bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo multimodal MRI of the healthy optic nerves
Authors: Ricciardi Antonio , Yiannakas Marios , Boonsuth Ratthaporn , Bogatsion Rodas Ghilom , Wheeler-Kingshott Claudia Gandini , Samson Rebecca
Published: August 2024

The optic nerve (ON) is implicated in a variety of neurological disorders but is challenging to study through magnetic resonance imaging due to its small size and jittering. In this study, we developed an acquisition protocol and analysis pipeline that enables to produce quantitative proton density (PD), macromolecular tissue volume (MTV), T2* and T1 maps of the ON from a 20-minute scan. Results show good scan-rescan reproducibility of ON values, and agreement with regional brain values. Significant differences in PD, MTV and T1 were observed between left-right ON measures, and left-right fronto-temporal white matter, which warrant further investigation.
3D MR Elastography: Exploring Quality Assurance Measures
Authors: Cai Shan , Tellman Jens , Simonsson Christian , Bartholomä Wolf , Eriksson Jonatan , Dahlström Nils , Kechagias Stergios , Nasr Patrik , Ekstedt Mattias , Sinkus Ralph , Lundberg Peter
Published: August 2024

Magnetic resonance elastography (MRE) is a powerful tool that can grade liver fibrosis non-invasively. In comparison with 2D MRE, 3D MRE can provide additional biomechanical tissue parameters for evaluating liver fibrosis. However, there is a great need to develop a quality assurance protocol for 3D MRE measurements. In this study, we have investigated quality assurance parameters for a 3D MRE research system and identified the cut-off values of the quality parameters to assign the 3D MRE data into three quality categories. A confidence map was constructed based on the evaluation of these quality parameters.
Dynamic glucose-enhanced imaging of the liver using breath-hold black blood quantitative T1rho MRI
Authors: Qian Yurui , Wong Vincent , Hou Jian , Jiang Baiyan , Zhang Xinrong , Wong Grace , Wu Zhigang , Chan Queenie , Yu Simon , Chu Winnie , Chen Weitian
Published: August 2024

Non-alcoholic fatty liver disease (NAFLD) is often associated with abnormal metabolic syndrome. In this study, we investigated dynamic glucose enhanced imaging of the liver using T1rho MRI after glucose ingestion. We hypothesize this approach can be used to assess metabolic activities in the liver. Sixteen young volunteers and four patients with NAFLD were recruited in this study. The preliminary results suggest that the proposed approach has the potential to detect metabolic variations between normal subjects and subjects with fatty liver.
Improved Free-Breathing Volumetric Liver Fat and R2* Quantification Using 3D Stack-of-Radial GRE Dixon MRI and XD-GRASP Reconstruction
Authors: Zhong Xiaodong , Nickel Marcel , Kannengiesser Stephan , Dale Brian , Wu Holden , Deshpande Vibhas
Published: August 2024

Respiratory motion compensation is necessary for free-breathing stack-of-radial liver fat and R2* quantification. While self-gating is a valid approach, it may lead to degraded quality of images and quantitative maps and possible prolonged acquisition. A 3D XD-GRASP stack-of-radial technique was developed and evaluated in a motion phantom and in vivo subjects. Results demonstrated PDFF and R2* agreement of the proposed method compared to reference methods. Improved image and map quality and PDFF and R2* quantification agreement of the proposed method using an acceleration factor of 4 (equivalent to 105 seconds of time saving) were observed compared to the self-gating method.
3D MRI-US multimodal alignment for real-time intervention - a tradeoff between accuracy and computation time
Authors: Mitra Jhimli , Bhushan Chitresh , Ghose Soumya , Mills David , Chan Heather , Tarasek Matthew , Wells Shane , Jupitz Sydney , Brace Chris , Bednarz Bryan , Foo Thomas , Holmes James , Yeo Desmond
Published: August 2024

Multimodal MRI-US image fusion in image-guided therapy such as liver microwave ablation aids in correct placement of the applicator device. Significant tissue deformation due to breathing motion requires alignment of pre-interventional MRI on real-time interventional US to compensate for the motion. In this work, we present a hybrid framework (conventional and deep learning) for multimodal deformable registration to provide higher accuracy and retain the low latency required for real-time interventions.
Unipolar design of head gradients for eliminating the encoding ambiguity
Authors: Weiger Markus , Overweg Johan , Hennel Franciszek , Baadsvik Emily , Bianchi Samuel , Björkqvist Oskar , Luechinger Roger , Metzger Jens , Michael Eric , Port Andreas , Schildknecht Christoph , Thomas Schmid , Sturzenegger Urs , Vissers Gerrit , Koonen Jos , Schuth Wout , Koeleman Jeroen , Borgo Martino , Pruessmann Klaas
Published: August 2024

Gradients with a conventional, bipolar design generally face a trade-off between performance, encoding ambiguity, and circumventing the latter by means of RF selectivity. This problem is particularly limiting in cutting-edge brain imaging performed at field strengths ≥ 7T and using high-performance head gradients. To address this issue, the present work proposes to fundamentally eliminate the encoding ambiguity in head gradients by using a unipolar z-gradient design that takes advantage of the signal-free range on one side of the imaging volume. This concept is demonstrated by design of a unipolar high-performance head gradient and simulated 7T imaging with such a system.
Association analysis of age-dependent changes in R1map at the brain region level with gene expression patterns
Authors: Chen Xiang , Zhang Xiaoyong
Published: August 2024

Quantitative MRI can observe biologically distinct microstructural processes that shows great potential in aging research. In this work, we studied the trajectories of R1map changes in aging brain and found R1map regions with significant changes in different age groups (young, middle-aged, and elderly groups). Graph theoretical analysis of covariance networks revealed global clustering coefficient of youth group is higher than that of middle-aged and elderly groups. Association analysis of spatial gene expression patterns with changes in R1map at the brain region level reveal that the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway is mainly enriched in various neurodegenerative diseases.
The impact of amyloid-β and ferritin on ultra-high-field R2* and quantitative susceptibility mapping
Authors: Luo Jierong , Everett James , Donnelly Jane , Slade Festus , Telling Neil , Collingwood Joanna
Published: August 2024

Amyloid plaques, an established hallmark of Alzheimer's disease, are often demonstrably associated with iron deposits post-mortem. Previous T2*-weighted and phase information from ultra-high-field MR microscopy and clinical MRI has shown the potential to detect amyloid deposits in vivo and ex vivo. We investigated the relative contributions to contrast from amyloid-β (Aβ) aggregates with and without ferritin-bound iron in vitro, for R2* and quantitative susceptibility maps (QSM) with 86 μm isotropic resolution at 9.4T. We also demonstrated the quantitative signal evolution with the formation of amyloid aggregates, and the correlation of the signals with the Aβ and ferritin content.
Sex-specific changes and association in multiparametric MRI measurement at 3T in adult livers
Authors: Liu Chia-Ying , Noda Chikara , van der Geest Rob , Triaire Bruno , Kassai Yoshimori , Bluemke David , Lima Joao
Published: August 2024

Imaging biomarkers derived from multiparametric MRI have been investigated for the evaluation of diffuse liver disease. We aimed to determine the sex-specific correlation of MRI parameters with age and BMI, and to evaluate the association between multiparametric MRI parameters. 100 study participants without known hepatic disease were prospectively enrolled. 3 T MRI including T1, T2 and T1ρ mapping and proton density fat fraction (PDFF) and R2* maps were acquired. Multiparametric MRI measures have sex-specific age and BMI dependency. Relaxometry mapping indices could be associated with PDFF. PDFF was significant associated with R2* and T1ρ, but not to T1 or T2.
Histological Validation of MR Cell Size and Cellularity Imaging with Human Liver Specimens
Authors: jiang xiaoyu , Gore John , Xu Junzhong
Published: August 2024

The size and cellularity of hepatocytes, their variations and changes over time, are fundamental characteristics of liver tissues, and measurements of cell sizes and cellularities may have high clinical significance but currently can be obtained only by liver biopsy. We quantified the microstructures of human liver specimens with different liver diseases, including normal liver tissues, cirrhosis, steatosis, hepatocellular carcinoma (HCC), cirrhotic regenerative nodules (CRN), and intrahepatic cholangiocarcinoma (iCCA), using MR cell size imaging ex vivo. The accuracy of MR-derived cell sizes and cellularities were evaluated by comparisons to histology.
Short single pulse optogenetic fMRI mapping of downstream targets in thalamo-cortical pathways
Authors: Xie Linshan , Wang Xunda , Ma Teng , Zeng Hang , Wen Junjian , Cao Peng , Wu Ed X. , Leong Alex T.L.
Published: August 2024

Short single pulse stimulation is advantageous to map the downstream neural targets compared to pulse train stimulation because it can minimize the excessive neural synchronization and avoid numerous series of complex neural events. It is desirable for fMRI studies to investigate the properties of neural circuits via delivering single pulse stimulation. However, the subtle BOLD responses evoked by short stimuli are hard to detect due to the sensitivity issue. Here, we employed fMRI to examine the long-range downstream targets of the somatosensory thalamus with 10ms single pulse stimulation. A model-free fMRI analysis was utilized to visualize the spatiotemporal activity propagation.
Multi-echo, multi-contrast functional activation: validation of combined spin- and gradient-echo EPI in fMRI
Authors: Keeling Elizabeth , Bergamino Maurizio , Ragunathan Sudarshan , Quarles C. , Stokes Ashley
Published: August 2024

Standard functional MRI (fMRI) suffers from susceptibility-induced dropout near air-tissue interfaces and is sensitive to larger vessels. Conversely, a combined spin- and gradient-echo (SAGE) acquisition can provide sensitivity to functional activation across macro- and microvascular scales with reduced signal dropout. Multi-echo analysis of SAGE-fMRI data was performed by using quantitative and relaxation-weighted T2* and T2. In a task-based experiment, SAGE relaxation-weighted analyses showed increased contrast- and temporal signal-to-noise ratios (CNR and tSNR, respectively), especially for microvascular analysis. SAGE-fMRI provides improvements over standard fMRI in image quality and robustness of functional activation, as well as inclusion of microvascular sensitivity.
Data-driven analysis of echo planar time-resolved MRI suggests frequency-specific mechanisms of brain fluctuations with unique TE signatures
Authors: Krishnamurthy Lisa , Krishnamurthy Venkatagiri , Wang Fuyixue , Wald Lawrence , Calhoun Vince
Published: August 2024

A novel analysis of EPTI rsfMRI to assess frequency contributions in unique echoes.
A ray of light against age-related Neurodegenerative disease: A 31P Magnetisation Transfer MRS study
Authors: Fear Elizabeth , Torkelsen Frida , Baseler Heidi , Kennerley Aneurin
Published: August 2024

Through combined theoretical Monte Carlo stimulation and practical 31P Magnetisation Transfer Magnetic Resonance Spectroscopy we quantify the effects of 670 nm photobiomodulation treatment on healthy aging brains. Mitochondrial function declines with age and many pathological processes of neurodegenerative diseases stem from this mitochondrial dysfunction when they fail to produce the necessary energy required. Therefore, an aging population coupled with associated increases in cases of neurological conditions amplifies the need to develop safe, inexpensive treatments to restore mitochondrial function and offer neuronal protection as we grow old. Evidence shows that non-invasive transcranial red/infrared photobiomodulation (PBM) therapy can offer such neuroprotective benefits.
Structural network integrity in limbic-predominant age-related TDP-43 encephalopathy neuropathological change (LATE-NC)
Authors: Tazwar Mahir , Evia Arnold , Ridwan Abdur Raquib , Bennett David , Schneider Julie , Arfanakis Konstantinos
Published: August 2024

Limbic-predominant age-related TDP-43 encephalopathy neuropathological change (LATE-NC) is a common pathological finding in the brain of older adults, but its impact on structural network integrity remains unknown. In this work, we studied structural connectivity network abnormalities associated with LATE-NC using graph theory. Our results demonstrated that severity of LATE-NC was independently associated with weaker network integration and segregation, and increased vulnerability in a network of brain regions typically affected by LATE-NC.
Brain Age Prediction Based on Quantitative Susceptibility Mapping
Authors: Chen Mingxing , Shi Yuting , Zhang Yuyao , Wei Hongjiang
Published: August 2024

The aging process of the human brain is known to be complex, resulting in considerable structural and functional changes in the brain. In this study, a brain age prediction method based on QSM was proposed and then applied to predict the brain age of PD patients. The model achieved a high prediction accuracy with the MAE of 4.40 years and the R2 of 0.91 in healthy subjects. The PADs of the PD patients were significantly higher than HC subjects. The results show that brain age prediction based on QSM can provide a new biomarker to explore iron-related brain age changes.
Cardiovascular and cerebrovascular health in 70-year-olds: a population-based ASL study
Authors: Dijsselhof Mathijs , James Sarah-Naomi , Lorenzini Luigi , Collij Lyduine , Thomas David , Scott Catherine , Manning Emily , Józsa Tamás , Cash Dave ,   Insight 46 study team, Sudre Carole , Hughes Alun , Richards Marcus , Barkhof Frederik , Schott Jonathan , Petr Jan , Mutsaerts Henk
Published: August 2024

While mid-life cardiovascular pathology may lead to late-life cognitive decline, our understanding of the role of cerebrovascular health as an intermediate biomarker is limited. We explored the association between cardiovascular health biomarkers and cross-sectional and longitudinal cerebrovascular health assessed by ASL MRI in Insight46, a well-characterised cognitively normal population-based sample. We found several cross-sectional and longitudinal associations between blood pressure and CBF. These findings suggest that the effects of BP on cerebrovascular health can be imaged with ASL perfusion MRI, possibly offering opportunities to prevent or intervene before cognitive decline sets in.
Highly-Efficient 3D free-breathing whole-heart MRA in 3 min: Clinical validation in patients with adult congenital heart disease
Authors: Fotaki Anastasia , Munoz Camila , Rush Christopher , Velasco Carlos , Kunze Karl , Neji Radhouene , Pushparajah Kuberan , Botnar Rene , Prieto Claudia
Published: August 2024

Cardiovascular MRA is established for serial anatomical evaluation of patients with congenital heart disease (CHD). However, this approach is limited by diaphragmatic respiratory navigation, that leads to long acquisition times and degraded image quality due to residual motion artefacts. Here we evaluate a novel accelerated whole-heart framework in patients with adult CHD. This approach incorporates image-based navigation for translational and non-rigid motion-correction along with 3D patch-based denoising for efficient, free-breathing 3D whole-heart imaging. Comparison between the conventional and the research sequence shows superior diagnostic confidence and diagnostic accuracy for the proposed technique in significantly faster acquisition time (~3min proposed,~15min clinical).
Similarity-driven motion-resolved reconstruction for ferumoxytol-enhanced whole-heart MRI of congenital heart disease patients
Authors: Romanin Ludovica , Milani Bastien , Roy Christopher , Bustin Aurélien , Si-Mohamed Salim , Prsa Milan , Rutz Tobias , Tenisch Estelle , Schwitter Juerg , Stuber Matthias , Piccini Davide
Published: August 2024

Ferumoxytol-enhanced free-running whole-heart MRI allows for a comprehensive evaluation of the cardiovascular anatomy in 3D. A similarity-driven multi-dimensional binning algorithm (SIMBA) has been proposed as a fast and efficient reconstruction of such data, by clustering and selecting motion-consistent information. In this work, we extend the SIMBA reconstruction to make use of the inherent redundancy of motion-consistent information using a compressed-sensing reconstruction, in which sparsity is maximized by the integration of inter-cluster non-rigid 3D motion-fields. With this new framework we demonstrate improved image quality, increased coronary sharpness and vessel conspicuity.
Sex differences between total cerebral blood flow and age-related changes in the brain using 4D flow MRI
Authors: Spahic Alma , Roberts Grant , Peret Anthony , Koscik Rebecca , Jonaitis Erin , Hoffman Carson , Rivera-Rivera Leonardo , Cody Karly , Rowley Howard , Johnson Sterling , Wieben Oliver , Johnson Kevin , Eisenmenger Laura
Published: August 2024

Vascular disease is strongly associated with Alzheimer’s disease. Therefore, it is important to establish normative cerebrovascular changes in aging populations. In this study, we assess sex-specific, age-related changes in total cerebral blood flow (tCBF) and total parenchymal volume in 754 cognitively healthy, older adults. We further investigate whether the same changes are observed in flow normalized by total parenchymal volume. We found (1) significant decrease in tCBF and total parenchymal volume with age in both sexes, (2) no correlation between age and normalized flow in male subjects, and (3) significant decrease in normalized flow with age in female subjects.
Tortuosity and Proximal-specific Wall Shear Stress Associated with Plaque Location in Carotid Bulb: A High-resolution MRI and CFD Study
Authors: Ren Lei , Xia Shuang
Published: August 2024

This study was performed from a vessel wall imaging database, and investigated plaque characteristics, as well as geometric and hemodynamic parameters among different carotid bulb plaque locations caused by atherosclerosis. The results showed that wall shear stress (WSS) magnitudes around plaque side were lower than non-plaque side. Tortuosity of stenosed region, magnitudes of relative residence time and transverse WSS in the proximal part of the lesion were the key factors independently associated with plaque location. This suggested that plaque formation was associated with local flow pattern; and tortuosity, proximal-specific hemodynamics were significantly associated with plaque location in the carotid bulb.
Relaxation-Enhanced Angiography without Contrast and Triggering （REACT） for evaluation of iliac vein compression syndrome at 3T
Authors: Tao Fengming , Tao LI , Zhang Xiaoyong
Published: August 2024

Relaxation-Enhanced Angiography without Contrast and Triggering (REACT) is a novel flow-independent MR angiography technique without cardiac triggering, breath holding and contrast agent injection and has promising results to show robust blood-to-tissue contrast over multiple anatomies. This study aims to investigate the feasibility of REACT for evaluation iliac vein compression syndrome in comparison with catheter angiography. Results showed that with comparable image quality to catheter angiography and high sensitivity and specificity for the detection of stenosis, REACT was proven to be a clinically applicable method for assessing iliac vein compression syndrome.
Lung water estimation using cardiac magnetic resonance imaging for predicting adverse cardiovascular outcomes in patients with heart failure
Authors: Jagia Priya , Verma Mansi , Kumar Sanjeev
Published: August 2024

The present study sought to determine whether CMR-derived lung water density (LWD) measurement in pulmonary congestion has prognostic relevance in predicting adverse cardiovascular outcomes in patients with heart failure. The primary endpoint was all-cause mortality or HF-related hospitalization within 6 months from CMR. It concluded - 1. The mean lung water density was significantly higher in heart failure patients compared to healthy controls. 2. Patients with “wet lungs” i.e., lung water density >18.1%, had higher incidence of adverse cardiovascular outcomes compared to patients with “dry lungs”. 3. Lung water density was an independent predictor of adverse cardiovascular outcomes
Application of IVIM, DKI, FROC and CTRW in vascular normalization induced by recombinant human endostatin in nasopharyngeal carcinoma.
Authors: Huang Lixuan , Ren Hao , Yang Zongxiang , Hu Yao , Zhang Huiting , Long Liling
Published: August 2024

This study explored the vascular normalization induced by recombinant human endostatin (RHES) in nasopharyngeal carcinoma (NPC) based on IVIM, DKI, FROC and CTRW. Results showed that the DKI_D, CTRW_alpha, and FROC_D had a significant difference between prior-treatment and Day 5 in RHES group, FROC_mu in Day 5 and CTRW_alpha in post-treatment were statistically significant in two groups, and DKI_K with decreased trend with the progress of RHES + IC treatment. These results suggest that the four diffusion models can detect the noninvasively monitor the vascular normalization induced by RHES in NPC.
Carotid plaque predicts progression of intracranial atherosclerosis: A MR imaging-based community cohort study
Authors: Yu Miaoxin , Yang Dandan , Zhang Runhua , Jiang Yong , Qiao Huiyu , Zhao Xihai , Liu Gaifen , Wang Yongjun
Published: August 2024

Intracranial atherosclerotic disease progression is associated with recurrent stroke risk. In the present study, we investigated the association between carotid plaque and intracranial atherosclerosis progression in stroke-free participants using MR vessel wall imaging. In 312 participants recruited from a community cohort, we found that carotid plaque was independently associated with intracranial atherosclerosis progression during around 3-years’s follow-up. Our findings suggest that carotid plaque may be an effective predictor for intracranial atherosclerosis progression.
Dose finding and sequence tailoring in sentinel lymph node detection of tongue cancer using superparagmagnetic iron-oxide particles
Authors: Heldens Gijs , Driessen Daphne , Dijkema Tim , Arens Anne , Zámecnik Patrik , Pegge Sjoert , Weijs Willem , van Engen-van Grunsven Adriana , Takes Robert , Kaanders Johannes , Scheenen Tom
Published: August 2024

To clarify the amount, timing and optimal pulse sequence settings of using interstitial superparamagnetic iron oxide particles (SPIO) as a contrast medium to detect sentinel lymph nodes in head and neck radiology, we injected SPIO peritumorally in six patients with early-stage oral squamous cell carcinoma. Anatomical and T2*-weighted MR images were acquired, and dose was altered after every two patients. Images with different computed echo times were created to determine the signal attenuation effect of SPIO on the sentinel lymph nodes.
FibraVasc: towards ex vivo MRI mapping of cerebral vascular territories, application to the vascularization of deep white matter bundles
Authors: Legeay Simon , Smirnov Mykyta , Chauvel Maëlig , Herlin Bastien , Barantin Laurent , Uszynski Ivy , Maldonado Igor Lima , Destrieux Christophe , Poupon Cyril
Published: August 2024

The arterial distribution territories of the brain remain poorly characterized and are of major importance for treating ischemic strokes. We propose a new quantitative MRI approach for ex vivo mapping of vascular territories using paramagnetic gelatin injection into cerebral arteries to enhance MRI contrast at the gelatin level. This method was applied on one healthy human brain injected into the middle cerebral artery and accurately quantified the volume fraction of blood using a dedicated protocol and a modeling of the injected tissue signal. We projected the resulting mapping along the deep white matter fiber bundles.
Investigations of T1 Anisotropy in ex-vivo White Matter using a Tiltable Coil
Authors: Wallstein Niklas , Pampel André , Jäger Carsten , Müller Roland , Möller Harald
Published: August 2024

In general, a broad consensus exists that dipolar couplings between water protons and motional restricted macromolecules are prominent modulators of longitudinal relaxation in WM. Recent studies demonstrate anisotropic relaxation in human white matter (WM) in dependence of the fibre-to-field orientation. Our approach for further investigations of such effects overcomes previous limitations, in particular, sample reorientations for a direct demonstration of orientation effects, which were missing in earlier studies. Samples of ex-vivo WM tissue of pig brain yielded slightly reduced spin-lattice relaxation times by 1-2% around an angle of 40° between the main fibre direction and B0.
Reproducibility and sensitivity of in vivo human brain R1 map at ultralow field 64 mT
Authors: Kim Joong , Nair Govind , Reich Daniel , Brody David
Published: August 2024

MR parameter mapping provides objective biomarkers for living tissues. However, long scan times and high field MR imaging are typically required, whereas few ultralow field MR scanner studies have been performed. Here we propose a simplified R1 mapping protocol with only two inversion delay time points (R1approx), taking advantage of the fast R1 at ultralow field. The R1 characteristics of human brain were largely preserved in R1approx compared to standard inversion recovery R1 mapping. R1approx. required under 30 minutes vs. ~two hours for standard R1 mapping. In addition, R1approx. shows high reproducibility and good sensitivity to an R1 contrast agent.
Suppressing blood signal in myocardial T1ρ mapping at 3T through novel dark-blood adiabatic spin-lock preparations.
Authors: Coletti Chiara , Bozic-Iven Maša , Tourais Joao , van de Steeg-Henzen Christal , Akcakaya Mehmet , Weingärtner Sebastian
Published: August 2024

T1ρ-mapping is emerging as a promising, contrast-free alternative to LGE for assessment of myocardial viability. However, high blood T1ρ values can obfuscate endocardial scar. In this work, we propose a dark-blood adiabatic T1ρ preparation to suppress the blood signal and improve depiction of the blood-myocardium interface. A slice-selection gradient is added to an odd number of adiabatic full passage pulses to achieve blood inversion outside the imaging slab. Phantom results show that DBT1ρ yields unbiased estimation of T1ρ time. In vivo, thorough blood suppression is achieved for the trade-off against a moderate increase in DBT1ρ variance.
Improved Bayesian Brain MR Image Segmentation by Incorporating Subspace-Based Spatial Prior into Deep Neural Networks
Authors: Zhang Yunpeng , Zhuang Huixiang , Meng Ziyu , Liu Ruihao , Jin Wen , Li Wenli , Liang Zhi-Pei , Li Yao
Published: August 2024

Accurate segmentation of brain tissues is important for brain imaging applications. Learning the high-dimensional spatial-intensity distributions of brain tissues is challenging for classical Bayesian classification and deep learning-based methods. This paper presents a new method that synergistically integrate a tissue spatial prior in the form of a mixture-of-eigenmodes with deep learning-based classification. Leveraging the spatial prior, a Bayesian classifier and a cluster of patch-based position-dependent neural networks were built to capture global and local spatial-intensity distributions, respectively. By combining the spatial prior, Bayesian classifier, and the proposed networks, our method significantly improved the segmentation performance compared with the state-of-the-art methods.
Predicting Gestational Age at Birth in the Context of Preterm Birth Using Comprehensive Fetal MRI Acquisitions
Authors: Fajardo-Rojas Diego , Heinsalu Riine , Hall Megan , Rutherford Mary , Hajnal Joseph , Robinson Emma , Story Lisa , Hutter Jana
Published: August 2024

The accurate prediction of preterm birth is a clinically crucial but challenging problem due to its complex aetiology. In this work, data from fetal anatomical and functional multi-organ MRI acquisitions are used to train Random Forests and Support Vector Machines to predict gestational age at delivery. These predictions are classified as 'term' or 'preterm'. The model with highest sensitivity, a Random Forest, achieved 0.85 sensitivity, 0.81 accuracy, 0.8 specificity, 1.99 weeks Mean Absolute Error, and 0.58 R2 score. This work proves the potential of Machine Learning models trained on anatomical and functional MRI data to predict gestational age at delivery.
Uncertainty maps for training a deep learning model that automatically delineates the skeleton from Whole-Body Diffusion Weighted Imaging
Authors: Candito Antonio , Torcè Martina , Holbrey Richard , Dragan Alina , Messiou Christina , Tunariu Nina , Koh Dow-Mu , Blackledge Matthew D
Published: August 2024

Whole-Body Diffusion Weighted Imaging (WBDWI) requires automated tools that delineate malignant bone disease based on high b-value signal intensity, leading to state-of-the-art imaging biomarkers of response. As an initial step, we have developed an automated deep-learning pipeline that automatically delineates the skeleton from WBDWI. Our approach is trained on paired examples, where ground truth is defined through a set of weak labels (non-binary segmentations) derived from a computationally expensive atlas-based segmentation approach. The model showed on average a dice score, precision and recall between the manual and derived skeleton segmentations on test datasets of 0.74, 0.78, and 0.7, respectively.
Functional connectome allows individual prediction of gait function within Parkinson’s disease and is linked to molecular architecture
Authors: Wu Haoting , Zhang Minming
Published: August 2024

The predictive connectome of PD gait overlapped with the dopaminergic and cholinergic systems.
Respiratory Motion-Resolved 4D Pulmonary Imaging with Stack-of-Spiral UTE at 0.55T and 3T
Authors: Su Pan , Majeed Waqas , Miao Xin , Pfeuffer Josef , Javed Ahsan , Ramasawmy Rajiv , Campbell-Washburn Adrienne , Bhat Himanshu , Thoermer Gregor , Pang Jianing , Benkert Thomas
Published: August 2024

Recently, ultrashort echo time (UTE) has gained renewed interest for lung imaging at 1.5T and 3T, which captures short T2* signal from lung parenchyma. Lower field is attractive for lung MRI due to prolonged T2* and reduced susceptibility, and it was demonstrated that high-resolution high-quality structural lung imaging can be achieved with UTE at 0.55T. In addition to anatomical information, pulmonary function such as regional ventilation is also of great clinical interest. In this study, we developed free-breathing respiratory-motion-resolved 4D pulmonary imaging using stack-of-spirals acquisition with compressed-sensing at both 0.55T and 3T, which could enable quantitative evaluation of ventilation dynamics.
Phantom validation of continuous radial sampling MRI for robotic interventional cardiovascular surgery
Authors: Zhong Sijie , Tao Ran , Wang Ruoxi , Chen Hao , Jin Chen , Zhang Zhiyong
Published: August 2024

Cardiovascular dilation surgery is usually performed with DSA navigation, and excessive radiation during imaging harms both the patient and the physician. Magnetic resonance imaging can avoid ionizing radiation, but its imaging efficiency severely limits the performance of real-time imaging. Therefore, we construct a complete real-time magnetic resonance navigation system through continuous radial scanning mode and corresponding reconstruction methods and formulate a group of scanning strategies. The characteristics of the special derivative catheter under magnetic resonance imaging were tested by combining the partner's magnetically compatible robotic equipment. And the results demonstrated the feasibility of this method.
Regional quantification of cardiac metabolism with hyperpolarized [1-13C]-pyruvate MRI
Authors: Larson Peder , Tang Shuyu , Liu Xiaoxi , Sinha Avantika , Dwork Nicholas , Sivalokanathan Sanjay , Liu Jing , Bok Robert , Ordovas Karen , Slater James , Gordon Jeremy , Abraham M. Roselle
Published: August 2024

Hyperpolarized (HP) 13C-pyruvate MRI is a promising new tool for non-invasive quantification of myocardial glycolytic and Krebs cycle metabolism. In this study we evaluated whole-heart imaging and metabolism quantification methods in 7 healthy volunteers under a fasted and fed state. We observed that the 13C-pyruvate-to-bicarbonate conversion rate, kPB, a measure of PDH flux, had the highest, statistically significant correlation with blood glucose levels, with smaller changes in the 13C-lactate/pyruvate ratio and 13C-pyruvate-to-lactate conversion rate, kPL. 13C-pyruvate and 13C-lactate were detected simultaneously in the RV blood pool, immediately after intravenous injection, reflecting LDH activity in blood.
3D whole-heart joint T1/T1ρ/T2 mapping and water-fat imaging for contrast-agent free myocardial tissue characterization at 1.5T
Authors: Crabb Michael , Kunze Karl , Munoz Camila , Tripp Donovan , Fotaki Anastasia , Velasco Carlos , Neji Radhouene , Prieto Claudia , Botnar Rene
Published: August 2024

Native T1 and T1ρ mapping has shown promising results for the detection of focal and diffuse myocardial fibrosis without the need of contrast agents, whereas T2 mapping enables characterisation of inflammation and edema. However, conventional myocardial maps are acquired in sequential 2D breath-hold scans with limited heart coverage. Here, we propose a novel free-breathing, 3D joint T1/T1ρ/T2 mapping sequence with Dixon encoding to provide whole-heart T1, T1ρ and T2 maps and co-registered water/fat volumes with isotropic spatial resolution for comprehensive contrast-agent free myocardial tissue characterization. Preliminary results demonstrate good agreement with reference values in phantoms and promising results in-vivo.
Accuracy, Precision, and Reproducibility of 3D Whole Heart Simultaneous T1 and T2 Mapping Based on Multi-parametric SAVA: A Comparison Study
Authors: Si Dongyue , Guo Rui , Herzka Daniel , Ding Haiyan
Published: August 2024

MR parametric mapping including T1 and T2 enabled quantitative evaluation of changes of myocardium. We previously proposed a time-efficient technique for 3D free-breathing simultaneous T1 and T2 mapping based on multi-parametric SAturation recovery and Variable flip Angle (mSAVA). This study evaluated the accuracy, precision, and reproducibility of mSAVA in comparison with conventional 2D sequences. mSAVA achieved good accuracy, between that of MOLLI and SASHA, and better precision and reproducibility than SASHA for T1 measurements. T2 measured by mSAVA had better precision and reproducibility than both GraSE and bSSFP T2. mSAVA offers a promising option for myocardial tissue characterization.
Free-breathing simultaneous myocardial T2 and T1ρ mapping for non-contrast assessment of uremic cardiomyopathy
Authors: Miao Qinfang , Lv Zhenfeng , Hua Sha , Zhang Zhongqi , Xu Jian , Hu Peng , Qi Haikun
Published: August 2024

Uremic cardiomyopathy is the adverse cardiac remodeling that commonly occurs in patients with chronic kidney disease. Previous studies have indicated increased intramyocardial fluid and myocardial fibrosis in uremic patients, which makes native myocardial T2 and T1ρ mapping ideal imaging biomarkers to characterize these changes. Therefore, we propose a free-breathing simultaneous T2 and T1ρ mapping technique to provide co-registered T2 and T1ρ maps. The proposed technique was firstly evaluated in phantoms and ten healthy subjects, which achieved similar performance to the conventional separate T2 and T1ρ mapping methods. The preliminary validation in four hemodialysis patients showed promising results.
Probing muscle recovery following downhill running using precise mapping of MRI’s T2 relaxation times
Authors: Holodov Maria , Markus Irit , Solomon Chen , Shahar Shimon , Blumenfeld-Katzir Tamar , Gepner Yftach , Ben-Eliezer Noam
Published: August 2024

Post-exercise recovery rate is vital for planning training protocols, maintaining high-level performance, and preventing injuries. Notwithstanding the advancement of noninvasive imaging, there is still a lack in efficient tools for monitoring muscle state and post-exercise due to the relatively small changes in the muscles’ microarchitecture, and the high variability in recovery rate between and within participants. Here we utilized the echo-modulation-curve (EMC) algorithm, a highly accurate and precise tool for mapping T2 relaxation times, to track muscle damage and recovery following exercise. Results show that this approach provides new insights into the microstructural processes that occur following exercise.
Lower-limb walking kinetics associated with acetabular and femoral bone remodeling in hip OA: a PET-MR study
Authors: Roach Koren , Tibrewala Radhika , Pedoia Valentina , Bahroos Emma , Majumdar Sharmila , Souza Richard
Published: August 2024

Early hip osteoarthritis is clinically hypothesized to include alterations in joint motion and bone remodeling. This study investigated the relationships between lower-limb joint kinetics and bone remodeling, measured via positron emission tomography. Our results suggest that greater hip flexion and internal rotation loading and more uniform knee abduction loading are associated with bone remodeling and may serve as early biomechanical biomarkers for hip OA.
CSF pseudo-diffusion spatial statistics for whole-brain voxel-wise analysis of CSF flow
Authors: Nazeri Arash , Dehkharghanian Taher , LaMontagne Pamela , Benzinger Tammie , Sotiras Aristeidis
Published: August 2024

Alterations in CSF flow patterns have been implicated in various brain disorders. At low b-values, diffusion-weighted imaging is sensitive to pseudorandom CSF flow. Here, we present CSF pseudo-diffusion spatial statistics (CΨSS), a whole-brain multi-subject voxel-wise analysis framework that exploits low-b-value diffusion-weighted imaging to study regional patterns of CSF flow. Using this technique, we show how brain atrophy and ventricular volumes affect regional CSF pseudorandom flow. In conclusion, CΨSS is a simple and effective approach for characterizing determinants of regional CSF pseudorandom flow.
Deep-learning based rectal tumor segmentation on multi-parametric MRI using pre-treatment and near-end-treatment data
Authors: Zhang Yang , Shi Liming , Sun Xiaonan , Su Min-Ying , Cui Taoran , Yue Ning , Nie Ke
Published: August 2024

In this study, the convolutional neural network (CNN) was implemented to segment the rectal cancer in 185 patients, with tumor ROI outlined by a radiologist on multiparametric magnetic resonance images (mp-MRI). The Dice similarity coefficient (DSC) and mean symmetrical surface distance (MSD) values were used to evaluate the results of the proposed algorithm. The mean DSC and MSD were 0.88 and 2.2 cm respectively for pre-treatment MR images. The transfer-learning model using paired pre-treatment and near-end-treatment images could also lead to acceptable result for boost volume segmentation with the mean DSC of 0.83 and MSD of 2.7 cm. Our work showed the deep-learning with combined image sequences was promising for automatic tumor localization and segmentation of locally advanced rectal cancer. After applying transfer learning with the prior information obtained from the pre-treatment images, the proposed method can be further used to identify boost volume for radiation dose escalation which has been demonstrated beneficial in improving pathological complete response rate.
Assessment of Breast Cancer Molecular Subtypes with a mMRI-based Feature Fusion Radiomics Model: Mimicking Radiologists’ Diagnostic Approach
Authors: Zhang Wanli , Liang Fangrong , Li Jiamin , Xu Yongzhou , Zhang Aaron , Jiang Xinqing , Zhen Xin , Yang Ruimeng
Published: August 2024

Since breast cancer is a highly heterogeneous tumor, prognosis and treatment response differ significantly according to different molecular subtypes. Based on multiparametric magnetic resonance imaging (MRI), we developed a feature fusion radiomics (RFF) model and investigated its performance in identifying the molecular receptor status of breast cancer. Mimicking the diagnostic approach of the radiologists by integrating image information from different MR sequences, the RFF model outperformed any single MRI-based radiomics model, demonstrating its potential for molecular subtypes classification of breast tumors.
A pH-sensitizer can improve cancer immunotherapy treatment as monitored with acidoCEST MRI
Authors: Chin Renee , de la Cerda Jorge , Schuler F William , Sinharay Sanhita , Pagel Mark
Published: August 2024

Tumor acidosis causes resistance to immune checkpoint blockade (ICB) immunotherapy. We have identified a “pH-sensitizer” that increases the extracellular pH of the tumor microenvironment, improving immunogenicity and tumor control with ICB. AcidoCEST MRI can measure the extracellular pH of the tumor microenvironment. We used acidoCEST MRI to correlate the increase in tumor pHe immediately caused by the pH-senstizer with the tumor volume at study endpoint, in a pre-clinical model of breast cancer. These results show that acidoCEST MRI can contribute to predicting the outcome of immunotherapy.
MRI assessment of abscopal effect enhanced by immune checkpoint blockade
Authors: Yamashita Kota , Horie Kazumasa , Yamamoto Kazutoshi , Brender Jeffery R. , Devasahayam Nallathamby , Krishna Murali C. , Kishimoto Shun
Published: August 2024

Radiation therapy (RT) on primary tumor rarely induces regression of non-irradiated metastatic lesions (abscopal effect), which is reported to be enhanced by immune-checkpoint blockade. In this study, we examined the physiological changes induced by abscopal effect using MRI-based imaging modalities such as EPR oximetry, DCE MRI, and 13C DNP MRI. Hypoxic fraction < 10 mmHg (HF10), permeability, perfusion, and CD8+ T cell infiltration in metastatic tumor increased after the combination of RT and PD-1 blockade. Interestingly, higher permeability/perfusion and lower HF10 in primary tumor before the treatment were associated with slower growth of the metastatic tumor after the treatment.
Texture Analysis of Diffusion Kurtosis Imaging for Predicting Early Recurrence of Hepatocellular Carcinoma After Hepatectomy
Authors: Wang Yue , Zhao Ying , Liu Ailian
Published: August 2024

The global incidence and mortality of hepatocellular carcinoma (HCC) are high [1]. Although radical resection of HCC is the most effective treatment, the postoperative recurrence rate is high. Diffusion kurtosis imaging (DKI) is based on the non-Gaussian diffusion motion of water molecules, which can quantitatively reflect the characteristics of lesions from the perspective of diffusion and heterogeneity[2]. Texture analysis provides information about tissue complexity and heterogeneity based on mathematical methods. This study showed that DKI-based entire-tumor texture analysis could assist in prediction of the early recurrence of HCC patients after hepatectomy, which was beneficial to improve the prognosis.
Demonstration of Intracranial Aneurysm Healing after Endovascular Coiling Evaluated by 3D T1 SPACE Magnetic Resonance
Authors: Cheng Sho-Jen , Lu Xue-Zhe , Wang Yi-Hsin
Published: August 2024

Angiography is a gold standard tool in the follow-up of the treated aneurysms to identify if there is aneurysm recanalization need further management. Despite non-invasive MR-based assessments be reported, the pathological changes of aneurysm on MRI was not clear. In this study, we employed three-dimensional variate flip angle MRI to evaluate the endothelial healing in ten cases with intracranial aneurysms after endovascular management. HRVWI routinely demonstrate the enhancement pattern of the aneurysmal neck not only the aneurysmal wall in both cross-sectional and time-serial follow up, increasing our confidence in making the decision whether to retreat or not.
Vascular contribution to the preclinical stages of Alzheimer’s disease: Insights from the EPAD cohort
Authors: Lorenzini Luigi , Maranzano Alessio , Collij Lyduine , Sudre Carole , Wolz Robin , Haller Sven , Blennow Kaj , Frisoni Giovanni , Payoux Pierre , Lage-Martinez Pablo , Ewers Michael , Chatelat Gael , Waldman Adam , Wardlaw Joanna , Fox Nick , Ritchie Craig , Scheltens Philip , Visser Pieter Jelle , Wink Alle Meije , Mutsaerts Henk JMM , Gispert Juan Domingo , Ingala Silvia , Barkhof Frederik
Published: August 2024

Evidence suggests that cardiovascular risk factors and cerebrovascular disease contribute to the Alzheimer’s disease (AD) pathophysiology. It is still unclear to what extent vascular and amyloid pathology have a synergistic or independent influence in preclinical AD stages. We used structural equation models in a cohort of cognitively unimpaired individuals to investigate if cerebrovascular pathology mediates the relationship between cardiovascular risk factors and CSF Aβ1-42, and show that cerebrovascular pathology accelerates downstream AD markers (p-Tau181 and hippocampal volume) by increasing amyloid pathology.
Increase of Magnetic Transfer Contrast in Middle Cerebellum Peduncles in Patients with Multiple System Atrophy
Authors: Lyu Haiying , Li Qing , Huang Yufei , Lu Yong
Published: August 2024

The magnetic transfer (MT) MRI imaging has long been used for quantifying neuromelanin containing nucleus, but its ability of quantifying the magnetization exchange between free water and macromolecules has also allowed its potential usage in detecting white matter changes. Patients with multiple system atrophy has unique pathological changes in pontocerebellar regions. In this study, we have not only found significant increase of MT contrast in MCP regions of MSA, but also proved significant correlation between this alteration and brainstem or cerebellar atrophy, which might offer new insights for future studies.
Examining the consistency of brain MRI structural and functional readouts using repeat imaging from the longitudinal UK Biobank MRI Study.
Authors: Jiang Guocheng , Rabin Jennifer , Swardfager Walter , Cogo-Moreira Hugo , MacIntosh Bradley
Published: August 2024

We aim to study structural and functional changes over time with a focus on the thalamus and hippocampus regions of interest. Longitudinal analysis was performed in N=274 UK Biobank participants. We find strong correlations between the baseline and follow-up MRI readouts. Namely, it is possible to predict thalamus and hippocampus volume changes across a mean of 2.25 years using baseline volume and resting state functional activation estimates. This work helps characterizing the longitudinal consistencies within both hippocampal and thalamic MR readouts and helps setting up prediction models as the next step.
Effects of neuropathic pain on cerebral hemodynamics in spinal nerve ligation model
Authors: JIN SEOKHA , Cho Hyung Joon
Published: August 2024

In this study, the effects of neuropathic pain on cerebral hemodynamics was investigated. For the neuropathic pain model, a spinal nerve ligation model was operated and validated by Von Frey test. To estimate the cerebral hemodynamics, DSC-MRI was performed up to 28 days after surgery. As a result, it is possible to specify when or where the neuropathic pain strongly affects cerebral perfusion.
A Cohort Study of Spinal Cord Diffusivity After Treatment of Cervical Spondylotic Myelopathy with Instrumented Spinal Fusion
Authors: Koch Kevin , Nencka Andrew
Published: August 2024

This study analyzed spinal cord diffusivity in CSM subjects treated with metallic spinal fusion decompression. Metal-artifact-suppressed diffusion-weighted MRI were collected on 38 CSM subjects and 25 controls. Diffusivity was analyzed as a function of cohort and level instrumentation (instrumented, non-instrumented, and adjacent segment). In addition, the impact of mJOA symptom scores and duration since the fusion procedure on diffusivity were modeled. Multi-linear mixed effects models accounted for demographic variations and multiple-measures (at different cord levels) within each subject. The results of the study identified consistent reductions in diffusivity due to the presence of fusion instrumentation.