bluuebunny/crossref_metadata_2025 huggingface dataset:
Generating Synthetic MR Spectroscopic Imaging using MRI and Single-voxel MR Spectroscopy
Authors: Maruyama Shuki , Takeshima Hidenori
Published: August 2024

The authors proposed new methods to generate synthetic proton MR spectroscopic imaging (MRSI) data. The proposed methods were derived from Image-to-Image Translation with Conditional Adversarial Networks (pix2pix), taking MRI data or MRI and single-voxel MR spectroscopy (SVS) data as inputs. To integrate the features of MRI and SVS data, additional encoder and decoder networks were incorporated. The experimental results demonstrated that the proposed methods generated metabolite ratio maps with same resolution as MRI data. The synthetic maps generated from MRI+SVS were more consistent with the reference ones than those generated from MRI alone.
Ultra-high spatial resolution for ex-vivo structural brain MRI
Authors: Abaei Alireza , Antonucci Stefano , Scekic-Zahirovic Jelena , Heuvel Florian olde , Roselli Francesco , Rasche Volker
Published: August 2024

This study aims at demonstrating the feasibility of ex vivo MRI for structural imaging of brain. High spatial resolution in the range of 15-20 µm is obtained by an optimized FLASH sequence together with a cryogenically cooled RF coil. A 15µm-resolution was obtained for the brain, revealing cortical grey matter lamination, white matter and vascular architecture. As proof of concept, we showed in an Amyotrophic Lateral Sclerosis ( FUSΔNLS) mouse the pattern of atrophy as proxy of vulnerability using high degree of anatomical granularity. Overall, we demonstrate an ex-vivo MRI strategy with histology-grade resolution, comprehensive and non-destructive brain sampling.
Lead Insulation and Wavelength Effects on Active Implantable Medical Device Heating under MRI at 1.5T and 3T using Transfer Function (TF) Modeling
Authors: Kumar Ananda , Chen Ji , Islam Md Zahidul , Jeong Hongbae
Published: August 2024

The influence of the thickness, loss tangent value of the lead insulation material along with lead length effects on the heating of an active implantable medical device (AIMD) lead electrode is analyzed using full-wave EM simulations. Decreasing the thickness of the insulation decreases heating of the electrode significantly when lead lengths are less than or equal to wavelengths in the medium. Increasing the loss tangent of the insulation material has a moderate effect in reducing heating at the electrode. Standing wave distortions affect lead electrode heating at lead lengths greater than wavelengths in the medium.
Cerebral Mapping of Glutamate-Weighted MR Imaging (GluCEST) in a Rat Model of Lipopolysaccharide-Induced Sepsis
Authors: Lee Do-Wan , Kwon Jae-Im , Heo Hwon , Woo Chul‐Woong , Chae Yeon Ji , Yu Na Hee , Na Seongwon , Ko Yousun , Kim Nari , Min Joongkee , Choi Monica Young , Kim Kyung Won , Woo Dong‐Cheol
Published: August 2024

Glutamate-weighted chemical exchange saturation transfer (GluCEST) is a useful imaging tool which is used to detect glutamate signal alterations caused by neuroinflammation. The present study quantitatively evaluated glutamate level changes in the hippocampal region of a rat model of sepsis-induced brain injury using GluCEST and proton magnetic resonance spectroscopy (1H-MRS). The GluCEST and 1H-MRS results showed that GluCEST values and glutamate concentrations were significantly higher in the sepsis-induced rats than in the controls. GluCEST imaging could be a helpful technique for defining a biomarker to estimate the glutamate-related metabolism in sepsis-associated diseases.
The MRDust: An Implantable Neural Interface Powered via Focused Ultrasound with Data Communication via MR Image Modulation
Authors: Zhao Biqi , Wen Yuhan , Chou Alexander , Alon Elad , Muller Rikky , Liu Chunlei , Lustig Michael
Published: August 2024

We propose a new device for neuroscience studies: the MRDust, a sub-mm wireless programmable neural recording mote with on-device memory and compute. It receives power via focused ultrasound, records neural signals in burst mode, and uses a micro-coil to perturb local magnetic fields to achieve data uplink via dynamic MRI signal modulation. We demonstrate proof-of-concept experiments in which digital information is encoded in images of an SE-EPI dynamic sequence, and in which a piezoelectric harvester can harvest enough ultrasonic power to sustain device operation, and receive control signals through amplitude modulation.
Feasibility of MR phase-contrast imaging for proton beam visualisation in liquid water phantoms
Authors: Peter Juliane , Gantz Sebastian , Hoffmann Aswin , Pawelke Jörg
Published: August 2024

Proton beam-induced convection in water triggered local MRI magnitude signal loss in combined imaging and irradiation experiments performed on a new research prototype in-beam low-field MRI proton radiotherapy device. In this study, the influence of convection on the MRI phase signal was tested. Both mechanical and thermal inhibition of convection in dedicated water phantoms resulted in the absence of MRI phase signatures, which were clearly visible under conditions were convection could develop. Moreover, a change in either convection velocity or Venc sequence motion sensitivity changed the observed phase contrast, confirming the convection-driven phase contrast mechanism.
Thalamic segmentation methods in the characterization of Alzheimer's disease
Authors: Williams Brendan , Nguyen Dan , Saranathan Manojkumar
Published: August 2024

We present a systematic comparison of three state of the art thalamic segmentation methods for T1 MRI. Segmentation performance against Krauth-Morel atlas was quantified on 100 young healthy subjects and thalamic atrophy as a function of Alzheimer's disease status was characterized on 540 older subjects.
K2S Challenge: From Undersampled K-Space to Automatic Segmentation
Authors: Tolpadi Aniket , Bharadwaj Upasana , Gao Kenneth , Bhattacharjee Rupsa , Gassert Felix , Luitjens Johanna , Morshuis Jan Nikolas , Fischer Paul , Hein Matthias , Baumgartner Christian , Razumov Artem , Dylov Dmitry , van Lohuizen Quintin , Fransen Stefan , Zhang Xiaoxia , Tibrewaka Radhika , de Moura Hector , Liu Kangning , Zibetti Marcelo , Regatte Ravinder , Majumdar Sharmila , Pedoia Valentina
Published: August 2024

Image reconstruction and downstream tasks have typically been treated independently by the image processing community, but we hypothesized performing them end-to-end could facilitate further optimization. To these ends, UCSF organized the K2S challenge, where challenge participants were tasked with segmenting bone and cartilage from 8X undersampled knee MRI acquisitions. Top challenge submissions produced high-quality segmentations maintaining fidelity to ground truth, but strong reconstruction performance proved not to be required for accurate tissue segmentation, and there was no correlation between reconstruction and segmentation performance. This challenge showed reconstruction algorithms can be optimized for downstream tasks in an end-to-end fashion.
Robust Quantitative Susceptibility Mapping via Approximate Message Passing with Parameter Estimation
Authors: Huang Shuai , Lah James , Allen Jason , Qiu Deqiang
Published: August 2024

We propose a robust Bayesian approach with built-in parameter estimation for quantitative susceptibility mapping (QSM). From a Bayesian perspective, wavelet coefficients of the susceptibility map are modeled by Laplace distribution. Noise is modeled by a two-component Gaussian-mixture distribution, where the second component is reserved to model the noise outliers. The susceptibility map and distribution parameters are jointly recovered using approximate message passing (AMP). The proposed approach achieves better performance in challenging cases of brain hemorrhage and calcification. It automatically estimates the parameters, which avoids subjective bias from the usual visual-tuning step of in vivo reconstruction.
Effects of Free-Breathing on Cerebral Veins: study by Real-Time Phase-Contrast MRI
Authors: LIU Pan , Monnier Heimiri , Owashi Kimi , Metanbou Serge , Capel Cyrille , Balédent Olivier
Published: August 2024

Real-time phase-contrast sequences are increasingly used to study the effect of breathing on cerebral circulation, however, there is a lack of studies on the effect of free breathing (E-Fb) on cerebral veins. In this study, we quantified the intensity and phase shift of the E-Fb on cerebral veins in 19 healthy volunteers using a time-domain multiparameter analysis method. We analyzed the characteristics of the E-Fb on four parameters of four cerebral veins. We found that during expiration, the mean flow rate, amplitude, stroke volume, and cardiac period of internal jugulars veins and sinuses increased.
VarNet-based Simultaneous Multislice Reconstruction for Low Noise Amplification and Flexible Calibration
Authors: Mei Lifeng , Dong Celia.M. , Liu Sixing , Huang Shoujin , Lyu Mengye
Published: August 2024

In this study, we combine the readout-concatenation framework with VarNet based deep learning method to achieve SMS reconstruction of low noise amplification. It can flexibly handle arbitrary slice aliasing patterns with in-plane acceleration. Moreover, the modified network architecture allows coil calibration using a prescan of different contrasts, which is preferred in many scenarios.
Comparing Techniques for Multi-Site Harmonization of Structural Connectivity
Authors: Newlin Nancy , Cai Leon , Archer Derek , Pechman Kimberly , Schilling Kurt , Jefferson Angela , Resnick Susan , Hohman Timothy , Shafer Andrea , Landman Bennett
Published: August 2024

Tractography is a method to reconstruct white matter microstructure from DWI information and connectomics maps this reconstruction to a graph representation. We compute modularity, assortativity, global efficiency, and average betweenness centrality on this graph. We model changes in these measures with age and sex using DWI for healthy patients from two sites. Data from different sites requires harmonization to remove site-effects. We compare performances of ComBat and LinearRISH harmonization techniques at reducing CoV and removing confounding site-effects from associated linear models. We find that ComBat is effective at both and using LinearRISH in addition acts synergistically at harmonizing site differences.
Hybrid Active and Passive Local Shimming (HAPLS) Targeting Ultra-high-order B0 Spherical Harmonic (SH) Terms in Two-Region MRI
Authors: Ren Zhi Hua , Stockmann Jason , Dewdney Andrew , Lee Ray
Published: August 2024

An MRI scanner equipped with global shim systems fails to reach state-of-the-art when shimming two isolated ROIs simultaneously for two reasons: non-optimal spherical harmonic based shimming routine, and significant high-order B0 inhomogeneities, even though the two-area shimming can be essential in scan scenarios, such as bilateral breasts or dyadic brains. To address these challenges, a hybrid active and passive local shimming (HAPLS) technique is proposed to shim two isolated areas in one FOV simultaneously. Both the simulation and experimental results validated that HAPLS can complementarily address the bifocal and high-order inhomogeneities, and locally improve in vivo B0 homogeneity as well.
Development of the fetal brain structural connectivity during the second-to-third trimester based on diffusion MRI
Authors: Chen Ruike , Zhao Ruoke , Xu Xinyi , Li Mingyang , Sun Cong , Wang Guangbin , Wu Dan
Published: August 2024

Extensive cortico-cortical connections emerge in the fetal brain during the second-to-third trimester with the rapid development of white matter fiber pathways. However, the early establishment and prenatal development of the brain’s structural network are not yet understood. In this work, we built structural connectivity networks of the fetal brain using in-utero diffusion MRI data. Network analysis revealed the increasing overall efficiency of the fetal brain network. The strengthening of short-ranged cortico-cortical connections and the emerging hubs contributed to the reorganization of its sub-units. These findings provided valuable information on the early developmental patterns of brain cortico-cortical structural connectivity
Spectrally Selective On-Resonance Inversion Recovery at 7T for Multiple Component T1 Mapping
Authors: Jacobs Paul , Wilson Neil , Nanga Ravi Prakash Reddy , Benyard Blake , Ruparel Kosha , Kumar Dushyant , Elliott Mark , Roalf David , Reddy Ravinder
Published: August 2024

Two sets of images were acquired on four healthy subjects using separate on-resonance selective and broadband inversion recovery (IR) sequences at nine different inversion times. These images were fit to a bi-exponential T1 fitting model aiming to separate out specific long and short components. The selective IR data showed a substantial increase in white matter contrast compared to the broadband data with an average T1 of approximately 300ms. This agrees with reported literature values of the T1 of myelin and suggest it may be a potential driver of this selective short T1 component contrast.
Detecting cancer immunotherapy response in ccRCC patients from 1H MRS of plasma
Authors: Sharma Raj Kumar , McMahon Michael T. , Solaiyappan Meiyappan , Ged Yasser , Bhujwalla Zaver
Published: August 2024

A minimally invasive, blood-based assay to predict and detect response to immune-checkpoint inhibitors (ICIs) would be of significant importance.1H MRS of plasma samples provides a robust reproducible assay that require minimal sample preparation, and convenience of sample storage. Here we evaluated changes in plasma metabolites of clear cell renal cell carcinoma (ccRCC) patients receiving ICIs using 1H MRS. We identified a significant increase of acetate, formate, glutamine, glycine, myoinositol, and lactate following ICI that may reflect response.
Portable MRI for major sporting events – a case study on the MotoGP World Championship
Authors: Guallart-Naval Teresa , Algarín José Miguel , Bosch Rubén , Juan-Lloris Francisco , Pallás Eduardo , Rigla Juan Pablo , Martínez Pablo , Borreguero José , Benlloch José María , Galve Fernando , Alonso Joseba
Published: August 2024

Here we study the potential MR value of a low-field portable system for use in major sporting events, specifically in the Motorcycle Grand Prix held in Valencia (Spain) between November 3rd and 6th, 2022. The system was transported in a small truck, installed in the main surgery room of the circuit medical facilities, and operational around 30 minutes after arrival. Overall, 15 subjects were scanned in four days, with a total of 21 extremity acquisitions. This work demonstrates that portable MRI machines can aid the diagnostic capabilities of medical staff in sporting events and competitions.
Accelerated Sampling Strategy for High-resolution 3D T1rho Dispersion MRI with 4D Dynamic Radial Acquisitions
Authors: Peng Gregory , Wu Can , Ramin Jafari , Zhao Yansong , Peng Qi
Published: August 2024

T1ρ dispersion imaging based on repeated T1ρ measurements at multiple spin-lock frequencies allows characterization of different dynamic processes of tissues. The clinical potential of these techniques is, however, limited by the total scan time needed to obtain reliable and consistent quantitative measurements. In this abstract, we propose the application of a 4D dynamic sequence with radial acquisitions in combination with an accelerated data-point sampling strategy to achieve efficient coverage of the high-dimensional data space in T1rho dispersion MRI, which leads to high-resolution 3D T1rho dispersion imaging acquired within clinically acceptable scan duration of ~5 minutes.
Histogram-based analysis of recurrence pattern correlations with MGMT methylation status in glioblastoma using synthetic MRI and 3D-ASL
Authors: Dang Pei , Huang Xueying , Ge Xin , Wang Lidong , Wang Aijun , Wang Minglei , Yang Xuhong , Xiong Yuhui , Wang Xiaodong
Published: August 2024

At least 10% of glioblastoma relapses occur at distant and even contralateral locations. This disseminated growth limits surgical intervention and contributes to neurologicalmorbidity. The aim of the present study was to evaluate factors predicting the recurrencepattern determined. The results revealed that the pattern of recurrence in glioblastoma patients after combined radio-chemotherapy treated are strictly correlated with age at diagnosis and MGMT methylation status. Whole-tumor histogram analysis of quantitative parameters from synthetic MRI and 3D-ASL was to evaluate the value of predicting MGMT methylation status. Combining T110th, T210th ,and CBFentropy may explore as an effective strategy to predict of MGMT methylation status.
Harmonized multi-site MRI-based quantification of human liver fat and stiffness: a pilot study
Authors: Singh Maninder , Carmichael Owen , Bashir Adil , Russel Anne , Bolding Mark , Redden David , Storr Judd , Willoughby William , Claudio Candace , Hsia Daniel , Kimberly Robert , Gray Meagan , Ravussin Eric , Denny Thomas
Published: August 2024

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of end-stage liver disease. NAFLD diagnosis and follow-up relies on a combination of clinical data, liver imaging, and/or liver biopsy. However, inter-site imaging differences impede diagnostic consistency and reduce the repeatability of the multi-site clinical trials necessary to develop effective treatments. The goal of this pilot study was to harmonize commercially available 3T magnetic resonance imaging (MRI) measurements of liver fat and stiffness in human participants across academic sites and MRI vendors.
Development of an external butterfly coil for sodium (23Na) MRI of human prostate cancer
Authors: Tan Josephine , Kalia Vibhuti , Thiessen Jonathan , Scholl Timothy , Akbari Alireza
Published: August 2024

This abstract focuses on the development of an external, non-invasive butterfly coil for sodium MRI of human prostate cancer. Sodium MRI of healthy male volunteers and patients revealed higher sodium signal and ADC in the peripheral zone compared to the transition zone of the prostate, and a lower sodium signal and ADC in tumour lesions relative to healthy tissue. Further work will aim to characterize the sensitivity of this coil to detect tumours, which may enhance the workflow of sodium MRI in prostate cancer studies compared to conventional endorectal coils.
Evaluation of progressive evolution of oxygen extraction fraction in the brain during acute stroke by using quantitative susceptibility mapping
Authors: Zhang Xiaodong , Meng Yuguang , Li Chun-Xia
Published: August 2024

Oxygen extraction fraction (OEF) has been suggested to be an effective measure to assess the oxygen metabolism and viability of tissue at risk. The preliminary results in a monkey model of stroke demonstrated progressive OEF reduction in both grey matter and white matter after pMCAO, in agreement with the neuron loss and fiber denegation as indicated by diffusion MRI indices following stroke. The findings suggest QSM derived OEF could provide additional information about the oxygen metabolism of the tissue and may be used to assess the ischemia-induced damage of the brain during acute stroke.
The value of MRI 3D-DESS technique in preoperative evaluation of polydactyly in children
Authors: Jingling Li
Published: August 2024

Polydactyly is very common disease in pediatric orthopeadic. In this study, 18 patients with polydactyly were included. All the 3D-DESS image were evaluated by two senior diagnostic radiologists using a double-blind 3-point scale, the intraoperative results were used as the “gold standard” to analyze the consistency of image results and intraoperative results. The purpose of this study is to assess whether the 3D-DESS sequence can provide the growth and development information of cartilage epiphysis, tendon and bone tissue of polydactyly in children before surgery, which has value for preoperative evaluation and preparation of surgical treatment.
Efficient MRF at 0.55T with long readouts and concomitant field effects correction
Authors: Zhu Zhibo , Lee Nam Gyun , Tian Ye , Nayak Krishna
Published: August 2024

We demonstrate FISP-MRF at 0.55T with improved efficiency using longer spiral readouts and concomitant field effect correction. 2D axial FISP-MRF is performed with 3 different readout durations and at 2 different off-isocenter locations, reconstructed without and with MaxGIRF concomitant field correction. Spatial blurring induced by concomitant field effect was successfully mitigated. In-vivo MRF white matter T2 achieved tighter distribution with longer readouts, e.g., the coefficient of variation decreased from 9.9% to 4.9%.
Off-resonance and B1+ Resilience of Relaxation Along a Fictitious Field (RAFF) pulses
Authors: Naaktgeboren Roeland , Coletti Chiara , van de Steeg-Henzen Christal , Weingärtner Sebastian
Published: August 2024

Spin-lock relaxation times can provide valuable markers for pathological remodelling, but their acquisition with constant amplitude spin-lock pulses is limited by SAR and sensitive to field inhomogeneities. Relaxation along a Fictitious Field (RAFF) can be used to measure spin-lock relaxation with reduced SAR burden. In this work, we evaluate the resilience of RAFF against field B0 and B+1 field inhomogeneities. Yet another RAFF (yaRAFF) pulse is introduced for fictitious field spin-locking with increased effective field strength. yaRAFF shows >5.9% reduced susceptibility for field inhomogeneities compared with RAFF in simulations and phantom measurements. In vivo images of yaRAFF in the calf show higher precision for small off-resonances, the mapping quality for large off-resonance is maintained for in phantom and in vivo TRAFF2 times at 3T.
MRI monitors the abnormal muscle glycogen and creatine kinase activity in Pompe disease mice
Authors: Bo Shaowei , Bie Chongxue , Yadav Nirbhay , van Zijl Peter , Xu Jiadi , Zou Chao , Zheng Hairong , Zhou Yang
Published: August 2024

Pompe disease (PD) is a glycogen storage disease, characterized by progressive lysosomal glycogen accumulation and changes in energy metabolite levels. There is a lack of methods to noninvasively assess PD progression and treatment response. We demonstrate that saturation transfer MRI can detect changes in glycogen, total creatine (tCr), and phosphocreatine (PCr) in a mouse model of PD and show more than doubling of muscle glycogen levels and a gradual decrease of tCr and PCr levels with age. The simultaneous mapping of these energy metabolites with MRI has potential to assess PD and other diseases involving mitochondrial or energy metabolic disorders.
Comparing the efficacy of data-driven noise regression techniques in preserving age-related resting-state connectivity information
Authors: Golestani Ali , Chen J
Published: August 2024

Data-driven denoising methods (global-signal regression (GS), white matter and CSF (cerebrospinal fluid) regression, anatomical and temporal CompCor, ICA AROMA) have been shown to remove cardiac and respiratory contributions from the fMRI signal. In this study, we compared the effectiveness of these methods in preserving the signals associated with age-related brain connectivity changes. We show that GS and AROMA resulted in diminished age-related brain connectivity differences, aCompCor and tCompCor retained the most connectivity differences while denoising effectively.
BISEPI high-resolution fMRI at 7T with NORDIC-PCA
Authors: Liu Guoxiang , Ueguchi Takashi , Ogawa Seiji
Published: August 2024

Recently, a new noise reduction technique NOise Reduction with Distribution Corrected (NORDIC) PCA has been proposed for High resolution fMRI, and the improvements in keys including temporal-SNR, BOLD detectability have been demonstrated using this technique. In this work, we applied this technique to 0.4-mm isotropic human fMRI data acquired with our Block-interleaved segmented EPI, and compare the BOLD detectability of the data with and without NORDIC-performed.
Time-Varying Functional Connectivity of the Hippocampus Is Associated With Cognitive Performance in Multiple Sclerosis Patients
Authors: Valsasina Paola , Marchesi Olga , Vizzino Carmen , Mistri Damiano , Rocca Maria Assunta , Filippi Massimo
Published: August 2024

In this study, we explored hippocampal static and time-varying functional connectivity and its association with cognition in patients with multiple sclerosis. We found decreased static and time-varying connectivity of the hippocampus with temporo-parietal regions, and increased connectivity of the hippocampus with pre- and postcentral gyri, inferior temporal gyrus, precuneus and frontal regions. Better visuospatial and verbal memory were associated with higher hippocampal time-varying connectivity with precentral and inferior temporal gyri, while better attention scores were associated with higher hippocampal time-varying connectivity with the superior frontal cortex.
A test-retest analysis for ventral intermediate nucleus localization with CSD tractography for deep brain stimulation.
Authors: Verhaaren Benjamin , Radwan Ahmed , Peeters Ronald , Boogers Alexandra , Peeters Jana , Vandenberghe Wim , De Vloo Philippe , Nuttin Bart , Sunaert Stefan
Published: August 2024

We found that the location of the ventral intermediate nucleus (Vim) as determined with dMRI tractography differed only 0.92 mm on average on subsequent scans within the same individual (SD: 0.51 mm) in a test-retest study of 29 healthy individuals. The difference with a commonly used manual method that locates the Vim at fixed distances in relation to the commissures and third ventricular wall was more pronounced: on average 2.44 mm (SD: 0.92 mm). We believe that dMRI tractography based DBS target determination seems feasible and rather accurate, given that acquisition parameters and post-processing are optimal.
Abnormal glymphatic system function in patients with chronic migraine using diffusion tensor image analysis along the perivascular space
Authors: Zhang Xue , Wang Wei , Zhang Xueyan , Bai Xiaoyan , Yuan Ziyu , Bai Ruiliang , Jiao Bingjie , Zhang Yingkui , Li Zhiye , Zhang Peng , Tang Hefei , Zhang Yaqing , Yu Xueying , Wang Yonggang , Sui Binbin
Published: August 2024

Chronic migraine (CM) is a common and highly disabling primary headache associated with vasomotion dysfunction. It is unclear whether glymphatic dysfunction develops due to frequent and chronic headache attacks in CM. In the current study, we evaluated the glymphatic system function in patients with CM using diffusion tensor image analysis along the perivascular space (DTI-ALPS) technique. We found a significantly higher ALPS index compared with healthy controls, and the alteration was significant only observed in the right hemisphere. Patients with CM have abnormalities in glymphatic function, and the right-prominent alterations might be a certain feature of CM.
Machine Learning for Quantitative IVIM (qIVIM) Cerebral Perfusion Imaging
Authors: Liu Mira , Bertini Julian , Saadat Niloufar , Warioba Chisondi , Gorre Donovan , Carroll Timothy , Christoforidis Gregory
Published: August 2024

Intravoxel Incoherent Motion (IVIM) is a non-contrast perfusion scan that measures various speeds of molecular movement. Segmentation of IVIM signal origin, i.e. from blood, cerebrospinal fluid (CSF), or tissue water, is crucial. Simulation suggested Inversion Recovery should not be used in IVIM to remove CSF, and analysis of signal patterns suggested differing signal decay as a method of removing CSF during post-processing. A threshold determined by k-fold leave-one-out cross-validation on IVIM diffusion coefficient returned successful CSF segmentation (dice = .69), and CSF removal by supervised machine learning via linear discriminant analysis returned quantitative IVIM with strong agreement to microsphere perfusion.
Automated Quality Assessment of Liver Magnetic Resonance Images with Fully Automatic Segmentation and Radiomics Approach
Authors: Ren Hai Nan , Qian Li Jun , Gong Xu Hua , Zhou Yan , Song Yang
Published: August 2024

This study investigated the feasibility and performance of quality assessment of hepatic magnetic resonance (MR) images using a deep-learning-based segmentation and radiomics approach. We used a pre-trained deep learning model to segment the liver on different contrast-enhanced MR phases and then extracted quantitative features to assess the image quality by a machine learning method. The results showed that the radiomics model had a high performance for image quality identification in both training and test sets. This suggests that it was feasible to automate the identification of image quality by using radiomics approaches.
The diagnostic value of synthetic MRI in ovarian epithelial cell neoplasms and its correlation with Ki-67 expression: a preliminary study
Authors: Zhang Lingjie , Cheng Meiying , Pan Teng , Wang Kaiyu , Tan Shifang , Lu Lin , Liao Junjie , Zhao Xin
Published: August 2024

This study aimed to evaluate the diagnostic value of synthetic MRI in ovarian epithelial cell neoplasms and to explore the correlation between the quantitative parameters like T1, T2, and proton density derived from synthetic MRI and Ki-67 expression. Our preliminary study shows that the values of these quantitative parameters were significantly lower in the malignant group than in the benign group, and the parameters were negatively correlated with Ki-67 expression, which can indirectly reflect the degree of tumor invasion.
Super-resolution imaging on an MRI-linac to improve real-time MRI used in MRI guided radiation therapy.
Authors: Grover James , Liu Paul , Dong Bin , Shan Shanshan , Whelan Brendan , Keall Paul , Waddington David
Published: August 2024

Real-time MRI is limited in its spatiotemporal resolution due to imaging time being proportional to the spatial resolution. Super-resolution imaging was integrated into an MRI-linac to improve the spatiotemporal resolution of images used in real-time adaptive MRI guided radiation therapy. Real-time up-sampling techniques included conventional bicubic interpolation and deep learning-based super-resolution. Up-sampling increased the spatial resolution as characterised by healthy volunteer brain and thorax MRIs with negligible impact on the temporal resolution as measured in a motion phantom tracking experiment.
Fiber-specific modelling in spherical deconvolution
Authors: De Luca Alberto , Leemans Alexander
Published: August 2024

Spherical deconvolution is commonly employed to reconstruct fiber orientations distributions with brain diffusion MRI. A key assumption in spherical deconvolution is that all brain fibers share the same microstructural properties. This is unlikely the case in white matter, but even more so in grey matter. Here, we propose a novel framework to perform spherical deconvolution with fiber specific models. As such, this framework allows to quantify diffusion properties associated to each fiber orientation. In this work, we showcase the application of this framework to investigate the organization of the brain cortex high resolution diffusion MRI data.
Brain iron content increase and oxygen extraction fraction reduction after iron repletion in blood donation induced iron deficiency
Authors: Zhuang Hangwei , Dimov Alexey , Brittenham Gary , Spincemaille Pascal , Nyugen Thanh , Wang Yi , Hod Eldad
Published: August 2024

We examined brain iron content using susceptibility source separation and oxygen extraction fraction (OEF) in adult healthy blood donors with blood donation-induced iron deficiency treated with intravenous iron repletion at the first donation and a second donation after approximately 5 months and compared it with a control group who was not treated after the first donation. Iron content increases in the parietal cortex, the caudate and the putamen were observed in the treatment group. OEF reduction was observed in the whole brain and multiple ROIs, suggesting iron repletion treatment helps reduce oxidative stress.
Self-navigated high-resolution 3D diffusion MRI using an extended blipped-CAIPI sampling and structured low-rank reconstruction
Authors: Li Ziyu , Chen Xi , Chiew Mark , Miller Karla , Wu Wenchuan
Published: August 2024

3D multi-shot multi-slab imaging can provide superior SNR efficiency for high-resolution dMRI but suffers from motion-induced shot-to-shot phase variations. We propose a highly-efficient, self-navigated method to correct for phase variations in 3D multi-slab dMRI. The sampling of each shot is designed to intersect with the kz=0 plane. These intersections are used to reconstruct a 2D phase map for each shot using a structured low-rank reconstruction that leverages the redundancy in shot and coil dimensions. The phase maps are used to eliminate the phase inconsistency in the final 3D multi-shot reconstruction. We demonstrate the method’s efficacy using highly realistic simulations.
Using laminar fMRI and modeling to study auditory predictive processing
Authors: Faes Lonike , Zulfiqar Isma , Vizioli Luca , Yu Zidan , Wu Yuan-Hao , Shin Jiyun , Auksztulewicz Ryszard , Melloni Lucia , Uludag Kamil , Yacoub Essa , De Martino Federico
Published: August 2024

We use ultra-high field fMRI to explore the differential role of cortical layers in the information flow between top-down predictions and bottom up sensory evidence in a predictive coding (PC) framework. As the measured BOLD signal is affected by vascular draining, we use a computational model that combines neuronal dynamics with laminar vascular physiology to help us understand prediction signals at cortical depths and underlying neuronal responses. We show that a violation in prediction caused response modulation in superficial and deep layers in the primary auditory cortex, which is in line with the PC framework.
Separation of sensory and attention input to the human primary somatosensory cortex by spin- and gradient-echo BOLD fMRI
Authors: Han SoHyun , Kim Dongho , Kim Seong-Gi
Published: August 2024

High spatial resolution laminar specific fMRI has a potential to separate between top-down and bottom-up signals. In this study, we investigated the effect of attention across cortical layers in the human S1 using SAGE-EPI sequence. fMRI experiments during vibrotactile stimulation with passive and attention tasks with 0.8mm isotropic resolution at 7T were performed. We demonstrated that the SE-BOLD can identify laminar profiles of bottom-up and top-down processes: the laminar profile of passive task showed the peak at layer 4, but that of attention task showed the peak at the superficial layers.
Recovering high quality FODs from reduced number of diffusion weighted images using a model-driven deep learning architecture
Authors: Bartlett Joseph , Davey Catherine , Johnston Leigh , Duan Jinming
Published: August 2024

SDNet utilises the learning ability of deep neural networks with the robustness of model-based approaches to produce high quality fibre orientation distributions (FODs) from a reduced set of multi-shell diffusion weighted images (DWI). The cascaded architecture, with data consistency layers throughout, makes use of model based prior knowledge and spatial correlations within the DWI signal to achieve state-of-the-art performance in both sum of squared errors and angular correlation coefficient. Our model also shows competitive results with respect to apparent fibre density error and peak amplitude error over a range of regions of interest.
Exploration of interstitial fibrosis in chronic kidney disease by diffusion-relaxation correlation spectrum MR imaging
Authors: Liu Fang , Hu Wentao , Dai Yongming , Zhang Minfang , Zhou Yan
Published: August 2024

Non-invasive evaluation of interstitial renal fibrosis would help monitoring chronic kidney disease (CKD) progression and prognosis prediction. This study was aimed to evaluate renal interstitial fibrosis by diffusion relaxation correlated spectrum imaging (DR-CSI). Correlation was found between DR-CSI volume fractions and interstitial fibrosis level (IFL). VB illustrated best diagnostic performance among MRI indicators. We suggest DR-CSI is of potential value in the evaluation of renal interstitial fibrosis.
Evaluation of renal allograft function using arterial spin labeling and blood oxygen level-dependent imaging
Authors: Peng Jin , Hong Yajun , Zhu Feipeng , Li Yanjun , Luo Song , Wu Pu-Yeh , Lu Guangming
Published: August 2024

In this study, we aimed to assess the renal allografts function after transplantation using ASL and BOLD MRI. We found that RBF and R2* values were significantly lower and higher in the renal transplant injury group, respectively. RBF and R2* were positively and negatively correlated with eGFR, respectively. ROC analysis demonstrated both RBF and R2* reflected injured renal function, and the combination of RBF and R2* showed an AUC of 0.86, comparable to that of RBF alone. In conclusion, compared to BOLD, ASL may be a more promising imaging technique for noninvasive assessment of renal graft function for clinical purposes.
Neurochemical differences between 1p/19q codeleted and non-codeleted gliomas assessed by in vivo magnetic resonance spectroscopy
Authors: Branzoli Francesca , Liserre Roberto , Deelchand Dinesh , Poliani Pietro Luigi , Bielle Franck , Nichelli Lucia , Sanson Marc , Lehéricy Stéphane , Marjańska Małgorzata
Published: August 2024

Mutations in the genes encoding for isocitrate dehydrogenase (IDH), and 1p/19q codeletion are genetic alterations that can be often found in low-grade gliomas and are associated with better prognosis and response to treatment. Nevertheless, the biological effects of the 1p/19q codeletion are still not well known. In this study, we compared the neurochemical profile of IDH-mutated, 1p/19q codeleted gliomas and their non-codeleted counterparts using in vivo magnetic resonance spectroscopy. We showed that the only metabolite that differed significantly between the two groups was cystathionine, pointing to this metabolite as the most useful biomarker for the identification of 1p/19q codeleted gliomas.
Convex Optimized Diffusion Encoding (CODE) with M1-Nulling for Pancreatic Diffusion Weighted Imaging
Authors: Wang Kang , Middione Matthew , Loening Andreas , Ennis Daniel , Brunsing Ryan
Published: August 2024

Multi-shot DWI reduces image distortion while increasing SNR. More recently, motion-compensated diffusion encoding has been shown to reduce artifacts and improve ADC consistency in single-shot DWI. Motion-compensated multi-shot pancreatic DWI may also mitigate artifacts arising from shot-to-shot incoherence. Herein, we conducted a pilot study of multi-shot DWI of the pancreas with and without motion-compensated diffusion encoding. Image quality and artifacts were scored by expert radiologists. ADC values of different pancreatic anatomical segments were computed. Multi-shot DWI with motion-compensated gradient encoding increased homogeneity of signal intensity and ADC values across the pancreas.
Lung Multi-Breath Wash in/out MRI with 19F with Sub 0.5 Second Scan Time
Authors: Chung Sang Hun , Huynh Khoi Minh , Chen Yong , Yap Pew-Thian , Goralski Jennifer , Donaldson Scott , Lee Yueh
Published: August 2024

We studied the feasibility of multi breath wash-in/out lung acquisition with 19F gas and a sub 0.5 second acquisition spiral sequence. We compared the sub 0.5 seconds acquired data ability to measure wash-in/out time constants to a regular breath-hold 19F lung imaging and report correlation as well as differences in mean. Our results yielded high correlations (r > 0.88) for both wash-in and wash-out time constant calculations. The results indicate our proposed method yield similar calculated time wash-in/out time constants without the need for breath-holds and show promise for the use of free breathing 19F gas lung MRI.
Deep Learning-accelerated, Single-breath-hold T2-weighted Imaging for Tumor Invasion Assessment in Gastric Cancer
Authors: Xu Wei-Yue , Li Qiong , Hou Ya-Jun , Hsu Yi-Cheng , Nickel Dominik , Zhang Yu-Dong , Liu Xi-Sheng
Published: August 2024

T2-weighted imaging (T2WI) is an indispensable sequence of gastric magnetic resonance imaging (MRI) for tumor assessment. This study compared the deep learning-accelerated T2WI sequence (DL-T2WI) with BLADE T2WI in image quality assessment and tumor invasion evaluation of gastric cancer (GC). It revealed that DL-T2WI, acquired within a single-breath-hold, performed better than BLADE T2WI in terms of image quality for both quantitative and qualitative analyses. Furthermore, DL-T2WI images displayed comparable accuracy to BLADE T2WI images for serous invasion evaluation. The study suggests that DL-T2WI might be superior to BLADE T2WI for GC.
The preliminary application of fully quantitative CMR myocardial perfusion in ST elevation myocardial infarction
Authors: Zhao Shi-hai , Chen Wei-bo
Published: August 2024

Fully quantitative CMR-MPI was preliminarily applied for evaluating the area at risk in patients with acute ST elevation myocardial infarction. As a result, the fully quantitative CMR-MPI provided quantitative myocardial blood flow of the infarction territories, which was correlated with the extent of Salvageable zone.
Engineering novel functional brain imaging contrast agents via iron oxide encapsulation in human red blood cells
Authors: Fear Elizabeth , Antonelli Antonella , Abdalla Pasant , Zamboni Elisa , Labarthe-Last Marie-Christine , Annis Victoria , Duckett Simon , Magnani Mauro , Kennerley Aneurin
Published: August 2024

We have developed a next generation, safe, personalised iron-based contrast agent (CA) for empowering functional Magnetic Resonance Imaging (fMRI). Our proprietary method uses state-of-the-art red blood cell (RBC) encapsulation technology to engineer biocompatible super-paramagnetic CAs able to withstand rapid clearance from the bloodstream by macrophages (as part of the mononuclear phagocytic/reticuloendothelial system). The agent is validated in a multi-modal (concurrent fMRI and intrinsic optical imaging) preclinical rat model as a novel CA for the mapping of cerebral blood volume (CBV) in response to somatosensory stimulation, providing a non-BOLD alternative for accurate, high-resolution mapping of brain function.
Statistical Approach to Single-Point Water-Fat Imaging with Independent Component Analysis (ICA)
Authors: Xiang Qing-San
Published: August 2024

Water-Fat Imaging with only a single acquisition is desirable for its pulse sequence simplicity and scan time efficiency. However, robust reconstruction is more challenging due to limited available information. In this work, it is discovered that some previously unused information can be found by statistical analysis, leading to effective reconstruction of water and fat images. In particular, Independent Component Analysis (ICA) was used to determine the phase error. Well separated water and fat images were subsequently obtained after phase correction.
Fast $$$T_{2}^{*}$$$ and QSM using locally low rank methods for complex-valued, multi-echo GRE reconstruction
Authors: Iglehart Charles , Bilgin Ali , Saranathan Manojkumar
Published: August 2024

$$$T_{2}^{*}$$$ and quantitative susceptibility mapping are of increasing clinical interest, but typically require lengthy ME-GRE scans. To accelerate such acquisitions, we propose and implement a volumetric reconstruction method employing locally low rank (LLR) techniques to recover complex-valued ME images from highly undersampled k-space data that is suitable for parameter mapping. We present results for reconstructed magnitude and phase across multiple datasets and acceleration ratios, as well as computed $$$R_{2}^{*}$$$ and QSM from reconstructed images.
Dual-Band Adiabatic Pulses in cardiac MRI: Application in Black Blood Imaging at 3T
Authors: Arami Ayda , Steeg-Henzen Christal , J.Lamb Hildo , Weingärtner Sebastian
Published: August 2024

Black-Blood imaging is an integral part of clinical cardiac MRI, due to it’s clear depiction of the cardiac morphology. Double inversion recovery, is most commonly used for black-blood contrast, by successively applying a non-selective inversion and a slice-selective reinversion. In this work, we investigate dual band adiabatic inversion pulses, as an alternative, to achieve nulling of the blood signal outside of the imaging slice. Thorough blood suppression and comparable noise performance to double inversion recovery were demonstrated in vivo while achieving an 11% reduction in SAR and a 10% reduction in pulse duration.
Multi-Scanner Reproducibility of IVIM Quantification in the Liver using Pseudo-Diffusion and Physical IVIM Signal Models
Authors: Simchick Gregory , Allen Timothy , Hernando Diego
Published: August 2024

Intravoxel incoherent motion (IVIM) quantification in the liver suffers from instability associated with separating multiple decaying signal components sampled along a single dimension (b-value). In this work, monopolar and 2D (b-value and first-order motion moment (M1)) noise-optimized IVIM-DWI acquisitions were acquired on three MR scanners with different MR gradient hardware. From each acquisition, IVIM estimates were obtained using pseudo-diffusion and physical (M1 dependent) IVIM signal models. Inter-scanner reproducibility and interlobar agreement were compared across acquisitions and models. 2D (b-M1) IVIM-DWI acquisitions combined with physical IVIM signal modeling improved reproducibility of IVIM quantification in comparison to monopolar acquisitions and pseudo-diffusion modeling.
Feasibility of detecting subvoxel deformation in intervertebral disc using quantitative ultrashort echo time (UTE) techniques
Authors: Jerban Saeed , Moazamian Dina , Statum Sheronda , Jang Hyungseok , Chang Eric , Du Jiang , Chung Christine , Ma Yajun
Published: August 2024

Quantitative ultrashort echo time (UTE) MRI can be used for quantitative assessment of intervertebral discs (IVDs). It is hypothesized that the investigation of quantitative UTE MRI properties of IVD under mechanical loading may highlight the affected regions of IVD by diseases and injuries. We investigated the feasibility of using UTE-T1, UTE-Adiab-T1ρ, and UTE-MT measures for detecting the IVD deformation under loading. T1 and T1 ρ decreased in IVDs under loading while MMF from UTE-MT modeling as an index for collagen content increased by loading. This study highlights the potential of UTE-MRI to detect subvoxel deformations in IVDs caused by loading.
Deep Learning-Based Reconstruction of Accelerated Cardiac Cine MRI at 0.55T
Authors: Vornehm Marc , Wetzl Jens , Giese Daniel , Pang Jianing , Ahmad Rizwan , Knoll Florian
Published: August 2024

Acceleration of cardiac cine MRI is highly desirable in order to decrease the required breath-hold duration. On low-field MRI systems in particular, this could help make cardiac MRI more widely available. We present a method based on the Variational Network for reconstruction of cardiac cine MRI, trained on data from 1.5 and 3T systems. Reconstructions of retrospectively and prospectively undersampled acquisitions at 0.55T with an acceleration rate of eight are shown and compared to Compressed Sensing reconstructions. Despite the domain shift to low-field data, the neural network achieved an SSIM of 94.6%, which is comparable to the Compressed Sensing results.
Characterization of Functional MR Elastography Responses to Variations in Visual Stimulus Frequency and Contrast
Authors: Palnitkar Harish , Murphy Matthew , Sui Yi , Glaser Kevin , Manduca Armando , 3rd John Huston , Ehman Richard , Arani Arvin
Published: August 2024

The response of BOLD fMRI to changes in both visual contrast frequency and contrast intensity have been well documented. Recently, an increase in the stiffness of activated regions of the visual cortex due to a controlled variation of block duration has been demonstrated with fMRE elastograms. The current study aims to investigate the relationship between BOLD fMRI and fMRE due to a controlled variation of both contrast intensity and contrast frequency of a visual stimulation. This study demonstrates that the fMRE-measured stiffness change varies linearly with the underlying neural activity, which can be modulated by stimulus parameterization.