bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Spin-Echo EPI MR Elastography for Rapid Free-Breathing Quantification of Liver Stiffness
Authors: Kafali Sevgi , Bolster Bradley , Delgado Timoteo , Shih Shu-Fu , Deshpande Vibhas , Leon Pedro Itriago , Johnson Kevin , Altbach Maria , Lu David , Han Steven-Huy , Adamos Timothy , Ghahremani Shahnaz , Calkins Kara , Wu Holden
Published: November 2024

Motivation: Hepatic stiffness (HS), detected by MR elastography (MRE), is a biomarker for hepatic fibrosis. Liver MRE requires breath-holding (BH), which is challenging in children or people with liver disease. Spin-echo echo-planar-imaging (SE-EPI) MRE can quantify HS rapidly(~10 s), even with iron overload. Goal(s): To evaluate free-breathing (FB) SE-EPI MRE without respiratory triggering or motion compensation in terms of agreement, repeatability, and measurable liver area [%] with respect to BH SE-EPI MRE. Approach: BH and FB SE-EPI MRE were acquired in 23 children and 2 adults with liver biopsy. Results: FB SE-EPI MRE provided fast, accurate, and repeatable HS with high measurable liver area. Impact: The free-breathing (FB) MR elastography (MRE) of the liver based on spin-echo echo-planar-imaging (SE-EPI) produced accurate and repeatable hepatic stiffness with respect to standard breath-held SE-EPI MRE. FB SE-EPI MRE can be useful for populations who cannot hold their breath.
Comparison of 2D and 3D MRE Performance in Prediction of MASLD-Associated Risk Factors
Authors: Owusu Nana , Kalutkiewicz Kyle , Li Jiahui , Chen Jun , Glaser Kevin , Manduca Armando , Sirlin Claude , Loomba Rohit , Allen Alina , Ehman Richard , Yin Meng
Published: November 2024

Motivation: Pathology of steatotic liver disease is characterized by fat burden, inflammation, and ballooning. Mechanical properties of tissue acquire by 2D-MRE has improved the detection of this disease. However, 3D-MRE, an improvement over 2D-MRE is not widely adopted by clinicians. Goal(s): We aimed to compare the predictive capabilities of these two in risk factors associated with this disease using machine learning to help motivate clinicians to use 3D-MRE. Approach: Use machine learning to determine the predictive capabilities of 2D-MRE and 3D-MRE. Results: Results showed 3D-MRE best predicts steatohepatitis, inflammation, and ballooning. Impact: The demonstrated predictive value of 3D-MRE in identifying those with certain risk factors allows clinicians to better plan treatment for patients with steatotic liver disease.
Accelerated 4D Flow MRI with Low-Rank Modeling and A Deep Generative Prior
Authors: Sun Aiqi , Lu Hengfa , Zhao Bo
Published: November 2024

Motivation: Conventional 4D flow MRI provides valuable insights into blood flow but suffers from long scan times. Recent machine learning methods improve MRI reconstruction; however, they often require a large amount of training data to achieve desired performance. Goal(s): This work is aimed to introduce a novel learning-based image reconstruction method to accelerate 4D flow MRI without using training datasets. Approach: The proposed method integrates low-rank modelling with a deep generative prior by utilizing an untrained generative neural network to represent the spatial subspace of the model. Results: The effectiveness of the proposed method has been demonstrated with in-vivo aortic 4D flow experiments. Impact: This work introduced an innovative learning-based image reconstruction method for accelerating 4D flow MRI, which produces accurate velocity measurements even under high acceleration factor, all without the need for training datasets.
ASL combined with T1 mapping for assessment of renal function and histopathology in patients with long-term renal transplant survival
Authors: Jiang Bin , Wu Peng , Wan Jiayi , Ma Jiali , Xu Rui , Tian Yangyang , Hu Linkun , Zhu Mo
Published: November 2024

Motivation: Early and sensitive detection of graft renal dysfunction can help timely diagnosis of the disease and improve prognosis. Goal(s): We aimed to investigate the value of ASL and T1 mapping for assessing renal function in patients with long-term renal transplant survival. Approach: 63 patients were included, and all patients underwent MRI examination. MRI parameters were calculated and analyzed. Results: This study revealed that the combined application of ASL and T1 mapping can accurately assess the degree of renal impairment, and significant correlations were found between MRI parameters and several important Banff pathological scores which determined the diagnosis of renal allograft rejection and chronicity. Impact: The significant correlations between MRI parameters and pathological changes involving allograft rejection and chronicity highlight the clinical value of multiparametric MRI as a noninvasive and comprehensive modality for early diagnosis and longitudinal monitoring of renal allograft injury.
Value of placental stiffness using virtual magnetic resonance elastography in pregnancies complicated by pre-eclampsia
Authors: Xu Jialu , Cheng Jiejun
Published: November 2024

Motivation: To evaluate virtual magnetic resonance elastography in healthy and preeclamptic(PE) pregnancies. Goal(s): To compare the stiffness value (μdiff) and apparent diffusion coeffificient (ADC) in healthy and PE pregnancies. Approach: DWI(b-value of 50 ,200and 800 s/mm2 ) were performed on all pregnant women using a 1.5 T MRI scanner. The value of μdiff and ADC were calculated and compared between groups. Results: The mean ADC value of the control and PE groups were 1.414±0.228×10-3 mm2/s and 1.737±0.107×10-3 mm2/s, respectively. The mean μdiff value of PE were 5.901±1.757 and 4.618±2.055 kPa, respectively. The area under the curve for μdiff was 0.903 and ADC was 0.796, respectively. Impact: Placental μdiff value was found to be more reliable than ADC in differentiating between normal and preeclampsia placentas.
DWI Parameters Correlated with Ki-67 Expression, a Prognostic Biomarker, in a Triple-Negative Breast Cancer PDX Mouse Model
Authors: Iima Mami , Akamatsu Marino , Imai Hirohiko , Suzuki Hana , Gotoh Noriko , Takeuchi Yasuto , Honda Maya , Nobashi Tomomi , Kataoka Masako , Yoshizawa Akihiko , Ito hiroaki , Nakagawa Tomoe , Kim Minsoo , Le Bihan Denis , Nakamoto Yuji
Published: November 2024

Motivation: The lack of reliable biomarkers for assessing tumor characteristics and the limitations of histological analysis due to tumor heterogeneity led to the exploration of diffusion-weighted parameters. Goal(s): To investigate the association between DW parameters and Ki-67 expression in triple-negative breast cancer, with a focus on whether they can serve as prognostic biomarkers. Approach: Seventeen triple-negative breast cancer mice with a PDX model underwent 7T MRI scans, yielding DW images. Advanced analysis evaluated ADC and non-Gaussian diffusion parameters, validated through histological Ki-67 staining. Results: DWI parameters (S-index, sADC, and ADC0) show strong correlations with Ki67 levels, at short and long diffusion times (9, 27.6ms). Impact: Promising prognostic biomarkers for triple-negative breast cancer, DWI parameters (S-index, sADC, and ADC0) displayed strong correlations with Ki-67 expression, at short and long diffusion times. This validation through accurate DWI-pathology comparison highlights imaging's pivotal role in advancing breast cancer diagnosis.
Quantitative Imaging Habitat Risk Score (HRS) Combined with PI-RADSv2 Improves Predictive Value of Prostate Lesion Identification on mpMRI
Authors: Wallaengen Veronica , Breto Adrian , Kimbel Isabella , Zacharaki Evangelia , Algohary Ahmad , Prakash Nachiketh Soodana , Gaston Sandra , Acosta Rosa Castillo , Kryvenko Oleksandr , Nahar Bruno , Parekh Dipen , Pollack Alan , Punnen Sanoj , Stoyanova Radka
Published: November 2024

Motivation: Discrimination between true and false positive targets identified using PI-RADSv2 is needed to avoid unnecessary biopsies. Goal(s): To investigate how quantitative analysis of prostate mpMRI through Habitat Risk Scoring (HRS) combined with PI-RADS can improve prostate lesion identification compared to using PI-RADS alone. Approach: In prospective clinical trials lesions identified by PI-RADS and/or HRS were targeted through MRI/ultrasound fusion biopsies. Results: Using HRS yields 100% NPV in the PI-RADS 3 cohort and increases PPV by 7.4% in the PI-RADS 4-5 cohort with respect to clinically significant cancer. Overall, the NPV and PPV increased by 21.4% and 13.2% respectively. Impact: We present a quantitative imaging approach to complement the current standard for assessing prostate cancer risk in mpMRI data and demonstrate that the use of HRS strengthens fidelity in both positive and negative detections.
Intravoxel incoherent motion diffusion-weighted imaging in diagnosing perineural invasion status of rectal cancer: a histogram analysis study
Authors: He Rong , Song Gesheng , Fu Junyi , Dou Weiqiang , Li Aiyin , Chen Jingbo
Published: November 2024

Motivation: Currently, perineural invasion (PNI) of rectal cancer (RC) can only be confirmed by pathological examination of postoperative specimens. Goal(s): It aimed to investigate the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in diagnosing the PNI status of RC by histogram analysis. Approach: We extracted histogram features from 7 parametric maps derived from IVIM-DWI. The independent predictive histogram features of rectal cancer PNI were combined with the percentage of rectal wall enclosure（PCI ) reported by MRI to construct a combined model for preoperative diagnosis of PNI. Results: The AUC of the combined model is higher than that of each single-parameter model and histogram model. Impact: This study demonstrated that full-volume histogram parameters basing on IVIM-DWI can be used to assess PNI status in rectal cancer. Histogram analysis, as a non-invasive tool, may be more valuable not only in rectal cancer research in the future.
Multi-Center and Multi-Vendor Platform DCE-MRI Prediction of Breast Cancer Therapy Response: A Preliminary Comparison of Imaging Biomarkers
Authors: Moloney Brendan , Li Xin , Hirano Michael , Eddin Assim Saad , Lim Jeong Youn , Biswas Debosmita , Kazerouni Anum , Tudorica Alina , Li Isabella , Bryant Mary Lynn , Wille Courtney , Pyle Chelsea , Rahbar Habib , Hsieh Su Kim , Rice-Stitt Travis , Dintzis Suzanne , Bashir Amani , Hobbs Evthokia , Zimmer Alexandra , Specht Jennifer , Phadke Sneha , Fleege Nicole , Holmes James , Partridge Savannah , Huang Wei
Published: November 2024

Motivation: Validate Shutter-Speed model (SSM) DCE-MRI as a robust predictor of breast cancer (BC) response to neoadjuvant chemotherapy (NAC) in a multi-center and multi-vendor platform setting. Goal(s): Compare tumor size, semi-quantitative, and quantitative DCE-MRI for early prediction of NAC response. Approach: BC patients treated with NAC underwent longitudinal high spatiotemporal resolution DCE-MRI at three sites using a 3T Siemens, GE, or Philips system. Semi-quantitative signal-enhancement-ratio (SER) and quantitative Tofts model (TM) and SSM pharmacokinetic (PK) parameters were derived from DCE time-course data. Results: PK parameters outperformed size and SER while SSM was superior to TM in early prediction of pathologic response. Impact: It is feasible to implement quantitative high spatiotemporal resolution SSM DCE-MRI in trials with multi-center and multi-vendor platform settings for robust assessment of BC response to NAC.
A realistic in-silico brain phantom for magnetic susceptibility-separation algorithm validation
Authors: Ridani Daniel , De-Leener Benjamin , Alonso-Ortiz Eva
Published: November 2024

Motivation: Positive and negative susceptibility mapping is an emerging method that can benefit from the availability of validation tools. Goal(s): To create an in-silico brain phantom for positive and negative susceptibility and to assess the impact of white matter’s anisotropic susceptibility on susceptibility-separation techniques. Approach: Simulate positive and negative susceptibility maps and gradient-echo data with/without anisotropy. Process simulated data with different susceptibility-separation algorithms. Compare the results with the ground truth. Results: The error associated with negative susceptibility measurements is ~9% greater when anisotropy effects are present in the phantom, suggesting that a new susceptibility-separation algorithm that considers myelin’s anisotropic susceptibility may be warranted. Impact: Researchers developing novel magnetic susceptibility-separation methods can use our proposed phantom to test different aspects of their technique, ranging from the biophysical model to image processing methods and imaging protocol parameters.
QSM-CI: An automated continuous QSM challenge
Authors: Stewart Ashley , Eckstein Korbinian , Dao Thuy Thanh , Bollmann Steffen
Published: November 2024

Motivation: Reconstruction challenges for Quantitative Susceptibility Mapping (QSM) offer a common evaluation but are challenging to run and offer only a single snapshot of algorithm performance in time. Goal(s): To develop a QSM challenge with continuous integration (QSM-CI), enabling automatic, transparent evaluation of community-submitted algorithms across diverse datasets and metrics. Approach: QSM-CI was implemented using GitHub Actions and a user interface for displaying metrics and collecting community visual ratings, which inform a qualitative Elo metric alongside quantitative assessments. Results: The QSM-CI prototype implementation is publicly available and has been tested using a range of QSM algorithms. Impact: QSM-CI will facilitate a QSM challenge that allows for continuous evaluations using current and future datasets, algorithms, and metrics. This ensures the continued accessibility of the challenge and continued relevance as new methods, metrics and test data are made available.
Improved QSM Pipeline to Investigate the Effect of Sickle Cell Anaemia on Brain Magnetic Susceptibility in Tanzanian Children at 1.5 Tesla
Authors: Lee Mitchel , Murdoch Russell , Jakob Mboka , Kirkham Fenella , Shmueli Karin
Published: November 2024

Motivation: Sickle cell anaemia (SCA) is a major global health burden, but disease mechanisms in the brain are not well understood. Goal(s): To improve a quantitative susceptibility mapping (QSM) pipeline and apply it to updated data to investigate brain susceptibility differences between SCA patients and controls. To investigate correlations between blood haemoglobin and brain magnetic susceptibility. Approach: QSM was optimised using denoising/masking approaches. Linear regressions of susceptibility against log(age) were used to compare age-corrected susceptibility in grey matter structures across the age range and correlate with haemoglobin. Results: Susceptibility increases with age differently for SCA vs controls. Haemoglobin was not significantly correlated with susceptibility. Impact: This work provides novel insight into the relationship between grey matter magnetic susceptibility and sickle cell anaemia, demonstrating differential trajectories with age between SCA patients and healthy controls. This may support the view of SCA as an accelerated aging syndrome.
Elastic modulus of acetabular labrum correlates with UTE apparent spin-spin (T2*) and spin-lattice (T1) magnetic resonance relaxation times
Authors: Moazamian Dina , Hananouchi Takehito , Mohammadi Hamidreza Shaterian , Suprana Arya , Tayarani Alireza , Dorthe Erik , D’Lima Darryl , Ma Yajun , Jerban Saeed
Published: November 2024

Motivation: The acetabulum labrum plays a critical role in the hip function. Medical imaging techniques for detecting labral degeneration may help improve our knowledge of its role in hip osteoarthritis (OA). Goal(s): This study aimed to explore the correlation between the mechanical properties of the acetabulum labrum and MRI properties. Approach: The correlations of UTE-T2* and -T1 sequences with the tensile elastic modulus of human acetabular labrum specimens have been investigated. Results: There was a significant correlation between quantitative UTE-T2*, and UTE-T1 techniques and the mechanical properties of the labrum. Impact: UTE-T2* and -T1 sequences showed the potential to evaluate acetabulum labrum mechanical assessment, which is needed to improve labrum degeneration detection and monitoring, a primary unmet need in areas where hip osteoarthritis is common and conventional MRI is being implemented.
Multi-parametric Quantitative Magnetic Resonance Imaging Phantom
Authors: Alderson Hannah , Swanson Scott , Reichert William , Gochberg Daniel , Does Mark
Published: November 2024

Motivation: Currently there is no qMRI phantom that simultaneously reproduces the many contrasts that are present in white matter. Goal(s): The goal of this work is to characterize a single multiparametric qMRI phantom that exhibits diffusion, magnetization transfer and MET2 properties. Approach: Aqueous MTF and PVP were combined in varying concentrations and evaluated with both NMR and MRI. Results: A homogenous, multiparametric qMRI phantom was created with an array of tissue relevant parameters: T2L ranging from 71.9-183 ms, T2s ranging from 13.6-17.7 ms, fs ranging from 0.118-0.177, T1free ranging from 1479-1919 ms and fm ranging from 0.053-0.109. Impact: A multiparametric phantom allows for improved quality assurance analysis, as well as sequence development by allowing for multiple contrasts to be evaluated simultaneously. Ultimately providing a sample that is controlled, yet more akin to what occurs in biological samples.
Does the stability assessment of an MRI scanner depend on the phantom used?
Authors: Amirafshari Negar , Passalis Anestis , Bolton Frank , Hampshire Tom , Ricciardi Antonio , Oliver-Taylor Aaron , Golay Xavier , Yiannakas Marios
Published: November 2024

Motivation: The demonstration of the independence of fBIRN QA metrics on the phantom used would enable an easy cross-scanner comparison of scanner stability, thus improving such QA for clinical use (e.g., presurgical mapping). Goal(s): The goal of this study was to assess the variance measured using such metrics across phantoms. Approach: Nine identical phantoms were scanned on a single 3T scanner. Relaxometry and fBIRN scanning was performed on all phantoms and compared to those measured on a single phantom scanned 15 times. Results: No significant difference was found between phantoms on either their relaxivities, or their QA fBIRN parameters. Impact: The independence of fBIRN QA metrics on the phantom used found in this work enables the use of generalised QA across MRI scanners to assess their capacity at providing high quality fMRI for presurgical mapping, thereby ensuring optimal patient outcomes.
A Generalized Real-time Frequency Adjustment Approach for MRSI
Authors: Couch Marcus , Cui Lumeng , Ahn Sinyeob
Published: November 2024

Motivation: Spectroscopy is sensitive to frequency drift. After running sequences that have a high gradient duty-cycle, frequency continues to drift due to gradient cooling. Goal(s): To propose a generalized prospective real-time frequency correction that can be applied to imaging and spectroscopic sequences, where TR-variant and -invariant events are separable in time. Approach: Real-time frequency adjustment was implemented for CSI, using a navigator placed where the spin phase is consistent across TR cycles prior to the CSI readout. Results: Phantom measurements with the generalized navigator provide accurate estimates of the frequency drift, thereby minimizing spectral distortion and providing an improved baseline in the final spectra. Impact: Prospective real-time frequency adjustment using a generalized navigator approach, where the spin phase is consistent across TR cycles, can be applied to spectroscopic imaging to correct for frequency drift caused by gradient heating and cooling.
Acoustic Noise Optimization of Trapezoid Oscillating Diffusion Encoding Gradient
Authors: Chen Xingzhou , Kang Liyi , Zhu Qinfeng , Hsu Yi-Cheng , Yan Xu , Wu Dan
Published: November 2024

Motivation: Oscillating gradient spin-echo (OGSE) diffusion MRI sequence involves diffusion preparation and EPI readout, both having rapidly switching trapezoid gradient. Consequently, OGSE sequence generates strong acoustic noise that may introduce comfortless patient experience. Goal(s): Our study aims to develop an optimization framework to suppress the acoustic noise by softening the trapezoid gradient. Approach: We measured the acoustic noise frequency response function of scanner. Based on linear model of MRI acoustic noise generation, we designed a convex optimization framework to reduce the predicted A-weighting sound pressure level(SPL) Results: Optimized gradient achieved 14.09dBA SPL reduction according to our FRF based prediction. Impact: We developed an effective optimization method to reduce the acoustic noise of oscillating trapezoid gradient waveform, and potentially facilitate the clinical applications of OGSE. This optimization framework also has potential to reduce acoustic noise of EPI readout waveform
Predictive Value of Biochemical Recurrence in Advanced Prostate Cancer: Development of Deep Learning-based Radiomics Model
Authors: Wang Huihui , Wang Kexin , Zhang Yaofeng , Wang xiaoying
Published: November 2024

Motivation: Deep learning forpredicting biochemical recurrence (BCR) is feasible but needs further evaluation in advanced prostate cancer (PCa). Goal(s): We aimed to develop radiomics models with automatic segmentation derived from pretreatment ADC maps that may be predictive of BCR in advanced PCa. Approach: In this study, PCa areas were segmented on ADC images by using a pre-trained artificial intelligence (AI) model. Three models were constructed to evaluate BCR prediction level. Results: The deep-radiomics model was superior than the clinical model and the conventional radiomics model in the aspect of prediction accuracy, clinical impact and risk assessment. Impact: With accurate BCR prediction by deep-radiomics model, more appropriate treatment plans may be formulated and intervention treatment can be carried out as soon as possible, resulting in better prognosis for patients with PCa.
Automatic Quantification of Abdominal Subcutaneous and Visceral Adipose Tissue based on Dixon Sequences using Convolutional Neural Networks
Authors: de Celis Alonso Benito , García José Gerardo Suárez , Wah-So Po , López Javier Hernández , Tobón Silvia Hidalgo , Suárez Pilar Dies
Published: November 2024

Motivation: Currently there is a widely validated commercial semi-automatic method called AMRA® Researcher, which quantifies ASAT and VAT. However, it is not accessible to everyone due to the necessary economic means. Goal(s): To develop an automatic, simple and free methodology to quantify ASAT and VAT, with at least the same precision as AMRA® Researcher. Approach: Preprocessing and simple CNNs applied on in-phase Dixon MRI sequences were proposed for quantify VAT and ASAT. Results: There were no significant differences between the quantifications from AMRA Researcher and our methodology. Both obtained a high correlation and our methodology reached the precision of AMRA® Researcher. Impact: Our automatic, simple and free ASAT and VAT quantification methodology, studying MRI through preprocessing and CNNs, achieved the precision of the commercial semi-automatic AMRA Researcher method. After future independent validation, this could become an accessible tool to assist specialists.
Classification of Grade II and III Astrocytomas for Multi-modal MRI using Deep Volumetric Attention Networks.
Authors: Ayaz Hamail , Oladimeji Oladosu , Tormey David , McLoughlin Ian , Unnikirishnan Saritha
Published: November 2024

Motivation: Diagnosis and grading of astrocytomas tumour present considerable challenges. Manual grading is time-consuming and error prone. Preoperative MRIs are a useful, yet deep learning presents challenges due to computing limitations and complex architecture. Goal(s): Study introduces novel multimodal MRI classification for grade II and III astrocytomas, aiming to improve accuracy, reduce complexity, and address interclass homogeneity via attention mechanism. Approach: Single slice from eight MRI modalities forms a three-dimensional cube. Normalized, iPCA processed, and passed to deep model with volumetric attention network. Results: The DVA using advanced and traditional MRI information outperforms existing models achieving an overall accuracy of 77% using five-fold cross-validation. Impact: The proposed multimodal MRI classification approach enhances astrocytoma diagnosis and grading. The deep volumetric attention model improves accuracy, reduces model complexity, and holds potential for trustworthiness impacts in clinical practice.
High-variability synthetic fat-water MRI dataset for testing the robustness of Deep Learning-based reconstruction models
Authors: M Ganeshkumar , Kandasamy Devasenathipathy , Sharma Raju , Mehndiratta Amit
Published: November 2024

Motivation: Deep Learning (DL) models have recently been used for fat-water separation in Multi-Echo MRI (ME-MRI). However, DL models may not always be robust and under-perform when not trained with a large and diverse dataset. Goal(s): This research proposes high-variability synthetic ME-MRI generated using the biophysical model of fat-water separation as a tool for testing the generalizability and robustness of DL-based fat-water separation models. Approach: High-variability synthetic ME-MRI was used to evaluate the robustness of the recent state-of-the-art DL-based Ad-Hoc Reconstruction (AHR) method for fat-water separation. Results: The AHR method lacked robustness and synthetic ME-MRIs can be effectively used to test DL models. Impact: The fat-water maps obtained by processing the Multi Echo-MRI (ME-MRI) are of diagnostic and prognostic value in many diseases. This study investigates the role of synthetic ME-MRIs with high variability in testing the robustness of Deep Learning-based fat-water separation models.
The application value of modified time of flight magnetic resonance venography in iliac vein compression syndrome
Authors: Tao Li , Peng Gang , Zhu Wei , Zhang Xiaoyong
Published: November 2024

Motivation: The use of respiratory-gated TOF-MRV in assessing the degree of iliac vein compression is easily affected by respiratory uniformity, leading to vascular distortion and corresponding false images. Goal(s): This study evaluated the diagnostic effectiveness of an improved TOF-MRV (mTOF-MRV) in Iliac vein compression syndrome (IVCS) diagnosis by optimizing key parameters, compared with conventional TOF-MRV. Approach: Objectively evaluated the deviation of vascular stenosis degree between TOF MRV and mTOF MRV using DSA as the standard. Results: The mTOF-MRV has better image quality and can accurately detect venous stenosis. It can be applied in the diagnosis of IVCS and further assessments after endovascular interventions. Impact: mTOF-MRV more accurately located iliac vein stenosis without obvious stair-step artifacts and magnetic sensitivity artifacts, thereby meeting the diagnostic and clinical requirements It can be applied in the diagnosis of iliac vein compression syndrome and further assessments after endovascular interventions.
Fast and High-Resolution Intracranial MR Angiography at 7T using FLEXA
Authors: Takei Naoyuki , Burns Brian , Roberts Nathan , Zhu Xucheng , Wakayama Tetsuya
Published: November 2024

Motivation: Non-contrast 3DTOF demonstrates visualizing the cerebral microvasculature at 7T MRI, but the scan time is too long, typically about 10 minutes due to requiring high spatial resolution.Goal(s): Our goal was to reduce the acquisition time by a factor of 2.Approach: We utilize FLEXA on the high gradient performance system at 7T.Results: Comparable image quality to 3DTOF was obtained with FLEXA technique with a factor of 2 decrease in acquisition time.Impact: The improvement in acquisition speed through FLEXA comes from the strategy of short TR with thin slab and opens new standard for scan protocol optimization at 7T MRA.
Comparing Bowsher’s Method to MRgBSREM in PET Recon with MR-priors in the Presence of Mismatch Between MRI and PET Images
Authors: Khalighi Mehdi , Spangler-Bickell Matthew , Jansen Floris , Litwiller Daniel , Holley Dawn , Vossler Hillary , Mormino Elizabeth , Moseley Michael , Zaharchuk Greg
Published: November 2024

Motivation: Using MR-priors in PET reconstruction has been performed in numerous studies. While MR-priors provide more SNR and better resolution ti PET-images, without considering motion there may be misalignment between PET and MR images which leads to crosstalk artifacts. Another concern is mismatch between MR and PET images which can potentially affect the final PET image. Goal(s): To compare the two most-widely used PET recon with MR-priors methods: the Bowsher's method and MRgBSREM. Approach: We created an MR-series with severe line artifacts and used in as MR-priors in both methods. Results: We have shown that MRgBSREM handles these mismatches better than the Bowsher’s method. Impact: MRgBSREM is more robust to mismatches between PET and MR. This is achieved by adding a PET-seed image to identify similar-voxels which avoids the situation in which voxels with significantly different PET-uptake would be considered similar based only on MR-images.
Design of a nonlinear human-breast gradient coil with controllable gradient variation
Authors: Jia Feng , Amrein Philipp , Zaitsev Maxim , Littin Sebastian
Published: November 2024

Motivation: To assess diffusion metrics on a cellular scale necessitates much higher gradient amplitudes. A local nonlinear breast gradient coil needs methods of controlling the field variation during the coil design stage. Goal(s): Control the y-axis gradient variation of a double layer local breast gradient coil to achieve far above 1T/m in the whole target region. Approach: Incorporation of a constraint to control the variation of the gradient along the y-axis with a double-layer current-carrying surface. Results: A non-linear local human breast gradient coil with a gradient strength between 1.61 and 3.74 T/m for a current of 650 A was designed. Impact: The coil design with a subsequent implementation paves the way to the application of novel diffusion imaging techniques for the detection and characterization of breast cancer.
Characterisation of 3D Printed Materials for MRI Applications
Authors: Bruce George , Brennan David , Barrientos Pauline Hall
Published: November 2024

Motivation: 3D printed materials offer the capability of manufacturing custom phantoms or coil prototypes. While materials for other modalities (such as CT) are widely available, the same cannot be said for MRI. Goal(s): The goal of this project was to characterise a wide range of 3D printed materials for use in MRI. Approach: Using standardised sample sizes, and relaxation property mapping sequences. Results: Some materials, such as Nylon, proved invisible to MRI. Other materials, such as OrganLike, showed relaxation properties similar to those in the brain at 3T. Impact: 3D printing offers the potential to rapidly create low cost, reproducible prototypes for MRI. This work provides an extensive list of the properties of materials, aiding others in narrowing down a material of choice.
Macromolecular fraction and magnetization exchange rate acquired with UTE-MRI differ in the tibial bone of diabetic rats: a feasibility study
Authors: Moazamian Dina , Shin Soo Hyun , Jerban Saeed , Tyarani Alireza , Suprana Arya , Mohammadi Hamidreza Shaterian , Fu Eddie , Chung Christine , Ma Yajun , Calcutt Nigel , Chang Eric , Du Jiang
Published: November 2024

Motivation: Increased risk of fractures in patients with type-2 diabetes mellitus (T2DM) despite higher average bone mineral density is unexplained with routine diagnostic tools like DEXA and CT. Goal(s): This study aimed to examine the feasibility of using ultrashort echo time (UTE) magnetization transfer (MT) modeling to detect the potential differences between T2DM and normal rats. Approach: The macromolecular fraction (MMF) and proton exchange rate (kab) from UTE-MT modeling on the tibial bone of Zucker diabetic fatty (ZDF) and Zucker lean (ZL) rats were compared. Results: There was a significant difference in MMF and kab measures between the two groups. Impact: The MMF and kab measures can detect potential bone alternations related to T2DM which may help to better understand the pathogenesis of T2DM bone fractures.
Bilateral Orthogonality Generating Acquisitions Method for Homogenous Balanced Steady-State Free Precession at 7T
Authors: Boğa Çelik , Henning Anke
Published: November 2024

Motivation: Elimination of the transmit field inhomogeneity effects in the brain for T2 contrast at 7T. Goal(s): Removing the transmit field inhomogeneity effects in balanced steady state free precession acquisitions using Bilateral Orthogonality Generative Acquisitions method. Approach: Bilateral Orthogonality Generative Acquisitions method is implemented at dual channel parallel transmit 7T system using several balanced steady state free precession acquisitions with varying scan parameters to eliminate the transmit field inhomogeneity effects and reduce the banding artifacts effects via different combining schemes in the final image. Results: T2 contrast was obtained without the transmit field inhomogeneity effects but residual banding artifacts exists in the final images. Impact: T2 contrast can be achieved without the transmit field inhomogeneity effects in the brain using balanced steady state free precession sequence.
Identifying potential therapeutic targets for focal transcranial magnetic stimulation (TMS) in a rat model of cocaine dependence
Authors: Lu Hanbing , Hoffman Samantha , Yang Yihong
Published: November 2024

Motivation: Transcranial magnetic stimulation (TMS) shows promise as a therapeutic intervention for many neuropsychiatric conditions. Yet, pinpointing the appropriate stimulation target remains elusive. Goal(s): To identify brain regions affected by prolonged cocaine exposure, and to identify potential targets for focal TMS. Approach: Basal CBV were mapped by injecting iron-oxide contrast. Multi-echo gradient echo and spin echo sequences were employed to generate maps of 05732972-a323-4027-8676-ccee7744913e">R2. Results: Many brain regions, including the prelimbic cortex, exhibited a significant decrease in basal CBV following prolonged cocaine exposure. The prelimbic cortex is situated relatively close to the cortical surface and presents a promising candidate for TMS. Impact: Likely the first attempt to identify TMS targets using the CBV mapping approach.
Water diffusion is influenced by the changes in regional volume
Authors: Yoshimaru Daisuke , Tsurugizawa Tomokazu , Hayashi Naoya , Hata Junichi , Shibukawa Shuhei , Saito Kazuhiro , Okano Hideyuki , Okano Hirotaka
Published: November 2024

Motivation: A direct examining the volume and diffusion indices of in vivo and ex vivo brains from the same individual is of great interest in linking clinical and histological studies. Goal(s): The goal of this study is to investigate the relationship between brain volume and diffusion indices in brain using in vivo and ex vivo brains from the same individual. Approach: Dwi indices and brain volumes of the whole brain, white matter, cerebral cortex, cerebellum, and 52 brain regions were compared in vivo and ex vivo from same individuals. Results: For each DWI index, AD was correlated with volume change in 40 cortical regions. Impact: This study successfully compared the same brain in vivo and ex vivo directly, and it sufficiently demonstrates the relationship between volume and diffusion indices. In particular, AD is most sensitive to regional volume changes.
reproducibility and accuracy of PC-MRI for low velocity measurement: A pilot study.
Authors: ABDERRAHIM KAMEL , Baledent Olivier , fall sidy
Published: November 2024

Motivation: Non-invasive measurement of intracranial flow can elucidate fluid interactions within the brain. However, it's essential to determine the range of velocities that can be reliably measured using this approach. Goal(s): Our aim is to assess the ability of PC MRI "Flow Compensated Fast low angle Shot (fcFLASH)" based sequence for velocity measurements in small blood vessels and cerebrospinal fluid in rats. Approach: A phantom is built to simulate fluid flow. Measurements are repeated for each velocity range. Results: Non gated fcFLASH-based PC MRI allows a rough estimation of flow velocities on the order of 0.5 cm/s. Impact: our study shows that the fcFLASH-based PC MRI can be used for a rough estimation of a small fluid circulation. A methodological development is necessary for a reliable measurement.
Prognostic Value of Right Ventricular 3D Trabecular Complexity in Arrhythmogenic right ventricular cardiomyopathy
Authors: Zheng Jin-Yu , chen Bing-Hua , Wu Chong-Wen , Wu Rui , An Dong-Aolei , Shi Ruo-Yang , Xie Jingyu , Jiang Shan-shan , Wu Lian-Ming , Zhao Lei
Published: November 2024

Motivation: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by progressive myocardial fibro-fatty infiltration accompanied by trabecular disarray. The prognostic value of trabecular disorder assessed by three-dimensional (3D) fractal dimension (FD) measurement is unclear. Goal(s): To investigate the prognostic value of 3D right ventricular trabecular complexity of ARVC. Approach: Using cine images, trabecular complexity was measured with 3D fractal analysis to calculate 3D-FD in ARVC patients retrospectively. Cox regression analyses and Kaplan-Meier survival analysis were performed to identify the prognostic value of 3D-FD. Results: RV 3D-FD was a significant risk predictor for MACE in ARVC and provided incremental prognostic value to conventional predictors. Impact: Based on the results, we suggested 3D RV trabecular complexity, derived from non-invasive imaging examination, as a new biomarker for early clinical therapy in medication and ICD implantation in order to moderate the onset of adverse endpoints in ARVC patients.
The clinical application of 5.0 T 3D TOF MRA in the imaging of AChA and related cerebrovascular diseases
Authors: Li Zhangzhu , Shang Mingyan , Fu Min , Wang Zhensong , Liu Jianxian , Yin Liang , Yu Dan , Gan Jie
Published: November 2024

Motivation: Improved cerebrovascular disease diagnosis requires enhanced imaging of the anterior choroidal artery (AChA). Goal(s): To evaluate the effectiveness of a 5.0T ultra-high-field MR scanner for cerebrovascular imaging compared to traditional 3.0T scanners. Approach: Retrospective analysis using 5.0T MR imaging to assess AChA visualization in patients with cerebrovascular complaints. Results: The 5.0T scanner significantly outperformed the 3.0T in image quality and detail, providing superior AChA delineation, which is essential for diagnosing related cerebrovascular diseases. Impact: The 5.0T MR imaging's superior visualization of AChA paves the way for better diagnosis and management of deep brain vascular diseases, potentially influencing treatment outcomes and advancing neurovascular research.
The role of glymphatic function and CSF circulation in patients with glioma
Authors: Liu Xiaodan , Jakary Angela , Adegbite Oluwaseun , Luks Tracy , Eghbali Reza , Javier Villanueva-Meyer , Chang Susan , Xu Duan , Lupo Janine
Published: November 2024

Motivation: Limited research has been performed on the role of CSF circulation in the glymphatic transport in patients with glioma. Goal(s): To evaluate the relationship between CSF circulation disturbance and glymphatic dysfunction in different glioma subtypes. Approach: A novel measure of glymphatic function (ALPS index) was quantified and compared among 100 patients with different genetic subtypes and associated with CSF circulation related factors and tumor volume. Results: We found that lower ALPS index in the tumor hemisphere was found in IDH-wildtype glioblastomas and with increasing grade in IDH-mutant gliomas. CSF circulation related factors were correlated with disruptions in glymphatic function. Impact: Our promising results provide a novel insight of glymphatic dysfunction in patients with glioma.
Improvement of Glymphatic System Using Low-Intensity Focused Ultrasound (LIFU) for Lymphatic Enhancement
Authors: Lee Hyochul , Jang Taekyu , Park Ok kyu , Choi Taewon , Chang Seoyun , Park Jinhyoung , Choi Seung Hong
Published: November 2024

Motivation: Enhanced lymphatic flow may improve the glymphatic system for metabolic waste clearance from the brain. Goal(s): Our goal was to demonstrate that stimulating the lymphatics can enhance the glymphatic system. Approach: We introduced low-intensity focused ultrasound (LIFU) to enhance the lymphatics and assessed the glymphatic system in rats by visualizing signal changes in contrast-enhanced MRI. Results: The LIFU group exhibited a more rapid increase and decrease in signal intensity compared to the control group. Impact: Lymphatic enhancement using LIFU could influence the improvement of the glymphatic system. This enhancement could positively affect cognitive function, with potential implications for preventing and treating neurodegenerative diseases.
How Breathing and Cardiac functions interact with Cerebral arterio-venous blood flows: Origin of CSF oscillations
Authors: LIU Pan , Owashi Kimi , Monnier Heimiri , Capel Cyrille , Metanbou Serge , Balédent Olivier
Published: November 2024

Motivation: The main drivers of CSF oscillations are currently controversial. Goal(s): To investigate whether the breathing or cardiac regulated Cerebral blood flow are the major driver of CSF dynamics. Approach: Investigate Cerebral blood and CSF flows through the intracranial compartment during free and deep breathing using real-time phase-contrast sequence. To quantify the neurofluids volume displacement along the cardiac cycle. Results: Both cardiac and breathing cycles influenced neurofluids volume displacements. CSF dynamics is significantly correlated with intracranial blood volume change. CSF dynamic acts as a compensatory mechanism of intracranial blood volume dynamics. Impact: This study confirms that intracranial blood volume change due to cardiac and breathing activities are the main drivers of CSF dynamic. This study provides valuable insights for understanding CSF circulation's complex mechanism and investigating idiopathic cerebral diseases.
Exploring the development of glymphatic system function in very preterm infants through the diffusion along perivascular space index
Authors: Liu Congcong , Da Chunxu , Huang Xinyi , Chen Tianjiao , Wang Miaomiao , Li Xianjun , Yang Jian
Published: November 2024

Motivation: Despite white matter perivascular spaces visual grades in preterm was not different from term infants, whether the glymphatic system function differently with preterm and term infants remains unclear. Goal(s): Exploring development of glymphatic system function in very preterm (VP) infants, comparing with term infants. Approach: The diffusion along perivascular space index (ALPS) was used to evaluate the glymphatic system function via diffusion tensor images (DTI). Results: The DTI-ALPS index was significantly lower in VP neonates than VP infants at term equivalent age (TEA) or term neonates. However, the DTI-ALPS index in VP infants at TEA was not found differences with term neonates. Impact: The glymphatic system function was developing with gestational age, while very preterm infants presented “catch-up” growth pattern up to TEA.
Diffusion tensor imaging analysis along the perivascular space in different burdens of cerebral small vessel disease
Authors: Wang Na , Li Meng , Li Jing , Zhang Xinyue , Liang Changhu , Guo Lingfei
Published: November 2024

Motivation: Cognitive decline is associated with the impairment of glymphatic clearance, which can be investigated noninvasively using diffusion tensor imaging along the perivascular space (DTI-ALPS). Goal(s): To investigate the linkage of cerebral small vessel disease (CSVD) burdens with left/right glymphatic function based on DTI-ALPS. Approach: Glymphatic system function was assessed using diffusion tensor imaging along the perivascular space. Results: The DTI-ALPS indexes in the CSVD groups were lower than the HC group. Hazard factors for right DTI-ALPS included CSVD severity and sex. Although the right DTI-ALPS index was associated with cognition in univariate analysis, it was not significant in regression analysis. Impact: The DTI-ALPS technique provides a new opportunity for exploring the damage of CSVD burdens.
3D MR Thermometry Sequences for Abdominal Microwave Ablation Monitoring on Phantom Simulating Breathing Motion
Authors: Horstmann Dominik , Hensen Bennet , Belker Othmar , Gerlach Thomas , Gutt Moritz , Schröer Simon , Vogt Ivan , Wacker Frank , Gutberlet Marcel
Published: November 2024

Motivation: 3D MR-thermometry enhances microwave ablation success by providing real-time temperature and ablation insights. However, clinical availability is limited due to challenges such as breathing motion and electromagnetic interferences. Goal(s): Our study conducts 3D MR-thermometry comparing stack-of-stars and a stack-of-spirals sequences using a clinically approved generator and phantoms simulating breathing motion. Approach: Temperature precision and precision of ablation zones of both sequences were compared. Results: Stack-of-spirals sequence seems to be the superior MR-thermometry sequence. Dice scores of around 90 % and temperature precisions around 1°C were reached with very little image degradation due to motion or electromagnetic interferences. Impact: Our study shows the possibility of motion robust 3D MR-thermometry using a clinically approved microwave generator. Future developments might provide real-time 3D MR thermometry during clinical abdominal thermal therapies, enhancing their success and increasing the total number of MR interventions.
In Vivo 3D Hybrid fat-water MR Thermometry via Simultaneous Proton Resonance Frequency Shift and T1 Measurement
Authors: Richards Nicholas , Malmberg Michael , Adams-Tew Samuel , Odéen Henrik , Parker Dennis , Payne Allison
Published: November 2024

Motivation: In current clinical magnetic resonance-guided focused ultrasound (MRgFUS) ablation applications, only aqueous tissues are monitored with MR thermometry. Accurate thermometry of heterogeneous aqueous and fat tissue volumes would increase treatment safety and efficacy. Goal(s): Evaluate a single reference variable flip angle (SR-VFA) sequence for hybrid proton resonance frequency shift and ΔT1 MR thermometry in heterogeneous tissue volumes. Approach: MRgFUS ablation in an in vivo rabbit model was monitored with SR-VFA thermometry. Cumulative thermal dose (CTD) maps calculated from SR-VFA images were compared with non-perfused volumes and histological samples. Results: SR-VFA derived CTD maps accurately predicted volumes of thermal damage in muscle and fat. Impact: Hybrid proton resonance frequency shift and T1 thermometry allows for accurate temperature monitoring of heterogeneous tissue volumes. This increases the safety and efficacy of MR-guided focused ultrasound treatments in mixed-tissue treatment areas by ensuring target temperatures reach appropriate thresholds.
Implementation of a Data Analysis Pipeline for intraoperative fMRI
Authors: Weilguny Nicolas , Licandro Roxane , Tomschik Matthias , Wais Jonathan , Hedrich Cora , Shawarba Julia , Kasprian Gregor , Rössler Karl , Dorfer Christian , Hangel Gilbert
Published: November 2024

Motivation: Immediate changes in functionality during brain surgery in tumor and epilepsy patients are worth investigating in order to improve prediction of surgical outcomes. Goal(s): We want to implement a preprocessing-pipeline for pre- and post-resection data that allows comparison between both scans and the application of further analysis methods. Approach: We propose a two-step approach, where we first pre-register the anatomical data to MNI-space with consideration of the resection area and then use this data in a second step for preprocessing of fMRI data. Results: The preprocessing gives satisfactory results that enable further analysis of intraoperative fMRI data, such as PICA. Impact: We showed that the difficult case of pre- and post-resection data preprocessing is feasible and allows analysis of intraoperative fMRI data. This enables further investigation of changes in brain functionality during surgery which might lead to improvements in neurosurgery.