
Published: November 2024

Motivation: Peripheral nerve stimulation (PNS) can be problematic on ultra-high-performance gradients systems, especially during diffusion encoding. We developed a gradient waveform optimization approach to mitigate PNS. Goal(s): Our goal was to investigate the minimum achievable TE (TEmin) using arbitrary gradient waveform design while mitigating PNS for brain, liver and heart DWI. Approach: We used gradient optimization (GrOpt) to design gradient waveforms for TEmin of different protocols, then imaged a phantom and a volunteer with a brain DWI protocol implemented with Pulseq. Results: GrOpt consistently reduces TEs compared to conventional approaches and avoids PNS. Image quality was the same in phantom and in vivo studies. Impact: Ultra high-performance gradient systems increase diffusion sensitivity and resolution, but their application can be constrained due to peripheral nerve stimulation (PNS). We used open-source gradient optimization (GrOpt) to design arbitrary gradient waveforms for minimum time that mitigate PNS.
Three-dimensional phase-based diffusion imaging using RF phase-modulated gradient echo imaging with Stack-of-Stars
Authors: Tamada Daiki , Hernando Diego , Reeder Scott
Published: November 2024

Motivation: There is increased interest in high-resolution diffusion-weighted imaging (DWI); however, conventional DWI methods have limitations such as image distortion and motion sensitivity. Goal(s): To demonstrate the feasibility of high-resolution DWI using phase-based diffusion with radial Stack-of-Stars acquisition (PBD-SoS). Approach: To evaluate PBD-SoS, quantitative ADC measurements were performed with a phantom and compared with conventional methods. In vivo imaging was performed to demonstrate the clinical feasibility of PBD-SoS. Results: The results showed ADC values of the phantom measured using PBD-SoS were consistent (R2=0.99) with conventional DWI, and there were fewer motion artifacts compared to conventional methods in vivo. Impact: PBD-SoS enables high-resolution DWI that is robust to motion, which can be particularly beneficial for body imaging where motion artifacts are common. While current PBD-SoS scans may take longer, future implementation of acceleration techniques could overcome this limitation.
Diffusion-weighted GRASE sequence with 3D navigator for high-resolution time-dependency measurements in the human cortical gray matter
Authors: Li Haotian , Zhu Qinfeng , Lu Jie , Ba Ruicheng , Hsu Yi-Cheng , Yan Xu , Wu Dan
Published: November 2024

Motivation: Oscillating gradient sequences enable diffusion measurement at short diffusion-time (td), but it suffered from low resolution and SNR on clinical systems. Goal(s): To explore the td-dependency in sophisticated structures, like cortical gray matterApproach: We proposed a 3D navigator-based 3D gradient spin-echo (GRASE) sequence for whole-brain td–dMRI at 1.5 mm isotropic resolution, which enabled us to depict the cerebral cortex. Results: We unveiled unique td-dependency patterns across cortical regions with different diffusion dispersion exponent (θ) based on the power-law, which was higher in the sensory cortex, like the occipital region, and lower in the high-order cortex like the temporal region. Impact: The high-resolution td-dMRI technique provided a new approach to characterize the cortical micro-environment and is potentially useful to capture changes due to neurological diseases.
Low-rank Constrained Reacquired-navigator reconstruction of multi-shot diffusion weighted image
Authors: Zhou Jiantai , Zhang Huabin , Luo Penghui , Wang Changliang , Qi Fulang , Yuan Kecheng , Hu Jiaojiao , Qiu Bensheng
Published: November 2024

Motivation: Multi-Shot Diffusion-Weighted Imaging (MS-DWI) requires additional phase correction data and parallel imaging prescans to respectively suppress artifacts caused by positive-negative readout gradient and motion-induced phase variation. Goal(s): Our objective is to mitigate two common artifacts without the need for additional linear-phase corrections and parallel imaging prescans. Approach: We propose subtle modifications to the dual spin-echo DW sequence 1, where positive and negative gradients are employed to separately acquire complete navigator-echo data for low-rank constrained reconstruction. Results: Simulation studies and in vivo brain imaging experiments demonstrate that the proposed method effectively mitigates image artifacts caused by phase variations, resulting in better image quality. Impact: This paper presents a novel artifact correction method applied to spin-echo DW sequence, offering an effective prescan-free acquisition and reconstruction strategy that mitigates the impact of prescan data mismatch and additional prescan time consumption.
A Least Difference Block Sharing (LDBS) Method for Optimizing the View-sharing iblocks-DTI
Authors: Liang Liyuan , Chu Mei-Lan , Chen Nan-Kuei , Chen Shihui , Yuan Chenglang , Xiong Hailin , Xu Xiaorui , Chang Hing-Chiu
Published: November 2024

Motivation: View-sharing iblocks-DTI (VSiblocks-DTI) can substantially reduce the long scan time of iblocks-DTI while providing accurate DTI tensor calculations. However, its neighbor sharing method may limit its performance when using a randomized ordering of diffusion directions or small imaging matrix. Goal(s): This work aims to optimize the sharing method for VSiblocks-DTI. Approach: The least difference block sharing (LDBS) method was proposed and evaluated under different conditions. Results: The proposed LDBS method provided more accurate DTI tensor calculations than the previous neighbor sharing method under six different conditions, demonstrating its robustness to provide accurate DTI tensor calculation for VSiblocks-DTI. Impact: This study proposes a least difference block sharing (LDBS) method for optimizing view-sharing iblocks-DTI. It alleviates the limitation of previous sharing method on the ordering of diffusion directions and shows robust and accurate DTI tensor calculation with different matrix sizes.
Automatic Quantitative Identification of Disproportionately Enlarged Subarachnoid-Space Hydrocephalus in iNPH Using Deep Learning Models
Authors: YAMADA SHIGEKI , Ito Hirotaka , Matsumasa Hironori , Ii Satoshi , Otani Tomohiro , Tanikawa Motoki , Iseki Chifumi , Watanabe Yoshiyuki , Wada Shigeo , Oshima Marie , Mase Mitsuhito
Published: November 2024

Motivation: Automated detection for disproportionately enlarged subarachnoid-space hydrocephalus (DESH) using 3D MRIs. Goal(s): We developed robust deep learning models for accurate DESH detection by automatically segmenting regions. Approach: Utilized 3D U-Net for segmentation and multimodal convolutional neural network for classification. Achieved high accuracy, with mean Dice scores ranging 0.60 – 0.84 and softmax probability scores exceeding 0.95. All of the area under the curves exceeded 0.97. Results: Successfully developed the highly accurate deep learning models in automatically segmentation of ventricles and regional subarachnoid spaces and in the detecting DESH, ventricular dilatation, tightened sulci in the high convexities, and Sylvian fissure dilatation. Impact: Combining a 3D U-Net model and a multi-modal convolutional neural network model, disproportionately enlarged subarachnoid-space hydrocephalus (DESH) for idiopathic normal pressure hydrocephalus (iNPH) was automatically detected with automatically segmented regions from 3D T1- and T2-weighted MRIs.
Echo-uT1RESS Sequence with Radial Stack-of-Stars Acquisition for Dynamic Contrast-Enhanced Dark Blood Imaging
Authors: Zi Ruoxun , Edelman Robert R , Maier Christoph , Keerthivasan Mahesh , Lattanzi Riccardo , Block Kai Tobias
Published: November 2024

Motivation: Scans with dark-blood contrast can improve the conspicuity of small metastases in contrast-enhanced brain examinations and may be useful for vessel-wall imaging. Goal(s): To describe a novel sequence, called echo-uT1RESS, that overcomes the limitations of the frequently utilized T1 SPACE sequence. Approach: The proposed stack-of-stars echo-uT1RESS sequence applies saturation-recovery preparation followed by 3D PSIF readout. Due to radial k-space acquisition, scans are motion-insensitive and can be acquired during free breathing. Dynamic contrast-enhanced images can be obtained through GRASP reconstruction. Results: Evaluation in a small patient cohort demonstrated high conspicuity of enhancing lesions and vessel walls with reduced motion artifacts compared to conventional sequences. Impact: The described radial echo-uT1RESS sequence offers improved lesion-to-background and dark-blood contrast. The sequence may help to increase the sensitivity for detecting small metastases and may find application in vessel-wall imaging. It is also compatible with dynamic imaging using GRASP reconstruction.
Toward Reliable Quantification of Global Cerebrovascular Reactivity to Hypoxic Hypoxia
Authors: Johnson Hannah , Wang Max , Stickland Rachael , Chen Yufen , Bright Molly
Published: November 2024

Motivation: The cerebrovascular response to mild hypoxia has not been well-characterized, but hypoxic cerebrovascular reactivity (CVR) may be an important metric that could complement hypercapnic CVR in clinical applications, giving distinct information about cerebrovascular health. Goal(s): We aimed to increase reliability of hypoxic CVR and modulate the effects of concurrent CO2 changes. Approach: Using phase-contrast MRI, we measured cerebral blood flow during baseline, hypoxic, and hypercapnic respiratory states, induced with a computer-controlled gas blender. We used hypercapnic CVR to implement a simple correction for changes in PETCO2 that occurred during hypoxia. Results: While substantial inter-subject variability remained, PETCO2 correction reduced variability and improved reliability. Impact: Minimizing and correcting for concurrent changes in PETCO2 during a mild inhaled hypoxic stimulus improves the reliability of hypoxic cerebrovascular reactivity, but normal inter-subject variability and the utility of hypoxic cerebrovascular reactivity in clinical populations have yet to be determined.
Age-related assessment in a subset of SHIP data of intracranial vessel geometry from TOF MRI data
Authors: Wilk Dennis , Winter Patrick , Ittermann Till , Langner Sönke , Kromrey Marie-Luise , Schnell Susanne
Published: November 2024

Motivation: Intracranial vessels undergo age-related changes with increased risk of vascular pathologies such as atherosclerosis, or intracranial aneurysms. The occurrence probability of these pathologies could be indicated based on an altered vascular geometry. Goal(s): The application of a geometric analysis to the vascular system of healthy volunteers of two age groups to study age-related changes in the geometry of intracranial arteries. Approach: The analysis involved labeled centerline determination of intracranial arteries and calculating geometric parameters. Results: Our study provided quantitative insights into age-related changes in intracranial artery geometry. Future research with larger, diverse samples can enhance the understanding and enable ML-based analyses. Impact: The objective was to examine age-related changes in women of intracranial arteries by performing a geometric analysis on healthy volunteers. The quantitative evaluation enhances the comprehension of how intracranial artery geometry evolves with age.
Radiomics Features of the Hippocampus Based on 3D-TIWI Improve the Diagnosis of Cerebral Small Vessel Disease with Cognitive Impairment
Authors: huang bingqin , zheng wei , mu ronghua , deng kan , kuang jia , qin xiaoyan , yang peng , feng yuling , xiao yue , zhu xiqi
Published: November 2024

Motivation: Tracking hippocampal radiomic changes over time may provide a biomarker to monitor disease progression and treatment response in cerebral small vessel disease (CSVD). Extending proven hippocampal radiomic methods from AD research to the study of CSVD represents a promising approach worthy of further investigation. Goal(s): To develop a radiomics model based on 3D-T1WI images to improve the diagnosis of CSVD with cognitive impairment. Approach: LASSO regression was used for feature selection and model constructionResults: The model attained an accuracy of 0.781, AUC of 0.818, sensitivity of 0.538, and specificity of 0.947 in distinguishing group 2 from NCs in the test sets. Impact: Overall, our findings support the potential for hippocampal textural features to serve as neuroimaging biomarkers of CSVD, providing a useful tool to aid clinical decision-making in precision medicine.
Development of automated vessel labeling for multiple cerebrovascular conditions based on magnetic resonance angiography
Authors: Kuo Pei-Hsuan , Wang Shuu-Jiun , Chen Shih-Pin , Lirng Jiing-Feng , Wu Chia-Hung , Kuo Yu , Lu Chia-Feng
Published: November 2024

Motivation: Intracranial vessels exhibit significant variations stemming from anatomical distinctions and pathological conditions; therefore, automated vessel labeling is challenging. Goal(s): We aimed to investigate the performance of automated intracranial vessel labeling for multiple cerebrovascular conditions, including normal structure, severe stenosis, occlusion, aging, and calcification. Approach: We developed an automated vessel labeling model solely based on the dataset with normal structures (202 real cases) and evaluated its labeling performance in different cerebrovascular conditions (50 real and 200 simulated cases). Results: The proposed model showed high generalization across cerebrovascular conditions with an average labeling accuracy of 0.82, which could facilitate future quantitative analysis of vessel anomalies. Impact: This study contributes to the application of automated intracranial vessel labeling in different cerebrovascular conditions and offers insights into the model applications in future quantitative analysis for the diagnosis and treatment of vessel anomalies.
Altered patterns of cerebral perfusion in systemic lupus erythematosus patients with cognitive dysfunction, pain and fatigue.
Authors: Salomonsson Tim , Rumetshofer Theodor , Zervides Kristoffer , Jönsen Andreas , Nilsson Petra , Knutsson Malte , Bengtsson Anders , Wirestam Ronnie , Lätt Jimmy , Knutsson Linda , Sundgren Pia
Published: November 2024

Motivation: Cognitive dysfunction (CD), fatigue and pain are common and debilitating in systemic lupus erythematosus (SLE). Symptom-based neuroimaging could contribute to pathophysiological models and patient-centered care. Goal(s): Investigating brain perfusion and blood-brain barrier permeability in SLE patients with CD, fatigue and pain. Approach: 66 SLE patients underwent 3T dynamic susceptibility contrast (DSC) MRI. The leakage parameter K2 and normalized leakage corrected perfusion parameters were estimated in 14 brain regions, compared by symptomatology. Results: Patients with CD or fibromyalgia displayed increased cerebral blood flow and/or cerebral blood volume in regions associated with pain processing. No differences were found for fatigue, K2 or mean transit time. Impact: DSC-MRI detects cerebral hyperperfusion in systemic lupus erythematosus patients with cognitive dysfunction or the pain syndrome fibromyalgia, but not fatigue, suggesting different inflammatory or compensatory mechanisms. Investigating each of these debilitating symptoms separately might further characterize and guide patient-centered interventions.
Diffusion Basis Spectrum Imaging in Midlife Obesity: Associations with Abdominal Adipose Tissue
Authors: Dolatshahi Mahsa , Commean Paul , Rahmani Farzaneh , Nguyen Caitlyn , Lloyd LaKisha , Kassani Sara Hosseinzadeh , Mittendorfer Bettina , Dai Weiying , Sirlin Claude , Song Sheng-Kwei , Benzinger Tammie , Ippolito Joseph , Morris John , Raji Cyrus
Published: November 2024

Motivation: Whether midlife obesity and abdominal adiposity contributes to neuroinflammation, is key to Alzheimer disease (AD) prevention. Goal(s): We aimed to investigate the association between obesity and abdominal visceral and subcutaneous adipose tissue (VAT and SAT) and neuroinflammation. Approach: For this aim, we performed brain and abdominal MRI scans to compare inflammation cellularity, edema, and axonal density using diffusion basis spectrum imaging (DBSI), between the obese vs. non-obese, the high- vs. low-VAT and high- vs. low-VAT groups. Results: A widespread higher inflammation cellularity and a lower axonal density was observed in the obese vs. non-obese, high-SAT vs. low-SAT, and high-VAT vs. low-VAT females. Impact: Higher neuroinflammation and lower axonal density in females with obesity and higher abdominal fat, highlights the sex-specific role of midlife abdominal obesity in neuroinflammation and neurodegeneration, which prompts future studies to target body fat for modifying neuroinflammation and AD prevention.
Targeted MRI (tMRI) of Small Changes in the T1 of White Matter of the Brain in Methamphetamine Dependency Before and After Abstinence.
Authors: Condron Paul , Newburn Gil , Kwon Eryn , Emsden Taylor , Bristow Benjamin , Tayebi Maryam , Ngarimu Tuta , Mohi Wendy , Holdsworth Samantha , Cornfeld Daniel , Scadeng Miriam , Bydder Graeme
Published: November 2024

Motivation: Targeted MRI (tMRI) of small changes in T1 in lesions in normal appearing white matter using divided Subtracted Inversion Recovery (dSIR) sequences can show high contrast and abnormalities that are not seen with conventional IR sequences. Goal(s): To depict subtle changes in T1 in otherwise normal appearing white matter with dSIR images. Approach: Applying tMRI in a patient with methamphetamine dependency before and eight months after abstinence. Results: Widespread abnormalities on dSIR images in areas of normal appearing WM n T2-FLAIR images. There was striking remission of the changes after eight months' abstinence. The changes may be due to neuroinflammation regression with abstinence. Impact: In a patient with methamphetamine dependency, tMRI using dSIR sequences showed striking abnormalities in white matter that appeared normal with T2-FLAIR sequences of the brain. These changes showed marked regression after eight months' abstinence.
Rim Lesion Segmentation on 1MM QSM Positive Source : a Comparison between Deep Learning and Conventional Methods.
Authors: Luu Ha Manh , Gauthier Susan , Kovanlikaya Ilhami , Wang Yi , Spincemaille Pascal , Sisman Mert , Nguyen Thanh
Published: November 2024

Motivation: To automate rim lesion segmentation in multiple sclerosisGoal(s): To compare deep learning and conventional methods for rim lesion segmentation in multiple sclerosisApproach: We compare Unet with chan-vese and Grabcut segmention of MR rim positive lesions. Results: Deep learning achieve the highest Dice score among the compared methods. Impact: Automate rim lesion segmentation in Multiple Sclerosis may allow determine those patient with persistent inflammation.
Interpretable and Intuitive Machine Learning Approaches for Predicting Disability Progression in Relapsing-Remitting Multiple Sclerosis
Authors: Li Yongmei , Yan Zichun
Published: November 2024

Motivation: Improving the interpretability and intuitiveness of the machine learning models can help physicians in clinical decision-making. Goal(s): To investigate whether clinical and grey matter atrophy indicators can predict disability in relapsing-remitting multiple sclerosis (RRMS) and to enhance the interpretability and intuitiveness of a predictive model. Approach: Six machine learning classifiers were trained and tested to predict disability progression. Partial dependence plot (PDP) analysis and a Shiny web application were conducted. Results: The logistic regression model performed best, with an AUC of 0.950. PDP analysis showed which indicators had increased probabilities of disease progression. Finally, a Shiny web application was developed. Impact: The PDP analysis and Shiny web application can improve the interpretability and intuitiveness of the machine learning models to help physicians predict disability progression in RRMS.
Enlarged choroid plexus in relapsing-remitting multiple sclerosis may lead to brain structural changes through glymphatic impairment
Authors: Xie Yan , Zhu Wenzhen
Published: November 2024

Motivation: The enlarged choroid plexus (CP) in relapsing-remitting multiple sclerosis (RRMS) patients may further cause glymphatic function change and brain tissue damage. Goal(s): To explore potential links between structural brain changes in RRMS patients and CP volume as well as glymphatic function. Approach: Brain structural volume was obtained by Freesurfer segmentation. The diffusion tensor image analysis along the perivascular space (DTI-ALPS) index was used to assess the function of glymphatic system. Results: In both cross-sectional and longitudinal studies, RRMS patients had increased CP volume and decreased DTI-ALPS index. Impaired glymphatic clearance partially mediates the effects of CP enlargement on brain structural changes. Impact: Enlarged CP and impaired glymphatic system in RRMS patient may cause brain tissue damage. Using CP as a target for interventions may be beneficial to improve glymphatic system function and become a promising treatment strategy.
Diffusion tensor imaging of multiple sclerosis patients with progression independent of relapse activity show increased white matter damage
Authors: Ocampo-Pineda Mario , Cagol Alessandro , Benkert Pascal , Barakovic Muhamed , Lu Po-Jui , Müller Jannis , Schaedelin Sabine , Weigel Matthias , Melie-Garcia Lester , Kappos Ludwig , Kuhle Jens , Granziera Cristina
Published: November 2024

Motivation: Progression independent of relapse activity (PIRA) is the most frequent manifestation of disability accumulation in multiple sclerosis (MS), but the mechanisms leading to PIRA are currently unknown. Goal(s): To investigate the link between PIRA and white matter degeneration in people with MS. Approach: To compare the integrity of normal-appearing white matter (NAWM) between patients with MS who experienced PIRA versus stable patients using diffusion tensor imaging (DTI) measures from a clinical-compatible protocol. Results: Patients with PIRA exhibited significant differences in DTI-derived measures compared to stable patients: reduced fractional anisotropy and increased mean and radial diffusivity in NAWM. Impact: This study sheds light on the relationship between progression independent of relapse activity (PIRA) and white matter degeneration in people with multiple sclerosis. The results have important implications for understanding the mechanisms of disability progression in relapsing-remitting multiple sclerosis.