bluuebunny/crossref_metadata_2025 huggingface dataset:
Noise Considerations for a Microsolenoid at 15.2T Designed for MR Microscopy
Authors: Hardy Benjamin , Zhu Yue , Does Mark , Anderson Adam , Gore John
Published: August 2023

Magnetic Resonance Microscopy aims to produce micron scale resolution images in reasonable times, but SNR decreases as voxel sizes shrink. RF coils must be optimized and their performance depends on coil resistance and sample size. We compared the relative performance of a commercially available cryogenically cooled surface coil of 24 mm in diameter to a smaller, 1.5 mm diameter, room temperature microcoil at 15.2T. A silver microsolenoid had threefold SNR increase but with decreased FOV and susceptibility artifacts. An optimized microcoil should be able to produce images with 10 µm isotropic resolution within 10 hours with an SNR of 10.
Non-selective refocusing pulse optimization for T2-prep in free-breathing 3D CMRA at 7T with single-transmit coil
Authors: Paul Shubhajit , Tomi-Tricot Raphael , Kunze Karl , Malik Shaihan , Hajnal Joseph , Bridgen Philippa , Wilkinson Thomas , Giles Sharon , Neji Radhouene , Razavi Reza , Prieto Claudia , Botnar René
Published: August 2023

In spite of the promised increase in signal-to-noise ratio and contrast to noise ratio, 3D whole-heart imaging at 7T remains challenging predominantly due to B1, B0 inhomogeneity, specific absorption rate limitations and coil-depth issues for single transmit. Here, we developed a toolbox to optimize the adiabatic hyperbolic secant refocusing pulse with respect to B1 and B0 inhomogeneity typically used for T2-preparation in non-contrast 3D Coronary Magnetic Resonance Angiography (CMRA). We present phantom and in vivo data for 3D CMRA employing a low excitation flip-angle scheme.
Arterial Input Function Estimation Using All-Channel Blind Deconvolution with Spatial Regularization in DCE-MRI
Authors: Jirik Radovan , Bartos Michal , Macicek Ondrej , Starcuk Zenon
Published: August 2023

This work is focused on estimation of an arterial input function (AIF) in DCE-MRI. We propose a new concept of blind deconvolution to use as much available information as possible. In contrast to multi-channel blind deconvolution based on processing of selected tissue signals, our all-channel blind deconvolution uses tissue signals of all voxels within the studied tissue to simultaneously estimate the AIF and perfusion maps. In addition, edge-preserving spatial regularization is included in the perfusion-map estimation scheme. The method is illustrated on DCE-MRI recordings of tumor-bearing mice.
Acquiring perfusion maps from contrast-enhanced MRA using deep learning approaches
Authors: Asaduddin Muhammad , Roh Hong Gee , Kim Hyun Jeong , Kim Eung Yeop , Park Sung-Hong
Published: August 2023

Perfusion maps and dynamic angiograms are both important for stroke/tumor treatment but commonly acquired in separate scans and thus may require additional injection of contrast agent for best results. In this work, we present a deep learning method to acquire perfusion maps from contrast-enhanced MRA data. Our results showed that an architecture of multiple decoders and an enhanced encoder produced perfusion maps that were visually and quantitatively similar to the standard DSC MRI-based perfusion maps. This approach enables us to acquire accurate perfusion maps and angiogram using a single contrast agent injection, reducing costs and risks while improving patient comfort.
Mammography-like MR images using a preconditioned water-fat-silicone total field inversion QSM algorithm
Authors: Boehm Christof , Stelter Jonathan , Meineke Jakob , Ruschke Stefan , Weiss Kilian , Wu Mingming , Borde Tabea , Makowski Marcus , Fallenberg Eva , Karampinos Dimitrios
Published: August 2023

Early stage malignant tumors are often accompanied by microcalcifications. X-ray-based mammography examinations are routinely used for screening and early detection due to the excellent contrast of calcified structures. However, due to the damaging nature of x-ray radiation, the use of an MR-based technique would be desirable for repeated examinations. In this work, we present initial results of quantitative-susceptibility-mapping-based (QSM) mammography-like MR-images that show robust detection of calcifications down to the resolution of the MR scan. Furthermore, the proposed method accounts for the potential presence of silicone breast implants allowing robust QSM in proximity to silicone implants for the first time.
Predicting response to neoadjuvant therapy using tumor morphologic features on breast MRI
Authors: Li Wen , Nadkarni Rohan , Newitt David , Onishi Natsuko , Gibbs Jessica , Wilmes Lisa , Joe Bonnie , Gennates Efstathios , Kornak John , Magbanua Mark , Veer Laura van't , LeStage Barbara , Consortium I-SPY 2 , Esserman Laura , Hylton Nola
Published: August 2023

Functional tumor volume (FTV) has been used to longitudinally assess tumor response to neoadjuvant therapy longitudinally in I-SPY trials. Previously, we found that a single 3D shape feature, sphericity, is associated with pathologic complete response (pCR). In this study, we expanded the analysis by including all radiomic shape features in an elastic net model and evaluated their role in prediction of pCR in the multi-center I-SPY 2 trial. Our results showed that the model with shape features outperformed the models with FTV or sphericity alone.
Solid-state MR based quantitative assessment of bone water and 31P differentiates between postmenopausal women with and without osteoporosis
Authors: Jones Brandon , Cheng Cheng-Chieh , Zhao Xia , Lee Hyunyeol , Mukaddam Mona Al , Snyder Peter , Rajapakse Chamith , Song Hee Kwon , Wehrli Felix
Published: August 2023

Fifteen osteoporotic, treatment-naïve, and 19 non-osteoporotic postmenopausal women have been examined in an ongoing study to evaluate tibial cortical bone health via solid-state MRI. Proton dual-echo UTE and IR-prepared rapid-UTE sequences were used for quantification of pore and bound water concentrations, and a 31P PETRA-ZTE sequence for quantification of bone mineralization. Osteoporotics showed elevated pore and total water concentration, thinner cortices, decreased 31P content and degree of bone mineralization (DBM). Our preliminary results suggest that solid-state MR biomarkers of bone porosity and DBM may be useful in evaluating cortical bone health.
A Locally Structured Low-Rank Tensor Method Using Submatrix Constraints for Joint Multi-echo Image Reconstruction
Authors: Chen Xi , Wu Wenchuan , Chiew Mark
Published: August 2023

Recently, we proposed an improved structured low-rank (SLR) reconstruction - locally structured low-rank (LSLR) method, which forces low-rank constraints on submatrices of the Hankel structured matrix. This simple modification leads to a robust improvement over conventional SLR reconstruction, which has been validated on the low-rank tensor reconstruction for the multi-echo GRE data.
Myelin-sensitive microstructure modeling of white matter using diffusion-T1-T2-relaxation MRI
Authors: Lampinen Björn , Szczepankiewicz Filip , Nilsson Markus
Published: August 2023

White matter pathology is characterized by demyelination and axonal loss. Diffusion MRI and relaxometry cannot separate these processes because they are primarily sensitive to axons and myelin, respectively. We used diffusion-T1-T2-relaxation MRI with tensor-valued encoding to support a twelve-parameter microstructure model including myelin. Results yielded brain parameter maps and values of the axonal and myelin volume fractions and the g-ratio that were in accordance with previous results from histology. The proposed approach can theoretically disambiguate between demyelination and axonal loss and could thus become a valuable tool for assessing disease severity and treatment response in pathologies that affect white matter.
Influence of breast biopsy clips on diffusion weighted MRI of the breast
Authors: Kremser Christian , Amort Birgit , Daniaux Martin
Published: August 2023

Patients undergoing breast MRI frequently have metallic biopsy clips placed within or adjacent to the lesion, producing metallic artifacts, which could lead to misinterpretation. The aim of our study was to investigate the extent of the artifact of four different clips commonly used in our hospital on diffusion-weighted images obtained with a readout-segmented sequence (RESOLVE) and their influence on ADC maps. It is found that artifacts vary in shape and size between different clips, DWI images and ADC-maps. For the marker with the smallest artifact the minimum size of detectable lesion seems to be approximately 10mm.
Magic Angle effect in Diffusion Tensor Imaging
Authors: Wang Nian , Wen Qiuting , Maharjan Surendra , Spritzer Charles
Published: August 2023

Magic Angle Effect (MAE) has been demonstrated to play an important role in both T2 and T1rho relaxation times in articular cartilage, its impact on the DTI measurements is still unknown. In this study we imaged rat knee, rat brain, and human brain at different orientation to explore the magic angle effect.
Sensitivity Analysis of the Bloch Equations
Authors: Scholand Nick , Uecker Martin
Published: August 2023

Algorithms for pulse optimization, quantitative MRI, or model-based reconstruction require knowledge about partial derivatives of the Bloch equations.While being available for specific analytical solutions, computing them becomes challenging in the general case. Difference quotient techniques can be used, but require perturbation tuning to avoid errors.

In this work, we investigate the use of direct sensitivity analysis to estimate the partial derivatives of the Bloch equations. We validate it with an analytical sequence model and compare it to the difference quotient in an example without analytical solution. In all cases, direct sensitivity analysis provided highly accurate estimates of the partial derivatives.
Sampling Mask Optimization for Compressed Sensing PETRA MRI
Authors: Ilbey Serhat , Özen Ali , Jungmann Pia , Fischer Johannes , Jung Matthias , Bock Michael
Published: August 2023

Single point imaging (SPI) is intrinsically time-inefficient resulting in very long scan times in PETRA. Compressed sensing PETRA (csPETRA) shortens the acquisition time – here, various csPETRA undersampling schemes were generated and an optimal undersampling scheme was determined experimentally. It was shown in csPETRA knee imaging that in Poisson sampling combined with a spherical fully-sampled center results in minimum error compared to the fully-sampled acquisitions.
Value of integrated 18F-FDG PET with fractional order calculus model-based MRI and DKI to evaluate the proliferation of lung squamous cell carcinoma
Authors: Huang Zhun , Meng Nan , Fu Fangfang , Bai Yan , Wei Wei , Fang Ting , Feng Pengyang , Li Ziqiang , Luo Yu , Yuan Jianmin , Yang Yang , Wang Zhe , Wang* Meiyun
Published: August 2023

18F-FDG-PET/MRI combines the functional and metabolic characteristics of PET with the good soft-tissue contrast of MRI. The results showed that high Ki-67-expressing tumors showed lower D and μ values and higher MK and SUVmax values. In addition, the diagnostic efficacy of all parameters is similar.
Developing a robust quantitative diffusion MRI protocol for longitudinal assessment of neurodegenerative disorders
Authors: Nayak Amritha , Bharucha-Goebel Diana , Irfanoglu M.Okan , Averion Gilberto , Saade Dimah , Bönnemann Carsten , Pierpaoli Carlo
Published: August 2023

In this work, we have developed a quantitative diffusion MRI (dMRI) pipeline, to include acquisition, processing, and analysis, robust enough to evaluate the evolution of a neurodegenerative disease in each individual patient.
Comparison of Language Areas determined by Resting State and Task Based fMRI using healthy subjects HCP data.
Authors: Pretorius Robert , Sunaert Stefan , Radwan Ahmed
Published: August 2023

Adding to the literature of resting state fMRI (rsfMRI) in preoperative planning, we investigated the similarity of a task based fMRI (tbfMRI) language protocol to a pan-language functional connectivity map in 10 healthy subjects. When comparing the whole brain there is relatively low Jaccard and Sorensen-Dice similarity between rsfMRI and tbfMRI language activity, however when looking at separate cortical anatomical regions the language areas are among those having the highest similarity. Additionally, there is a significantly higher similarity in the left IFG pars triangularis. This suggests that rsfMRI could be used reliably to determine Broca’s area in preoperative planning.
Simultaneous PET/fMRI of the Kappa Opioid Receptor System During Psychotropic Drug Challenge
Authors: Bagdasarian Frederick , Yoo Chi-Hyeon , Reid Sarah , Placzek Michael , Wey Hsiao-Ying
Published: August 2023

This research utilizes simultaneous PET/MR imaging to provide a preliminary analysis of the kappa-opioid receptor (KOR) system in a non-human primate (NHP) brain. We investigated the influence of a psychoactive drug challenge specific to the KOR system in a NHP using the KOR agonist Salvinorin-A. We report regionally specific uptake of a KOR agonist radiotracer ([11C]EKAP) and alterations to BOLD-derived cerebral blood volume (CBV) following the use of Salvinorin-A that are directly related to radiotracer uptake distribution. This work serves a preliminary foundation for KOR imaging and understanding KOR-agonist drug mechanisms through PET/MR.
Clinical evaluation of scout accelerated motion estimation and reduction (SAMER)
Authors: Tabari Azadeh , Lang Min , Polak Daniel , Splitthoff Daniel Nicolas , Clifford Bryan , Lo Wei-Ching , Wald Lawrence L. , Cauley Stephen , Rapalino Otto , Schaefer Pamela , Conklin John , Huang Susie Y.
Published: August 2023

Patient motion can degrade diagnostic image quality to the point that scans must be re-acquired, or patients called back. In this work, we performed a systematic clinical evaluation of SAMER, a highly efficient retrospective motion mitigation approach. 62 patients from emergency and inpatient care settings were scanned at 3T, and 14 cases were identified with a range of patient motion. Two neuro-radiologists performed blinded review of the images before and after motion correction, rating the images for motion severity. In 13 of the 14 cases, reduced motion severity and improved visualization of anatomy/pathology was obtained after SAMER motion mitigation.
Ultra-Fast Water/Fat Imaging of the Abdomen at 0.55T
Authors: Nayak Krishna , Tasdelen Bilal , Yagiz Ecrin , Cui Sophia
Published: August 2023

We demonstrate single-breath-hold volumetric water/fat imaging of the abdomen using spiral gradient echo imaging at 0.55T. This provides 4x finer spatial resolution with adequate SNR and spatial resolution to measure the visceral adipose tissue compartment.
Assessing the utility of low-resolution images for Hydrocephalus treatment planning
Authors: Harper Joshua , Cherukuri Venkateswararao , O'Reilly Tom , Yu Mingzhao , Mbabazi-Kabachelor Edith , Mulando Roland , Sheth Kevin , Webb Andrew , Warf Benjami , Kulkarni Abhaya , Monga Vishal , Schiff Steven
Published: August 2023

Brain images of a quality lower than is conventionally acceptable may still be useful for planning hydrocephalus treatment. Low-field MRI is a technology of growing global interest which has the capability of producing images of sufficient quality for treatment planning and is affordable enough to disseminate to rural regions of the world. Though deep learning enhancement of low-quality images does improve CNR and apparent quality, spatial errors of brain and CSF after enhanced reconstruction add significant risk to treatment management and should be avoided.
SSFD: Self-Supervised Feature Distance Outperforms Conventional MR Image Reconstruction Quality Metrics
Authors: Adamson Philip , Dominic Jeffrey , Desai Arjun , Bluethgen Christian , Wood Jeff , Syed Ali , Boutin Robert , Stevens Kathryn , Spielman Daniel , Vasanawala Shreyas , Pauly John , Chaudhari Akshay , Gunel Beliz
Published: August 2023

Evaluation of accelerated magnetic resonance imaging (MRI) reconstruction methods is imperfect due to the discordance between quantitative image quality metrics (IQMs) and radiologist-perceived image quality. Self-supervised learning (SSL) is a deep learning (DL) method that has become a popular pre-training tool due to its ability to capture generalizable and domain-specific feature representations of the underlying data without the need for labels. In this study, we derive a data-driven self-supervised feature distance (SSFD) IQM to assess MR image reconstruction quality. We demonstrate that SSFD is more highly correlated to three radiologist’s perceived image quality on DL-based sparse reconstructions than conventional IQMs.
Inter-scanner harmonization of T1-weighted brain images using 3D CycleGAN
Authors: Roca Vincent , Kuchcinski Grégory , Gautherot Morgan , Leclerc Xavier , Pruvo Jean-Pierre , Lopes Renaud
Published: August 2023

In MRI multicentric studies, inter-scanner harmonization is necessary to avoid taking into account variations due to technical differences in the analysis. In this study, we focused on CycleGAN models for 3D T1 weighted brain images harmonization. More precisely, we didn't follow the classical 2D CycleGAN architecure and developped a 3D cycleGAN model. We compared harmonization quality of these two kinds of models using 20 imaging features quantifying T1 signal, contrast between brain structures and segmentation quality. Results illustrate the potential of 3D CycleGAN for better synthesize images in inter-scanner MRI harmonization tasks.
The Effect of Differences in MRS Parameters on Data Harmonization of Normative Data
Authors: Louis Marcia Sahaya , Liao Huijun Vicky , Joshi Ajay , Lin Alexander
Published: August 2023

Building normative databases for MR spectroscopy studies is much needed to further the use of MRS in large clinical studies. The effect of differences in MRS parameters is not well documented and there are no established data harmonization methods for MRS data. Therefore, the goal of this study is to identify the effects of variations such as dwell time, coil type, and software version and describe a method for harmonizing data in healthy controls that will ameliorate those effects.
Full posterior estimation of Gray Matter cytoarchitecture using a three-compartment model with exchange: a simulation-based study
Authors: Meunier Thomas , Fang Chengran , Jallais Maëliss , Wassermann Demian
Published: August 2023

We extract cytoarchitectural characteristics of brain gray matter from diffusion MRI signals including soma size, neurite signal fraction and water exchange. Our model improves on state-of-the-art in that 1) we extract an invertible system leading to stable parameters estimation, 2) our simulation-based inference approach allows to obtain the full posterior distribution of the parameters given a signal. Our solution is a two-step model. First, a new forward model relates summary statistics of the dMRI signal to different tissue parameters. Then, a likelihood-free inference-based algorithm is applied to invert the model, and returns a full posterior distribution over the parameter space.
Comparison of ComBat harmonization methods for longitudinal magnetic resonance imaging data in a travelling subject cohort
Authors: Richter Sophie , Winzeck Stefan , Correia Marta , Kornaropoulos Evgenios , Manktelow Anne , Outtrim Joanne , Chatfield Doris , Posti Jussi , Tenovuo Olli , Williams Guy , Menon David , Newcombe Virginia
Published: August 2023

The trend in neuroimaging towards multi-site studies requires validated harmonization approaches to eradicate scanner differences which mask the biological effect of interest. Here, the harmonization algorithm ComBat and its modification for longitudinal data (LongComBat) were compared on a large travelling subject sample (n=23 for structural MRI and n=31 for diffusion tensor MRI).

In structural data scanner difference are not apparent in unharmonized data but can be created by harmonization. For DTI data, scanner differences in unharmonized data are large and, both ComBat and LongComBat successfully diminished those in most regions of interest, with LongComBat achieving slightly lower false positive rates.
fMRI Can Detect Functional Connections of Seizure Spread Regions to Onset Zones in Patients with Mesial Temporal Sclerosis
Authors: Sathe Anish , Kogan Michael , Kang KiChang , Miao Jingya , Syed Mashaal , Ailes Isaiah , Matias Caio , Mohamed Feroze , Sharan Ashwini , Alizadeh Mahdi
Published: August 2023

Epilepsy is a disease involving seizure initiation and often spread. sEEG has shown that areas of seizure spread are correlated with onset regions. We find that seed-to-voxel analysis via amplitude synchronization of fMRIs of epilepsy patients can also detect significant correlations between seizure onset and spread zones. These results validate fMRI analysis as a promising noninvasive method to detect other correlated brain regions that may be involved in seizure propagation.
Age-related changes to perivascular and parenchymal fluid flow dynamics with multi-compartment diffusion MRI
Authors: Lynch Kirsten , Custer Rachel , Cabeen Ryan , Sibilia Francesca , Toga Arthur , Choupan Jeiran
Published: August 2023

Perivascular spaces (PVS) play a critical role in fluid transfer and waste clearance in the brain. PVS enlargement is associated with advancing age; however, the functional correlates of these changes are not well understood. Using multi-compartment diffusion models, we assessed the diffusion properties within the PVS and the surrounding parenchyma in a healthy aging cohort. We found age was significantly associated with increased perivascular free water content and reduced parenchymal free water content. These findings provide preliminary evidence of age-related changes to perivascular fluid transfer that may be indicative of waste clearance functional alterations.
Single-image superresolution of hyperpolarized 13C spectroscopic images
Authors: Deh Kofi , Kim Nathaniel , Zhang Guannan , Vesselin Miloushev , Keshari Kayvan
Published: August 2023

Hyperpolarized 13C spectroscopic images are acquired at a low spatial resolution, making it necessary to apply superresolution techniques to the metabolite maps prior to fusion with the proton anatomic image for visualization of metabolite biodistribution. In this work, we demonstrate great improvement in image quality for preclinical and clinical images when the metabolite map is upsampled by high spatial frequency transfer from magnetic resonance images of thermally polarized 13C phantoms to the invivo metabolic image.
Retrospective correction of B1 field inhomogeneities in T2w 7T prostate patient data
Authors: Harrevelt Seb , Reesink Daan , Lier Astrid , van  , Meijer Richard , Pluim Josien , Raaijmakers Alexander
Published: August 2023

Prostate imaging at ultra-high fields is heavily affected by B1 field induced inhomogeneities. This not only results in unattractive images but it also might affect clinical diagnosis . To remedy this we developed a deep learning model that retrospectively corrects for the bias field. We applied this model to a clinical data set and demonstrated its performance in a qualitative manner. The results indicate that the model is able to drastically reduce the inhomogeneities in a variety of cases while the tissue contrast is generally maintained and the underlying anatomy has been successfully recovered.
Biosynthesis of an Activatable Fluorescent MRI Contrast Agent
Authors: Lee Harvey , Grady Connor , Mallett Christiane , Nafiujjaman Md , Good Nathan , Martinez-Gomez N. , Kim Taeho , Shapiro Erik , Gilad Assaf
Published: August 2023

Sustainable products are becoming an integral part of our daily lives - in this study, we biosynthetically produced an MRI contrast agent from E.coli with an r1 of 6.0 (per-gadolinium, 7T field strength, room temperature) that provides the user with optical feedback through a jump in green fluorescence upon binding free gadolinium in solution. We anticipate this will reduce the amount of resources spent on quality control (in assessing the amount of unchelated gadolinium that could otherwise introduce toxicity), whereas its compatibility with lyophilization is expected to improve storage conditions in terms of longevity, stability, and transportation costs.
3D Bioprinted MRI-Trackable Regenerative Scaffold for Post-Implantation Monitoring
Authors: Loai Sadi , Szulc Daniel , Cheng Hai-Ling Margaret
Published: August 2023

3D bioprinted scaffolds are one of the most novel and promising tissue regenerative therapeutics currently in development (e.g. to repair damaged cardiac tissue). Validation of correct scaffold placement and retention post-implantation is essential, but it is challenging to visualize scaffolds in-vivo given their similar material properties to native tissue. In this study, a T1-reducing contrast agent, MnPNH2, was utilized to create an MR-trackable, bioprinted scaffold. In-vitro and in-vivo results confirmed the novel scaffold provided an environment conducive to cell growth and offered significant bright contrast for post-implantation scaffold monitoring in rats.
Dual Mode Acousto-optic RF Safety Sensor for Electric Field and Temperature Measurement at 1.5T MRI
Authors: Yaras Yusuf , Bradley Lee , Yildirim Dursun , Kocaturk Ozgur , Oshinski John , Degertekin F. Levent
Published: August 2023

Electric field and temperature sensors are essential tools for RF safety assessment of implants during magnetic resonance imaging. In this work, an acousto-optic sensor was used for both local tangential electric field and temperature measurements. The inherent electric field sensitivity of the piezoelectric crystal mechanically coupled to a fiber Bragg grating provides the electric field information while the thermal sensitivity of FBG is used for temperature measurement for dual mode sensing. The sensor was used to measure the electric field concentration around a reference implant with high SNR as well as the temperature rise at the tip of the implant.
Value of high b-value computed diffusion-weighted imaging in intraductal papillary mucinous neoplasia of the pancreas
Authors: Harder Felix , Weiss Kilian , Jung Eva , Kamal Omar , McTavish Sean , Van Anh , Graf Markus , Demir Ihsan , Phillip Veit , Friess Helmut , Schmid Roland , Lohöfer Fabian , Makowski Marcus , Kaissis Georgios , Karampinos Dimitrios , Braren Rickmer
Published: August 2023

The incidence of intraductal papillary mucinous neoplasms (IPMN), which represent a potential precursor of pancreatic cancer, is increasing. We herein investigate the potential of computed high b-value diffusion-weighted imaging (cDWI) in detection and stratification of IPMN. cDWI at b = 1000 s/mm2 increases lesion detection rates as well as diagnostic sensitivity and specificity regarding the presence of malignant imaging features. Combining cDWI and high-resolution reduced field-of-view imaging further increases diagnostic accuracy. cDWI seems particularly promising in view of the need for non-invasive lesion detection and characterization due to the recent paradigm shift from surgery to active surveillance of IPMN.
Gastric emptying whilst upright
Authors: Askill Hannah , Gaudoin Emily , Mistry Dipendra , Mougin Olivier , Hoad Caroline , Sharif Hayfa , Marciani Luca , Gowland Penny
Published: August 2023

Gastric accommodation and gastric tone are key measure in functional diseases such as gastroparesis, dyspepsia, and even reflux. Whilst gastric accommodation has been assessed using conventional MRI such measures will have been be perturbed by the subject lying supine. Gastric tone is either assessed using a barostat or pressure sensors. This work investigate the gastric response to a meal in the upright position with the aim of analysing the data to study accommodation and markers of tone in future.
Using MRI-based fat fraction histograms in dystrophic muscle to assess individual patient disease evolution
Authors: Reyngoudt Harmen , Baudin Pierre-Yves , de Almeida Araujo Ericky Caldas , Wong Brenda , Carlier Pierre , Marty Benjamin
Published: August 2023

In most clinical quantitative MRI studies, using fat-water imaging, a mean fat fraction value per region of interest is generally used. The aim of this study was to look into the longitudinal changes in FF distribution on an individual patient basis, in dystrophic muscle, and at the same time, investigate whether differences were observed between treated and non-treated patients. As shown here, even if the mean fat fraction is the same between two patients or across time, there might be significant differences in the respective FF distributions, and might reveal, in retrospect, differential clinical or functional changes.
Parallel Transmit DANTE-SPACE for improved black-blood signal suppression at 7 Tesla
Authors: de Buck Matthijs , Kent James , Hess Aaron , Jezzard Peter
Published: August 2023

DANTE-SPACE can be used for visualizing intracranial vessel walls at 7T, where the flow-sensitive signal attenuation of the DANTE preparation simultaneously suppresses signal from the internal blood and external CSF. However, the efficacy of DANTE is reduced for blood moving upstream through the neck due to limited B1+ coverage at 7T. Here, EPG simulations are used to estimate the effect of this limited B1+ coverage on the achieved contrasts. A pTx-based approach which uses separate RF shims for the DANTE-preparation and the SPACE readout to improve the attenuation of blood moving through the neck is proposed, and validated in vivo.
Initial Observations on the Association of Peri-prostatic Vascular Asymmetry and Extra-prostatic Extension of Prostatic Tumors
Authors: Summers Paul , Minchillo Alessia , Alessi Sarah , Renne Giuseppe , De Cobelli Ottavio , Musi Gennaro , Marvaso Giulia , Jereczek-Fossa Barbara , Petralia Giuseppe
Published: August 2023

We hypothesized that the presence of asymmetry in the arterial supply of the prostate may provide a correlate of extra-prostatic tumor extension in patients with prostate cancer. In this preliminary study of 40 patients (20 with and 20 without extra-prostatic disease), a radiologist blind to the status of the patients, made a binary choice as to the presence or absence of peri-prostatic vascular asymmetry. Taking the pathological grading as the reference standard, the sensitivity, specificity, positive and negative predictive values were all 0.9. The negative likelihood ratio (LR-) was 0.11, and the positive likelihood ratio (LR+) was 9.0.
Automatic segmentation of whole-body MRI using UnnU-Net: Feasibility of whole-skeleton ADC evaluation in plasma cell disorders
Authors: Gu Renyang , Antonelli Michela , Mehta Pritesh , Amlani Ashik , Green Adrian , Neji Radhouene , Ourselin Sebastien , Dregely Isabel , Goh Vicky
Published: August 2023

Multiple myeloma is a heterogeneous bone marrow cancer. Assessment of changes in mean apparent diffusion coefficient (ADCmean) is helpful for evaluating treatment response but has not been feasible for the whole skeleton due to the time-consuming nature of manual segmentation. Whole-skeleton and per-station ADCmean were quantified from whole-body MRI using automated segmentation by an uncertainty-aware nnU-Net in 30 patients with plasma cell disorders and compared against the manual segmentation by radiologists. No differences were observed in whole-skeleton or per-station ADCmean when using the automatic and manual segmentations. Further investigation is required in a larger dataset, but initial results are promising.
Real-time automatic temperature regulation during MRI-guided Laser Interstitial Thermal Therapy (MR-LITT)
Authors: Desclides Manon , Ozenne Valéry , Bour Pierre , Machinet Guillaume , Pierre Christophe , Chemouny Stéphane , Quesson Bruno
Published: August 2023

We present here a method to automatically regulate heat deposition during Laser Interstitial Thermal Therapy to precisely control temperature evolution during the procedure. The method relies on real-time rapid volumetric thermometry using the Proton Resonance Frequency Shift technique and a regulation algorithm that adjusts every second the emitted power by the laser to force temperature to follow a predefined temperature-time profile.
On-board pseudo-MRI guidance for prostate radiotherapy on a conventional X-ray guided LINAC
Authors: Harris Wendy , Subashi Ergys , Yu Victoria , Aliotta Eric , Otazo Ricardo , Cervino Laura
Published: August 2023

Current target localization for prostate radiotherapy on a conventional LINAC consists of acquiring a cone-bean CT (CBCT) image and matching it to implanted fiducial markers inside the prostate due to poor soft-tissue contrast of CBCT. MRI provides better soft tissue contrast and no ionization radiation, but there are very few MR-LINACs, and conventional LINACs with x-ray imaging capabilities are much more ubiquitous. This study proposes to use prior MRI acquisitions, PCA motion modeling, and on-board CBCT from a conventional LINAC to obtain on-board pseudo-MRI for target localization in prostate radiotherapy.
Estimation and visualization of geometric fidelity using geometric offset maps for improved guidance in H&N radiation therapy
Authors: Palmér Emilia , Ljungberg Maria , Karlsson Anna , Nordström Fredrik , Petruson Karin , Sohlin Maja
Published: August 2023

In an MRI-only workflow, high geometric fidelity of the MRI data is required. Head and neck (H&N) cancer patients, however, frequently have implants, e.g., dental restorations, causing distortions of the MRI data. Geometric offset maps were computed using B0-map calculated from the Dixon-sequence included in the standard clinical protocol. Even though the implants included in this pre-study did not contribute with a significant geometric offset in the delineated target volume, visualization of the geometric offset maps as such bring additional important information when delineating structures in an MRI-only H&N workflow and could thereby become a promising tool in clinical practice.
Hippocampal Subfields Volume in Middle Age Healthy Adults
Authors: Alkhateeb salem , Santini Tales , jinghang Li , Chu Robin , Ibrahim Daniel , Marsland Anna , Manuck Stephen , Gianaros Pete , Ibrahim tamer
Published: August 2023

As hippocampal volume has been extensively utilized as a diagnosing tool to confirm diagnosis of many neurological disorders, this study aims to employ the high resolution 7T TSE T2w data to segment high quality images with precision based on multi atlases and machine learning. Results have proved that this pipeline provides excellent outcomes and is validated to be used for more variables.
Pycoilib: a free and pedagogical tool for the calculation of self/mutual inductance of coils of arbitrary geometry in python
Authors: Labbé Aimé , Poirier-Quinot Marie
Published: August 2023

We introduce pycoilib, a python library developed for the computation of self and mutual inductance of coils. The library allows the user to design coils by dividing their three-dimensional geometry into collections of lines, arcs and circles, and by specifying the geometry of the cross-section of the coil wire. In a case study, the self-inductance of a deformable coil is computed as a function of its configuration. Pycoilib has the potential to become a valuable tool for prototyping, as well as teaching.
Brain correlates of voice disorders in early Parkinson’s disease
Authors: Jeancolas Laetitia , Mournet Sandy , Gallea Cécile , Biondetti Emma , Mangone Graziella , Chougar Lydia , Villain Nicolas , Gaurav Rahul , Benali Habib , Benkelfat Badr-Eddine , Arnulf Isabelle , Habert Marie-Odile , Petrovska-Delacrétaz Dijana , Vidailhet Marie , Corvol Jean-Christophe , Lehéricy Stéphane
Published: August 2023

We studied the neural mechanisms underlying Parkinson’s disease (PD) speech impairments. We assessed the relationships between the speech impairment in PD and changes in the nigrostriatal system (DAT imaging and neuromelanin-sensitive MRI) and in resting state fMRI functional connectivity within cortical language networks. Patients presented speech alterations depending on gender. Dopaminergic loss in the striatum as well as functional connectivity between the basal ganglia and the cortex were related to PD speech impairments in men, whereas in women only functional connectivity seemed to play a role in PD speech deterioration.
Comparison of vein diameter and susceptibility values in individuals with and without APOE ε4 allele
Authors: Huck Julia , Spreng Nathan , Intzandt Brittany , Group PREVENT-AD Research , Villeneuve Sylvia , Chakravarty Mallar , Bazin Pierre-Louis , Gauthier Claudine
Published: August 2023

Previous studies have shown an increase in oxygen extraction fraction (OEF) in individuals with Alzheimer’s disease (AD). Here, we investigate if vein diameters and susceptibility values measured with quantitative susceptibility maps (QSM), can be used as a biomarker in individuals with the APOE ε4 allele, which confers an increased risk of developing AD for detecting early changes in venous and metabolic properties.
Prediction of MCI conversion using sulcal morphometry
Authors: Sighinolfi Giovanni , Mitolo Micaela , Pizzagalli Fabrizio , Lodi Raffaele , Stanzani-Maserati Michelangelo , Remondini Daniel , Capellari Sabina , Liguori Rocco , Tonon Caterina , Testa Claudia
Published: August 2023

We investigated the capabilities of brain sulcal morphometry and cortical thickness (CT) to predict the conversion from MCI stage to AD and explored the correlation with neuropsychological performance. Sulcal surface, mean depth, length and width were analysed. The width showed the best capability to discriminate between HC, MCI and AD (also in comparison to CT), and was able to distinguish at baseline converter MCI from non-converter MCI. Moreover, the width of specific frontal sulci correlated with memory and language performance.

Sulcal morphometry emerged as a useful tool, capable of providing potential biomarkers for MCI conversion.
Development of 13C MRS measurements of hepatic glutathione production: monitoring oxidative stress in vivo
Authors: Bawden Stephen , Lanz Bernard , Thelwall Peter , Aithal Guruprasad , Gowland Penny
Published: August 2023

Oxidative stress plays a central role in the development of both acute and chronic liver injury, with glutathione being the primary anti-oxidant. This study develops a method of measuring glycine to glutathione flux in vivo using 13C MRS and a novel labelling strategy. Quantification of [2-13C] glycine and [2-13C] glutathione concentrations following glycine ingestion show that the protocol used in this study does successfully enrich the glutathione pool and confirm the assumptions of the metabolic model proposed. This provides a powerful methodology to investigate oxidative stress in patient populations and in response to drug intervention.
Articular Cartilage T2 Relaxation Time Decreases in Regions of Loaded Contact in Cadaver Knees
Authors: Bzowey Natasha , Black Marianne , Cui Lumeng , Thorson Chelsey , Martel Madeline , McWalter Emily
Published: August 2023

The aim of this work was to identify focal changes in T2 relaxation times inside and outside regions of tibiofemoral contact in loaded cadaver knee articular cartilage. We used a cluster analysis approach to identify focal regions of change in T2 relaxation time. We found clusters of increased and decreased T2 relaxation time when the cartilage was loaded; the majority of the clusters of decreased T2 relaxation time were observed within the tibial and femoral cartilage contact area.
Development of in vivo dynamic nuclear polarization (DNP)-MRI at 16 mT for large animals and redox metabolic imaging of acute hepatitis rat model
Authors: Hyodo Fuminori , Eto Hinako , Naganuma Tatsuya , ELHELALY Abdelazim , Murata Masaharu , Noda Yoshifumi , Kato Hiroki , Matsuo Masayuki
Published: August 2023

To use the current methods in clinical practice, the development of a prototype in vivo DNP-MRI system for preclinical examinations of large animals is indispensable for clarifying the problems peculiar to the increase in size of the DNP-MRI device. Therefore, we developed a in vivo DNP-MRI (Overhauser MRI) system with a sample bore size of 20 cm and a 16-mT magnetic field using a U-shaped permanent magnet. The in vivo DNP-MRI system developed was used to non-invasively image the redox reaction of a carbamoyl-PROXYL probe in the livers of large rats weighing 800 g and hepatitis-model rats.
Open-source modular 3D printed platform for in-vivo MRI experiments in awake mice and anesthetized mice and rats
Authors: Gironda Zakia , Vöröslakos Mihály , Wadghiri Youssef , Yaghmazadeh Omid , Alon Leeor
Published: August 2023

Despite their costly nature, the inexactitude of design in off-the-shelf MRI animal holders translates to a fastidious setup, iso-center misalignment, and incorrect animal body positioning. Our open-source 3D-print design provides precise iso-center alignment and minimizes motion artifact using its various head fixing mechanisms. It ensures comfortable positioning for rats and mice during in-vivo anesthetized and awake animal scan acquisition. The modular holder parts enable the same design to be used with other imaging modalities with minimal intervention. The design is low cost, ensures reproducibility and time efficiency of setup.
The effect of gadolinium contrast agent on T1 and T2 relaxation of brain in live and fixed zebrafish MRI
Authors: Hamilton Noémie , Allen Claire , Reynolds Steven
Published: August 2023

Zebrafish have become a ubiquitous animal model for studying a range of diseases and conditions. Typically, these studies are conducted in transparent juvenal fish where optical imaging techniques can be used. However, this is more difficult in adult zebrafish, restricting their use in longitudinal studies. Brain pathology in adult zebrafish can be imaged by preclinical MRI. Administering gadolinium based contrast agents (GBCA), which can also reduce scanning time, can highlight brain abnormalities such as lesions. T1/T2 values have been reported for gadolinium treated fixed/sacrificed zebrafish, however, this has not been reported for live zebrafish.
Evaluating ultra-short echo time (UTE) cerebral blood volume (CBV)-based fMRI using an iron-oxide contrast agent in mouse visual cortex at 9.4T
Authors: Jain Naman , Bollmann Saskia , Polimeni Jonathan , Chuang Kai-Hsiang , Barth Markus
Published: August 2023

CBV-based fMRI has been demonstrated to have better spatial specificity than BOLD. CBV estimates based on iron-oxide contrast agents (CA) reflect this microvascular sensitivity, however because of strong extravascular dephasing CBV changes within large vessels are more difficult to detect. Here, we measured functional CBV changes after injecting CA with UTE-MRI and found positive signal changes (+0.5%) predominantly localized at large vessels at a TE of 0.164ms, and negative signal changes (-2%) at a TE of 4ms localized within the tissue. This indicates sensitivity to different vascular compartments at different TEs reflecting the respective T1 and T2* effects of CA.
SENSE-based multipeak water/fat separation for diffusion-weighted imaging using self-navigated interleaved EPI
Authors: Dong Yiming , Koolstra Kirsten , Riedel Malte , van Osch Matthias J.P. , Börnert Peter
Published: August 2023

The presence of fat signals is one challenge for diffusion-weighted EPI, especially when considering the multi-peak spectrum nature of fat. In this work, we propose an improved SENSE-based water/fat separation algorithm to suppress multi-peak fat signals and apply this specifically to diffusion-weighted multi-shot EPI. The motion-induced shot-to-shot phase variations, an inevitable challenge in multi-shot DWI, are incorporated into the signal model using either a self-navigation or an extra-navigated method. The results show that the proposed SENSE-based algorithm yields good water/fat separation for non-diffusion and diffusion data with a multi-peak fat spectrum model.
COSMOS-Based Susceptibility Estimations: Accuracy Assessment and Comparisons of QSM and Multiple-Angle Acquisitions
Authors: Gkotsoulias Dimitrios , Müller Roland , Schlumm Torsten , Alsleben Niklas , Jäger Carsten , Jaffe Jennifer , Pampel André , Crockford Catherine , Wittig Roman , Möller Harald
Published: August 2023

Calculation Of Susceptibility through Multiple Orientation Sampling (COSMOS) is assessed comparing the optimal, a clinically feasible and multiple-orientation schemes. The optimal COSMOS estimation is used as a gold standard and is compared to the other schemes using the similarity index (SSIM), mean absolute error (MAE) and Pearson’s coefficient (PC). Further comparisons include Thresholded K-space Division (TKD) quantitative susceptibility mapping. For selected white-matter regions, linear regression is used to assess the similarities between the different estimations.
Multiecho sandwich spatial saturation neuromelanin imaging: improved nigral hyperintensity and need for T2* correction in NM-sensitive images
Authors: Ji Sooyeon , Choi Eun-Jung , Sohn Beomseok , Baik Kyoungwon , Kim Eung Yeop , Kim In Seong , Choi Jin Wook , Park Seongbeom , Song Soohwa , Shin Dong Hoon , Lee Phil Hyu , Lee Jongho
Published: August 2023

Multi-echo sandwich spatial saturation neuromelanin (sandwichNMmulti-echo) imaging is proposed to simultaneously acquire a high-quality neuromelanin-sensitive image, a co-localized T2* map, and an improved susceptibility map weighted image for nigral hyperintensity. When this method is applied for PD patients and healthy controls, the results suggest that the reduced neuromelanin contrast in PD is partially explained by shorter T2* in substantia nigra of the PD patients. Initial results at 7T further support the finding, suggesting a need for T2* correction in assessing the NM-sensitive images.
Development and Testing of an In-House Phantom to Assess T2*/R2* Relaxometry Measurements of Liver Iron Concentration
Authors: Goodall Alex , Powell Stephen , Lister Jasmine , Fry Andrew
Published: August 2023

T2* relaxometry measurements of Liver Iron Concentration are demonstrated to be reliable and reproducible in publications. However, no suitable phantom exists for individual hospitals to validate the accuracy, reliability or precision of their methods. We demonstrate a novel phantom mimicking physiological T2* liver values for this purpose. The accuracy of 2 clinical sequences, reproducibility between 2 scanners and reliability of the phantom was investigated.
Explainable multi-contrast deep learning model with anomaly-aware attention for reduced gadolinium dose in CE brain MRI - a feasibility study
Authors: Venkata Srivathsa Pasumarthi , Duffy Ben , Gong Enhao , Zaharchuk Greg , Datta Keshav
Published: August 2023

Complementary information from multi-contrast MRI data is used in deep learning algorithms for reducing contrast dosage in brain MRI. Though existing models produce clinically equivalent post-contrast images, they lack explainability in terms of mapping the source of contrast information from input to output. In this work we explore the feasibility of an explainable deep learning model for gadolinium dose reduction in contrast-enhanced brain MRI.
BOLD PSF: Impact of k-space sampling on T2* contrast
Authors: Engel Maria , Kasper Lars , Pruessmann Klaas
Published: August 2023

The timing of BOLD-fMRI is typically chosen such that TE matches T2*. This assumes contrast being exclusively elicited by signal differences at TE. While sensible for short or TE-symmetric readouts, such as EPIs, it oversimplifies contrast generation for longer or TE-asymmetric trajectories, such as spirals.

We propose the concept of a BOLD PSF for a more comprehensive perspective on the imaging characteristics of a functional experiment. Our findings indicate that TE can be reduced for spiral-out without sacrificing BOLD-sensitivity when compared to EPI. Furthermore, we characterize the intrinsic trade-off between specificity and resolution of the BOLD response under varying TE.