bluuebunny/crossref_metadata_2025 huggingface dataset:
Adversarial Diffusion Probabilistic Models for Unpaired MRI Contrast Translation
Authors: Ozbey Muzaffer , Dalmaz Onat , Dar Salman , Bedel Hasan , Öztürk Şaban , Güngör Alper , Çukur Tolga
Published: August 2024

Synthesis of missing contrasts in an MRI protocol via translation from acquired contrasts can reduce costs associated with prolonged exams. Current learning-based translation methods are predominantly based on generative adversarial networks (GAN) that implicitly characterize the distribution of the target contrast, with limits fidelity of synthesized images. Here we present SynDiff, a novel conditional adversarial diffusion model for computationally efficient, high-fidelity contrast translation. SynDiff enables training on unpaired datasets, thanks to its cycle-consistent architecture with coupled diffusion processes. Demonstrations on multi-contrast MRI datasets indicate the superiority of SynDiff against competing GAN and diffusion models.
Anisotropic stiffness of ex vivo swine heart estimated by transversely isotropic nonlinear inversion MRE at 2mm isotropic voxel resolution
Authors: Tous Cyril , Flé Guillaume , McGarry Matthew , Bayly Philip , Paulsen Keith , Johnson Curtis , Stuber Matthias , Van Houten Elijah
Published: August 2024

MR elastography (MRE) must account for the anisotropic nature of myocardial tissue to accurately quantify stiffness. The constitutive matrix for this material was rotated to align with the fibers. One ex vivo swine heart was scanned with DTI and MRE sequences at 2 isotropic voxel resolution. Transversely isotropic viscoelastic stiffness was reconstructed using the Non-Linear Inversion (NLI) algorithm. Elastic properties (shear and Young’s modulus, tensile and shear anisotropy) were segment dependent, in agreement with the myocyte sheetlet formation, which varies in size and spacing according to the myocardial segment. Similarities between MRE and DTI metrics could be observed.
A voxel-wise composition ratio of DCE-MRI time-intensity curve profiles allows for visualizing and quantifying hemodynamic heterogeneity
Authors: Yao Bingyu , Liu Zhou , Chen Yumin , Wen Jie , Wang Meng , Ren Ya , Liang Dong , Liu Xin , Zheng Hairong , Luo Dehong , Zhang Na
Published: August 2024

We propose a novel model-free and data-driven approach, i.e., voxel-wise composition ratio on 19 dynamic contrast-enhanced MRI (DCE-MRI) time-intensity curve (TIC) profiles (Type-19) to visualize and quantify spatial hemodynamic heterogeneity. The proposed quantitative method for breast tumor was evaluated and compared with the two existing methods (qualitative and semi-quantitative methods) in 4 different clinical applications. In distinguishing malignancy on breast cancer lesions and predicting tumor proliferation status, we found that the machine learning model based on the Type-19 feature outperformed other two models in the validation set.
High-resolution DWI in the breast by Spatiotemporal encoding (SPEN): clinical utility in comparison with SS-EPI and RESOLVE
Authors: Nakayama Rena , Iima Mami , Kataoka Masako , Honda Maya , Urushibata Yuta , Otikovs Martins , Nissan Noam , Frydman Lucio , Ota Rie , Okazawa Aika , Tsuji Kazuki , Toi Masakazu , Nakamoto Yuji
Published: August 2024

This study investigated the breast lesion conspicuity and ADC reliability for 3 different DWI protocols; SPEN, SS-EPI, and RESOLVE. The in-plane resolution for SPEN and RESOLVE was 1x1mm2, and SS-EPI was 2x2mm2. SPEN showed a higher score for lesion conspicuity than SS-EPI, and a lower score than RESOLVE. ADC values in breast lesions were significantly lower in SPEN than others, presumably due to the choice of different b values, the sequences having different T1/T2 weightings, different robustness vs motions, the presence of unsuppressed fat, or different viewer systems used to analyze the data, which will need further investigation.
Multidimensional RF pulse design in spin-domain using auto-differentiation for 3D refocusing pulse
Authors: Yang Jiayao , Nielsen Jon-Fredrik , Jiang Yun
Published: August 2024

This study proposed a novel algorithm for designing multidimensional RF in spin-domain using auto-differentiation in PyTorch. Our algorithm uses spin-domain description of rotations to formulate the RF pulse design into optimization problems. We designed 3D refocusing pulses and verified the performance using spin-echo based sequences in phantom at 1.5T and in vivo in the brain at 3T.
A 3D Surface Coil with Deep Learning Based Noise Reduction for Parotid Gland Imaging
Authors: Gokyar Sayim , Zhao Chenyang , Gunamony Shajan , Yan Jiaruo , West Jonathan , Kokot Niels , Wang Danny
Published: August 2024

Parotid salivary gland neoplasms occur in conspicuous locations near the facial nerve and have a risk for malignant transformation – making early diagnosis and treatment essential. Here we present a novel three-dimensional surface coil (3D Coil) architecture and a deep learning-based noise reduction method that offers twice higher signal to noise ratio compared to single channel surface coil for parotid gland imaging at 7T.
Mapping curvature responses in human V4 using VASO at 3T
Authors: Zamboni Elisa , Watson Isaac , Alasiri Sharyfah , Fear Elizabeth , Formisano Elia , Goebel Rainer , Stirnberg Rüdiger , Huber Laurentius , Kennerley Aneurin , Morland Antony
Published: August 2024

The intermediate processing steps in human vision are not well characterised. We show however that the high specificity of VASO fMRI permits investigation functional organisation of curvature responses in human visual area V4, which is an intermediate region in the visual system. Understanding how the functional architecture and hierarchical integration of local contours (curvature) contributes to formation of shapes can inform computational models of object recognition. The emergence of inter-individual differences in these organisations can explain individual differences in healthy and impaired visual perception.
Dynamic ASL and Multi-echo BOLD in Hippocampus Functional Connectivity of Aging
Authors: Zhang Zongpai , Chen Shichun , Guo Yanchen , Zhang Yakun , Riley Lissa , Anderson Adam , DeRosa Eve
Published: August 2024

The effect sizes of aging in hippocampus (HPC) resting-state functional connectivity (rsFC) using dASL and multi-echo BOLD (ME-BOLD) imaging were evaluated in 20 subjects (10 young adults, 10 older adults). Both dASL and ME-BOLD showed reduced HPC rsFC in older adults but with larger extended region in dASL results. dASL demonstrated significantly higher effect sizes of aging in HPC rsFC compared to ME-BOLD, supporting more sensitivity of dASL in detecting the aging effect in HPC rsFC.
Neural underpinning of a respiration-related resting-state fMRI network
Authors: Zhang Nanyin , Tu Wenyu
Published: August 2024

Respiration can induce non-neural artifacts in the resting-state fMRI (rsfMRI) signal. In the meantime, as a crucial physiologic process, respiration that can directly drive neural activity change, and may thereby modulate the rsfMRI signal. Nonetheless, this potential neural component in the respiration-fMRI relationship remains elusive. To elucidate this issue, we developed a platform to achieve a concurrent measure of electrophysiology, respiration, and whole brain rsfMRI signals, and identified a respiration-associated network that was underpinned by neural activity, which represents a novel component in the respiration-rsfMRI relationship that is distinct from respiration-related rsfMRI artifacts.
Disrupted vein-dominated connectivity and increased CSF involvement in ischemic stroke human brain
Authors: Yuan Jianyu , Tang Chaogang , Zhang Lei , He Yi
Published: August 2024

High-resolution resting-state (rs) fMRI enables the functional mapping of vein-dominated connectivity, correlated with neuronal calcium signals. Here, we performed high-resolution rs-fMRI to examine 30 ischemic stroke patients with binocular isotropic hemianopia and 10 healthy controls. The results of seed-based and independent component analysis (ICA) demonstrated the reduced vein-dominated correlation patterns. Interestingly, ICA also found increased correlations between cerebrospinal fluid (CSF) and ischemic lesions in stroke patients, showing ultra-slow oscillation frequencies up to 0.04 Hz. Our findings suggest that ischemic lesions are associated with CSF, prompting disruption of vein-dominated connectivity.
Impact of Radiomic Features Stability of Myocardial Motion on Classification of Repaired Tetralogy of Fallot Patients
Authors: Chiu Pao-Han , Wu Ming-Ting , Weng Ken-Pen , Pan Nai-Yu , Huang Teng-Yi , Peng Hsu-Hsia
Published: August 2024

Myocardial motion influences the stability of radiomic features of cardiac magnetic resonance (CMR) cine images. We aimed to evaluate the impact of the stability of myocardial radiomic features on the classification performance of differentiation of repaired tetralogy of Fallot (rTOF) patients from normal volunteers. The stability of each radiomic feature during cardiac cycle was assessed by coefficient of variation (CV) of the feature value. 50 of 107 radiomic features (46.7%) in normal volunteers were stable features. The classification model established only with stable features presented the best classification performance (AUC=0.94) which was able to be improved by chi-square feature selection.
Quantifying geometrical properties of the Brain Surface in Alzheimer's Disease using 3D Tortuosity
Authors: Mateos Maria Julieta , Lah James J. , Deqiang Qiu
Published: August 2024

Alzheimer's disease causes significant gray matter loss, which leads to changes in the brain surface's shape. In this work, we used the local gyrification index (LGI) and the three-dimensional tortuosity (3) to characterize the cortical morphology, and to determine if the obtained values were significantly different amog the Alzheimers diagnosis. The subset of MRI studies was obtained from ADNI database. For the data analyzed, the results show that the 3 has a positive correlation with brain volume and can potentially be a biomarker for AD.
AI-enhanced comprehensive quiet neuroimaging
Authors: Solana Ana Beatriz , Mandava Sagar , Wang Xinzeng , Lebel Marc , Lythgoe David , Wood Tobias , Bowdler Matthew , Williams Steven , Wiesinger Florian
Published: August 2024

Most of today’s MRI scans are very loud and can be challenging for patients of all ages, e.g. sleeping babies, anxious children or elderly with tinnitus. Existing quiet and/or acoustic noise reduced MRI scanning solutions are in their infancy, primarily because of their incomplete nature and associated trade-offs in terms of image quality and/or scan time. Here, we present a comprehensive quiet neuroimaging solution, including standard anatomical scans (localizer, T1w-MPRAGE, T2w-FSE, T2w-FLAIR, MRA, Diffusion), quantitative parameter mapping (ADC, T2*, QSM, PD, T1, T2) and functional BOLD-fMRI. Scan time and overall image quality was improved using DL-based image reconstruction framework.
Association between Post-traumatic Osteoarthritis 10+ Years after ACLR and Quantitative MRI of Knee Cartilage, Menisci, and Thigh Muscles
Authors: Zaylor William , Khan Sameed , Lartey Richard , Eck Brendan , Li Mei , Gaj Sibaji , Kim Jeehun , Winalski Carl , Altahawi Faysal , Jones Morgan , Huston Laura , Harkins Kevin , Knopp Michael , Kaeding Christopher , Spindler Kurt , Li Xiaojuan
Published: August 2024

The purpose of this study was to evaluate the associations between radiomic features in knee and thigh quantitative MRI with symptomatic and radiographic post-traumatic osteoarthritis (PTOA) after anterior cruciate ligament reconstruction (ACLR). Radiomic features of knee cartilage, menisci (extracted from T1ρ maps), and thigh muscles (extracted from anatomic images and fat fraction maps) were extracted from patient MRI 10+ years after ACLR, and features were selected for symptomatic or radiographic PTOA associations. Symptomatic and radiographic PTOA were associated with features from the medial cartilage compartments, and menisci; features from the thigh muscles were associated with symptomatic PTOA only.
MRE-assessed meningioma stiffness and peripheral adhesion characteristics predict the extent of resectability and recurrence probability
Authors: Zheng Keni , Murphy Matthew , Camerucci Emanuele , Shan Xiang , Sui Yi , Manduca Armando , Van Gompel Jamie , Ehman Richard , Huston John III , Yin Ziying
Published: August 2024

This work explored the value of MR elastography (MRE)-measured tumor stiffness and slip interface imaging (SII)-assessed adhesion metrics in predicting the extent of tumor resection and the probability of meningioma recurrence in 52 patients with meningiomas. Tumor adhesion percentage was assessed based on pattern recognition of the normalized octahedral shear strain (NOSS) map. Tumor stiffness was calculated using a neural network-based inversion (NNI). We found that stiffness correlates with the extent of resection (EOR) that was possible at surgery, while the extent of tumor adhesion showed good correlation with tumor recurrence among aggressive tumors with atypical features.
Quantitative Comparison of Bone-Selective MRI Techniques for Craniofacial Imaging
Authors: Kamona Nada , Jones Brandon , Lee Hyunyeol , Wagner Connor , Clark Makayla , Thaploo Advait , Konar Sandhya , Cruz Carlos , Li Kevin , Bartlett Bartlett , Rajapakse Chamith , Song Hee Kwon , Wehrli Felix
Published: August 2024

Risk of ionizing radiation from CT remains a concern for pediatric patients, such as craniosynostosis patients who may require multiple scans at a young age. We quantitatively compared three MRI methods for imaging the skull by scanning healthy adults using our solid-state bone-selective ultrashort echo subtraction sequence, along with zero echo time and gradient-echo sequences. We demonstrate the similarities among the 3D rendered bone segmentations in terms of Dice similarity coefficient and craniometric measurements across all imaging methods. Our UTE echo subtraction technique shows clear visualization of craniofacial structures near the bone-air boundaries and superior signal suppression of soft-tissues.
Electrical Conductivity Mapping Using Ultrashort Echo Time Double Echo Steady State
Authors: Jang Hyungseok , Sedaghat Sam , Shin Soo Hyun , Jerban Saeed , Ma Yajun , Chang Eric , Du Jiang
Published: August 2024

Electrical conductivity is an intrinsic tissue property. At the Larmor frequency of the MR system (i.e., ~128 MHz at 3T), the electrical conductivity reflects the tissue composition and ionic contents. Electrical conductivity mapping (ECM) has recently emerged as a promising MR-based biomarker. In this study, we show the feasibility of ECM using ultrashort echo time double echo steady state (UTE-DESS). In addition, three ECM methods, including forward Laplacian, parabolic fitting, and inverse Laplacian, are compared in computer simulation and ex vivo experiments with four cadaveric human brain specimens.
The sequence of regional structural disconnectivity due to chronic active and inactive multiple sclerosis lesions
Authors: Tozlu Ceren , Olafson Emily , Jamison Keith , Demmon Emily , Kaunzner Ulrike , Marcille Melanie , Zinger Nicole , Michaelson Nara , Safi Neha , Nguyen Thanh , Gauthier Susan , Kuceyeski Amy
Published: August 2024

In this study, we showed that structural disconnectivity due to T2 FLAIR lesions in the ventral attention and subcortical networks, in particular within the supramarginal and putamen, occurs earlier in the sequence of disability (i.e., mild to severe) in multiple sclerosis. We also showed that paramagnetic rim lesion (PRL)-based structural disconnectivity in motor-related regions occurs earlier in the disability event sequence, followed by non-PRL-based structural disconnectivity in the caudate and postcentral gyrus. T2 FLAIR lesion-based structural disconnectivity in subcortical regions, including the thalamus, occurs earliest in the sequence of cognitive impairment (i.e. preserved to impaired).
Metabolic Imaging of Alzheimer’s Disease Related Inflammation Using Deuterium MRI
Authors: Merritt Matthew , Chang Mario , Hawkinson Tara , Rushin Anna , Kodibagkar Vikram , Bankson James , Sun Ramon
Published: August 2024

Alzheimer’s Disease (AD) is characterized by increased inflammation and increased glucose utilization as detected by FDG-PET. Using a new deuterium MRI method based on a [D7]glucose tracer, we can image the brain of a mouse model of AD with in plane resolution approaching 1 mm. Mass spectrometry imaging of the same brains shows characteristic changes in protein associated glycans that correlate well with immunohistochemical staining for inflammation. We believe this new research pipeline can provide powerful new insights into AD pathophysiology.
Short-term susceptibility correlations are sensitive to disrupted iron dynamics in multiple sclerosis
Authors: Reeves Jack , Salman Fahad , Dwyer Michael , Bergsland Niels , Weinstock-Guttman Bianca , Muldoon Sarah , Zivadinov Robert , Schweser Ferdinand
Published: August 2024

Deep gray matter (DGM) iron dyshomeostasis has been linked to neuroinflammation in multiple sclerosis (MS). In the present work, we hypothesized that a novel correlation analysis of magnetic susceptibility co-fluctuations between DGM regions reveals short-term (<1 year) MS-related iron dyshomeostasis that is undetectable with conventional ROI-based methods. Our results showed the correlations-based analysis was more sensitive to MS vs HC group differences than the standard ROI-based approach. A simulation indicated that the MS-related differences may be due to neuroinflammatory-based disruption to normal aging-related iron accumulation. Our methodology may be applied to study neuroinflammatory diseases at short timescales not previously possible.
MUSE reconstruction of multishot DW-EPI is not limited by SNR at 0.5T
Authors: Klassen Ally , Rioux James , Bowen Chris , Wiens Curtis , Clarke Sharon , Beyea Steven
Published: August 2024

Multi-shot echo planar imaging (EPI) can be used to reduce spatial distortion and improve spatial resolution in diffusion-weighted imaging; however, patient motion between shots can result in large intra-shot phase differences and increased artifact. It is unknown whether multiplexed sensitivity encoding (MUSE) can be applied to reduce these phase differences in DW-EPI images acquired at low field due to the inherently lower SNR. In this work we evaluate the performance of MUSE in DW-EPI data acquired at 0.5T, in terms of SNR and ghost-to-noise ratio (GNR) as a function of signal averaging, and demonstrate that multi-shot DW-EPI is feasible.
Multi-echo Diffusion-weighted Imaging for Quantifying Luminal Water Fraction in the Prostate
Authors: Sun Kaibao , Dan Guangyu , Karaman Muge , Luo Qingfei , Zhou Xiaohong Joe
Published: August 2024

Prostate cancer remains one of the leading causes of cancer-related deaths in men. Reduced luminal water fraction has been observed in prostate cancer using diffusion MRI, but the image acquisition takes a long time. We herein introduce a multi-echo DWI sequence that is capable of quantifying luminal water fraction with a substantially improved time efficiency. The sequence incorporated multiple readout echo-trains into diffusion-weighted EPI, together with a 2D RF excitation pulse to reduce the FOV, thereby enabling multiple TEs in one shot. With this sequence, we have evaluated the volume fractions of lumen and non-lumen tissues in the human prostate.
Comparison of dynamic B0 mapping approaches at 7T – AI-based prediction via U-net vs measurement via dual-echo EPI navigator
Authors: Motyka Stanislav , Weiser Paul , Strasser Bernhard , Goranovic Dario , Hingerl Lukas , Hangel Gilbert , Niess Eva , Wampl Stephan , Niess Fabian , Robinson Simon , Langs Georg , Trattnig Siegfried , Bogner Wolfgang
Published: August 2024

The abstract compares two approaches to dynamically estimate B0 maps at 7T. The U-net predicts B0 maps based on the initial B0 map and the movement information. The dual-echo EPI-based navigator directly measures B0 maps. Both methods yield comparable results. However, the deep learning approach could overcome the major disadvantage of the EPI-based navigator, thus the need for the dead time in the parent sequence, if the motion can be mapped externally.
IVIM-DWI for the preoperative prediction of perineural invasion status in rectal cancer: A feasibility study with multivariate model analysis
Authors: Yuping Jia , Weiqiang Dou
Published: August 2024

This study aimed to determine the clinical potential of intravoxel incoherent motion (IVIM) DWI in predicting perineural invasion (PNI) of rectal cancer (RC). IVIM parameters derived from different mathematical models, including apparent diffusion coefficient from mono-exponential model, true diffusion coefficientand and perfusion fraction from bi-exponential model, and the distributed diffusion coefficient from stretched-exponential model showed significant differences between 72 with PNI and 76 without PNI. With these findings, IVIM may thus be considered effective in preoperatively predicting PNI status in RC and further help clinicians make individual treatment plans.
MRI-movienet: fast motion-resolved 4D MRI reconstruction exploiting space-time-coil correlations without k-space data consistency
Authors: Murray Victor , Siddiq Syed , Jafari Ramin , Wu Can , Otazo Ricardo
Published: August 2024

Motion-resolved 4D MRI enables free-breathing imaging and access to important physiological information. However, long reconstruction times for 4D MRI techniques like XD-GRASP have restricted routine clinical use. Even with unrolled convolutional networks, reconstruction enforcing data consistency in a high-dimensional space is still long. This work presents a deep learning approach named MRI-movienet that exploits spatial-time-coil correlations without enforcing data consistency to enable 2-fold scan acceleration compared to XD-GRASP and 4D reconstruction in less than 2 seconds. MRI-movienet uses the intrinsic separation into static and dynamic components to avoid hallucinations. MRI-movienet high performance will promote 4D MRI for routine clinical use.
Diffusion abnormalities linked to brain arteriolosclerosis: An in-vivo MRI and pathology study in community-based older adults
Authors: Tomash Ana , Tazwar Mahir , Yasar Md Tahmid , Zhang Shengwei , Evia Arnold , Bennett David , Schneider Julie , Arfanakis Konstantinos
Published: August 2024

Brain arteriolosclerosis is one of the main pathologies of cerebral small vessel disease, is common in older adults, and is associated with lower cognitive and motor function and higher odds of dementia. This work combined in-vivo MRI and pathology in a community-cohort of older adults to investigate the independent association of brain arteriolosclerosis with diffusion abnormalities in white matter. Brain arteriolosclerosis was shown to be associated with lower FA and higher trace of the diffusion tensor that extended throughout white matter, and these associations were independent of the effects of other neuropathologies or white matter hyperintensities.
MRI Detection of Glymphatic Function in athletes after Sports-related Concussion
Authors: Ma Laiyang , Hu Wanjun , Zhang Jing , Huang Wenjing , Xiong Yuhui
Published: August 2024

Diffusion tensor image analysis along the perivascular space (DTI-ALPS) as a non-invasive method for evaluating the activity of the glymphatic system in human brain by using diffusion images. In this study, DTI-ALPS was used to evaluate the activity of the human lymphatic system in patients with Sports-related concussion (SRC). We found SRC has a higher ALPS index compared to the healthy controls. Our findings suggested that abnormal glymphatic function in brain might be a potential biomarker for explaining the cognitive function decline of SRC.
Phase-Based Registration for Visualisation of Pulsatile Brain Motion
Authors: Laven Robin , Richardson Sam , Hidalgo Nadine , Sasis Dale Justin , Kwon Eryn , Holdsworth Samantha , Nielsen Poul
Published: August 2024

Pulsatile brain motion is a valuable tool in understanding injury and congenital disorders. These pulsatile motions have a typical magnitude of < 1 pixel. Amplified MRI (aMRI) amplifies the pulsatile motion to the point of visibility, enabling qualitative examination. However, the amplification in frequency space results in nonlinear distortion of motion preventing the recovery of unaugmented displacements. Here, we propose using phase-based subpixel registration. This methodology enables the recovery of displacement quantification of pulsatile brain motion.
The value of Cinematic Volume Rendering Technique: magnetic resonance imaging in diagnosing tumors around the brachial plexus
Authors: Chen Rui , Ran Yuncai , Niu Junxia , Wu Yanglei , Zhang Yong , Cheng Jingliang
Published: August 2024

Cinematic Volume Rendering Technique (cVRT) can clearly display the contours of the tumor, brachial plexus, and peripheral blood vessels, and the extent of their involvement while simultaneously imaging them. The three-dimensional anatomical effect is more realistic, playing a direct role in guiding the surgical plan.
Improved NORDIC denoising for submillimetre BOLD fMRI using patch formation via non-local pixels similarity - pixel-matching (PM) NORDIC
Authors: Nigi Alessandro , Siero Jeroen
Published: August 2024

Submillimetre BOLD fMRI enables studying brain function at the mesoscopic level but is limited by low SNR. The NORDIC PCA algorithm reduces thermal noise levels in fMRI in a patch-wise manner via singular value thresholding (SVT). However, the NORDIC patch formation uses adjacent pixels that often contain signals from multiple tissues, which can degrade the denoising performance. We propose an alternative patch formation using the similarity between non-local pixels, dubbed pixel-matching (PM) NORDIC. PM-NORDIC outperforms standard NORDIC in terms of temporal SNR and spatial smoothness estimates.
Reconstruction of High-Resolution Metabolite Maps from Noisy MRSI Data by Incorporating Spatiospectral Constraints through Learned Kernels
Authors: Li Yudu , Ma Chao , Luo Shirui , Jin Wen , Liu Ruihao , Fakhri Georges , Li Yao , Jaromin Maria , Kindratenko Volodymyr , Sutton Brad , Liang Zhi-Pei
Published: August 2024

High-resolution MR spectroscopic imaging (MRSI) suffers from very low signal-to-noise ratio, which is often addressed using a priori information/constraints. Existing constrained reconstruction methods utilize spectral constraints in the form of spectral subspaces/manifolds, while impose spatial constraints though spatial regularization. This paper presents a novel kernel-based partial separability model for reconstruction of high-resolution of metabolite maps from noisy MRSI data. The proposed model uses spectral basis functions to absorb spectral prior and a learned kernel function to absorb spatial prior. Experimental results demonstrated very encouraging reconstruction performance.
Real-time MRI using deep learning in gastroesophageal reflux disease: a feasibility study
Authors: Liu Qing , Liu Qi , Li Jing , Chen Eric , Zhang Zhongqi , Chen Xiao , Sun Shanhui , Xu Jian , Sun Haoran
Published: August 2024

A real-time MRI technique is developed using deep-learning reconstruction. Its feasibility is evaluated in both healthy subjects and patients with gastroesophageal reflux diseases.
Slice Level 3D Motion Tracking For Motion Corrected IVIM DW-MRI In Crohn’s Disease
Authors: VASYLECHKO SERGE , LU LINA , ARIYUREK CEMRE , PEREZ-ROSSELLO JEANNETTE , CALLAHAN MICHAEL , AFACAN ONUR , KURUGOL SILA
Published: August 2024

Diffusion-weighted MRI is increasingly used for detection and characterization of Crohn’s disease. However, unavoidable respiratory motion and bowel motility reduces accuracy and precision of quantitative parameter fitting, which hinders clinical applicability DW-MRI. We use a 3D slice-to-volume registration approach that sequentially tracks rigid motion parameters for each slice and regularises the parameters with a Kalman filter in the order of acquisition of each slice. We assess the quality of images and estimated parameter maps and the precision of IVIM parameters in the areas of disease using the proposed motion correction technique, and compare them with results from the uncorrected data.
A Pretrained CNN Model Using Multiparametric MRI to Identify WHO Tumor Grade of Meningiomas
Authors: Azamat Sena , Buz-Yaluğ Buse , Ozcan Alpay , Danyeli Ayça Ersen , Pamir Necmettin , Dinçer Alp , Ozduman Koray , Ozturk-Isik Esin
Published: August 2024

Meningiomas are the most common primary extra-axial intracranial tumors in adults. Grade of meningioma helps to predict the patient prognosis. Sixty-two patients with preoperative MRI were included in this IRB approved study. The whole tumor volumes were segmented from FLAIR, followed by co-registration onto SWI. A pretrained convolutional neural network (CNN) was employed to classify meningiomas into high and low-grades based on SWI, CE-T1W and FLAIR MRI. The pretrained CNN with data augmentation resulted in an accuracy of 80.2% (sensitivity=82.6% and specificity=78.1%) for identifying grades in meningiomas.
Multiphoton Simultaneous Multislice Imaging with CAIPIRINHA Phase Encoding
Authors: Ipek Tanya Deniz , Han Victor , Liu Chunlei
Published: August 2024

Simultaneous multislice (SMS) imaging methods reduce scan time but increase specific absorption rate (SAR) because of additional radiofrequency (RF) pulses required for exciting multiple slices. Multiphoton excitation was recently proposed to significantly reduce SAR for SMS imaging. In this work, we further developed a phase-modulated multiphoton SMS excitation method that achieves CAIPIRINHA-type controlled aliasing, which improves image reconstruction quality significantly. Images obtained with our custom multiphoton CAIPIRINHA-SMS sequence have reduced aliasing artifacts and higher SNR compared to images obtained with a multiphoton SMS sequence without CAIPIRINHA. For a three-slice design, SAR is reduced by a factor of two.
Multi-echo RF spatial phase encoding for gradient-free imaging in a nonuniform B0-field at low-field
Authors: Selvaganesan Kartiga , Ha Yonghyun , Sun Chenhao , Samardzija Anja , Zhang Zhehong , Sun Heng , Galiana Gigi , Constable Todd
Published: August 2024

The cost and complexity of MR scanners can be significantly reduced by eliminating conventional linear gradient coils, and instead using RF coils for spatial encoding. Here we have developed a novel multi-echo RF phase encoding pulse sequence that exploits the Bloch-Siegert shift for nonlinear spatial encoding in a nonuniform, field-cycling, low-field MR system. Phantoms of varying sizes were successfully imaged using this pulse sequence, demonstrating that this technique can be used to perform gradient-free imaging in an inhomogeneous B0-field at low-field.
MR-double-zero in vivo: Model-free and live MRI contrast optimization running a loop over a real scanner with a real subject.
Authors: Mueller Sebastian , Glang Felix , Scheffler Klaus , Zaiss Moritz
Published: August 2024

Recently, we proposed a framework for automatized, model-free MR sequence design for contrast generation. The concept was proven by optimizing the contrast-generating sequence using a real MRI scanner for scanning model solutions repeatedly until convergence to the target. In this work, we demonstrate for the first time that this live optimization loop can also be used directly on a real subject’s brain. As an example, GM/WM contrast for a GRE sequence was optimized fully automatically in a model-free and reference-free manner live in a healthy subject at a 3T MR scanner.
Highly-Accelerated Real-Time Myocardial Tagging for Exercise CMR at 3T
Authors: Morales Manuel , Yoon Siyeop , Fahmy Ahmed , Rodriguez Jennifer , Herzka Daniel , Manning Warren , Nezafat Reza
Published: August 2024

Combined cardiac MRI and exercise (Ex-CMR) is a stress imaging test with promising applications in cardiovascular disease (CVD). Ex-CMR myocardial tagging could provide insights into myocardial deformation post-exercise. We sought to develop an SSFP-based highly-accelerate (12-fold) free-breathing ECG-free real time tagging sequence for quantification of beat-to-beat variation of myocardial deformation at rest and after exercise. The proposed real time sequence achieved a spatiotemporal resolution of 2 x 2 mm2 and 27.6 ms. Feasibility of real time imaging at 3T post-exercise was demonstrated in patients with heart failure with preserved (HFpEF) and reduced (HFrEF) ejection fraction.
Real Time Cardiovascular MR During Exercise in Heart Failure with Preserved Ejection Fraction (HFpEF)
Authors: Seiter Daniel , Corrado Philip , Raza Farhan , Wieben Oliver
Published: August 2024

Right heart catheterization during exercise is the current gold standard for diagnosis of heart failure with preserved ejection fraction (HFpEF) but carries the risk of an invasive procedure. In this work, we present preliminary data using real time cardiac magnetic resonance imaging during exercise in a HFpEF cohort with comparison to healthy controls.
Intra- and inter-session reliability of lumbar spinal cord resting-state fMRI
Authors: Combes Anna , Sweeney Grace , Houston Delaney , Prock Logan , Narisetti Lipika , Rogers Baxter , McKnight Colin , Gore John , Smith Seth , O'Grady Kristin
Published: August 2024

We investigated the intra- and inter-session reliability of functional connectivity indices derived from resting-state fMRI in the lumbar spinal cord. Slicewise and average indices of connectivity for the ventral and dorsal networks were collected across three experiments in healthy participants at 3T. Intra-session reliability was high for back-to-back scans (ICC>0.9), and moderate-to-good when introducing repositioning, surveying and reshimming (COV=3-25%). Repeatability of indices across separate visits was low, although similar grey matter functional networks could be independently observed and showed high spatial overlap using ICA, a data-driven approach. This is the first evaluation of resting-state fMRI reliability in the lumbar cord.
Application of multi-shot EPI to mitigate image distortion in diffusion tensor imaging of the human lumbar spinal cord
Authors: O'Grady Kristin , Seehorn Caroline , Sweeney Grace , Prock Logan , Houston Delaney , Combes Anna , Schilling Kurt , McKnight Colin , Robison Ryan , Smith Seth
Published: August 2024

The lumbar spinal cord is significantly understudied with quantitative MRI methods such as diffusion tensor imaging (DTI), in part due to challenges of spatial and temporally-varying field inhomogeneities that cause distortion in commonly used single-shot EPI sequences. In this pilot study, we implemented IRIS Zoom, a multi-shot, reduced field-of-view method that corrects for shot-to-shot variations, phase errors (2D navigation), and T2* dephasing. Multi-shot EPI was successfully acquired in healthy volunteers at 3T, led to reduced geometric distortions, and provided quantitative DTI values comparable to those derived from single-shot EPI. Multi-shot EPI is feasible for high-resolution DTI of the lumbar cord.
Realizing sub-second and sub-millimeter spinal cord fMRI at 7 Tesla
Authors: Rangaprakash D , Barry Robert
Published: August 2024

Spinal cord fMRI is an emerging field with clinical potential. Sub-millimeter in-plane fMRI acquisitions are desirable and achievable, but published studies have had modest temporal resolutions (>2s). Using a custom-built 7T spine coil, we demonstrate sub-second and sub-millimeter cervical cord fMRI for the first time. Employing a 3D multi-shot sequence with appropriate phase corrections and NORDIC denoising, our data demonstrated temporal signal-to-noise ratios similar to those of standard supra-second protocols, and we replicated functional connectivity patterns previously published in the cord. This opens new avenues of discovery similar to those realized through high spatiotemporal resolution brain fMRI.
Diffusion MRI reveals rescue of structural changes in a mouse model of Huntington’s disease by mutant Huntingtin lowering
Authors: van Rijswijk Joëlle , Vidas-Guscic Nicholas , Van Audekerke Johan , Vasilkovska Tamara , Pustina Dorian , Tang Haiying , Cachope Roger , Marchionini Deanna , Munoz-Sanjuan Ignacio , Van der Linden Annemie , Adhikari Mohit , Verhoye Marleen
Published: August 2024

Huntington’s disease (HD) is a neurodegenerative disorder for which no cure is available. There is an urgent need to find early biomarkers which are sensitive enough to determine and follow up the efficacy of novel therapies. In this study, we present the outcome of a treatment study in the LacQ140 HD mouse model using diffusion tensor/kurtosis imaging (DTI/DKI) and fixel-based analysis (FBA). We observed that early, moderate lowering of mutant Huntingtin (mHtt) rescues structural alterations measured in this mouse model with diffusion MRI in the olfactory bulb and striatum, which are prominent regions affected in HD.
Brain and cervical spinal cord myelination and age-related changes in adulthood: a preliminary study based on ihMTsat and T1 relaxometry mapping
Authors: Forodighasemabadi Arash , Soustelle Lucas , Girard Olivier , Troalen Thomas , Ranjeva Jean-Philippe , Duhamel Guillaume , Callot Virginie
Published: August 2024

Inhomogeneous Magnetization Transfer (ihMT) has shown to be a biomarker of myelin with enhanced specificity as compared to conventional MT. To compensate for B1+ and T1 effects, a 3D ihMT-RAGE sequence with an ihMTsat framework has recently been proposed. In this study, ihMTsat was used in combination with an optimized MP2RAGE sequence to study both brain and spinal cord adulthood aging process. The ihMTsat and R1=1/T1 metrics followed an inverse U-shaped evolution with age in different ROIs, from which a maturation age was extracted. A multiparametric (R1,ihMTsat) voxel-wise analysis revealed significant age effect in the microstructure of different cord tracts.
Comparison of measured and simulated cardiac magnetostimulation thresholds in eight pigs
Authors: Klein Valerie , Vendramini Livia , Davids Mathias , Ferris Natalie , Schad Lothar , Sosnovik David , Nguyen Christopher , Wald Lawrence , Guérin Bastien
Published: August 2024

We use a combined electromagnetic-electrophysiological modeling framework to predict cardiac stimulation (CS) thresholds in individualized porcine body models and compare those simulations to thresholds measured in eight pigs using strong dB/dt pulses. For all pigs, the simulated and measured thresholds agree within 30%, and no significant differences between simulations and measurements were detected (p<0.05, paired t-test). The threshold model uncertainty was found to be ~25% in a sensitivity analysis of the relevant model parameters. A well-validated model may help inform appropriate safety limits for MRI gradients to protect patients from CS without overly restricting gradient performance.
Simulated radiation patterns of MRI without a shielded room from 0.5 to 7 Tesla
Authors: Kazemivalipour Ehsan , Guerin Bastien , Wald Lawrence
Published: August 2024

Far-field electromagnetic radiation patterns and levels were simulated on the 10m radius regulatory sphere for conventional MRI scanners at 0.5T, 1.5T, 3T, and 7T operated without an RF shielded room. The levels and patterns were strongly affected by the symmetry of the load. With a body load, the peak E-fields on a 10m radius surface rose with roughly the square of the frequency and far exceeded regulatory limits even for 0.5T. With the body in the bore, the radiated patterns also take on a highly asymmetric pattern not present for more symmetric loads.
Minimum Electric Field Gradient Array Body Coil with Adjustable Regions of Linearity
Authors: Babaloo Reza , Takrimi Manouchehr , Atalar Ergin
Published: August 2024

A large region of linearity in whole-body gradient coils exposes large body areas to switching magnetic fields, inducing high electric fields, which may cause peripheral nerve stimulation. A body gradient array coil (made up of multiple coil elements) can produce linear gradients in different region of linearity shapes by optimizing the feeding currents, which can minimize the induced E-fields.
A method to assess the orientation of the maximum heating of an arbitrarily shaped object inside a homogeneous magnetic field
Authors: Zanovello Umberto , Chiampi Mario , Bottauscio Oriano , Arduino Alessandro , Zilberti Luca
Published: August 2024

The ISO/TS 10974 standard proposes a test method to assess the heating of a metallic AIMD due to switched gradient magnetic fields. Aiming at achieving a conservative evaluation, the standard suggests to evaluate the heating for the worst orientation of the AIMD inside a homogeneous harmonic magnetic field. The abstract presents a strategy to assess this orientation for an arbitrarily shaped metallic object. The strategy has been successfully tested numerically against expectations with a disk object and it has been applied to a realistic hip and knee implant.
A geometrical approach to rapidly evaluate and optimize pTx transmission vectors for imaging and RF safety of implants
Authors: Silemek Berk , Seifert Frank , Ittermann Bernd , Winter Lukas
Published: August 2024

A simple geometrical approach is presented to rapidly calculate safe pTx excitation vectors for implants, while further optimizing imaging performance. The proposed approach does not require any additional imaging protocols to be performed and pTx vector optimizations can be calculated solely e.g. based on low-cost sensors embedded in implants. The methodology was tested on a custom-built sensor-equipped wireless implant in 3T MRI experiments and realistic DBS lead configurations.
Characterisation of laminar spatiotemporal dynamics of CBV and BOLD signals using fast sampling at 7T fMRI in humans
Authors: Dresbach Sebastian , Huber Renzo , Gulban Omer , Pizzuti Alessandra , Trampel Robert , Ivanov Dimo , Goebel Rainer , Weiskopf Nikolaus
Published: August 2024

Characterisation of cortical laminar activity requires detailed knowledge of the spatiotemporal haemodynamic response across vascular compartments. Additionally, laminar models of the BOLD-response are dependent on CBF and CBV responses to neural activity. Therefore, we characterised the depth-dependent CBV- and BOLD-haemodynamic responses across varying stimulus durations with 0.9mm spatial, 0.785s effective temporal resolution. Furthermore, we obtained fine-scale vascular details using ME-GRE data at 0.35mm to investigate signal contributions from different vascular compartments. Our results contribute to the understanding of the laminar VASO response, provide guidance for neuroscientific applications, and support modelling of the laminar haemodynamic responses in humans.
Evaluation of an accelerated Deep Learning-reconstructed T2 mapping technique through knee cartilage regional analysis using DOSMA framework
Authors: Gómez Laura Carretero , Fung Maggie , Nunes Bruno , Pedoia Valentina , Majumdar Sharmila , Chaudhari Akshay , Desai Arjun , Gatti Anthony , Kogan Feliks , Padron Mario
Published: August 2024

The clinical translation of MRI Quantitative Imaging is still hampered by the high variability and suboptimal reproducibility of the cartilage biomarkers. The purpose of this work is to validate the consistency of a novel accelerated DL reconstructed T2 mapping technique compared to conventional reconstructed acquisition, on knee patient population. To access both femoral cartilage T2 maps, we propose a semi-automatic workflow through AI-based cartilage segmentation and regional quantification using DOSMA framework. Relaxometry analysis showed no difference between both T2 mapping techniques, implying a great step into an extensive clinical adoption.
Unraveling Bone Marrow Adipose Tissue Composition Through 3T Deep Learning Chemical Shift Encoded-MRI
Authors: Martel Dimitri , Leporq Benjamin , Monga Anmol , Honig Stephen , Chang Gregory
Published: August 2024

Chemical Shift Encoded (CSE) MRI method has been used to highlight subregional differences in the femoral bone marrow in terms of fatty acids composition in proximal femur, suggesting an important role of the marrow in bone quality. This method requires a certain number of echoes (3 for fat/water separation and >8 for fatty acids mapping). Deep Learning (DL) has been recently applied to accelerate, improve the quality and efficiency for fat/water separation in CSE-MRI. Our aim was to develop a DL-CSE method and evaluate it for fatty acids composition mapping; using different echo numbers.
Self-supervised T1 Mapping from Two Variable Flip Angle Images without Requiring Ground Truth T1 Maps
Authors: Wu Yan , Ma Yajun , Li Zhitao , Du Jiang , Pauly John , Vasanawala Shreyas
Published: August 2024

We propose a self-supervised learning method that derives T1 map from a reduced number of variable flip angle images without requiring ground truth maps, aimed at minimizing data acquisition efforts for obtaining training and testing data.
Functional Connectivity of the Cerebellar Vermis in Bipolar Disorder
Authors: Magnotta Vincent , Saleem Arshaq , Harmata Gail , Jain Shivangi , Voss Michelle , Fiedorowicz Jess , Williams Aislinn , Shaffer Joseph , Richards Jenny , Barsotti Ercole , Sathyaputri Leela , Schmitz Samantha , Christensen Gary , Long Jeffrey , Xu Jia , Wemmie John
Published: August 2024

This study used resting state functional connectivity to study connectivity of the cerebellar vermis with the cerebrum in bipolar disorder.
Glymphatic system dysfunction in Primary Insomnia evidenced by diffusion tensor imaging with the perivascular space (DTI-ALPS)
Authors: Jin Yu , Zhang Xiaoyong , Ding Xin , Chen Guangwen
Published: August 2024

Sleep has been hypothesized to assist waste clearance from the brain. We aimed to determine whether primary insomnia is associated with glymphatic system dysfunction by using diffusion tensor imaging (DTI) with the perivascular space (DTI-ALPS), a potential marker of impaired brain waste clearance. In this study, we found that the DTI-ALPS in patients with primary insomnia was significantly lower than in healthy controls and the DTI-ALPS index was significantly negatively correlated with neuropsychological performance score. The results suggests that DTI-ALPS may be a useful imaging tool for studying glymphatic system function with primary insomnia.
High Fat Diet Induced Cerebrovascular Pathology and Immune Cell Recruitment: A MRI Guided Histology Study
Authors: Liu Li , Hunt Ryan , Rallapalli Hari , Pothayee Nikorn , Dodd Stephen , Bouraoud Nadia , Maric Dragan , Zabow Gary , Koretsky Alan
Published: August 2024

High fat diet (HFD) causes chronic low-grade inflammation and is associated with an increased risk of cerebrovascular pathology and neurodegenerative disorders. Hypothalamus can sense peripheral signals and has been the major focus of HFD induced neuroinflammation. This work aims to study the activation of BBB endothelial cells, immune cell infiltration, and brain cell inflammation in the whole brain in real time caused by short-term HFD. Molecular MRI, using a new ultrahigh moment microfabricated gold-iron micro-disc, provides non-invasive guidance to the histology study. Our data indicate that HFD causes neuroinflammation in a remarkably short time in many structures of brain.
Imaging the perivascular and cerebrospinal fluid spaces in TgF344-AD rats using ultra-long echo time MRI
Authors: Kozár Martin , Parkes Laura , Boutin Hervé , Chernyavsky Igor , Dickie Ben
Published: August 2024

Enlargement of perivascular and ventricular spaces are associated with neuroinflammation in neurodegenerative diseases, including cerebral small vessel disease and Alzheimer’s disease. In this study we develop methodology for measuring the anatomy of the perivascular space around the anterior cerebral artery and partial-volume-free estimates of total CSF volume and apply this approach to TgF344-AD rats. Neither the area under the curve of perivascular space profiles, nor overall width of the perivascular space, or the total CSF volume differed between TgF344-AD rats and wild-types.