bluuebunny/crossref_metadata_2025 huggingface dataset:
Medical Image Registration Using Deep Learning Techniques Applied to Pediatric Magnetic Resonance Imaging (MRI) Brain Scans
Authors: Dimitrijevic Andjela , Noblet Vincent , De Leener Benjamin
Published: August 2023

Deep learning techniques have a potential in allowing fast deformable registration tasks. Studies around registration often focus on adult populations, even if there is a need for pediatric research where less data and studies are being produced. In this study, we compared three methods for intra-subject registration on publicly available Calgary Preschool dataset. Using the DeepReg framework, pre-registering with a rigid and affine transformation (proposed RigidAffineReg method) showed the least negative JD values and the highest Dice score (0.924±0.045). By achieving faster alignments, this tool for pediatric MRI scans could help proliferate larger scale population research in brain developmental studies.
EPI Nyquist Ghost Artifact Correction for Brain Diffusion Weighted Imaging (DWI) using Deep Learning
Authors: Sattar Fatima , Ahsan Sadia , Aamir Fariha , Aslam Ibtisam , Shahzadi Iram , Omer Hammad
Published: August 2023

Echo-planar imaging suffers from Nyquist ghost (i.e., N/2 ghost) artifacts because of poor system gradients and delays. Many conventional methods have been used in literature to remove N/2 artifacts in Diffusion Weighted Imaging (DWI) but often produce erroneous results. This paper presents a deep learning approach to eliminate the phase error of k-space for removing the Nyquist ghost artifacts in DWI. Experimental results show successful removal of the ghost artifacts with improved SNR and reconstruction quality with the proposed method.
Artificially-generated Consolidations and Balanced Augmentation increase Performance of U-Net for Lung Parenchyma Segmentation on MR Images
Authors: Crisosto Cristian , Voskrebenzev Andreas , Gutberlet Marcel , Klimeš Filip , Kaireit Till , Pöhler Gesa , Alsady Tawfik , Behrendt Lea , Müller Robin , Zubke Maximilian , Wacker Frank , Vogel-Claussen Jens
Published: August 2023

Accurate fully automated lung segmentation is needed to facilitate Fourier-Decomposition employment-based techniques in clinical routine among different centers. However, the lung parenchyma segmentation remains challenging for convolutional neural networks (CNN) when consolidations are present. To improve training balanced augmentation (BA) and artificially-generated consolidations (AGC) were introduced. The proposed CNN was compared to conventional CNNs without BA and AGC using Sørensen-Dice coefficient (SDC) and Hausdorff coefficient (HD). The SDC / HD of the proposed model is significantly higher (p of 0.0001 and p of 0.0146 / p of 0.0009 and p of 0.0152) when compared to CNNs without BA and AGC.
Development of a Quantitative Susceptibility Mapping (QSM) phantom for validation of acquisition strategies and post-processing tools at 3 T
Authors: Hooper Padriac , Tourell Monique , O'Brien Kieran , Jin Jin , Robinson Simon , Barth Markus
Published: August 2023

The phantom was developed to cover the full range of physiological and pathological magnetic susceptibility seen in iron- and calcium-containing tissue, using 4 materials within the one phantom. The phantom facilitates quality assurance for acquisition strategies and post-processing tools.
PedQ-NET : Unsupervised Model-Based Joint-Loss Deep learning for Pediatric QSM
Authors: Jung Siyun , Jeon Soohyun , Nam Yoonho , Kim Hyun Gi , Kim Dong-Hyun
Published: August 2023

In conventional QSM methods, it is difficult to analyze gray matter subcortical in pediatrics, because of small contrast difference between gray matter and white matter. In addition, there are no deep learning approaches that reflect the characteristics of the pediatric brain. In this study, we propose an unsupervised model-based joint-loss deep learning network for pediatric QSM, PedQ-NET. The proposed method achieved better edge preservation on the deep gray matter subcortical areas in pediatric QSM. According to the evaluation of in-vivo pediatric data, QSM generated by PedQ-NET shows enhanced edges in the subcortical areas and clear details with reduced artifacts.
Realistic in silico abdominal QSM phantom
Authors: Silva Javier , Milovic Carlos , Lambert Mathias , Montalba Cristian , Arrieta Cristobal , Uribe Sergio , Tejos Cristian
Published: August 2023

Compared to Quantitative Susceptibility Mapping (QSM) in the brain, abdominal QSM faces additional issues due to the presence of gas and fatty tissue. Recent works in abdominal QSM are more focused on its feasibility as a biomarker for disease diagnosis than improving or assessing the robustness and quality of the reconstructions. In this work, we present an abdominal QSM phantom with realistic tissue textures. Our flexible simulation pipeline allows emulating different stages of diseases and MRI signal contributions. Our reconstruction experiments show the potential of our phantom to compare QSM algorithms in different scenarios.
Development of an image reconstruction algorithm to assess brain oxygenation in neonatal asphyxia using quantitative susceptibility mapping
Authors: Ridani Daniel , Ducros-Chabot Noée , Dehaes Mathieu , De-Leener Benjamin
Published: August 2023

Neonatal asphyxia is a condition that causes lack of oxygen in the infant brain which lead to adverse neurodevelopmental outcomes. MRI provides a very clear image of the brain which lead to a detection of a variety of brain abnormalities. Quantitative susceptibility mapping (QSM) is a MRI tool to quantify brain oxygenation. In this study, we developed QSM reconstruction algorithms and tested them in data acquired in patients following neonatal asphyxia. Results include the comparison of five methods to generate QSM images in the brain specific segmented regions. Our preliminary data suggest that image intensity depends on the reconstruction method.
Pentafluorosulfanyl (SF5) is a Superior 19F Magnetic Resonance Reporter Group: Signal Detection of Teriflunomide Derivatives
Authors: Jacob Ashrith , Starke Ludger , Prinz Christian , Millward Jason , Delgado Paula , Fillmer Ariane , Niendorf Thoralf , Waiczies Sonia
Published: August 2023

Modifications to the CF3 side-group of teriflunomide were made to improve its detection by 19F MRI. Pentafluorosulfanyl (SF5) was shown to be a superior alternative to CF3. The SNR efficiency of three 19F MRI methods showed that within a biological environment, SF5-substitutions gave the highest SNR efficiency in combination with an ultrashort echo-time (UTE) MRI method. Chemical modifications did not hamper biological activity but SF5-TF was more effective to inhibit T cell proliferation, indicating better anti-inflammatory activity. This study proposes SF5 as a novel superior 19F MR reporter group for the drug teriflunomide.
GlucoCEST under the influence of head motion at 3 T: A numerical head phantom
Authors: Lehmann Patrick , Andersen Mads , Seidemo Anina , Xu Xiang , Li Xu , Yadav Nirbhay , Wirestam Ronnie , Liebig Patrick , Testud Frederik , Sundgren Pia , van Zijl Peter , Knutsson Linda
Published: August 2023

D-glucose is proposed as a cheap biodegradable alternative to gadolinium-based contrast agents. By performing glucoCEST imaging during and after administration of glucose, an approach referred to as dynamic glucose-enhanced (DGE) MRI, information about glucose delivery and uptake can be obtained. However, the small DGE signal changes at 3 T can easily be corrupted by motion. Furthermore, standard retrospective motion correction may erroneously alter true DGE signal, which may lead to misinterpretation. We designed a numerical head phantom that can be used for validation of motion correction and providing insight into the corresponding effects in vivo.
Automated tuning of gate driver circuit using eGaN FETs
Authors: Gudino Natalia
Published: August 2023

An automated tuning of the dual resonance LC network that forms the gate driver circuitry of a dual tuned RFPA is presented. Through this automated tuning the RFPA could be adapted from the control to operate at the selected 1H and X-nucleus frequencies.
Design of a Miniaturized High Impedance Preamplifier for 7T MRI
Authors: Almokdad Saadou , Gapais Paul-François , Luong Michel , Amadon Alexis , Georget Elodie , GIACOMINI Eric
Published: August 2023

Coil arrays enhance human body performance for an MRI measurement both in speed and signal-to-noise ratio. However, size and cabling of such arrays can deteriorate the performance of the imaging, or put at risk the safety of the patient. A miniaturized preamplifier is proposed (dimensions 24mm x 11mm), to be placed directly onto the receive coil. The design needs to preserve a good performance (noise figure ≤ 1dB, gain ≈ 28dB), and provide high impedance to minimize the coupling to nearby coils.
Compatibility of a 3D Time-of-Flight Video Camera for Motion Capture with a 0.55T MRI System
Authors: Brantner Douglas , Pancoast Leanna , Walczyk Jerzy , Wiggins Roy , Brown Ryan , Collins Christopher
Published: August 2023

We evaluated compatibility of a 3D Time-of-Flight (ToF) video camera with a 0.55T MRI system. Initial tests showed severe MR image artifacts when the ToF camera was operating, and USB communication with a computer outside the MR suite was interrupted during MR image acquisition. With adequate conductive shielding of the ToF camera and typical MR imaging bandwidths, MR images could be acquired with no measurable effects from the ToF camera, and with no effects of the MRI system on ToF signal acquisition.
3D MRI characterization of 3D printed tumor tissue models using a plastronic MR-Bioreactor : Preliminary results
Authors: Gnanago Jean-Lynce , Gerges Tony , Chastagnier Laura , Petiot Emma , Semet Vincent , Lombard Philippe , Marquette Christophe , Cabrera Michel , Lambert Simon
Published: August 2023

Tissue engineering for regenerative medicine have been developing for a few decades now and the number of applications is increasing to tackle the shortage of organ donors. To date, only few systems can allow both monitoring and 3D characterization of tissue constructs during their growth. In this study, we decided to focus on following the Apparent Diffusion Coefficient (ADC) known to be a marker of cell density and built a MR-Bioreactor to probe the ADC of a growing tissue. In this preliminary work, we were able to follow the cell density of a tumor tissue model using our dedicated MR-bioreactor.
Assessing Universal Code Compression to Lower Wireless MRI Data Rates
Authors: Scott Greig
Published: August 2023

For wireless MRI data links employing simple ASK or DPSK binary modulation, there is a need to compress the k-space data to lower data rates and use less spectral bandwidth. We explored Fibonacci and Exp-Golomb universal codes for lossless compression. Our results indicate that compression can reduce rates to 1/3 to 1/4 of the original levels. Actual compression will depend on signal gain, as well as k-space trajectories. These results suggest the development of an MRI codec for future wireless or fiber optic RF coil array data links.
Novel Compact Dual-Band E-Field Generator for MR Safety Testing of Active Implantable Medical Devices
Authors: Kranold Lena , Capstick Myles , Goren Tolga , Kuster Niels
Published: August 2023

A compact dual-band E-field generator for MRI implant safety testing has been developed to produce diverse, well-defined tangential incident E-fields along defined implant test routings for efficient validation of the transfer function of AIMD. The MITS medical implant test system consists of two pairs of electrodes whose relative amplitude and phase are controlled to create E-field conditions at the frequencies corresponding to 1.5 T and 3 T MRI. Simulations of different exposure settings were validated by measurements of the resulting field distributions with an E-field vector probe along the routing paths.
Wireless reference implant and communication methodology to assess and investigate RF safety and pTx mitigation strategies for AIMDs
Authors: Silemek Berk , Seifert Frank , Ittermann Bernd , Winter Lukas
Published: August 2023

Parallel transmission (pTx) systems can substantially improve the RF-safety of active implantable medical devices (AIMDs) in MRI. Here, a wireless reference implant is presented to test pTx mitigation strategies of RF induced implant heating. It is demonstrated that the proposed hardware and communication workflow can measure the sensor Q matrix and use this information to mitigate RF induced heating. The proposed setup enables conceptualization and further testing of a safety strategy relying on an implant communicating with a pTx capable MRI to improve RF safety without major restrictions in MR imaging performance.
Multimodal high-resolution mapping of subcortical regions in the macaque monkey revealed by combined MAP-MRI and histology
Authors: Saleem Kadharbatcha , Avram Alexandru , Glen Daniel , Komlosh Michal , Basser Peter
Published: August 2023

Despite its essential use as a model for neurological disorders in humans, the rhesus macaque lacks a comprehensive MRI-histology-based segmentation of subcortical regions. Here, we mapped the subcortical regions in the macaque monkey using MAP-MRI, and postmortem histology of the same brain. Our results demonstrate that, at high spatial resolution, MAP-MRI can distinguish a large number of gray and white matter structures in deep brain areas. The ability to delineate and validate these in a given subject is useful for neurosurgical planning and navigation of implantable devices to potential targets for deep brain stimulation in the macaque model of neurological or psychiatric disorders.
A Neurochemical Atlas of the Cingulate Cortex in Relation to Pain.
Authors: Archibald Jessica , MacMillan Erin , Zölch Niklaus , Kramer John
Published: August 2023

1H-MRS provides a window into brain chemistry without the need to directly sample tissue. The growing prevalence of neurological conditions highlight the need for evidence based treatments. Specifically, preclinical and clinical evidence suggest a link between glutamate and pain. This study shows spatial neurochemical differences from different voxels across the cingulate cortex using sLASER at 3 T. A significant correlation between pain ratings and the anterior cingulate cortex is seen. As MRS moves towards becoming a standardized clinical technique, understanding the spatial distributions and variability will provide an important basis for the understanding of the healthy human brain’s biochemical environment.
Neuromelanin MRI as biomarker for treatment resistance in first episode schizophrenia patients
Authors: Van der Pluijm Marieke , Reijers Pascalle , Wengler Kenneth , De Haan Lieuwe , Booij Jan , Horga Guillermo , Van de Giessen Elsmarieke
Published: August 2023

The current study assesses neuromelanin sensitive MRI (NM-MRI) as a potential biomarker for treatment resistance (TR) in first episode schizophrenia patients. NM-MRI is a novel MRI sequence, which indirectly measures dopamine synthesis. Research using positron emission tomography (PET) imaging suggest that TR patients show lower dopamine synthesis than responders. We acquired NM-MRI in 61 first episodes schizophrenia patients. Treatment response was determined during 6 months follow-up. TR patients showed significantly lower NM-MRI signal compared to responders. These findings are in line with previous PET studies and demonstrate the potential of NM-MRI as alternative and more accessible biomarker for TR.
Quantitative MRI in Major Depressive Disorder at 7T
Authors: Heij Jurjen , van der Zwaag Wietske , Caan Matthan , van Wingen Guido , Aghajani Moji
Published: August 2023

Large scale efforts are being employed to link Major Depressive Disorder (MDD) to cortical alterations in gray and white matter, though often, limited resolution prevents conclusions regarding the source. Here we used quantitative 7T MRI to explore the myeloarchitecture of the cortex in people suffering from MDD in order to unravel potential mechanisms underlying the psychopathology of MDD. We find altered T1-profiles in the rostral ACC, lateral PFC and OFC in MDD compared to healthy controls, indicating changes in cortical myeloarchitecture. Overall, cortical T1 values were higher in MDD, suggesting lower cortical myelination.
MRI Tagging of Colonic Contents in Healthy Subjects: Reliability of the Measurement with Time
Authors: Alshammari Meshari , Marciani Luca , Moran Gordon W. , Hoad Caroline L.
Published: August 2023

We aimed to investigate the temporal variation of the MR colonic tagging technique to measure mixing of colonic contents following a water based laxative drink by acquiring multiple scans on healthy participants. The study results indicate that time did not influence the measurement of colonic content mixing, however the scans were variable over the 10 minute acquisition window which suggests multiple scans are needed to accurately assess this parameter. Multiple measurements of this non-invasive technique can be used in future studies that aim to look at bowel motility and treatment response of IBD patients, using the same water-based laxative.
Characterization of Symptomatic Vertebrobasilar Plaques in Diabetic Patients Using Computed Tomographic Angiography and Vessel Wall Imaging
Authors: Yang Huan , Liu Bo , Yin Qingqing , Wang Haipeng , Lin Liangjie , Wang Ximing
Published: August 2023

Diabetes mellitus is significantly associated with posterior circulation ischemic stroke. We aimed to compare the characteristics of vertebrobasilar plaques in symptomatic patients with and without diabetes using vessel wall magnetic resonance imaging and computed tomographic angiography. Characteristics of symptomatic vertebrobasilar plaques were compared between patients with and without diabetes. Multivariate analysis demonstrated differences in the presence of T1 hyperintensity and number of spotty calcifications were statistically significant. Symptomatic patients with diabetes have a higher incidence of T1 hyperintensity and larger calcification burden than those without diabetes, indicating the association of diabetes with more advanced plaque features in the posterior circulation.
Redefining Access to High-Value MRI: Results from the CAMERA MRI in Africa Needs Assessment Survey
Authors: Ng Jinggang , Ehiogu Boaz , Obungoloch Johnes , Fatade Abiodun , Diop Mamadou , Mutsaerts Henk-Jan , Alexander Daniel , Secca Mario , Nunes Rita , Figueiredo Patricia , Figni Matteo , Minja Frank , Gulani Vikas , Webb Andrew , Asllani Iris , Nganga Edward , Adeleke Sola , Ogbole Godwin , Dako Farouk , Anazodo Udunna
Published: August 2023

We examined access to MRI in Sub-Saharan Africa to provide a novel framework to address MRI needs. A 68-question needs assessment survey was distributed to collaborators, radiologists and radiographers in Africa, yielding 158 unique responses. Survey responses were analyzed to provide insight into challenges and opportunities for MRI access. Geographical information systems (GIS) were applied to responses from Nigeria to model access to high-value MRI. To our knowledge, this is the first study that used GIS mapping to estimate MRI access. This novel approach can be applied to low-resource settings globally to provide a comprehensive framework to understand MRI access.
Myelination patterns support the last-in-first-out and gain-predicts-loss paradigms in normative aging
Authors: Kiely Matthew , Triebswetter Curtis , Gong Zhaoyuan , Alsameen Maryam , Bouhrara Mustapha
Published: August 2023

Using myelin water fraction (MWF), a proxy of myelin content, and diffusion tensor imaging (DTI) indices, we investigated the retrogenesis paradigm in a large cohort of cognitively unimpaired participants spanning a wide age range. Specifically, we assessed the last-in-first-out and gain-predicts-loss hypotheses, describing trends of tissue degeneration across cerebral regions and comparing maturation and degeneration rates within regions. Our MWF results support the last-in-first-out hypothesis, indicating that posterior regions are generally spared from degeneration compared to anterior regions, as well the gain-predicts-loss paradigm, suggesting that the regional maturation and degeneration rates were approximately symmetric.
Virtual coil concept applied to motion corrected and low rank undersampled reconstructions
Authors: Cruz Gastao , Munoz Camila , Botnar René , Prieto Claudia
Published: August 2023

Partial Fourier strategies leverage the Hermitian symmetric properties of k-space into higher acceleration factors. Motion corrected (MC) reconstructions incorporate generalized motion into the process. Contrast resolved reconstructions, e.g. low rank inversion (LRI), exploit temporal redundancies in highly accelerated acquisitions. Both the MC and LRI reconstructions are usually ill-posed and can benefit from additional sources of encoding. The Virtual Coil Concept (VCC) has been recently introduced, combining Parallel Imaging with Partial Fourier. Here we investigate the combination of VCC with MC and VCC with LRI to enable further acceleration of both approaches.
Novel methods for correcting motion regression errors caused by global intensity changes in scans of cerebrovascular function
Authors: Beckerleg Ryan , Whittaker Joseph , Gallichan Daniel , Murphy Kevin
Published: August 2023

Previously we showed that when global intensity changes (GIC’s) are present in data (e.g., CO2 stimuli during measurement of CVR, ASL tagging), volume registration algorithms misrepresent such signal change as motion. Here we look at motion estimates derived from VRA’s, an external marker-less camera, and novel data-derived techniques, to evaluate if this problem can be overcome. We determined that in most cases where GIC’s are present, the use of an ICA in correction can improve erroneous results from VRA estimates. This isn’t the case in all scans however and the GIC causing this error should be removed prior to correction.
Quantifying myelin water exchange using optimized bSSFP sequences
Authors: Murthy Naveen , Nielsen Jon-Fredrik , Whitaker Steven T. , Haskell Melissa W. , Swanson Scott D. , Seiberlich Nicole , Fessler Jeffrey A.
Published: August 2023

Mapping myelin water exchange rates could potentially be useful in helping us understand and characterize different diseases in the brain. It is a challenging quantitative parameter mapping problem to estimate multi-compartment exchange. This work focuses on scan design, with an aim of estimating exchange maps with good precision. In particular, a set of balanced steady-state free precession (bSSFP) sequences are optimized to estimate exchange rates in white matter (WM), for a two-pool model. Quantitative exchange maps are shown for a simulated phantom, using this optimized scan design.
Towards validation of in vivo U-fibre mapping using post-mortem DWI tractography of V1-V2 connections
Authors: Attar Fakhereh Movahedian , Kirilina Evgeniya , Schneider Christian , Haenelt Daniel , Edwards Luke , Pine Kerrin , Jäger Carsten , Reimann Katja , Pohlmann Andreas , Periquito Joao , Streubel Tobias , Mohammadi Siawoosh , Niendorf Thoralf , Morawski Markus , Weiskopf Nikolaus
Published: August 2023

U-fibres are the most abundant white matter fibres and yet are highly underrepresented in the MRI-derived human brain connectome. Development of validated in vivo pipelines for comprehensive mapping of these short association fibres is therefore essential. Here, we show the correspondence of the geometries of U-fibres connecting early visual cortices mapped in vivo using sub-millimetre resolution diffusion weighted imaging (DWI) tractography to those obtained in a post-mortem brain tissue sample using ultra-high resolution DWI tractography.
Steady-state CEST-MRI using a reduced saturation period: Application to volumetric APT and rNOE brain imaging at 3T
Authors: Breitling Johannes , Korzowski Andreas , Ladd Mark , Bachert Peter , Goerke Steffen
Published: August 2023

In this study, we demonstrate the feasibility of obtaining steady-state 3D CEST contrasts of the human brain at 3T using a reduced saturation period. To this end, we applied our previous approach, which utilizes the analytical equation of the CEST signal, to an optimized clinical protocol using a fast volumetric snapshot-CEST acquisition. Measurements on model solutions and a volunteer demonstrated the feasibility with almost identical APT and rNOE contrasts for saturation durations as short as 1 second. Consequently, this facilitates quantitative CEST-MRI in humans within a reasonable and clinically relevant time frame.
Optimization of Pulsed Chemical Exchange Saturation Transfer MRI by Optimal Control
Authors: Stilianu Clemens , Graf Christina , Diwoky Clemens , Soellradl Martin , Rund Armin , Zaiss Moritz , Stollberger Rudolf
Published: August 2023

We optimized CEST saturation pulse train using an optimal control framework and validated the simulation results on a preclinical scanner that allowed also Gold Standard continuous wave saturation. The optimized pulses almost reached the same saturation as the continuous wave pulse while addressing the allowed duty cycle and SAR limitations of clinical scanners. In measurements, the optimized pulses outperform state-of-the-art Gaussian pulses by over $$$47\%$$$.
Super-Resolution for CEST MRI
Authors: Folle Lukas , Tkotz Katharina , Liebert Andrzej , Gadjimuradov Fasil , Kapsner Lorenz , Fabian Moritz , Bickelhaupt Sebastian , Simon David , Kleyer Arnd , Krönke Gerhard , Roemer Frank , Zaiss Moritz , Nagel Armin , Maier Andreas
Published: August 2023

The resolution of chemical exchange saturation transfer (CEST) magnetic resonance imaging is limited by physical constraints. To visualize metabolic processes of small structures using CEST in patients knees, an increased resolution is necessary. In this work, we compared trilinear interpolation and zero-filling to neural network-based approaches to estimate a high-resolution image given the corresponding low-resolution data. We could show that a substantial quantitative improvement using neural networks could be achieved for unsaturated images while maintaining a comparable CEST contrast. Generalization of the method to brain CEST MRI was achieved without retraining of the network.
Principal Component selections and filtering by spatial information criteria for multi-acquisition CEST MRI denoising
Authors: Casagranda Stefano , Papageorgakis Christos , Romdhane Feriel , Firippi Eleni , Boutelier Timothé , Mancini Laura , Zaiss Moritz , Bisdas Sotirios , Longo Dario
Published: August 2023

This work provides a new denoising methodology for multi-acquisition magnetic resonance images (MRI) based on principal components analysis (PCA). We are proposing a new principal component selection criterion that identifies spatial information in the extracted component coefficients, leading to a better preservation of anatomical structures and pathological information. In addition, our adaptive filtering step allows us to further denoise the MRI data, rejecting persistent spatial noise from the extracted component coefficients. In our investigations the proposed method outperformed the eigenvalue based selection criteria on Amide Proton Transfer weighted CEST data.
Intracellular Acidification Monitored by Chemical Exchange Saturation Transfer MRI: Effect of Cariporide in Rat C6 Brain Tumor
Authors: Mozaffari Maryam , Nystrom Nivin , Li Alex , Bellyou Miranda , Scholl Timothy , Bartha Robert
Published: August 2023

Our objective was to acidify rat C6 gliomas by inhibiting NHE1 with cariporide and to monitor the pH changes with AACID-CEST MRI. AACID-CEST MRI was successfully used to monitor changes in tumor pHi over time after cariporide injection. Our results showed a pH decrease in both the tumor and the contralateral tissue following cariporide injection. CEST-MRI measurement of tumor response pH could help to enhance the efficacy of this treatment paradigm in different human malignancies.
Traveling pulses visit 7T Terra sites: Getting ready for Parallel Transmission in routine use
Authors: Mauconduit Franck , Massire Aurélien , Gras Vincent , Pracht Eberhard , Lapert Marc , Leppert Ilana , Tardif Christine Lucas , Kim Sugil , Uludag Kamil , Stoecker Tony , Naudin Mathieu , Guillevin Rémy , Vignaud Alexandre , Boulant Nicolas
Published: August 2023

Parallel transmission universal pulses (UPs) consist of pre-optimized RF pulse solutions mitigating the RF field inhomogeneity problem for a given RF coil. Optimized offline on a database of representative field maps, they are designed to be robust to intersubject variability and spare the user a cumbersome online calibration. Initially designed for the MAGNETOM 7T Classic system from Siemens Healthineers, with the RF coil being strictly identical, this abstract describes the set of transformations on the pulses necessary to meet the MAGNETOM Terra specifications as well as successful in vivo results already achieved at four Terra sites using the same UPs.
Brainstem 7T 1H-MRS: comparison between single-channel (1Tx32Rx) and parallel transmit (8Tx32Rx) coils
Authors: Graf Carina , Ding Belinda , Rua Catarina , Rodgers Christopher
Published: August 2023

7T MRS offers increased SNR and peak separation. Many Siemens 7T sites have both 1Tx32Rx and 8Tx32Rx head coils. Workflow is similar when using the TrueForm/CP+ mode. We compared MP2RAGE and semiLASER 1H-MRS in brainstem in healthy volunteers to identify a preferred coil for future studies.

Results: voxelplacement, linewidth, and concentrations were not significantly different. SNRNAA increased 27% and CRLBs for Gln, GABA & GSH trended to be lower for the 8Tx coil.

This encourages regular use of the 8Tx32Rx coil for brainstem 1H-MRS and facilitates method development by allowing full pTx sequences to be added on to scheduled examinations.
Increases in Quantitative T2 Values in Spinal Cord of Chiari Patients with Syrinx
Authors: Baumbach Maia , Allen Jason , Barrow Daniel , Reiter David , Oshinski John
Published: August 2023

Here we use quantitative T2 mapping of the spinal cord in Chiari malformation patients to evaluate the ability to discriminate between spinal cord tissue in Chiari patients with syrinx and spinal cord tissue without. Spinal cord tissue adjacent to syrinx lesions show significantly elevated T2 values suggesting potential utility of T2 mapping for clinical management of Chiari patients.
Age-associated White Matter Microstructure and Connectome Abnormalities in Autism Spectrum Disorder
Authors: Weber Clara , Haider Stefan , Mukherjee Pratik , Lake Evelyn , Scheinost Dustin , Bamford Nigel , Ment Laura , Constable Todd , Payabvash Sam
Published: August 2023

Analyzing four study cohorts spanning from infancy to adulthood, we compared DTI-derived diffusion metrics as well as connectome Edge Density between subjects with Autism Spectrum Disorders (ASD) and neurotypical controls. Additionally, we explored the performance of several machine learning algorithms applied to tract-based values for prediction of ASD. We found age- and ASD-related alterations in white matter microstructure and connectome in both voxel-wise and tract-based analyses that show how ASD-associated abnormalities emerge and change over time. Our machine learning analysis evaluated several different approaches and identified a model that achieved 0.75 AUC in the prediction of an ASD diagnosis.
Investigation of the inferior fronto-occipital fasciculus in the macaque fascicularis brain using 11.7 T ultra-high field diffusion data
Authors: Chauvel Maëlig , Uszynski Ivy , Fischer Clara , Poupon Fabrice , Destrieux Christophe , Maldonado Igor , Poupon Cyril
Published: August 2023

In this study, we investigated the controversial presence of the inferior fronto-occipital fasciculus (IFOF) in the macaque species (Macaca fascicularis) using ultra-high field MRI (11.7 T) diffusion data. Thanks to a fiber clustering approach, we were able to reconstruct the IFOF in both hemispheres. We observed thin frontal connections and a more developed fasciculus on the right hemisphere compared to the left. The presence of this special fasciculus, known in Humans as being part of the ventral pathways for multi-modal language processing, is a new step forward concerning the comprehension of the macaque brain, and the primate brain in general.
Structural connectivity estimates are accurate: the outcome of diffusion-simulated connectivity (DiSCo) challenge
Authors: Girard Gabriel , Rafael-Patino Jonathan , Truffet Raphaël , Aydogan Dogu , Adluru Nagesh , Nair Veena , Prabhakaran Vivek , Bendlin Barbara , Alexander Andrew , Bosticardo Sara , Gabusi Ilaria , Ocampo-Pineda Mario , Battocchio Matteo , Piskorova Zuzana , Bontempil Pietro , Schiavi Simona , Daducci Alessandro , Stafiej Aleksandra , Ciupek Dominika , Bogusz Fabian , Pieciak Tomasz , Frigo Matteo , Sedlar Sara , Deslauriers-Gauthier Samuel , Kojcic Ivana , Zucchelli Mauro , Laghrissi Hiba , Ji Yang , Deriche Rachid , Schilling Kurt , Landman Bennett , Cacciola Alberto , Basile Gianpaolo , Bertino Salvatore , Newlin Nancy , Kanakaraj Praitayini , Rheault Francois , Filipiak Patryk , Shepherd Timothy , Lin Ying-Chia , Placantonakis Dimitris , Boada Fernando , Baete Steven , Hernández-Gutiérrez Erick , Ramírez-Manzanares Alonso , Coronado-Leija Ricardo , Stack-Sánchez Pablo , Concha Luis , Descoteaux Maxime , L Sina Mansour , Seguin Caio , Zalesky Andrew , Marshall Kenji , Canales-Rodríguez Erick , Wu Ye , Ahmad Sahar , Yap Pew-Thian , Théberge Antoine , Gagnon Florence , Massi Frédéric , Haro Juan Luis Villarreal , Pizzolato Marco , Caruyer Emmanuel , Thiran Jean-Philippe
Published: August 2023

The estimation of structural connectivity from DW-MRI is a challenging task, in part due to false-positive connections. Building on previous efforts, the MICCAI-CDMRI Diffusion-Simulated Connectivity (DiSCo) challenge was organized with the aim of evaluating connectivity methods using large-scale synthetic datasets obtained from DW-MRI Monte-Carlo simulations. The outcome of the challenge suggests that methods selected by the 14 teams participating in the challenge provide both high correlations between estimated and ground-truth connectivity weights and high accuracy in binary connectivity identification. Furthermore, the challenge provided unique data with realistic connectivity and microstructure properties to foster the development of connectivity estimation methods.
Investigation of the singularity of the chimpanzee brain superficial white matter bundles using diffusion MRI and clustering-based approaches
Authors: Chauvel Maëlig , Uszynski Ivy , Popov Alexandros , Hopkins William , Mangin Jean-François , Poupon Cyril
Published: August 2023

A way to better appreciate the complex human brain evolution relies on comparative investigations with homologous species. We present here the superficial connectivity organization of the Chimpanzee brain using a combination of image processing and DBSCAN clustering analyzes obtained from 39 chimpanzees DTI scans. The results revealed the presence of U-fiber, V-fiber and Curved-fiber shapes already identified in Human superficial fiber connectivity studies. This non-negligeable short fibers organisation resemblance between Chimpanzees and Humans, brings out new perspectives on hominid brain singularity knowledge.
Altered rich club organization and dynamic structure-function relationship in treatment-naïve new-onset juvenile myoclonic epilepsy
Authors: Liu Guangyao , Liu Hong , Zhang Pengfei , Zhang Jing , Zhang Zhe
Published: August 2023

Neuroimaging studies have shown that juvenile myoclonic epilepsy (JME) is characterized by impaired brain networks. However, few studies have investigated the potential disruptions in the rich club organization. Our study described the alterations of anatomical rich club organization and abnormalities of dynamic SC-FC coupling in treatment-naïve newly diagnosed JME. The results showed that the anatomical rich club organization was disrupted in the patient group, along with decreased connectivity strength among rich club hub nodes. The aberrant dynamic SC-FC coupling of rich club organization suggests a selective influence of interconnected network core in JME at the early phase of the disease.
A novel free-running framework for Blood Oxygen Level Dependent functional MRI
Authors: Franceschiello Benedetta , Rumac Simone , Hilbert Tom , Roy Christopher , Degano Giulio , Gaglianese Anna , Yerly Jerome , Stuber Matthias , Kober Tobias , Heeswijk Ruud , Murray Micah , Fornari Eleonora
Published: August 2023

We demonstrate the efficacy of a new free-running framework for quantitatively measuring blood-oxygen-level-dependent functional MRI (BOLD-fMRI) signals. Whole-brain data were acquired uninterruptedly during a blocked-design ON/OFF visual paradigm (checkerboard vs. grey image). 5-D volumes were reconstructed (i.e. the three spatial dimensions (x,y,z), the trial dimension (N=33), and the ON vs. OFF dimension (N=2)). BOLD-activated regions were measured as the difference between volumes reconstructed from all read-outs acquired during the ON vs. OFF condition, rather than resulting from a canonical, model-based, GLM analysis. The framework enables high temporal T2* k-space sampling and opens up new horizons for BOLD-fMRI.
Temporal properties of fast BOLD fMRI responses in veins and parenchyma
Authors: Gomez Daniel , Fultz Nina , Polimeni Jonathan , Lewis Laura
Published: August 2023

Blood-oxygen-level-dependent (BOLD) signals can produce much faster (>0.2Hz) responses than predicted by canonical hemodynamic response models. The timing of hemodynamic responses depends on vascular anatomy, and whether these fast responses differ in veins and parenchyma is unknown. Linear models predict that with faster stimuli, venous responses should attenuate more than the parenchyma. We tested this hypothesis by imaging visual responses at high spatial resolution with 7T fMRI. We found that both veins and parenchyma produce larger fMRI responses to fast stimuli than predicted by linear models, suggesting that faster stimuli produce narrower hemodynamic responses in both compartments.
Comparison of different multiband acceleration factors on rhyming-task fMRI on a compact 3T scanner
Authors: Ahmed Zaki , Welker Kirk , Halverson Maria , Meyer Nolan , Kang Daehun , In Myung-Ho , Gray Erin , Black David , Trzasko Joshua , Huston John , Bernstein Matt , Shu Yunhong
Published: August 2023

Multiband acquisition can improve the temporal resolution of task-based fMRI at the cost of increased noise and artifacts. The optimal multiband acceleration depends on the task being studied, specific imaging protocol, and hardware involved. In the current work, multiband acceleration factors of 4, 5, and 6 were compared for a rhyming-task fMRI study using a 32-channel head coil on a compact 3T scanner with high-performance gradients. Multiband factors of 4 and 6 provided significant improvement over no acceleration, whereas a multiband factor of 5 was inconsistent and did not provide a significant improvement in half of the volunteer cohort.
Olfactory Signal processing in functional MRI oddball task
Authors: Karunanayaka Prasanna , Hobkirk Andréa , Wang Jianli , Elyan Rommy , Spreen Lauren , Pang Ran , Kanekar Samgan , Yang Qing
Published: August 2023

Odor-identification is thought to be subserved by a distributed brain network that includes both the medial and inferior temporal lobes, still, its neural substrate remains poorly understood. Odor identification deficits are one of the hallmark symptoms of early Alzheimer’s disease (AD). Here, we propose the development of an oddball olfactory fMRI paradigm to establish the neural basis of odor-identification in healthy subjects. This task may provide a basis for establishing relationships between olfactory deficits, neurodegeneration, and memory impairment for current AD research.
Mass Univariate Regression Analysis on a Three-Dimensional Liver Phenotype: Associations with Disease States
Authors: Thanaj Marjola , Basty Nicolas , Cule Madeleine , Sorokin Elena , Bell Jimmy , Thomas Elizabeth , Whitcher Brandon
Published: August 2023

Organ MRI measurements have the potential to enhance our understanding of the precise phenotypic changes underlying many clinical conditions. Using liver mesh-based shape analysis we were able to detect significant changes in organ shape in specific anatomical regions associated with anthropometric traits and health conditions including type-2 diabetes and liver disease. We have shown that presence of T2D is associated with increase in liver shape and size. We also showed that the liver disease when accounting for liver fat showed more negative associations with the 3D liver shape phenotype.
Correlation between 18F-FDG PET/MR imaging parameters and histopathological factors from image-guided biopsy in breast
Authors: Neri Ilaria , Canevari Carla , Venturini Elena , Gallivanone Francesca , Ghezzo Samuele , Bezzi Carolina , Di Micco Rosa , Menichini Raffaele , Savi Annarita , Bettinardi Valentino , Picchio Maria , Gentilini Oreste , Panizza Pietro , Gianolli Luigi , Scifo Paola
Published: August 2023

This work investigates the correlations between PET/MR imaging parameters and histopathological factors of breast tumors extracted from image-guided biopsy. Results from our work show that PET and some MR parameters are statistically correlated to histopathological factors. Moreover, the integration of PET and MR (DCE-MR and ADC) parameters might help in the prediction of histopathological factors.
Feasbility of 3D MRCP for patients in both supine and prone position: a comparison study of qualitative and quantitative assessment
Authors: zhang yu , zha yun fei , Liu Weiyin
Published: August 2023

Increasing evidence has suggested that endoscopic retrograde cholangiopancreatography (ERCP) in the supine position is technically more technically demanding for operators than prone ERCP and leads to a greater risk of adverse cardiorespiratory events. Our results showed no differences in the CR, SNR, and CNR of the CBD between MRCP image sets. The visibility of most pancreaticobiliary ducts, motion artifact, and overall image quality were slightly better on the prone MRCP images than on the supine ones (P < 0.005). Therefore, 3D prone MRCP could provide better visualization and a roadmap directly matched with prone ERCPs for clinicians performing a surgery.
The Subcutaneous Thickness Fraction: A new quantitative imaging metric that correlates with Lymphedema Stage.
Authors: Sibley Robert , Yoon James , Loening Andreas
Published: August 2023

Given the dearth of quantitative metrics for staging lymphedema, we assessed subcutaneous and muscle tissue imaging metrics for patients with lower extremity lymphedema. Subcutaneous and muscle tissue thickness, subcutaneous thickness fraction (subcutaneous /sum of subcutaneous and muscle tissue thickness), and subcutaneous area fraction (subcutaneous / sum of subcutaneous and muscle tissue area) were measured. Leg subcutaneous measures strongly and significantly correlated with International Society of Lymphology lymphedema stage, while thigh subcutaneous measures demonstrated a trend to moderate correlation with stage. As lymphedema typically progresses from the distal to proximal extremity, the greater correlation with the leg is expected.
Iron Oxide Nanoparticle Magnetic Resonance Lymphangiography (ION-MRL): A New Technique for Imaging the Peripheral and Central Lymphatic System
Authors: Sibley Robert , Moroz Maxim , Vasanawala Shreyas , Loening Andreas
Published: August 2023

MR lymphangiography (MRL) utilizing the clinically available small molecular weight gadolinium contrast agents suffers from diffusion of contrast out of the lymphatic system and into the blood pool. We describe a modified MRL technique where a clinically available iron oxide nanoparticle (ferumoxytol) is used as the lymphatic contrast agent. The higher molecular weight of these nanoparticles results in retention of contrast within the lymphatic system. This simplifies peripheral lymphatic imaging by eliminating the need for vascular contamination suppression techniques and should allow better tracking of contrast through the central lymphatics following pedal injections.
Vendor Independent Visualization Platform for Neuro Device Guidance and Therapeutic Monitoring Based on Stereotactic OR Workstations
Authors: Moskwa Robert , Ozhinsky Eugene , Lilieholm Thomas , Ahmed Azam , Block Walter
Published: August 2023

The NIH-sponsored international Phase III MISTIE Trial showed that that patients whose residual clot volume was reduced below 15 ml exhibited a statistically higher degree of functional independence. However, CT-image guidance has trouble visualizing clot, brain tissue, and intermediate levels of evacuation. MRI-guidance of ICH evacuations would support far better visualization of clots during attempts at suction or administration of lysing drugs. We present a six panel display whose viewpoints are patterned directly from the Medtronic Stealth workstation. This interface allows for acquisition and display of MR-images in real-time. Viewing planes and image parameters can be changed in real-time.
Measurement of End-to-End latency in real-time MRI
Authors: Schaten Philip , Azhar Mueed , Adler Ansgar , Steinmetz Michael , Uecker Martin
Published: August 2023

For interventional MRI-guided applications image reconstruction should be without delay to avoid unwanted failure. Since latency is unavoidable it is very important to know it beforehand. For this reason, we present a new method to measure the latency of real-time MRI systems.

The main components are two inexpensive optical cameras. No modification of the scanner system is required. Different validations show that our method works reliably. Results from our RT MRI system provide insight into the latency of different protocols. We believe that we have found an inexpensive, easy, and robust way of determining RT MRI latency.
Infant Brain Segmentation based on Multi-dMRI contrast Attention (BISMA)
Authors: Zhu Tianjia , Ouyang Minhui , Feng Lei , Sindabizera Kay , Hyland Jessica , Huang Hao
Published: August 2023

On widely used relaxation-based T1-weighted (T1w) and T2-weighted (T2w) MRI images, 0-2-year-old infant brain images exhibit poor gray and white matter contrasts due to dynamic and poor myelination in this stage. Such poor T1w and T2w contrasts hinder accurate segmentation of infant brains based on T1w or T2w images. Instead, diffusion MRI (dMRI)-derived maps offer high contrasts throughout infancy. To leverage rich dMRI contrasts, we established an Infant Brain Segmentation based on Multi-dMRI contrast Attention (BISMA) technique. BISMA fills the gap in accurate deep learning segmentation of infant brain by fusing multi-contrasts of dMRI-derived maps.
A deep-learning non-contrast MRI lesion segmentation model for liver cancer patients that may have had previous surgery
Authors: Vogt Nora , Arya Zobair , Núñez Luis , Connell John , Aljabar Paul
Published: August 2023

Segmentation of lesions within the liver is pivotal for surveillance, diagnosis and treatment planning, and automated or semi-automated approaches can aid clinical workflows. Many patients that are under surveillance may have had previous surgery, meaning their scans will contain post-surgical features. We investigate the use of a deep learning segmentation model for non-contrast MRI that can distinguish between lesions, surgical clips and resection-induced fluid-filling regions. We report mean dice scores of 0.55, 0.72 and 0.88 for these classes respectively, demonstrating the potential of this model for semi-automated workflows.
Improving the Accuracy of Fat Fraction Values from a 2-Point Dixon Acquisition
Authors: Lin Sheng-Qing , Fonseca Sebastian , Udayakumar Durga , Madhuranthakam Ananth
Published: August 2023

Fat fraction (FF) mapping using whole-body MRI is clinically valuable for the assessment of treatment response in diseases such as multiple myeloma. MRI FF maps can be accurately measured using multi-point acquisitions such as mDixon-Quant, however, they are not feasible for whole-body acquisitions. We have previously developed a “dark-fat” masking algorithm that can account for residual fat signal in water-only images from 2-point Dixon fat/water separation, that are readily feasible with whole-body MRI. In this study, we demonstrate the utility of this algorithm across a range of proton-density FF using a multi-compartment commercial FF phantom.