bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving Prostate Cancer Detection Using Bi-parametric MRI with Conditional Generative Adversarial Networks
Authors: Patsanis Alexandros , Sunoqrot Mohammed R. S. , Sandsmark Elise , Langørgen Sverre , Bertilsson Helena , Selnæs Kirsten , Wang Hao , Bathen Tone , Elschot Mattijs
Published: August 2024

This study investigated automated detection and localization of prostate cancer on biparametric MRI (bpMRI). Conditional Generative Adversarial Networks (GANs) were used for image-to-image translation. We used an in-house collected dataset of 811 patients with T2- and diffusion-weighted MR images for training, validation, and testing of two different bpMRI models in comparison to three single modality models (T2-weighted, ADC, high b-value diffusion). The bpMRI models outperformed T2-weighted and high b-value models, but not ADC. GANs show promise for detecting and localizing prostate cancer on MRI, but further research is needed to improve stability, performance and generalizability of the bpMRI models.
Prediction of NF2 Loss in Meningiomas Using T1-Weighted Contrast Enhanced MRI Generated by Deep Convolutional Generative Adversarial Networks
Authors: Dindar Sukru Samet , Buz-Yalug Buse , Tan Kubra , Danyeli Ayca Ersen , Can Ozge , Pamir Necmettin , Dincer Alp , Ozduman Koray , Kahya Yasemin P. , Ozturk-Isik Esin
Published: August 2024

Neurofibromatosis type 2 (NF2) gene mutations have been linked to tumorigenesis in meningiomas. This study aims to improve the prediction of NF2 loss in meningiomas using T1-weighted contrast-enhanced MRI augmented by a deep convolutional generative adversarial network (DCGAN). Synthetically generated MRI increased the training accuracy from 78.9% to 93% and test accuracy from 69.4% to 79.5% in this study.
Synthetic data driven learning for full-automatic hemoperfusion parameter estimation
Authors: Wang Lu , Zhang Pujie , Xing Zhen , Cai Congbo , Chen Zhong , Cao Dairong , Wu Zhigang , Cai Shuhui
Published: August 2024

Hemoperfusion magnetic resonance (MR) imaging derived parameters characterize both endothelial hyperplasia and neovascularization that are associated with tumor aggressiveness and growth. However, the hemoperfusion parameter estimation is still limited by low reliability, high bias, long processing time, and operator experience dependency up to now. In this study, a synthetic data driven learning method for hemoperfusion parameter estimation is proposed. Image analysis shows that the proposed method improves the reliability and precision of hemodynamic parameter estimation in a full-automatic and high-efficient way.
3D Lesion Generation Model considering Anatomic Localization to Improve Object Detection in Limited Lacune Data
Authors: Kim Daniel , Lee Jae-Hun , Al-masni Mohammed , Kim Jun-ho , Choi Yoonseok , Ha Eun-Gyu , Jung SunYoung , Noh Young , Kim Dong-Hyun
Published: August 2024

Recently, research on the detection of cerebral small vessel disease (CSVD) has been mainly implemented in two-stages (1st: candidate detection, 2nd: false-positive reduction). Previous studies presented the difficulty of collecting labeled data as a limitation. Here, we synthesized the lesion through 3D-DCGAN and insert it at different locations on the MR image considering anatomical localization and alpha blending to augment labeled data. Through this, the detecting architecture was simplified to a single-stage, and the precision and recall values were improved by an average of 0.2.
Use of an Automated Approach for Generating vADC for a Large Patient Population Studied with 129Xe MRI
Authors: Babaeipour Ramtin , Mihele Maria , Raguram Keeirah , Fox Matthew , Ouriadov Alexei
Published: August 2024

Hyperpolarized 129Xe lung MRI is an efficient technique used to investigate and assess pulmonary diseases. However, the longitudinal observation of the emphysema progression using hyperpolarized gas MRI-based ADC can be problematic, as the disease-progression can lead to increasing unventilated-lung areas, which likely excludes the largest ADC estimates. One solution to this problem is to combine static-ventilation and ADC measurements following the idea of 3He MRI ventilatory ADC (vADC). We have demonstrated this method adapted for 129Xe MRI to help overcome the above-mentioned shortcomings and provide an accurate assessment of the emphysema progression.
7T MRI in Tourette syndrome and correlations with clinical ratings
Authors: Gkotsoulias Dimitrios , Bujanow Anna , Schmitt Simon , Barthel Henryk , Mueller-Vahl Kirsten , Moeller Harald
Published: August 2024

In this study, we used 7T MRI for identifying potential local associations of Quantitative Susceptibility Mapping (QSM) with tic severity in patients with Gilles de la Tourette syndrome (GTS), as well as T1w volumes for VBM analysis of the cerebellum. Our results indicate direct correlations of tic severity with the QSM values in substantia nigra and other basal ganglia regions, supporting the hypothesis that iron imbalance play a significant role in neurotransmitter dysregulations that lead to the symptomatology of GTS. VBM results show previously unreported GM morphometry alterations in Crus-I, a cerebellar region implicated in visual-motor integration, attention and cognition.
A study of AFQ-based method in adolescents with first-episode treatment-naive major depressive disorder
Authors: Jian Lingyu , Li Junfeng , Li Kefeng , Zhang Xiaoyong , Luo Min
Published: August 2024

The study is to explore the changes of white matter fiber tracts in adolescents with first-episode treatment-naive depression using a DTI-based AFQ method. Adolescent depression can cause damage to multiple white matter fiber tracts. The severity of depression is positively correlated with white matter fiber damage. The depression prediction model established has a certain accuracy in the diagnosis of adolescent depression. White matter fiber tract abnormalities may be the pathophysiological mechanism of depression and can be used as a potential biomarker for the diagnosis of depression.
Alteration in white matter tracts in early onset schizophrenia Using Diffusion tensor imaging
Authors: Kumar Mukesh , Kumaran S Senthil , Pankaj Pankaj , Sagar Rajesh
Published: August 2024

The study investigated white matter tracts disruption in early-onset Schizophrenia (EOS). Our finding revealed decreased white matter tracts fractional anisotropy (FA) and increased radial, axial and mean diffusivity in EOS as compared to controls, suggesting thinner packing of axon and fiber bundle. Disrupted white matter fibers may be associated with impaired neurobehavior in EOS.
Investigation of Triple-Tuned Trap Designs
Authors: Busher Joseph , McDougall Mary
Published: August 2024

Multi-frequency coils are typically known to have substantial losses as compared to their single-tuned counterparts. Here we investigate sensitivity tradeoffs of triple-tuned (1H-23Na-31P) trap designs on receive coils in a tightly controlled experiment to isolate the sensitivity effects of the traps. Triple-tuned LCC traps were shown to have significant improvement in sensitivity for 23Na and 1H as compared to an LC trap design. The increase came at the expense of 31P sensitivity, however continued optimization of the trap design will likely further improve the final experimental SNR.
Signal-to-noise and B1 characterization of linear and quadrature 13C-cryocoils for preclinical MRSI
Authors: Nagel Luca , Topping Geoffrey , Schilling Franz
Published: August 2024

Cryogenically-cooled 13C radiofrequency (RF) coils (cryocoils) improve SNR by reducing thermal coil noise compared to room-temperature coils. Coil geometry impacts B1 patterns, which impact experiment design and must be characterized. The sensitivity profiles of a linear and a quadrature coil were characterized with varied RF powers, which is complicated by transmit B1 variation with position and resulting excitation variations. The sensitivity was compared to a room-temperature volume resonator. The quadrature cryocoil configuration offers better B1 uniformity but lower SNR closest to the coil compared to the linear configuration, both have an overall better SNR performance compared to the volume resonator.
A high impedance radio-frequency system improves the decoupling between receiving coils in MRI
Authors: Tang Yu-Lung , Lee Hsin-Ju , Lin Fa-Hsuan
Published: August 2024

The decoupling between coils significantly impacts the amount of independent information between channels in a receiver coil array. Using a pre-amplifier with a low input impedance is limited by the technology in achieving the lowest possible impedance, typically around a few ohms. Here we propose a strategy to improve the decoupling between coil elements in a receiver array by increasing the impedance of the coil system. Simulations and bench measurements show that increasing the impedance from a typical 50 ohm to around 1,000 ohm can increase the decoupling by 25 dB.
Overlapped or gapped multi-row self-decoupled transmit array: which is better?
Authors: Lu Ming , Cao Zhipeng , Yan Xinqiang
Published: August 2024

This work is aiming to answer which multi-row self-decoupled array outperforms in parallel transmission to generate a uniform transmit RF field (B1+).
The Lord of the EndRings: A roadmap for the design and construction of a Tx/Rx 31P birdcage head coil and feed network at 3 Tesla
Authors: Truong Peter , Stark Helmut , Abraham Agessandro , Zinman Lorne , Near Jamie
Published: August 2024

Join us as we take you on a journey in the development of a Tx/Rx 31P birdcage head coil. Even though there is a wealth of available knowledge explaining the theory of MRI RF coil design, there are many unforeseen situations one will encounter in practice. The road for coil development is filled with many valuable lessons. We hope to provide a practical guide for new builders by describing our experiences in coil design, construction, and troubleshooting.
High-density dipole array for human lumbar spine cord imaging at 7T
Authors: Lu Ming , Chai Shuyang , Yan Xinqiang
Published: August 2024

The Dipole antenna, which has a long longitudinal coverage and deep penetration, has demonstrated a better transmit efficiency for spinal cord imaging compared to the standard loop coil. However, owing to the inevitable coupling, the number of dipoles is highly limited. In this work, we find that the number of dipoles could be doubled if they are be shortened in different ways and arranged to interleave. An 8-channel dipole array consisting of 4 inductor-shortened dipoles and 4 folded dipoles was designed and numerically investigated for 7T lumbar spinal cord imaging.
Hydrogel-based quantitative multi-parametric MRI phantom with controlled T2, diffusion and kurtosis
Authors: Swanson Scott , Lynch Ted , Ono Shigeto , Malyarenko Dariya
Published: August 2024

A set of materials with tunable T2, diffusion, and kurtosis were assembled to create quantitative biomimetic MRI phantoms. T2 is controlled with variable agarose concentration, mono-exponential diffusion by polyvinylpyrrolidone, and kurtosis by addition of lamellar vesicles. The phantoms are mechanically stabilized by polyacrylamide gels to allow biomimetic morphologies. These nanostructured systems provide an ideal platform for moldable multiparametric MRI phantoms that are useful for pulse sequence design and protocol standardization for multi-site multi-vendor imaging trials, as well as for refinement of emerging AI analysis methods.
Establishing absolute temperature scale and diffusion metrics in PVP phantoms for cross-center standardization
Authors: Gai Neville , Dong Ruifeng , Hopkins Jeffrey , Pierpaoli Carlo
Published: August 2024

Clinical acceptance of quantitative diffusion MRI faces difficulties due to lack of standardization. Quality control across platforms and centers is vital for multicenter efforts. Polyvinylpyrrolidone(PVP) phantoms provide excellent properties suitable for cross-center validation. However, diffusion metrics vary with temperature. Measuring phantom temperature along with diffusion metrics is necessary. Spectroscopic temperature mapping of the PVP phantom and ADC values were investigated on two different vendor platforms. It is shown that the water peak moves relative to easily identifiable stable peaks in PVP allowing intrinsic temperature measurement. Excellent agreement for temperature and ADC mapping across both platforms should make cross-site standardization possible.
Long-term QSM reproducibility phantom from a commercially available design
Authors: Pierre Eric , Vaughan David , Syeda Warda , Tahayori Bahman , Pardoe Heath , Abbott David , Jackson Graeme
Published: August 2024

We propose the customization of a commercially-available phantom design to be used for QSM reproducibility research with long-term stability, allowing reproduction of the phantom itself commercially. The proposed phantom is based on master-dilution of Gadolinium in pure water vials, offering long-term stability, with theoretical susceptibility range chosen to match normal tissue and common pathologies in the brain. We evaluate the suitability of the phantom for QSM reproducible research for different sequences, orientation within the scanner and regularization algorithms.
T1 and T2 measurement variability across commercial and prototype 0.55T systems
Authors: Keenan Kathryn , Tasdelen Bilal , Campbell-Washburn Adrienne , Sharma Harish , Javed Ahsan , Ramasawmy Rajiv , Martin Michele , Seiberlich Nicole , Nayak Krishna
Published: August 2024

We compare T1 and T2 measurements between the Free. Max and ramped-down Aera using the ISMRM/NIST system phantom at multiple sites. All 0.55T systems had comparable, to each other, measurements of T1 and T2 on both the NiCl2 and MnCl2 arrays. The T1 measurement of the NiCl2 array by VFA-GRE with B1+correction was overestimated compared to the site-reference by 1% to 92%. The rest of the measurements – MnCl2 T1, NiCl2 T2, and MnCl2 T2 – were within +/-20% of the site-reference and NMR-reference values. As adoption of 0.55T platforms increases, it is important to characterize and compare systems across sites.
Synthesizing CT Image from Single-echo UTE-MRI using Multi-Task Framework
Authors: Xin Zhuoyao , Rao Vishwanatha Mitnala , Liu Dong , Yang Yanting , Tian Ye , Zhang Chenghao , Laine Andrew F. , Guo Jia
Published: August 2024

This abstract proposed a cross-modality conversion method from UTE MRI to CT images. Using the TABS and ResidualAttentionU-net model in a processing framework combining image segmentation and prediction, the skull structure can be extracted from UTE MRI with high similarity of CT based skull. Five UTE-CT image pairs of mouse brains were used in the study. And a 3D-patch based training strategy was adopted, which took the advantage of structural continuity between slices in very limited datasets. The results show that the proposed combined image segmentation and prediction framework can achieve higher accuracy in medical image synthesizing for cross-modality conversion.
Motion Corrected Multi-scale Low Rank Reconstructions for Highly Accelerated 3D Dynamic Acquisitions
Authors: Miller Zachary , Torres Luis , Fain Sean , Johnson Kevin
Published: August 2024

This work develops a method for large-scale motion compensated 4D reconstructions of fully 3D radial acquisitions at near 1mm isotropic spatial resolution and sub-second temporal resolution. We combine and extend multi-scale image reconstruction (Extreme MRI) with k-space based motion field estimation (MOTUS) to solve for a multi-scale low rank representations of both images and motion fields. This combined approach outperforms the multi-scale low rank reconstruction without motion fields.
Multi-contrast multi-resolution UTE for simultaneous quantitative and high-resolution MRI
Authors: Ilbey Serhat , Susnjar Antonia , Emir Uzay , Bock Michael , Özen Ali Caglar
Published: August 2024

A multi-contrast multi-resolution UTE sequence was developed with a dual-echo acquisition between 1-1 binomial water excitation pulses and a conventional UTE readout. This acquisition scheme provides 3 images with different echoes, flip angles, spatial resolution, and contrast (water excitation). T2* was quantified in the whole brain in TA<15min, and UTE images of the brain were reconstructed with 0.5mm isotropic resolution without additional scan time.
Quantitative Ultrashort Echo-Time MRI to Assess In Vivo Rotator Cuff Tendon Degeneration
Authors: Han Misung , Larson Peder , Link Thomas , Lansdown Drew , Feeley Brian , Majumdar Sharmila
Published: August 2024

Rotator cuff tears are a common source of pain and disability. Surgical treatment is normally considered for patients who fail in non-operative management, but a failure of tendon healing after surgery can be dependent on tendon quality. In this work, we applied two ultrashort-echo time (UTE) quantification imaging methods, UTE T2* quantification as well as UTE magnetization transfer (MT) quantification, on healthy subjects and patients with rotator cuff tears, and evaluated their ability to assess tendon degeneration. Significant difference was observed for quantified T2* and MT parameters over segmented supraspinatus tendon between the healthy control and patient groups.
Validation of open-source minimal TE sequences across three independent sites
Authors: Tong Gehua , Gaspar Andreia , Nunes Rita , Nielsen Jon-Fredrik , Vaughan John , Geethanath Sairam
Published: August 2024

We validated five open-source PyPulseq minimal TE sequences (half/full pulse 2D/3D UTEs and COncurrent Dephasing and Excitation (CODE)) at three sites with different scanner models. The ISMRM/NIST T2 array and a porcine muscle and bone sample were imaged. SNR, contrast-to-noise ratio (CNR), and T2 contrast curves were calculated and compared. We found that the sequences were able to recover more SNR from bone tissue compared to vendor GRE (an additional 50% - 1060% for 3T and 34% - 474% for 1.5T) and higher signal for short-T2 spheres but intersite differences existed that were consistent with field strengths.
Deep Learning Pipeline for Preprocessing and Segmenting Cardiac Magnetic Resonance of Single Ventricle Patients from an Image Registry
Authors: Yao Tina , Clair Nicole St. , Gold John , Miller Gabriel , Schidlow David , Ghelani Sunil , Rathod Rahul , Steeden Jennifer , Muthurangu Vivek
Published: August 2024

We have created an end-to-end machine learning pipeline that takes cardiac magnetic resonance scans straight from a registry of single ventricle patients, performs image classification, calculates bounding boxes, and segments the ventricles. The clinical utility of the pipeline is that there is very little human preprocessing required from the clinicians. The pipeline has great robustness as it is trained on multicenter data from different countries, with different scanners, image sizes and aspect ratios, patient ages (relating to heart sizes), and the inherent variability of single ventricle patients. Heart metrics calculated from our pipeline can guide treatment for single ventricle patients.
Improved T1, T2 and PDFF mapping with rosette MRF using virtual-coil + low-rank + patch-based regularization
Authors: Cruz Gastao , Liu Yuchi , Cummings Evan , Hamilton Jesse , Gulani Vikas , Seiberlich Nicole
Published: August 2024

In this work, T1/T2/PDFF mapping with rosette cardiac MRF is improved by exploiting the idea of virtual coils along with subspace constrained reconstruction. The Hermitian symmetry of k-space is explicitly included in the forward model via virtual coils and combined with global low-rank models. This model is further combined with a regularizer leveraging prior information from dictionaries, patch-similarity, and locally low-rank. This virtual-coil + low-rank + patch-based approach is used to jointly reconstruct multi-echo rosette MRF data for improved quality of the final T1, T2, and PDFF maps.
Detection of Congenital Heart Disease in MR images using Machine Learning
Authors: Gabbert Dominik , Petersen Lennart , Burleigh Abigail , Grazioli Simona Boroni , Krupickova Sylvia , Koch Reinhard , Uebing Anselm , Santarossa Monty , Voges Inga
Published: August 2024

We present a new method for detection of hypoplastic left heart syndrome (HLHS) based on the spatial arrangement of 7 distinctive anatomical landmarks in CMR images. The method was applied to the axial SSFP CMR scans of 46 patients with HLHS and 33 healthy controls. A tailor-made U-net-like deep convolutional network (CNN) with a shared 3D-convolutional encoder backbone and 7 segmentation heads was used for prediction of landmarks. Classification based exclusively on the coordinates of the detected landmarks had an accuracy of 98.7%. In future studies, the method may be applied to HLHS subgroups or other cardiac diseases.
Assessment of cardiac function using free-breathing, motion corrected artificial intelligence cine: comparison with conventional cine
Authors: Ran Lingping , Huang Lu , Yan Xianghu , Zhao Yun , Xia Liming
Published: August 2024

Routine cardiac functional assessment with conventional balanced steady state free precession (bSSFP) cine sequence generally requires multiple breath-holding (BH) and long examination time. The purpose of this study was to evaluate the image quality and bi-ventricular functional analysis using a novel free-breathing (FB) artificial intelligence (AI) cine method with motion corrected (MOCO) in a clinical context. Compared to conventional multiple BHs cine, the proposed FB-MOCO AI cine method achieved comparable image quality with shortened scan times. No significant difference in ventricular volumetric and functional parameters were found, suggesting its potential applicability for clinical applications.
Evaluation of image quality and global cardiac function for deep learning accelerated cardiac Cine
Authors: Zhu Xucheng , Kaushik Suryanarayanan , Chan Frandics , Atkins Melany , Nagpal Prashant , Busse Reed , Janich Martin
Published: August 2024

Cardiac bSSFP Cine is widely used clinically; however, it is time consuming and requires multiple breath-holds. Deep learning-based accelerated Cine (DLCine) is a novel technique combining accelerated variable density sampling and deep learning regularized reconstruction that allows much higher acceleration compared to conventional Cine with parallel imaging. The purpose of this work was to compare image quality and global cardiac function utilizing DLCine versus conventional Cine by three expert readers. The results demonstrate that DLCine can be used to reduce the scan time while maintaining image quality and providing accurate global cardiac function measurement.
Testing the potential of DWI-based virtual elastography in patients with brain cancer
Authors: Svensson Siri , Geier Oliver , Fuster-Garcia Elies , Ager-Wick Gunnhild , Bugge Robin , Farstad Anne-Hilde , Skogen Karoline , Emblem Kyrre
Published: August 2024

A previous study in the liver suggested that DWI can be used for virtual elastography. Here, we investigate the potential correlations between DWI-derived parameters and MR elastography (MRE) stiffness measurements in sixteen patients with brain cancer. The highest cross-correlation was obtained between stiffness and the shifted ADC map with b-values 1000 and 3000 s/mm² (median cross correlation 0.91). However, no correlation between mean values of MRE and sADC1000,3000 was found in normal-appearing white and gray matter, nor in tumor regions. This could be due to a too simple diffusion model and the anisotropic tissue structure of the brain.
Response of Brain Tissue Mechanical Properties to Applied Pre-Strain in Magnetic Resonance Elastography
Authors: Bailey Olivia , Diano Alexa , Lateef Ali , Corbin Elise , Johnson Curtis
Published: August 2024

This study uses magnetic resonance elastography (MRE) with incremental compression to measure the apparent viscoelastic properties of bovine brain tissue as pre-strain is applied. Results from our tissue-agar phantom showed an increase in stiffness, and a decrease in damping ratio for the bovine brain. The agar showed an increase in stiffness and no consistent change in damping ratio. This research serves as the foundation for future studies measuring the nonlinear properties of human cadaveric brain tissue. Output from this work will be instrumental in advancing current traumatic brain injury (TBI) models.
Intrinsic MR elastography for classification of focal liver lesions using normalized viscoelastic parameters: a pilot study
Authors: Najar Amirhosein Baradaran , Karam Elige , Gilbert Guillaume , Barat Maxime , Montagnon Emmanuel , Castel Hélène , Giard Jeanne-Marie , Nguyen Bich , Cloutier Guy , Tang An , Van Houten Elijah
Published: August 2024

Intrinsic activation MR elastography (iMRE) method has been applied to a cohort of patients undergoing liver MRI for assessment of focal liver lesions. We used segmentation, masking, and normalization of viscoelastic parameters to investigate the capability of this method to differentiate benign and malignant liver lesions. The normalized storage modulus (G') computed by nonlinear inversion-iMRE showed significant differences between benign and malignant lesions.
Quantifying inhomogeneity of kidney, liver and muscle before and after the freeze-thaw cycle using 1-Norm waveform analysis and MR elastography
Authors: Reiter Rolf , Palnitkar Harish , Majumdar Shreyan , Crutison Joseph , Lin Shujun , Royston Thomas , Klatt Dieter
Published: August 2024

The recently developed 1-Norm technique can be used to quantify the extend of scattering of mechanical waves generated by inhomogeneities. This explorative study shows that 1-Norm can detect mechanical inhomogeneity of ex vivo kidney, liver and muscle without the need to use ill-posed wave inversion techniques. The 1-Norm technique has potential to serve as an MRE-based diagnostic biomarker independent of stiffness for the characterization of pathological conditions associated with changes in tissue mechanical inhomogeneity.
Sagittal free-breathing MR elastography of the pancreas with motion-correction at 3T
Authors: van Schelt Anne-Sophie , Wassenaar Nienke , Runge Jurgen , Stoker Jaap , Nederveen Aart , Schrauben Eric
Published: August 2024

Breathing motion can be detrimental to quantitative accuracy in pancreatic MR elastography (MRE). We investigated motion-correction strategies on sagittal multi-frequency free-breathing SE-EPI MRE acquisitions to mitigate breathing-motion and increase accuracy. Breathing-states were determined through a respiratory-belt and multiple number of bins were tested. Three intensity-based registration methods (with and without non-rigid post-processing) and non-rigid registration were ranked on MRE quality measures. The best method showed improved data quality, inversion precision and repeatability compared to no correction, but resulted in apparently increased shear wave speed (SWS), which warrants further investigation.
Repeatability of multifrequency MR elastography in pancreatic ductal adenocarcinoma patients and healthy volunteers
Authors: Wassenaar Nienke , van Schelt Anne-Sophie , Schrauben Eric , van Laarhoven Hanneke , Stoker Jaap , Nederveen Aart , Runge Jurgen
Published: August 2024

MR elastography (MRE) could be useful as an imaging biomarker in pancreatic cancer. To this end, pancreatic MRE parameters should be repeatable and be able to differentiate between healthy and tumour tissue. In this study, 10 patients with pancreatic ductal adenocarcinoma and 8 sex- and age-matched healthy volunteers underwent three MRE scans in a test-retest set-up. Results showed that MRE parameters were repeatable in patients and healthy volunteers. Furthermore, a significant increase in shear wave speed was found in pancreatic tumours compared to healthy pancreatic tissue.
Investigating Variable Density Sampling Patterns in Spiral Trajectories for use in MREPT
Authors: Özdemir Safa , Ilicak Efe , Schad Lothar , Zöllner Frank
Published: August 2024

Magnetic Resonance Electrical Properties Tomography (MREPT) is used for obtaining conductivity by utilizing B1 phase images. In order to obtain B1 phase, different pulse sequences can be used. Among these, spiral trajectory based imaging has various advantages including high SNR efficiency and acquisition speed and was demonstrated in MREPT previously. In this work, to further improve spiral trajectory based imaging in MREPT, we investigate variable density sampling patterns. In vivo brain results indicate that conductivity images are quite robust with the choice of undersampling pattern and whole brain coverage can be completed under a minute with multiple averages.
Brain water-content based Electrical Properties Tomography in healthy volunteers, tumor and multiple sclerosis patients
Authors: Mandija Stefano , Jacobs Sarah , Kleinloog Jordi , Liu Hongyan , van der Heide Oscar , van der Kolk Anja , Sbrizzi Alessandro , van den Berg Cornelis
Published: August 2024

In this work, we first extend the validation of the water-content based Electrical Properties Tomography (wEPT) model from brain white matter to gray matter conductivity reconstructions in healthy volunteers. Secondly, we show that wEPT reconstructions calibrated on 10 healthy volunteers from an MR-STAT clinical trial dataset show a conductivity increase in pathological regions for 6 primary brain tumor and 9 multiple sclerosis (MS) patients from the same study. For diffuse glioma, a positive correlation between grade and conductivity is observed. For MS white matter lesions a clear conductivity increase is observed compared to healthy white matter.
Spiral readout improves in vivo MR axon radius estimation in human white matter
Authors: Veldmann Marten , Edwards Luke , Pine Kerrin , Ehses Philipp , Weiskopf Nikolaus , Stöcker Tony
Published: August 2024

We compared spiral and EPI diffusion imaging at ultra-high b-values for axon radius estimation in the white matter. For data acquisition, a custom multiband spiral sequence was combined with trajectory monitoring and higher order image reconstruction. The lower echo time of the spiral sequence led to increased relative SNR compared to EPI and improved estimation of axon radii. The resulting axon radius maps from spiral scans were more homogeneous especially in low-SNR regions. We also found, that denoising performed on complex data instead of magnitude data significantly improved axon radius estimation.
Integrating intravoxel incoherent motion and diffusion tensor MRI of the brain into a single fast acquisition - a model-selection study
Authors: Dietrich Olaf , Cai Mengfei , Tuladhar Anil , Jacob Mina , Drenthen Gerald , Jansen Jacobus , Marques José , Ricke Jens , de Leeuw Frank-Erik , Duering Marco , Backes Walter
Published: August 2024

The acquisition of IVIM and DTI data of the brain can be integrated into a single measurement, which offers the possibility to determine orientation-dependent (tensorial) perfusion parameters in addition to established IVIM and DTI parameters. The purpose of this study was to evaluate the feasibility of such an integrated IVIM-DTI protocol with a clinically feasible scan time below 6 minutes and to establish the maximum number of DTI and IVIM tensor parameters that can reliably be determined with this approach by comparing 17 different IVIM-diffusion models with 4 to 19 model parameters.
Single-shot water/fat separation T2* mapping with multiple overlapping-echo detachment imaging
Authors: Lin Qing , Chen Weikun , Wu Jian , Kang Taishan , Chen Xinran , Wu Zhigang , Cai Shuhui , Cai Congbo
Published: August 2024

Most of the water/fat separation techniques need to acquire multiple images with different echo time, which usually take long acquisition time. Multiple overlapping-echo detachment (MOLED) imaging can shorten acquisition time by acquiring multiple MR echo signals in the same k-space. Here, a new method for fast water/fat separation T2* mapping with MOLED technology was proposed, which can obtain quantitative T2* maps and M0 maps of water and fat in a single shot. In vivo experiment demonstrates that the proposed method can obtain accurate quantitative parameter values and accurate separation of water and fat images.
Constraint function for IVIM quantification using unsupervised learning
Authors: Lee Wonil , Kang Beomgu , Lee Jongyeon , Fakhri Georges , Ma Chao , Han Yeji , Chung Jun-Young , Noh Young , Park HyunWook
Published: August 2024

Recently, various methods have been proposed to quantify intravoxel incoherent motion parameters. Many studies have shown that quantification methods using deep learning can accurately estimate IVIM parameters. Unsupervised learning is useful when quantifying IVIM parameters for in-vivo data because it does not require label data. However, in some cases, loss function does not converge as iteration increases. Constraint functions can be used to solve these problems by limiting the range of estimated outputs. In this study, we investigated the effects of constraint function to limit the range of estimated output.
Glioma Classifications with 7T MR Spectroscopic Imaging
Authors: Sharma Sukrit , Cadrien Cornelius , Lazen Philipp , Gilbert Hangel , Licandro Roxane , Bogner Wolfgang , Widhalm Georg
Published: August 2024

To contribute to better tumour classification and thus enhancing patient outcomes, we statistically analysed metabolic maps of 37 glioma patients obtained using high resolution 7T MRSI. We tested and optimised different semi-supervised learning based classification approaches. Random forest classification of IDH mutation status and tumour grade in clinical imaging based segmented tumour regions yielded high diagnostic accuracy with AUC of 86% and 99% respectively. We found Glu, Gln, GSH, tCho, Ins, Gly and tCr as important determining features. These are similar to comparable SVS studies while providing the advantage of whole-brain coverage.
3D CNN for Oxygen Extraction Fraction Mapping with combined QSM and qBOLD
Authors: Kinz Patrick , Schad Lothar
Published: August 2024

We developed a CNN for OEF mapping from QSM+qBOLD data, which utilizes utilizes 3D convolutional layers. Two dimensions for the spatial components of an image and one dimension for the temporal component in the qBOLD data. The results are an improvement over our previous 2D CNN, but even the more advanced network architecture struggles with voxels, that have a very low deoxyhemoglobin content. In this abstract we also study with simulated data when the CNN produces reliable results and when it predicts default values for the reconstructed parameters instead.
The diagnostic value of mean apparent propagator (MAP) MRI in temporal lobe epilepsy (TLE) with unilateral amygdala enlargement: A pilot study
Authors: Zu Lu , Zhao Peng , Liu Mengxiao , Li Xiaoli , Zhang Wei , Cheng Yani , Lin Xiangtao
Published: August 2024

For patients with routine MRI-negative epilepsy, noninvasive imaging is important for differential diagnosis. AE might be a subtype of MRI-negative TLE. The aim of this study was to evaluate the diagnostic efficacy of MAP-MRI and traditional DTI between TLE-AE patients and healthy controls. Results showed that MSD, QIV, RTAP, RTOP from MAP-MRI and FA from DTI in amygdala can be used as an imaging indicator to identify TLE-AE(P<0.05). Furthermore, MSD, RTAP, RTOP had a significant correlation with seizure types. MAP-MRI outperformed DTI in the diagnosis of TLE-AE, and MAP-MRI is expected to contribute in probing MRI-negative epileptogenic lesions.
The potential value of PCASL in reflecting cognitive performance for older adults with MRI-negative epilepsy
Authors: Yin Xuyang , Wang Jianhong , Zeng Yanwei , Xiao Zhenxu , Fu Junyan , Zhao Qianhua , Ding Ding , Zhang Jun
Published: August 2024

Older adults with epilepsy accompanied by cognitive impairment represent a huge proportion, which calls for novel clinical techniques for early diagnosis and intervention. By applying pseudo-continuous arterial spin labeling (PCASL), we identified whole-brain voxel-based perfusion pattern of epilepsy associated with cognitive impairment, and explored correlations between cerebral blood flow (CBF) and domain-specific cognitive performance. The enrolled patients exhibited decreased CBF mostly in the bilateral frontal lobes, and there were positive associations between mean CBF and memory as well as executive function. Therefore, CBF measured by PCASL may be a useful indicator for cognitive performance in older adults with MRI-negative epilepsy.
T2 mapping with GRAPPATINI in temporal lobe epilepsy improves epileptogenic zone characterization: a pilot study
Authors: Bonacci Maria Celeste , Caligiuri Maria Eugenia , Sammarra Ilaria , Kober Tobias , Zacà Domenico , Fortunato Francesco , Gambardella Antonio
Published: August 2024

The use of qMRI techniques in the routine imaging assessment of epilepsy patients may improve sensitivity in detecting subtle MRI abnormalities which can further aid lateralization and localization of the epileptogenic zone. T2 relaxometry might be a promising tool for a better and non-invasive lateralization of the epileptogenic zone, as well as for identifying lesions that are not visible on standard MRI.
Epileptogenic periventricular nodular heterotopia BOLD fluctuations are anti-correlated to non-epileptogenic nodular heterotopias
Authors: Lowe Mark , Lin Jian , Nemani Ajay , Morris Spencer , Krishnan Balu , Martinez David , Bulacio Juan , Jones Stephen , Najm Imad , Wang Irene
Published: August 2024

In this study, using a limited sample size, we establish with 95% confidence that epileptogenic and non-epileptogenic periventricular nodular heterotopias can be distinguished based on their relative resting state connectivity
Design and Production of a 3D Printed Anthropomorphic Head Phantom for MRI – The Story so Far
Authors: Bruce George , Hall-Barrientos Pauline , Brennan David
Published: August 2024

Commercial phantom objects for use in MR can be expensive and poorly representative of human anatomy. 3D printing provides the potential to produce cheaper, novel and reproducible phantoms. This project investigates the potential use of 3D printed materials in the construction of an anthropomorphic head phantom for MRI. It can be effectively split into two different, smaller projects: investigation into MR properties of 3D printed materials and design of an anthropomorphic head phantom for MRI.
Design and Validation of a Multi-Modality Lung Phantom
Authors: Bowen Donald , Touchet Tyler , Maitland Duncan , McDougall Mary
Published: August 2024

Phantoms often mimic only one specific property of the body, and without relevant anatomical structure. We report the design and construction of an anatomic phantom that accurately mimics the in vivo properties of the lungs for both ultrasound and magnetic resonance imaging. The phantom demonstrated qualitative likeness to the lungs under ultrasound and quantitatively similar tissue relaxation characteristics using magnetic resonance imaging. Future work will determine if the phantom can be used to validate early-stage medical devices that operate within the lungs.
Do anthropomorphic phantoms enhance compliance with the professional bodies' quality assurance guidelines for MRI in radiotherapy
Authors: Alzahrani Meshal , Broadbent David , Teh Irvin , Al-Qaisieh Bashar , Walker Adrian , Lamb Rachel , Speight Richard
Published: August 2024

With the increasing use of magnetic resonance imaging (MRI) in radiotherapy (RT), guidelines for the use of MRI in RT have recently been published, including recommendations for quality assurance (QA) tests. This project investigates whether anthropomorphic phantoms can be more beneficial to comply with these guidelines compared to other phantoms. The performance of the anthropomorphic phantom has been compared to other phantoms. The anthropomorphic phantom has been shown to be useful in QA for MRI-CT registration and end-to-end test that cannot be performed by other phantoms.
Imaging-Based Subject-Specific SAR Maps using B1-mapping and Electrical Properties Tomography in a heterogenous Brain Phantom
Authors: Martinez Jessica , Troia Adriano , Arduino Alessandro , Moulin Kevin , Zanovello Umberto , Bottauscio Oriano , Zilberti Luca
Published: August 2024

In this work a heterogeneous realistic brain phantom, with electric and magnetic properties in the range of healthy gray-matter and white-matter, was constructed. The phantom was scanned at 3 T where T1 maps, T2 maps, magnitude, and phase information of the B1 field were acquired. The electrical conductivity was derived using a convection reaction EPT approach and the E field was obtained by solving Ampere’s law from the B1 field. From this information, imaging-based subject-specific SAR maps were acquired and compared to simulation-based SAR maps. The analysis time (acquisition and SAR calculation) was under 6 minutes.
What should I use to fill my Ultra-high Field MRI phantom?
Authors: Horger Felix , Mangal Jyoti , Tomi-Tricot Raphael , Carmichael David , Hajnal Joseph , Malik Shaihan
Published: August 2024

We explored commonly used substances for phantoms, air, water, oil and Perfluoropolyether, for their suitability for imaging at ultra-high field (7T). We illustrate the impact of susceptibility matching and how to prevent transmit field doming by selecting a substance with low dielectric constant. This work provides insights into the variety and expected magnitude of effects and can serve as guidance when designing a phantom for a specific application.
Quantitative and qualitative analysis of left ventricular remodeling after myocardial infarction: 4D flow MRI in a swine model
Authors: Huh Hyungkyu , Park Sungho , Ahn Yura , Koo Hyun Jung , Yang Dong Hyun
Published: August 2024

Left ventricular remodeling and functional changes may affect the intra-cardiac hemodynamics, however, has not yet been systematically studied. This study provides comprehensive understanding on chronic hemodynamics changes after myocardial infarction (AMI) in a swine model by using sequential cardiac magnetic resonance imaging (MRI) and 4D flow MRI. The orientations of infilling blood flow and vortex cores were shifted due to the infarcted tissue, decreasing the local rotation of the intracardiac flow as MI progresses. It’s trends also correlated well with the decreased radial strain and global function. These findings may provide new hemodynamic based diagnosis markers for MI.
Comparing 129Xe gas MRI across major MRI vendors and sites
Authors: Rolland Asu , Willmering Matthew , Cleveland Zackary , Hahn Andrew , Fain Sean , Mata Jaime , Mugler John , Driehaus Bastiaan , Woods Jason
Published: August 2024

Multi-site studies and clinical hyperpolarized 129Xe are imminent, yet image quality is challenging to quantify across MR platforms since hardware, gradient-corrections, and data-filtering are proprietary. We developed a straightforward protocol for scanning a commercial, thermally-polarized 129Xe phantom, and implemented it across three major MRI vendors, with near-identical coils. Images were acquired at 5 sites (Cincinnati, Iowa, Wisconsin, Duke, and Virginia). SNR was 18.4±1.6, with low variation in SNR between sites (13%), and vendors (10%). This confirms the ability to quantitatively compare signal and noise across sites and vendors. It is also demonstrated, here, that quality control can be implemented simply in multi-site studies.
Framework for Internal Gradient Distribution Tensors to characterize tissue microstructure with MRI
Authors: Pérez Leonardo Pedraza , Álvarez Gonzalo
Published: August 2024

Typically MRI resolution is limited to millimeters in clinical scanners, but other sources of information, derived from diffusion processes of water in biological tissues, allow us to get information at micrometric scales. Here we consider extracting morphological information by probing the internal magnetic gradients induced by the heterogeneous magnetic susceptibility of tissues. From the cumulant expansion of the magnetization signal we derive an internal gradient distribution tensor (IGDT) expansion and propose modulating gradient spin-echo sequences to probe them. These IGDTs contains microstructural information of tissues. Our results provide a framework to describe IGDTs to exploit them as quantitative diagnostic tools.
Multicontrast ZTE Neuroimaging with T1-Shuffling
Authors: Wood Tobias , Ljungberg Emil
Published: August 2024

We show that multiple clinical contrasts can be obtained from silent Zero Echo Time scans by using preparation pulses and a physics-informed subspace "T1-shuffling" reconstruction approach. This models and removes the effect of T1-recovery during the readout segment, which would otherwise wash out the desired contrast.
Optimized B0 and B1+ insensitive RF pulses for non-selective T2 and diffusion preparation
Authors: Zhou Xuetong , Hargreaves Brian , Lee Philip
Published: August 2024

The performance of conventional T2 or diffusion preparation using linear phase pulses or adiabatic pulses is limited by the B1+ and B0 field inhomogeneities, particularly relevant in body imaging. In this work, we proposed a numerical optimization strategy to design RF pulse pairs for non-selective T2 or diffusion preparation that perform robustly over a wide range of B1+ and B0 variations. Phantom and in vivo experiments compared the performance of preparation using the optimized pulses to that of linear-phase and adiabatic pulses.
Apparent diffusion coefficient in the low-frequency limit when measured with oscillating-gradient spin-echo diffusion-weighted imaging
Authors: Kershaw Jeff , Obata Takayuki
Published: August 2024

The target of oscillating-gradient spin-echo diffusion-weighted imaging (OGSE-DWI) is the spectral density of molecular diffusion, $$$u_2(\omega)$$$, which is predicted to obey a set of asymptotic universality relations that are linked to the global organisation of the sample. In principle, the complex microstructure of a medium can be classified by measuring the spectral density in its low- and high-frequency limits. However, the quantity most often measured with OGSE-DWI is the apparent diffusion coefficient (ADC). It was the purpose of this study to investigate how the low-frequency asymptotic behaviour of the spectral density is reflected in the ADC.
A Channelized Front-End for Single Port Multi-Tuned RF Coils
Authors: Bauer Courtney , Hou Jue , Sun Chenhao , Wright Steven
Published: August 2024

Increased interest in simultaneous and interleaved MR imaging and spectroscopy has led to the increased interest in multi-tuned coils and coil arrays. The introduction of single port, multinuclear coils resolves the complexity resulting from nested coils, but introduces new challenges in optimization of signal conditioning. Presented here is a channelization approach that enables frequency specific gain and filtering of signals from single port multinuclear coils.
An 8-channel Transmit Array for Prostate MRI at 7T Using Six Loops and Two Dipoles: A Simulation Study.
Authors: Polpudenko Aleksej , Porter David , Gunamony Shajan
Published: August 2024

Prospective 8 channel (6Tx loop + 2Tx dipole) body array intended for prostate MRI at 7T was simulated and its B1+ and SAR performance evaluated. The study demonstrated the capability of loop-based arrays to offer competitive levels of prostate imaging performance compared to current state-of-the-art hybrid and dipole arrays reported in the literature.
Glutamate in the visual cortex changes within the migraine cycle in children and adolescents
Authors: Cho Lydia , Bell Tiffany , Godfrey Kate , Hershey Andrew , Kuziek Jonathan , Stokoe Mehak , Millar Kayla , Orr Serena , Harris Ashley
Published: August 2024

Migraine is a common neurological disorder in pediatrics, yet the pathophysiology remains unclear. Migraine is characterized by episodic attacks, suggesting a shifting excitation-inhibition imbalance that when tipped, will trigger an attack. We used magnetic resonance spectroscopy to measure glutamate and gamma-aminobutyric acid (GABA) concentrations to examine changes in these brain metabolites across different phases of the migraine attack in children and adolescents. We show fluctuations in glutamate with migraine cycle phases in the visual cortex. There were no observed changes in glutamate nor GABA in the sensorimotor cortex and the thalamus.