bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Assessment of Synthetic MR with Deep Learning Reconstruction in Clinical Diagnosis of Nasopharyngeal Carcinoma
Authors: Peng Kangqiang , Liu Huiming , Meng Tiebao , He Haoqiang , Zhang Jialu , Xie Chuanmiao
Published: November 2024

Motivation: To enhance nasopharyngeal carcinoma (NPC) diagnostics, this study aims to assess the accuracy and image quality of relaxometry maps using fast synthetic MRI with deep learning reconstruction. Goal(s): The primary goal is to evaluate the potential of DL Recon for NPC diagnosis, focusing on reduce scan time, improve image quality and quantitative accuracy to enable early lesion detection. Approach: Two protocols (Trad: lower acceleration rate without DL Recon, DLR: higher acceleration rate with DL Recon) was performed on twenty-four NPC patients to evaluated T1/T2/PD measurements and image quality. Results: Fast MAGiC acquisition with DL Recon can retain accuracy and improve image quality. Impact: With DL Recon, the MAGiC acquisition can achieve in shorter scan time, with enhanced image quality and maintained quantitative accuracy in NPC diagnosis use.
Classification of Benign and Malignant Parotid Gland Tumors using Deep Learning and 2.5D MRI
Authors: Mai Wenfeng , Zhang Lingtao , Zhang Dong , Liu Weiyin , Luo Liangping , Shi Changzheng
Published: November 2024

Motivation: Preoperative distinguishment of the benign parotid gland tumors from the malignant determines the surgical scope; however, identifying tumor nature with only T1-weighted and fat-suppressed T2-weighted images is challenging. Goal(s): Inserting three adjacent slices of the tumor into the RGB channels of a 2D image as 2.5D images coupled with transfer learning was utilized. Approach: Using 2D and 2.5D images as input, a ResNet-101 model, pre-trained on ImageNet, was employed for transfer learning to facilitate the prediction. Results: Deep learning models discerned malignant parotid gland tumors from the benign, especially 2.5D model showed superior performance to 2D model. Impact: The transfer learning and 2.5D-MRI based classification model offered new insights to differentiate the malignant parotid gland tumors from the benign ones, especially when sample quantities are limited.
Neural network inversion in transversely isotropic materials
Authors: Trevathan Jonathan , Manduca Armando , Trzasko Joshua , Huston John , Ehman Richard , Murphy Matthew
Published: November 2024

Motivation: Most Magnetic Resonance Elastography (MRE) inversion algorithms assume isotropic materials. However, in tissues with a preferred fiber direction, the effective mechanical properties computed under this assumption will reflect a mixture of the true underlying elastic moduli. Goal(s): In this study, we extend neural network inversion (NNI) to include transversely isotropic (TI) materials. Assumptions are progressively relaxed and the TI inversion in each case is compared against isotropic inversion. Approach: Data was generated to train and test multiple TI inversions. Results: An NNI trained to handle TI material can more accurately estimate shear moduli in anisotropic materials and can predict the amount of anisotropy. Impact: This research expands on currently used MRE to allow for more accurate property estimation in highly organized tissues such as brain and muscle. Moreover, it opens new paths of investigation into pathological changes of the highly organized tissues.
Fully Automated Deep Learning 3D Segmentation of the Aorta from Contrast Enhanced Magnetic Resonance Angiography Images
Authors: Dushfunian David , Berhane Haben , Siddiqui Sara , Maroun Anthony , Allen Bradley , Markl Michael
Published: November 2024

Motivation: Contrast-enhanced MRA (CE-MRA) of the thoracic aorta is an essential to assess and monitor aortic complications, and to quantify aortic dimensions. However, aortic dimensions’ measurement is cumbersome. Thus, automating aortic 3D-segmentation from CE-MRA is important to improve analysis workflow efficiency. Goal(s): We aimed to, accurately and precisely, automate thoracic aorta 3D-segmentation from CE-MRA scans using deep-learning. Approach: Using 125 CE-MRA scans we trained and tested a convolutional neural network to automatically segment the thoracic aortic. Results: Automated-segmentations was faster to output and had excellent agreement with manual-segmentations in metrics like aortic diameters and volume, dice scores, Hausdorff distance and average symmetrical surface distance. Impact: To our knowledge, this is the first study that implemented a fully-automated 3D-segmentation of contrast-enhanced MRA images. Such automation could possibly facilitate the clinical workflow when combined with future applications aiming at automating dimensions’ calculation at standardized locations.
Quantitative Assessment of Segmented Masks: A Deep Learning Regression and Classification Study
Authors: GOUD Ponnam Mahendhar , Saxena Ashish , Bhushan Chitresh , Kaushik Sandeep , Ghose Soumya , Shanbhag Dattesh
Published: November 2024

Motivation: Ability to track real-world performance of AI based spine segmentation models without access to ground-truth data. Goal(s): Develop AI models which allow prediction of spine vertebrae segmentation model performance in real time. Approach: Developed a regression and classification deep learning (DL) models that determines quality of segmentation results in terms of Dice overlap metric from a parent segmentation DL model. Results: For regression model, dice prediction error of 4.3% was obtained, while for categorical classification model, sensitivity between 63-87% observed across evaluation categories. Combination of regression and classification models improves model performance evaluation with sensitivity between 71 to 91%. Impact: : We developed DL models to automatically evaluate accuracy of spine-vertebrae segmentation models during their deployment in clinical practice without access to ground-truth in both quantitatively (Dice) and qualitatively (Perfect, good, medium, poor). This ensures automatic-logging model effectiveness in real-world data.
Cross-frequencies Coil Sensitivity Profile Prediction Using Convolutional Neural Networks: Explorative study
Authors: Dai Jiying , Stoffijn Ruben , Gosselink Mark , Froeling Martijn , Raaijmakers Alexander , Klomp Dennis
Published: November 2024

Motivation: Coil sensitivity profiles are essential for multi-channel MRI/MRSI data processing, yet not acquirable within reasonable scan time for X-nuclei with low natural abundance. Goal(s): Predict sensitivity patterns of lowly abundant X-nuclear species based on sensitivities of highly abundant nuclei acquired by the same multi-tuned coil array. Approach: We scanned 8 subjects at 1.5T and 3T using similar commercial head arrays. A 3D patch-based convolutional neural network is used to predict 3T sensitivity patterns from 1.5T sensitivities. Results: Predicted 3T sensitivity patterns show high similarity to the ground truth. 3T signal-combination is feasible using the 1.5T-based predicted sensitivities, despite subject repositioning and hardware deviation. Impact: An adequate prediction of coil sensitivity profiles at 128MHz based on 64MHz sensitivity profiles using highly similar receiver arrays was achieved. It opens up new possibilities for combining multi-channel signals acquired by multi-tuned (e.g., 31P-23Na, 19F-1H, etc.) receiver arrays.
Single-Shot $$$T_1$$$ Mapping using an Interleaved SMS IR-FLASH Sequence and a NLINV Subspace Reconstruction
Authors: Mackner Daniel , Blumenthal Moritz , Scholand Nick , Telezki Vitali , Wang Xiaoqing , Uecker Martin
Published: November 2024

Motivation: Volumetric quantification of$$$~T_1~$$$is highly desirable but limited by long acquisition times especially for motion-affected organs, such as heart. Therefore, conventional cardiac$$$~T_1~$$$mapping techniques are limited to single slices and suffer from low spatial resolution. Goal(s): Develop a technique for rapid$$$~T_1~$$$mapping of multiple slices at high spatial resolution. Approach: A radial slice-interleaved SMS readout was developed for single-shot IR-FLASH acquisition. NLINV subspace reconstruction is further proposed to jointly estimate subspace coefficient maps and coil sensitivities for all slices. Results: Accurate$$$~T_1~$$$maps were achieved in a phantom and brain experiment for 9 slices within 4$$$~$$$seconds. Six cardiac short-axis myocardial$$$~T_1~$$$maps were reconstructed with an in-plane resolution of $$$1.25~mm^2$$$. Impact: Multi-slice $$$T_1$$$ mapping has been achieved with a slice-interleaved radial SMS IR-FLASH acquisition and subspace NLINV reconstruction. This development may facilitate high resolution whole-heart myocardial $$$T_1$$$ mapping within a short breathhold (4 seconds).
Diffusion and contrast-enhancement MRI phenotypes predict immune cell infiltration in brain metastases
Authors: Sanvito Francesco , Oshima Sonoko , Shiuan Eileen , Sun Lu , Cho Nicholas , Kim Asher , Salamon Noriko , Ellingson Benjamin , Prins Robert , Kim Won , Yao Jingwen
Published: November 2024

Motivation: Immune checkpoint inhibitors (ICIs) can promote immune cell infiltration and increase anti-tumoral immune response in brain metastases (BM). Imaging proxies of immune infiltration would facilitate ICI-response monitoring in BM. Goal(s): To test whether the combined assessment of diffusion and contrast-enhancement MRI phenotypes can provide insights into microscopic immune infiltration. Approach: We studied the associations of diffusion and contrast-enhancement MRI phenotypes with histological immune cell infiltration and with ICI-treatment statusResults: Correlation analysis showed that high diffusivity and pronounced contrast-enhancement were positively associated with increased immune cell infiltration and were more likely observed in ICI-treated lesions. Impact: Immune checkpoint inhibitors (ICIs) can promote immune cell infiltration and increase anti-tumoral immune response in brain metastases (BM). Diffusion and contrast-enhancement MRI phenotypes provide potential imaging biomarkers to non-invasively monitor tissue changes related to anti-tumoral immune response following ICIs.
Application of Contrast-Enhanced MULTIPLEX T1 and aT1-weighted Imaging in the Diagnosis of Brain Metastases
Authors: Liang Xue , Lin Yongjuan , Zhang Qinglei , Wang Kuan , Song Weitong , Tian Chuanshuai , Zhu Zhengyang , Zhang Yunfei , Yin Zhenyu , Zhang Bing , Zhang Xin
Published: November 2024

Motivation: Early monitoring for intracranial metastatic lesions through non-invasive methods will directly impact patient prognosis and quality of life. Goal(s): The aim of this study was to evaluate the performance of MULTIPLEX in detecting brain metastases. Approach: Signal-to-noise ratios (SNRs) for gray matter (GM) and white matter (WM), contrast-to-noise ratios (CNRs) for lesion/GM, lesion/WM, and GM/WM were quantitatively compared. Results: MULTIPLEX aT1 imaging is preferred for depicting lesions containing hemorrhage or calcifications. Impact: The combination of MULTIPLEX T1 and aT1 sequences enhances the detection of brain metastatic lesions compared to T1-GRE imaging, which could be helpful for detecting of small metastatic tumors.
The association between the intravoxel incoherent motion diffusion-weighted imaging(IVIM) with the DSC and 3DASL imaging in Glioma Recurrence
Authors: Liu Yanhong , Liang Yuhan , Sun Jiayi , Wang Yulin
Published: November 2024

Motivation: Diffusion-weighted imaging and perfusion-weighted imaging have shown promising accuracy in differentiating glioma recurrence and treatment-related changes. Intravoxel incoherent motion (IVIM) MRI enables the simultaneous acquisition of diffusion and perfusion parameters, providing true diffusion and capillary perfusion in the tumor. Goal(s): To evaluate the diagnostic performance of IVIM-derived parameters in glioma recurrence patients with DSC and 3DASL perfusion-weighted imaging. Approach: The correlation between IVIM parameter and perfusion-MRI parameters was evaluated in regions of contrast enhancement with Pearson’s correlation analysis. Results: ADC-F within T1-enhanced lesions positively correlated with relative cerebral blood volume (rCBV),nrCBF, and nCBF. Additionally,ADC-F was statistically significantly associated with rCBV and nrCBF. Impact: IVIM has the same diagnostic efficacy for recurrent glioma with the perfusion-MRI parameters and can used as a reliable alternative diagnostic sequence for glioma recurrence.
The Value of CEST MRI of Peritumoral Regions in Post-Therapy Malignant Glioma Assessment
Authors: Huang Qianqi , Wang Puyang , Wu Jingpu , Liu Mingchao , Zou Yunfan , Zhou Jinyuan , Jiang Shanshan
Published: November 2024

Motivation: Monitoring post-chemoradiotherapy malignant gliomas is a persistent challenge in neuro-oncology. The peritumoral region, closely related to tumor recurrence, has been infrequently examined in the imaging pattens and the potential mechanism. Goal(s): Our objective was to explore whether CEST MRI could distinguish tumor recurrence from treatment effects and uncover potential mechanisms behind high-grade gliomas' invasive behavior. Approach: We investigated the CEST effects at 3.5ppm and 2.0ppm, as well as T1 and T2 values from the peritumoral regions of malignant gliomas with histogram analysis. Results: Significant higher CEST effects across chemical shift offsets were presented in peritumoral regions in recurrent tumor compared with treatment effects. Impact: The different progressive patterns in peritumoral regions between treatment effects and tumor recurrence are assessable by CEST MRI. It provides a potential imaging maker matrix to unveil the mechanism of invasive behavior of malignant gliomas.
Vasari-based features nomogram to predict the tumor-infiltrating CD8+ T cell levels in glioblastoma
Authors: Xue Caiqiang , Zhou Junlin
Published: November 2024

Motivation: Tumor-infiltrating CD8+ T cells play a key role in glioblastoma development, malignant progression, and recurrence. Goal(s): The aim of the study was to establish nomograms based on the VASARI features of multiparametric MRI to determine the expression levels of CD8+ T cells in patients with glioblastoma. Approach: 140 patients with glioblastoma confirmed by surgery and pathology were retrospectively analyzed. Patients were divided into high and low CD8 expression groups. The MRI images of patients with glioblastoma were analyzed using the VASARI scoring system. Results: The features with the greatest predictive power for CD8 expression levels were, cystic, hemorrhage, and ependymal extension. Impact: The VASARI feature-based nomogram model can shows promise to predict the level of infiltrative CD8 expression in GB tumors noninvasively for earlier tissue diagnosis and more aggressive treatment.
Brain asymmetries from midlife to old adulthood and hemispheric brain age
Authors: Korbmacher Max , van der Meer Dennis , Beck Dani , Eikefjord Eli , de Lange Ann-Marie , Lundervold Arvid , Andreassen Ole , Westlye Lars , Maximov Ivan
Published: November 2024

Motivation: The human brain demonstrates structural and functional asymmetries which have implications for ageing and the development of mental and neurological diseases. Age-relationships of these asymmetries are largely unknown. Goal(s): We aimed to map brain asymmetries from midlife to older ages and develop hemispheric brain age (HBA) models, which consider apparent hemispheric differences. Approach: We used structural and diffusion magnetic resonance imaging metrics (N=48,040, UK Biobank) to evaluate the age-relationship of brain asymmetry. Results: Most metrics indicated asymmetry, which appears lower at higher age in white matter and higher in grey matter. HBA reflects other brain ages and unique information of each hemisphere. Impact: We present for the first time comprehensive analyses of brain asymmetries throughout midlife and older ages and establish a new conceptualisation of BrainAge. This ”hemispheric” BrainAge can serve as a marker of asymmetry by comparing left to right hemisphere-derived BrainAges.
Multi-scale cortical morphometry reveals pronounced regional and scale-dependent variations across the lifespan
Authors: Leiberg Karoline , Little Bethany , Wang Yujiang
Published: November 2024

Motivation: Brains are fractal-like objects, with shape information distributed across length scales. Accurate and comprehensive descriptions of healthy ageing effects are needed to study and compare other processes such as neurological disorders. Goal(s): We utilise fractal properties and multi-scale information to give a more thorough and accurate description of morphological changes due to healthy ageing. Approach: We compute shape metrics as scale-dependent variables and infer ageing trajectories across the lifespan, contrasting scale-dependent and regional differences. Results: Different length scales highlight different aspects of ageing effects, and regional differences in ageing trajectories are more pronounced at coarser scales. Impact: Our multi-scale description of lifespan healthy ageing effects on cortical morphology reveals complementary information contained in different spatial scales and can be used as a normative model in future. Viewing morphometrics as functions of length scale reconceptualises quantitative morphometry.
Linking Myelin Integrity to Longitudinal Cognitive Processing Speed Decline in Normative Aging
Authors: Gong Zhaoyuan , Bilgel Murat , An Yang , Bergeron Christopher , Bergeron Jan , Bae Jonghyun , Guo Alex , Faulkner Mary , Laporte John , Ferrucci Luigi , Resnick Susan , Bouhrara Mustapha
Published: November 2024

Motivation: This study probes the specific impact of white matter myelin integrity on processing speed in the aging brain, responding to the need for deeper insights into cognitive decline mechanisms. Goal(s): Our primary objective is to elucidate the relationship between myelin integrity and longitudinal changes in processing speed. Approach: Utilizing quantitative MRI, we performed a retrospective longitudinal analysis correlating myelin water fraction (MWF) values with processing speed measurements. Results: Significant correlations were found between decreased myelin integrity and faster decline in processing speed over the study period, affirming myelin integrity as a key factor in cognitive aging. Impact: This research spotlights the pivotal role of myelin integrity in cognitive aging, potentially shifting existing neuroprotective strategies. Clinicians may now consider myelin preservation in cognitive health assessments, while researchers explore myelin restoration as a viable intervention for age-related cognitive decline.
Forecasted Brain Structure Alteration Facilitates Cognitive Impairment Prediction: a 7-Year Community Elderly Follow-up Study
Authors: Chen Qiufeng , Yue Ling , Zhang Han
Published: November 2024

Motivation: Predicting the conversion from cognitive normal to mild cognitive impairment (MCI) at the asymptomatic stage is challenging. Goal(s): To investigate whether longitudinal alteration in brain structure can provide valuable information for normal-to-MCI conversion prediction. Approach: We conducted a 7-year longitudinal study on 222 community-dwelling elderly and built a two-stage intelligent prediction model to establish the mapping relationship from the baseline to 7-year changes, using brain T1 MRI scans and comprehensive neuropsychological tests. Results: The model, with forecasted 7-year changed features, achieved promising conversion predictions (accuracy=73.8%). Cortical thickness changes, particularly in the visual and default mode cortices, played a significant role in prediction. Impact: Long-term (7-year) brain cortical changes could be predicted and further used to help disease progression prediction for community elderly. Leveraging pre-built predictive model, physicians can evaluate the progression risk at the preclinical phase, well before the onset of Alzheimer's disease.
Deciphering the Mediator Role of White Matter Function in Age-Related Cognitive Decline
Authors: Li Muwei , Schilling Kurt , Gao Fei , Xu Lyuan , Choi Soyoung , Gao Yurui , Zu Zhongliang , Anderson Adam , Ding Zhaohua , Landman Bennett , Gore John
Published: November 2024

Motivation: Unraveling how age-related changes in brain structure and function affect cognitive functions. Goal(s): To determine the mediation role of white matter functional metrics in cognitive decline with aging. Approach: Employing fMRI, graph theory, and mediation analysis to assess how the effect of changes in WM BOLD activity with age influence or reflect cognitive performance. Results: Identified significant white-matter mediators linking age to cognitive performance. Impact: Contributes a fresh perspective to our understanding of the functional architecture of the aging brain.
Relationship between cardiovascular outcomes, hippocampal vascularization and hippocampal volume
Authors: Kim Tae , Gianaros Peter
Published: November 2024

Motivation: Studies have shown a correlation between cardiovascular health and the size of the hippocampus. However, how cardiovascular conditions impact blood flow and vessel health in the brain, and how this potentially affects hippocampus, is still not fully understandGoal(s): We tested whether hippocampal vascularization statistically mediates the association of multiple cardiovascular risk factors and hippocampal volumes in each hemisphere. Approach: Hippocampal vascularization was segmented from T1-weighted MPRAGE images at 7T. Mediation analysis was performed to test the relationship between various cardiovascular variables and hippocampal volume via hippocampal vascularizationResults: Hippocampal vascularization statistically mediates the association between cardiovascular health and hippocampal volumeImpact: understanding the exact causal pathways between cardiovascular outcomes, hippocampal vascularization, and hippocampal volume is crucial for establish novel strategies for potentially mitigating the risk of cognitive decline and cerebrovascular diseases
Assessment of Pulsatility Index of Lenticulostriate Arteries using 2D PC-MRI with Dual-VENC in elderly adults at 7T: A Preliminary Study
Authors: Tang Jianing , Zhao Tianrui , Joe Elizabeth , Chui Helena , Yan Lirong
Published: November 2024

Motivation: LSA plays an important role in the pathology of small vessel disease. Directly assessing LSA pulsatility may offer valuable insight into SVD pathology. Goal(s): To assess the utility of 7T dual-VENC PC-MRI for the LSA pulsatility assessment in elderly adults by investigating its association with age and cognitive impairment. Approach: LSA pulsatility was assessed using 7T PC-MRI using both dual- and single-VENC on 25 elderly participants. Cognitive tests including MMSE and MOCA were conducted. Results: Our results showed that the LSA pulsatility was significantly correlated with upstream major arteries and increased LSA pulsatility was associated with aging, education level, and cognitive impairment. Impact: Increased LSA pulsatility measured by dual-VENC PC-MRI shows a strong association with aging, education, and cognitive impairment. Compared to single-VENC, dual-VENC PC-MRI enhanced the detection and characterization of LSAs, providing a promising imaging tool for investigating vascular pathology of SVD.
ASL-derived cerebrovascular brain-age improves associations with cognitive decline
Authors: Dijsselhof Mathijs , Duits Floor , Nordhøy Wibeke , Beck Dani , Westlye Lars , Cole James , Van der Flier Wiesje , Barkhof Frederik , Petr Jan , Mutsaerts Henk
Published: November 2024

Motivation: Structural brain ageing models are associated with cognitive decline, and the addition of arterial spin labelling (ASL)-derived improved brain-age estimation accuracy, but the relation between cerebrovascular ageing and cognitive decline is not yet fully understood. Goal(s): To assess the contribution of ASL in the relationship between brain-age estimates and cognitive decline. Approach: Brain-age estimation accuracy and linear relationships with composite cognitive scores were compared between structural-only (T1w and FLAIR), ASL-only, and structural+ASL models. Results: Combined structural and ASL brain-age models showed the highest accuracy and increased effect sizes with composite cognitive scores, however, ASL-only models showed unexpected relationships. Impact: Combined structural-ASL brain-age models might present a surrogate biomarker in an earlier stage of cognitive decline, aiding in diagnosis and treatment monitoring. Possible mediation effects of ASL on the association of structural decline with cognitive domains should be investigated further.
3D pCASL with dual PLDs could reflect cerebral blood flow regulation in patients with hydrocephalus
Authors: Xiao Yawen , Chen Shiqi , Dai Jiankun , Xiao Xinlan
Published: November 2024

Motivation: It is unclear whether the 3D pCASL with dual PLDs can reflect blood flow (CBF) regulation in hydrocephalus patients. Goal(s): To investigate hemodynamic characteristics in patients with hydrocephalus and whether ΔCBF can reflect cerebral regulation. Approach: Patients with hydrocephalus and control subjects were retrospectively included. Regional CBF and ΔCBF were compared using covariance analyses. The relationship between ΔCBF and ventricular dilatation degree was investigated using linear regression analyses and interaction analysis. Results: Compared to the control group, hydrocephalus patients showed larger ΔCBF in all brain regions except for the bilateral parietal cortex and cerebellum. Impact: Patients with hydrocephalus initiate cerebral regulation to maintain CBF but require longer arterial transit times. The ability to regulate CBF in brain regions represented by the watershed is associated with the degree of ventricular dilation.
Neurovascular coupling dysfunction of hippocampus-visual network in Post-Concussive Syndrome
Authors: Yan Jiahao Yan , Zhang Jing
Published: November 2024

Motivation: The clinical relevance and modifications in perfusion and neural activity remain undetermined in Post-Concussive Syndrome. Goal(s): To delineate changes in NVC during the pathophysiology of PCS, multimodal magnetic resonance imaging was performed on patients and healthy controls. Approach: Five imaging-markers elucidates the relationship between neuronal activity and perfusion. Dynamic causal modeling evaluates associations with disease transitions, clinical variables, and information flow. Results: The fALFF-CBF of the hippocampal was diminished, and the ReHo-CBF in the Temporal-Occipital cortex decreased, correlating with declining spatial processing and memory tasks. Impact: The distinctive pattern of changes in neurovascular coupling in the hippocampal , temporal-occipital cortex provide fresh insights into PCS
Investigation the relationship between cerebral small veins and microbleeds using 7T QSM in Alzheimer’s disease
Authors: Ashouri Laya , Yildiz Sema , Ma Felisha , Delman Bradley , Balchandani Priti , Alipour Akbar
Published: November 2024

Motivation: Cerebral microbleeds (CMBs) are small hypointense lesions often associated with cerebral small vessel diseases like cerebral amyloid angiopathy and Alzheimer's disease (AD). Goal(s): Our aim is to evaluate the feasibility of using ultra-high resolution QSM at 7T MRI to find a link between small veins and CMBs in AD. Approach: We used 7T QSM to established a connection between CMBs and the venous vasculature to evaluate venous contributions to AD conditions. Results: Our data support the notion that CMBs might not exclusively derive from arteries, but that venous contribution could play an important, yet not much explored, role in CMBs in AD cohorts. Impact: Our results provide evidence of a potential connection between CMBs and small veins, suggesting a potential role for veins in AD.
Dynamic Changes in Automatic Generated Quantitative Biomarkers and Correlation with Pathology of Alzheimer’s Disease – A Longitudinal Study
Authors: Fan Xiang , Cai Yuan , Liu Wanting , Shi Lin , Mok Vincent
Published: November 2024

Motivation: AD-RAI is a novel MRI-based machine-learning derived biomarker and the value of longitudinal AD-RAI remains unclear. Goal(s): We aimed to assess longitudinal changes of the MRI biomarkers (i.e., AD-RAI, HV, HF, BPV, BPF) in correlation with change in time and conversion status with and without A+T+. Approach: We selected 168 CU and MCI in ADNI with four-year follow-up with serial MRI scans and corresponding CSF and used linear mixed-effects models to estimate and compare. Results: AD-RAI of subjects with A+T+ increased significantly faster than non-A+T+ over time and AD-RAI has the potential to track CSF Aβ1–42 as an effective longitudinal surrogate biomarker. Impact: If the serial AD-RAI change over time is associated with conversion status and AD pathologies. It may be used as a surrogate marker for monitoring disease progression or treatment response in AD.
Microstructure Informed Susceptibility Source Separation (MI-SSS) Reveals Demyelination in Alzheimer’s Disease
Authors: Şişman Mert , Nguyen Thanh , Zhou Liangdong , Spincemaille Pascal , Li Yi , de Leon Mony , Chiang Gloria , Wang Yi
Published: November 2024

Motivation: Alzheimer’s Disease (AD) is the leading cause of dementia and the pathogenesis of AD is not well understood. Microstructural changes such as demyelination is known to be involved in AD progression and can noninvasive estimation of myelin content can help us better understand AD. Goal(s): The aim of this study is to show MI-SSS potential in detection myelination changes in AD. Approach: AD patient negative susceptibility content is compared with that in healthy subjects on both region and voxel level. Results: MI-SSS demonstrated significantly lower negative susceptibility content in AD patients signaling AD pathology related demyelination. Impact: Noninvasive imaging of brain microstructure may help to better understand pathological changes in Alzheimer’s Disease. Microstructure Informed Susceptibility Source Separation (MI-SSS) provides important information about the brain microstructure such as myelin content that can easily be adopted in clinical settings.
Experimental Investigation of Interfering Factors in Cardiac Sensing of Beat Pilot Tone
Authors: Sun Haoyu , Zhong Sijie , Chen Suen , Hou Wei , Ding Qichen , Chen Hao , Zhang Zhiyong
Published: November 2024

Motivation: Beat Pilot Tone (BPT) has been proposed as a non-contact and accurate cardiac sensing method seamlessly integrated with MR systems. However, BPT is sensitive to interference, thereby limiting its ability to robustly obtain fine-grained cardiac waveform. Goal(s): Our goal was to demonstrate main factors that could lead to corrupted BPT signal. Approach: We conducted a series of comparative experiments on the hypothesized influencing factors. Results: The experiments suggested that BPT transmit power, imaging orientation and other physiological motion like respiration caused varying degradation to the BPT signal. Impact: The demonstration of interfering factors of BPT cardiac sensing could guide the correct BPT setup and interference suppression method design. This helps BPT to robustly obtain fine-grained cardiac waveform, which could be used for MR motion correction and clinical diagnosis.
Motion compensated SE diffusion tensor cardiovascular magnetic resonance at ultra-high gradient strength at Connectom scanner
Authors: Paul Shubhajit , Ferreira Pedro , Evans John , Escobar Camila , Fasano Fabrizio , Pennell Dudley , Nielles-Vallespin Sonia , Scott Andrew
Published: November 2024

Motivation: Second-order motion-compensated spin-echo (MCSE) DT-CMR is limited by long echo-times (TE), resulting in T2-related signal-loss. Goal(s): Use the ultrahigh gradient-strength of the Connectom scanner to reduce TE of second-order MCSE DT-CMR. Approach: A second-order MCSE DT-CMR pulse-sequence was developed. Ultra-high (180mT/m) and a high gradient-strength (80mT/m) were compared in acquiring in-vivo DT-CMR data at two cardiac phases. Results: The substantial reduction in TE enabled by ultra-high gradient-strength resulted in improvements in signal-to-noise ratio (SNR) in both cardiac phases. To our knowledge this is the first report comparing the performance of second-order MCSE DT-CMR at ultra-high gradient-strength (Connectom) to widely available high gradient-strengths. Impact: Second-order MCSE DT-CMR acquired using ultra-high diffusion gradient strengths increases SNR in both cardiac phases, paving the way for future clinical translation of efficient multiphase DT-CMR.
Slice-by-slice B0 Shimming for high-resolution diffusion MRI with an ultra-high performance head-only gradient
Authors: Huang Sherry , Lee Seung-Kyung , Shih Robert , Huang Raymond , Cornfeld Daniel , Maller Jerome , Mcnab Jennifer , Foo Thomas , Zhu Ante
Published: November 2024

Motivation: High-resolution diffusion MRI in high-gradient head-only systems, which is promising for advancing our understanding of human brain microstructure, is still prone to distortion from B0 field inhomogeneity. Goal(s): To reduce B0 field inhomogeneity for improved image quality of high-resolution diffusion MRI. Approach: Dynamic slice-by-slice B0 shimming of 0th and 1st order was implemented in diffusion MRI. Results: Preliminary results showed reduced image shift and distortion of slices at different locations in axial b=0 s/mm2 echo planar image with 1-mm isotropic resolution with dynamic slice-dependent B0 shimming, demonstrating the potential of high image quality of high-resolution diffusion MRI for brain microstructure imaging. Impact: Neuroimaging scientists and MR physicists, who use high-resolution diffusion MRI for studying brain circuits, connectivity, and microstructure, can benefit from improved image quality with reduced distortion from dynamic slice-by-slice B0 shimming technique in high-performance gradient MRI systems.
Simulation of B0 Magnetic Field Conditions in the Human Heart for Improved B0 Shimming in Cardiovascular MRI
Authors: Shang Yun , Theilenberg Sebastian , Castillo Michelle , Peng Boyu , Fung Maggie , Quarterman Patrick , Navot Benjamin , Jambawalikar Sachin , Einstein Andrew , Juchem Christoph
Published: November 2024

Motivation: Balanced SSFP sequences in cardiovascular MRI suffer from dark band artifacts due to B0 inhomogeneity. Limited detail of in vivo B0 conditions apparent in various population groups impede the development of optimal cardiac B0 shim methods. Goal(s): To validate our recently-published high-resolution B0 simulation approach of B0 conditions in the human heart based on structural CT images. Approach: Validation was achieved through direct comparison of B0 conditions computationally derived from structural CT images, vs. in vivo B0 maps obtained experimentally on the same five subjects. Results: Excellent agreement occurred between simulated and in vivo B0 maps, with an average spatial correlation of 0.91. Impact: The validated cardiac B0 simulation from readily-available structural CT images enables characterization of B0 conditions in populations with wide-spread demographics of age, sex, height, weight and the development of advanced B0 shimming methods to improve diagnostic accuracy in cardiovascular MRI.
Measurement and modeling of peripheral nerve magnetostimulation in a head solenoid from 200 Hz to 88.1 kHz
Authors: Barksdale Alex , Ferris Natalie , Mattingly Eli , Śliwiak Monika , Guerin Bastien , Wald Lawrence , Davids Mathias , Klein Valerie
Published: November 2024

Motivation: Two previous peripheral nerve magnetostimulation experiments reported increasing thresholds above 25 kHz, which deviates from the hyperbolic strength-duration curve describing thresholds versus frequency. However, high-frequency PNS measurements are sparse and established neurodynamic models have not been validated above 1 kHz. Goal(s): Characterize PNS thresholds in a solenoidal head coil between 200 Hz and 88.1 kHz. Approach: We measure PNS thresholds in four healthy volunteers and compare to predictions of our electromagnetic-neurodynamic PNS model. Results: The measured thresholds increase 36% on average from 16.9 kHz to 66.7 kHz, which is at odds both with the hyperbolic scaling as well as our detailed PNS modeling. Impact: Our strength-duration measurements show that the greatest stimulation propensity is ~17 kHz and PNS thresholds remain relatively low at frequencies greater than 20 kHz, which is important for informing the design of MRI and MPI coils.
Characterization of Eddy-Currents Associated with Multi-Coil B0 Field Control in an Accessible Head-Only Scanner
Authors: Theilenberg Sebastian , Ismail Rashad , Froelich Taylor , DeLabarre Lance , Nixon Terence , de Graaf Robin , Garwood Michael , Juchem Christoph
Published: November 2024

Motivation: The eddy current (EC) behavior of a multi-coil array for image encoding in a novel head-only MR scanner has been estimated theoretically, however, to date, the physical measurements have been outstanding. Goal(s): Our goal was the spatiotemporal characterization of the ECs of this system. Approach: We measured the ECs via local field probes by acquiring FIDs at a series of delays after the switching of individual MC channels. Results: Measurements at over 40 positions in the FOV enabled a comprehensive analysis of the ECs. The longest EC components last for more than a second, however, we show that EC compensation is possible. Impact: The presented eddy-current characterization is an important stepping stone towards eddy-current compensation for DYNAMITE image encoding in non-traditional MR scanner designs.
Measurements of the gradient-induced power deposition in the He-bath of the Iseult 11.7T magnet and comparison with theory
Authors: Boulant Nicolas , Guihard Quentin , Dubois Olivier , Lannou Hervé , Juster François-Paul , Belorgey Jean , Nunio François , Amadon Alexis , Bonnelye Cédric , Gras Vincent , Le Ster Caroline , Mauconduit Franck , Vignaud Alexandre , Quettier Lionel , Aubert Guy
Published: November 2024

Motivation: Experimental characterization and understanding of the power deposition in the He bath of an ultra-high field magnet is important for magnet safety. Goal(s): We report a quasi-analytical model for the Z gradient axis power deposition and compare it with measurements. Approach: The model was based on three cylinders consisting of the He vessel, the cryoshield and the outer vacuum chamber. Coupled partial differential equations involving both electromagnetism and elasticity were derived and solved. Results: Our model predicts accurately the positions of the cryogenic peaks but underestimates by about a factor of 2-3 the largest ones. Impact: When the symmetry and underlying assumptions are met, the model allows determining the location of the resonance peaks and can alert the user of potential dangerous frequency zones where caution during first experiments should be exercised.
Myocardial Tissue Characterization of Acute Myocarditis in Mice: T1, T2 mapping and Extracellular Volume Fraction at 9.4T
Authors: Miao Qinfang , Zhao Wenjing , Wen Zhaoying , Qi Haikun
Published: November 2024

Motivation: Myocarditis causes adverse ventricular remodeling. However, its early diagnosis and intervention measures remain to be explored. Goal(s): Exploring quantitative CMR for monitoring myocarditis developments. Approach: Cardiac T1, T2 and ECV mapping were performed in mice at two timepoints. Then the CMR parameters were compared between the control and myocarditis groups. The CMR results were validated against histology. Results: Early acute phase of myocarditis was characterized by increased T2 and ECV. As time progressed, T2 was reduced to the normal level, while myocarditis native T1 and ECV were much higher than the control. The CMR findings agreed with histology. Impact: Quantitative CMR parameters may serve as reliable indicators for edema, inflammation and fibrosis that are associated with the progression of myocarditis, and can be used for early diagnosis, monitoring and management of myocarditis.
Real time monitoring of Ca2+ homeostasis by manganese enhanced cMRI in a remotely induced myocardial ischemia reperfusion injury mouse model
Authors: Pusovnik* Matic , Algoet* Michiel , Gillijns Hilde , Gsell Willy , Janssens Stefan , Oosterlinck Wouter , Himmelreich Uwe
Published: November 2024

Motivation: Studies on cardiac ischemia reperfusion injury mainly focus on events following an ischemic event. Our focus were the initial moments during occlusion and reperfusion in a novel murine model. Goal(s): Our goal was to characterize the dynamic processes occurring during and immediately after ischemia. Approach: Manganese is a calcium analogue and potent T1-contrast agent for MRI that enters cardiomyocytes through active calcium channels. By exploiting this mechanism, the disruption of calcium homeostasis was monitored during and after ischemia. Results: Studying the early phase of ischemia is feasible and data suggest a link between the final scar extent and severity of Ca2+ homeostasis disruption. Impact: Preclinical ischemia-reperfusion injury studies can now be complemented with an early marker for subsequent injury. Revealing the dynamic processes occurring during and immediately after an ischemic event might help to assess the effects of applied therapeutics at an earlier stage.
Translational 3T MRI and micro-CT imaging of murine cartilage repair
Authors: Chary Karthik , Hosni Rawiya Al , Ramakrishnan Nisha , Gallagher Ferdia , McCaskie Andrew , Birch Mark , Kaggie Joshua
Published: November 2024

Motivation: This is a clinically inspired project related to Osteoarthritis which focuses on translational research to specifically enhance murine preclinical models with micro-CT and MRI. Goal(s): To optimize MRI methods for monitoring of longitudinal repair of a mouse model of osteochondral injury, to validate joint tissue response and assess intervention impact to the injury site. Approach: The study design features the micro-CT and MRI imaging of the knee joint in a murine osteochondral injury model. Results: The optimized MRI protocol was able to demonstrate differences between groups after longitudinal assessment. This technique is an important translational step allowing the measurement of clinically relevant differences. Impact: The developed multimodal imaging methodology to monitor tissue repair of mouse knee will extensively enhance the development of novel therapies for cartilage and bone repair, and their translatability into the clinic, whilst reducing the number of animals for preclinical research.
Development of an Ex-Vivo Porcine Model of the Bladder for 3D Dynamic MRI Validation
Authors: Rice James , Stellon Michael , Bushman Wade , Roldán-Alzate Alejandro
Published: November 2024

Motivation: Recently developed MRI-Urodynamics methods require rigorous validation. In vitro approaches have been implemented, however lack of tissue-like mechanical properties of the in models limits their applicability. Goal(s): Develop and implement an ex-vivo bladder model for validation of MRI-Urodynamics. Approach: Porcine bladder was obtained and connected to a syringe pump to conduct MRI experiments during filling and voiding at various flow-rates. Simultaneous pressure measurements were performed during MRI. Results: Ex-vivo bladder MRI experiments were successfully conducted. MRI-derived flow-rates agree within 10% when compared to the flow-rates imposed by the syringe pump. Pressure-volume analysis provided means of comparison of bladder performance between filling and voiding. Impact: 3D dynamic MRI can assess anatomical changes in the bladder during voiding and filling. Systematic validation of this technique can enhance its clinical use.
Preliminary clinical application of a fast abdomen T2 mapping technique based on single‑shot multiple overlapping‑echo acquisition
Authors: Zhu Liuhong , Yang Qinqin , Wu Zhigang , Cai Congbo , Zhou Jianjun
Published: November 2024

Motivation: The clinical value of newly ultrafast multiple overlapping-echo detachment T2 mapping (MOLED-T2 mapping) on common liver tumors has not yet been elucidated. Goal(s): To test the reliability of MOLED-T2 mapping in common hepatic tumors during clinical applications. Approach: Total of 23 healthy subjects and 59 patients were enrolled in our study. Free breath MOLED-T2 mapping, breath hold MOLED-T2 mapping and most used breath hold GraSE T2 mapping were compared. Results: There was no significant difference between free breath and breath hold MOLED-T2 mapping. T2 values obtained from two MOLED sequences were significantly lower than those obtained through fb-GraSE-T2 sequence. Impact: This work will stand up the foundation for subsequent research about MOLED-T2 mapping on abdomen quantitative MR imaging.
A novel ADAMTS-specific MR peptide probe for characterization of atherosclerotic plaques in a murine model
Authors: Mangarova Dilyana , Kaufmann Jan Ole , Brangsch Julia , Kader Avan , Moeckel Jana , Heyl Jennifer , Verlemann Christine , Adams Lisa , Ludwig Antje , Reimann Carolin , Poller Wolfram , Niehaus Peter , Karst Uwe , Taupitz Matthias , Hamm Bernd , Weller Michael , Makowski Marcus
Published: November 2024

Motivation: A precise diagnosis of atherosclerosis is of clinical importance, since cardiovascular disease remain one of the leading causes of death worldwide. Goal(s): The goal of this study was to evaluate the feasibility of characterizing a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS4) using molecular magnetic resonance imaging in a preclnical model of atherosclerosis. Approach: Molecular magnetic resonance imaging using a novel probe targeted against ADAMTS4 was used in a high-fat murine model. Results: It was possible to image atherosclerotic lesions in a mouse model using an ADAMTS4- specific probe for magnetic resonance imaging. Impact: Using molecular MRI targeting ADAMTS4 is a promising method for characterization of plaque composition and could possibly impact plaque vulnerability assessment in the diagnosis and treatment of atherosclerosis in patients.
Superparamagnetic iron oxide nanoparticles (SPIONs) as a calibration and validation tool for QSM MRI sequences
Authors: Chow Steven Kwok Keung , Walls Angela , Dwyer Andrew , O’Brien Kieran , Withey Stephanie , Dmochowska Nicole , Cousins Aidan , Thierry Benjamin
Published: November 2024

Motivation: Progressing the clinical translation of QSM is important for imaging of biometal dysregulation in neurodegenerative disease but available methods for calibrating QSM sequences between systems are limited. Goal(s): To develop and validate a superparamagnetic iron oxide nanoparticle (SPION) phantom replicating human brain iron concentration. Approach: Dilutions of Ferrotrace SPION (0.1-25 $$$\mu$$$g/mL) were scanned with research application QSM gradient echo sequence using two different 3T systems and multiple analysis methods. Results: A good linear fit was demonstrated between QSM values and SPION concentration across a clinically relevant interval and different QSM analysis methods. Values differed between two scanners but there was high within-scanner concordance. Impact: A SPION based phantom replicating in vivo iron of healthy and diseased brain could be an invaluable calibration and QA tool for QSM clinical translation, normative datasets and emerging SPION-based theranostics for brain cancer.
Synthesis and Evaluation of Porphyrin-Based Gadolinium complex as Multifunctional Theranostic Agent
Authors: Kim Soyeon , Ko In Ok , Kim Jung Young , Kim Kwang Il , Park Ji-Ae
Published: November 2024

Motivation: Currently used Neutron capture therapy agents in clinic have low tumor targeting ability and have different structures from imaging agents that can view bio-distribution, making it difficult to determine the exact distribution of the drug in the human body. Goal(s): Development of a new MR-image guided drugs for neutron capture therapyApproach: Two of gadolinium complexes of porphyrin derivative were designed and synthesized. Cell uptake study was performed using normal cell and glioblastoma cells. In vivo MR images and ex vivo fluorescence images were obtained. Results: We found that Gd-complexes could enter into the nucleus and be further uptaken by tumor tissues. Impact: Using the two gadolinium complexes, it is possible to compare the therapeutic efficacy of GdNCT and BNCT and expect a synergistic effect. The development of NCT treatments using small molecule substances may have the potential for clinical application.