bluuebunny/crossref_metadata_2025 huggingface dataset:
Whole-heart simultaneous CINE T2mapping and coronary MR angiography
Authors: Kodaira Kazuo , Yoneyama Masami , Nagao Michinobu , Kato Mana , Ogawa Takumi , Hamatani Yutaka , Shiina Isao , Goto Yasuhiro , Sakai Shuji
Published: August 2024

T2mapping is generally obtained only in diastole. However, because myocardial edema can affect both diastole and systole, acquisition of T2mapping of different cardiac phases is desirable. In addition, CMRA is also necessary in post-MI. However, scanning all these sequences prolongs exam time and increases patient stress. To overcome this limitation, we report a new T2mapping technique that enables quantitative systolic and diastolic T2mapping and CMRA acquisition in one scan by using dynamic trigger delay. In this study, we demonstrate the feasibility of this approach in healthy volunteer examination.
Ungated and free-breathing radial simultaneous multi-slice cardiac T1 mapping
Authors: Le Johnathan , Mendes Jason , Sideris Konstantinos , Stehlik Josef , Wilson Brent , DiBella Edward , Adluru Ganesh
Published: August 2024

Cardiac T1 mapping has been shown to be a promising method for assessing different cardiomyopathies. Most cardiac T1 mapping methods require ECG gating with long breath holds to capture specific desired cardiac phases and to minimize breathing motion. However, certain cardiomyopathies can make it difficult for patients to maintain a breath hold for the duration of a cardiac T1 mapping sequence. Furthermore, some of these diseases, for example atrial fibrillation with changing R-R intervals can make capturing a specific cardiac phase difficult. Here we propose a radial simultaneous multi-slice (SMS) cardiac T1 mapping sequence without ECG gating or breath holding.
Novel myocardial T1 analysis robust to transient longitudinal relaxation due to irregular heart rate variability in PCTIP
Authors: Endo Yuta , Takahashi Sanae , Shibo Haruna , Kobayashi Kuninori , Amanuma Makoto , Kuhara Shigehide
Published: August 2024

Myocardial T1 mapping by polarity-corrected inversion time preparation (PCTIP) is expected to reduce measurement underestimation compared to the MOLLI method. However, measurement precision is reportedly reduced, especially for heart-rate variability. We devised an analysis to overcome this problem in PCTIP and showed that it improved measurement accuracy at high heart rates. Conventional analysis has difficulty fitting to this complex T1 relaxation, resulting in less accurate and precise measurement of longer T1. T1 analysis of PCTIP using the proposed analysis showed the potential to achieve accurate and precise T1 measurements, even for irregular heart rate variability.
Cardiac MRI including myocardial T2 mapping for the differentiation of AL and ATTR amyloidosis
Authors: Kravchenko Dmitrij , Isaak Alexander , Mesropyan Narine , Pieper Claus , Kuetting Daniel , Bischoff Leon , Attenberger Ulrike , Luetkens Julian
Published: August 2024

Cardiac amyloidosis can be visualized on CMR, but to date no reliable imaging parameters exist to distinguish the two most common forms of cardiac amyloidosis, AL and ATTR. Retrospective analysis of 37 cardiac amyloidosis patients shows that T2 times are markedly elevated in AL compared to ATTR, and in both compared to a control group of patients with other reasons for cardiac hypertrophy. Myocardial T2 mapping may be a useful CMR parameter for the differentiation of AL and ATTR cardiac amyloidosis. Keywords: amyloidosis, cardiac, MRI, CMR
Whole-brain fMRI study of mice under medetomidine/ketamine anesthesia to identify brain regions activated by musk odors
Authors: Yoshinaga Sosuke , Tsubakihara Yumiko , Fukumoto Takayuki , Maita Shotaro , Takeda Mitsuhiro , Terasawa Hiroaki
Published: August 2024

Muscone, a major component of musk odor, attracts male mice. The odor-evoked behaviors are mediated by neural circuits activated by the stimulation. We have been working on whole-brain BOLD fMRI studies of mice, using a method that employs periodic odor stimulation and independent component analysis. In this study, we investigated the brain regions activated by muscone in mice under medetomidine and low-dose ketamine anesthesia. Ketamine reportedly exhibits disinhibition of glutamate signaling at a low dose. As the result, we identified numerous muscone-evoked activated regions located in the olfactory pathways and higher-order regions in the cerebrum.
DeepGraspT1: Deep Learning-Enabled GRASP T1 Mapping
Authors: Pei Haoyang , Xia Ding , Liu Fang , Feng Li
Published: August 2024

Golden-angle RAdial Sparse Parallel (GRASP) MRI has recently been extended for rapid, accurate and robust T1 mapping (GraspT1) that can be performed during free breathing. However, GraspT1 implements a conventional T1 mapping framework that reconstructs an image series from undersampled dynamic k-space in the first step and then performs pixel-wise parameter fitting in the second step. This leads to a slow and cumbersome pipeline to obtain T1 maps. In this work, we developed deep learning-based GraspT1 (DeepGraspT1), which directly estimates T1 maps from undersampled k-space and enables additional acceleration that outperforms conventional iterative reconstruction.
Fouier Convolution Nerual Network for MRI reconstruction
Authors: Sun Haozhong , Li Yuze , Yang Runyu , Li Zhongsen , Chen Huijun
Published: August 2024

Various image reconstruction methods have been proposed to reduce Magnetic resonance (MR) image acquisition time. One of recent trends is convolution neuron network (CNN) based deep learning model. However, most of these CNN models keep architecture of stacking small filters (e.g. 1×1 or 3×3) and the effective receptive field of these networks is limited, which is undesired for reconstruction because the random undersampling pattern causes global artifact. We proposed Fourier convolution block (FCB) to replace regular convolution filters. FCB can achieve both global receptive field and high computing efficiency by multiplication in frequency domain.
Self-Supervised Denoising for Longitudinal MRI
Authors: Hemsley Matt , Lawrence Liam , Lau Angus
Published: August 2024

In MR guided radiation therapy, images of patients are acquired daily. However, scan times are long to acquire images with an acceptable SNR for treatment planning and adaptation. In this study we test a self-supervised machine learning based approach for denoising data that can utilize previous scans of the same patient to improve quality of the denoised image. Results on a numerical phantom and clinical images are presented and compared to a popular non-machine learning denoising algorithm.
Relationship between the properties of paraspinal muscles and bone mineral density in patients with lumbar disc herniation
Authors: Li Ze , Fu Min , Yuan Xiaochun , Liang Huilou , Chen Junrong
Published: August 2024

Paraspinal muscles and vertebral bodies are important to maintain spinal stability. Muscles and bones are functional tissues that interact with each other. We investigated the relationship between the properties of paraspinal muscles obtained from MR imaging and bone mineral density of vertebral bodies measured from quantitative CT in patients with lumbar disc herniation (LDH). Our results showed that the fat fraction of paraspinal muscles was negatively correlated with bone mineral density of vertebral bodies in LDH patients, and the fat fraction of multifidus muscle at the L3/L4 lumbar disc level may be the optimal predictor of bone mineral density changes.
Towards patient-friendly arterial-spin-labeling MRI in muscle: Effect of exercise intensity and standardisation on perfusion parameters
Authors: Cameron Donnie , Schrama Esther , Boogaarts Linde , Veeger Thom , Baligand Celine , Hirschler Lydiane , van Osch Matthias , Kan Hermien
Published: August 2024

Perfusion is fundamental to muscle function, and is limited in muscular dystrophies—representing a promising biomarker for clinical trials. However, in-magnet exercise paradigms for measuring ASL perfusion are seldom standardised and require high-intensity exercise, which is impracticable in patients. In volunteers, we tested the acceptability of three protocols: two standardised paradigms with different intensities, and a non-standardised paradigm at a single intensity. Exercise standardisation improved SNR. In general, muscle blood flow, T2*, and SNR decreased, while arterial transit time increased with time after exercise; T2* was higher after high-intensity exercise. SNR at lower exercise-intensity was insufficient for robust perfusion-parameter estimation.
lower limbs skeletal muscle perfusion evaluation with the Fourier decomposition technique
Authors: Qu Jianxun , Lin Tianye
Published: August 2024

This study incorporated the Fourier decomposition (FD) technique to the lower extremity blood oxygen level-dependent, or reactive hyperemia, technique to evaluate the perfusion level of lower limbs. A periodically repeated ischemia-reperfusion paradigm was used to support the frequency analysis in FD. A characteristic frequency intensity corresponding to the ischemia-reperfusion cycle frequency was observed. The feasibility of the proposed method was demonstrated on healthy subjects.
Design of dual-band Coaxial‐transmission‐line coils with independent tuning capabilities
Authors: Payne Komlan , Bhosale Aditya , Zhao Yunkun , Zhang Xiaoliang
Published: August 2024

Recently, intensive research has been conducted on coaxial‐transmission‐line (CTL) RF coils for nuclear magnetic resonance (NMR) at frequency ranging from high field to ultra-high field. The flexibility of CTL is to some extent required to image dynamic anatomy of the human body. Analysis on the CTL coils based on transmission line theory has revealed multimode operating frequency. Consequently, CTL coils can be useful to implement dual-nuclear RF coil resonator designed for Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS). In this abstract, we design a dual-band CTL with independent tuning capabilities.
Evaluation of 8-Channel Transmit Dipoles and 8-Channel Transmit Loops for Pediatric Visual Cortex Imaging at 7T
Authors: Yazdanbakhsh Pedram , Sprang Christian , Couch Marcus , Hoge Richard , Tardif Christine , Rudko David
Published: August 2024

An 8-channel transmit radiofrequency (RF) coil array consisting of eight dipoles and another 8-channel transmit coil array consisting of 8-loops were designed, constructed and compared with each other for pediatric (4-9 years old) visual cortex imaging at 7T. To ensure robust safety of the 7T parallel-transmission (pTx) coil, local SAR matrices and the commensurate virtual observation points (VOPs) has been calculated for online SAR supervision. An 8-channel receive only array consisting of eight overlapped loops covering the back of the pediatric head area has been constructed and used inside the transmit coils for visual cortex imaging.
Significant Signal-to-Noise Ratio (SNR) Enhancement with Ultrahigh Dielectric Constant (uHDC) Ceramic Disks for 2H MRSI Application at 7T
Authors: Soon Soo Han , Wiesner Hannes , Li Xin , Lanagan Michael , Yang Qing , Zhu Xiao-Hong , Chen Wei
Published: August 2024

Ultrahigh-field (UHF) deuterium (2H) magnetic resonance spectroscopy imaging (DMRSI) is valuable to study neuroenergetics by quantitatively measuring the energy metabolic rates in the human brain. However, the low intrinsic signal-to-noise ratio (SNR) of deuterium signal due to its low gyromagnetic ratio and low metabolites concentration has been a technical challenge to achieving high imaging resolution. In this study, we have integrated ultrahigh dielectric constant (uHDC) ceramic disks with an 8-channel 2H-1H human head array coil to largely improve the receive sensitivity and DMRSI SNR (>60%) at 7T, aiming for human brain metabolic imaging application.
3D Deep Learning Segmentation of White Matter Hyperintensity on 3T and 7T Brain MRI Scans
Authors: Huang Yuanzhe , Li Jinghang , Wang Linghai , Forry Taylor , Ibrahim Tamer , Aizenstein Howard , Wu Minjie
Published: August 2024

White matter lesions (WMLs), commonly found as hyperintensities (WMHs) on T2-weighted FLAIR MR brain images, are associated with neuropsychiatric and neurodegenerative disorders. In the present study, we adapted a 3D U-Net deep learning method to automatedly segment the WMHs on 3T and 7T MRI T2w FLAIR brain images. Using 3D U-Net, the accuracy of WMH segmentation is 98.8% for 3T data, while it drops to 90.3% for 7T data. However, after incorporating histogram matching in the preprocessing, the accuracy of WMHs segmentation significantly improves to 97.5% for 7T data.
Interleaved Whole Brain 23Na MRI and 31P MRSI Acquisitions at 7T
Authors: Shams Zahra , Dai Jiying , Gosselink Mark , van der Kemp Wybe , Visser Fredy , Klomp Dennis , Hoogduin Hans , van der Velden Tijl , Mens Giel , Wijnen Jannie , Wiegers Evita
Published: August 2024

The purpose of this study is to assess the feasibility of an interleaved acquisition of 31P MRSI and 23Na MRI. Triple-nuclei [metabolic] imaging of the brain was performed in one scan session with an interleaved acquisition of 3D 31P MRSI and 3D radial UTE 23Na MRI at 7 Tesla. The results of the interleaved 23Na-31P were compared with those acquired from non-interleaved runs, concluding no influence of each nucleus on the SNR or spectra quality. In conclusion, we showed that these two nuclei pools do not interfere with each other during interleaved acquisition.
Measuring Air Flow Dynamics in the Lungs Using Hyperpolarized 129Xe MRI
Authors: Ismail Mostafa , Kadlecek Steve , Hamedani Hooman , Amzajerdian Faraz , Baron Ryan , Loza Luis , Boyes Madeline , Hopster Klaus , Hilliard Rachel , Schaer Thomas , Sinder Benjamin , Cahill Patrick , Snyder Brian , Ruppert Kai , Rizi Rahim
Published: August 2024

The ability to non-invasively measure air flow in the lungs could enable the early detection and assessment of abnormal air flow resulting from various obstructive and restrictive diseases. Here, we present a novel method for both obtaining and analyzing ventilation maps using hyperpolarized 129Xe MRI (HXe). In addition to assessing tidal volume and fractional ventilation, we introduce a novel sigmoid function describing inhalation and exhalation that enables the assessment of how fast air flows in the lungs and apply this method in a preclinical model of thoracic insufficiency syndrome (TIS) as well as three human lung transplant (LTx) recipients.
Optimizing Hyperpolarized 129Xe MRI of cardiopulmonary oscillations using a Digital Phantom
Authors: Lu Junlan , Bier Elianna , Leewiwatwong Suphachart , Mummy David , Kabir Sakib , Alanezi Fawaz , Rajagopal Sudarshan , Robertson Scott , Niedbalski Peter , Driehuys Bastiaan
Published: August 2024

Cardiogenic red blood cell (RBC) signal oscillations in 129Xe whole-lung dynamic spectroscopy provide a promising biomarker for identifying patients with pulmonary hypertension (PH). However, to detect more complex and heterogeneous diseases, it is necessary to move from simple global metrics to spatially resolved mapping. This has been demonstrated using keyhole reconstruction methods but little work has yet been done to optimize the reconstruction and visualization of these maps. Here, we introduce a digital phantom to investigate the effects of radial views, key radius, and SNR. From these simulations, we deduce a key radius of 9 points is optimal for minimizing radial undersampling-based heterogeneity and maximizing sensitivity.
Comparing supraclavicular brown adipose tissue fat fraction changes between mild cold and thermoneutrality in healthy adults
Authors: van Eenige Robin , Mishre Aashley Sardjoe , Straat Maaike , Martinez-Tellez Borja , Boon Mariëtte , Dzyubachyk Oleh , Webb Andrew , Rensen Patrick , Kan Hermien
Published: August 2024

Brown adipose tissue (BAT) is considered a therapeutic target in cardiometabolic health for its capacity to combust triglyceride-derived fatty acids into heat. Previous MRI studies consistently reported reductions in fat fraction (FF) in supraclavicular BAT (scBAT) after cold exposure. However, there is limited research on the validity of this outcome against thermoneutral conditions. We compared scBAT FF dynamics and thermal perception scores between mild-cold and thermoneutrality. Cold exposure decreased scBAT ΔFF (-0.73±0.19%), accompanied with colder thermal perceptions during cooling. At thermoneutrality, two out of three participants also showed a scBAT ΔFF decrease (-0.39±0.06%), yet normal thermal perceptions were reported.
Metabolic Profiling of Small Intestinal Mucosa of patients with Celiac Disease and their Family members by NMR Spectroscopy
Authors: Sharma Uma , Upadhyay Deepti , Das Prasenjit , Makharia Govind
Published: August 2024

The present study demonstrated distinct metabolic features of intestinal mucosa biopsies in first-degree relatives (FDRs) of patients with celiac disease (CeD) patients and disease controls (DC) using proton NMR spectroscopy. FDRs had significantly lower levels of proline and allantoin while higher levels of 7 metabolites compared to CeD patients. The results showed a higher concentration of glucose, fumarate, tyrosine, and formate in the FDRs as compared to CeD and DC indicating altered energy metabolism and gut microbiome of FDRs. The obtained results may provide insight into the underlying mechanism involved in the pathophysiology of CeD patients.
5T MRI of the pancreas in comparison to 3T: An initial study
Authors: Zheng Liyun , Yang Chun , Dai Yongming , Zeng Mengsu
Published: August 2024

Despite the growing clinical acceptability of magnetic resonance imaging (MRI) evaluation, continued efforts are required to increase the resolution and robustness of pancreatic imaging. The feasibility of pancreatic MRI at 5T was studied in this study, which used a brand-new 5T MR scanner. 5T pancreatic MRI exhibited greater signal-to-noise ratio (SNR) and sufficient image quality as compared to the 3T examination. Diffusion-weighted imaging (DWI) at 5T was sufficient for measuring the longitudinal pancreatic apparent diffusion coefficient (ADC). As a result, pancreatic MRI at 5T may be effective for diagnosing and managing pancreatic diseases.
Comparation of DCE-MRI and dual-energy CT imaging in discriminating tumor deposits from lymph node metastasis in rectal cancer.
Authors: HU WEN , Chen Anliang , Liu AIlian
Published: August 2024

Tumor deposits (TDs) in rectal cancer have been shown to be an important marker of poor prognosis. Although very similar to lymph node metastasis (LNMs), TDs have unique features in terms of biology and outcome, suggesting that distinguishing between these two entities may be of great importance. Results of this study indicate iodine-based material-decomposition (MD) images and DCE-MRI can effectively differentiate TDs and LNMs in rectal cancer, and iodine-based MD images showed better diagnostic efficiency.
Amide proton transfer-weighted imaging histogram analysis to predict pathological extramural venous invasion in rectal adenocarcinoma
Authors: Chen Weicui , Liu Guoqing , Chen Jialiang , Wei Qiurong , Ye Yongsong , Du Xiaohua , Feng Jiepin , Yan Zhaoxian , Deng Kan , Liu Xian
Published: August 2024

This study evaluate amide proton transfer-weighted (APTw) derived whole-tumour histogram analysis parameters in predicting pathological extramural venous invasion (pEMVI) positive status of rectal adenocarcinoma (RA). The method is to calculate APTw histogram parameters between the pEMVI-negative and positive groups, assess the independent risk factors and diagnosis performance. Our results demonstrated that RA with pEMVI-positive status is associated with higher APTw-SI. The best prediction for EMVI involvement was obtained with a combined model of histopathological factors and APTw histogram parameters. Therefore, the APTw histogram analysis may represent a valuable non-invasive tool in predicting pEMVI positive status of RA.
A nomogram based on IVIM-DWI and Clinical parameters to Predict Survival of Rectal Cancer Patients after Radical Resection
Authors: Jia Haodong
Published: August 2024

This is an abstract by Haodong Jia.
Prediction for Ki-67 Expression Using Intravoxel Incoherent Motion Imaging in Rectal Cancer
Authors: Chen Anliang , Dong Deshuo , Ma Changjun , Liu Ailian , Song Qingwei
Published: August 2024

The Ki-67 expression has been verified as a prognostic indicator in colorectal cancer, correlating with biological behavior of tumor and response to the chemotherapy. The purpose of this study was to evaluate the value of intravoxel incoherent motion (IVIM) imaging for prediction of Ki-67 expression status in rectal cancer. The results indicate that high Ki-67 status group had significantly lower ADC and D values than low Ki-67 status group. IVIM imaging allows non-invasive visualization and quantification of tissue composition for prediction of Ki-67 expression status in rectal cancer.
Association of CMR-verified diffuse myocardial fibrosis with depressed myocardial strain in HFpEF
Authors: Zhang Yi , Zhao Xiance
Published: August 2024

HFpEF was seen approximately in half of all hospitalized patients for heart failure and is associated with a poor prognosis. Using CMR, the present study shows that the increased diffuse myocardial fibrosis was associated with the degree of impaired myocardial strain in patients with HFpEF. As diffuse fibrosis is recognized as prognostic markers and reversible. Our findings demonstrate the utility of myocardial strain in assessing patients with HFpEF. The measurement of myocardial strain could be used to inform clinicians about whether HF medications could improve the degree of diffuse myocardial fibrosis in HFpEF.
Global Longitudinal and Global Circumferential Strain by Speckle-Tracking Echocardiography and Feature-Tracking CMRI: Comparison with LVEF
Authors: Liang Jing , Mu Dan , Zhao Xiance , Yue Xiuzheng
Published: August 2024

Understanding the relationship between left ventricular function and ventricular aneurysmafter myocardial infarction is crucial for surgical treatment and drug therapy. The CMR feature-tracking technique can quantitatively evaluate strain changes of LV and detect myocardial dysfunction. The study aims to use CMR-FT in patients with left VA after MI to assess strain changes and evaluate the clinical value for predicting patient prognosis. We found that the LV GLS, GCS, and GRS could be used for predicting the NYHA class after MI.
Probing gray matter microstructure with diffusion MRI in preclinical Alzheimer’s disease: A comparison of methods
Authors: Scheidt Teresa , Nilsson Markus , van Westen Danielle , Stomrud Erik , Hansson Oskar , Spotorno Nicola
Published: August 2024

Gray matter microstructural changes appear prior to macrostructural changes in Alzheimer’s disease, these changes can be probed by diffusion MRI. However, different methods can be used to extract metrics in the thin cortical ribbon. The influence of the choice of method on the results has not been investigated yet. In this work, two different methods of extracting diffusion metrics in the cortex are compared, a surface-based approach and gray matter based spatial statistics (GBSS). We improve upon GBSS and show it now yields comparable results to a surface-based method.
Longitudinal assessment of MD and FA in four whole human brains using the DTI model
Authors: Lüthi Nina , Fritz Francisco , Fricke Björn , Streubel Tobias , Mushumba Herbert , Püschel Klaus , Mohammadi Siawoosh
Published: August 2024

We investigated the longitudinal fixation effect of 4% paraformaldehyde and phosphate-buffered saline on diffusion imaging-derived mean diffusivity (MD) and fractional anisotropy (FA) across deep gray, cortical gray and white matter in human brains using suboptimal and optimal diffusion protocols with varying maximal b-values. We had two main findings: (1) a suboptimal diffusion protocol led to increased bias in the FA and MD up to 36.26% and 38.11%, the same trend was also observed for the across-brain variation; (2) MD changed by a maximum of 26.42% within the first 14 days in fixative and saturated afterward, whereas FA remained almost constant.
Feasibility of spiral diffusion imaging on a clinical 3T MR system
Authors: Kasper Lars , Wu Zhe , Jaffray Alexander , Kashyap Sriranga , Uludag Kamil
Published: August 2024

Spiral diffusion imaging has been shown to provide substantial SNR advantages (>50%) over state-of-the-art echo-planar imaging, due to the attainable shorter echo times. We investigate the feasibility of this approach on a standard 3T MR system without additional instrumentation. All tools for successful implementation are freely made available, i.e., the characterization measurement for the gradient system using a standard phantom, and an open-source, fast image reconstruction suite in Julia correcting for gradient imperfections, eddy currents, and static B0 off-resonance. We show that this low-cost, accessible solution provides high-resolution diffusion images (1.1mm) in-vivo with reduced geometric distortion and improved quantitative maps.
Study of QSM’s contrast sources in the brain using Electron Paramagnetic Resonance
Authors: Otsuka Fábio , Otaduy Maria Concepción García , Salmon Carlos
Published: August 2024

QSM is a promising MRI techniques that enables the assessment of magnetic properties of tissue. However, its underlying biophyisical source of contrast is still unknown. It has been shown that iron is well correlated in the basal ganglia, however this hasn't been investigates for other regions. Furthermore, iron can be presented in different forms in the brain, each one having different functions and properties. This work aims to assess the composition of brain structures regarding its paramagnetic ions' and total metal content, comparing their concentrations with magnetic susceptibility assessed by QSM
3D MRI super-resolution using convolutional generative adversarial network with gradient guidance
Authors: Xu Wei , Cheng Jing , Liang Dong
Published: August 2024

The application of MRI has been limited due to the restriction of imaging time and spatial resolution. Super-resolution is an important strategy in clinics to speed up MR imaging. In this work, we propose a novel GAN-based super-resolution method which incorporates gradient features to improve the recovery of local structures of the super-resolution images. Experiments on 3D MR Vessel Wall imaging demonstrate the superior performance of the proposed method.
Improvement of canine brain FLAIR image using super-resolution GAN
Authors: Son Yuseoung , Roh Sumin , Ryu Jae-Kyun , Jung Won Beom , Lee Seok-Mn , Lee A-Rim , Otgonbaatar Chuluunbaatar , Lee Jaebin , Choi Ho-Jung , Lee Young-Won , Shim Hackjoon
Published: August 2024

Most veterinary imaging has been achieved using human MRI scanners. Therefore, extensive averaging is required to obtain high-resolution images with high SNR for the animals, thereby leading to a long scan time. Veterinary MRI is typically performed under general anesthesia to minimize the level of stress and movement during image scanning. Therefore, long anesthetic conditions could affect animal normal physiology and be life-threatening, especially for patients in veterinary medical field. Here, we aimed to obtain higher image quality with short scanning time using super-resolution generative adversarial network (SRGAN) in the canine brain MRI.
Deep Learning Denoising Reconstruction Enables up to 2X Scan Time Reduction while Maintaining Image Quality for Musculoskeletal Imaging
Authors: Do Hung , Berkeley Dawn , Tymkiw Brian , AlGhuraibawi Wissam , Kadbi Mo
Published: August 2024

Two-average (2NAQ) scans are often required to acquire high resolution images with adequate Signal-to-Noise Ratio (SNR). Deep Learning Denoising Reconstruction (DLR) effectively removes noise hence improving the SNR of reconstructed images. The SNR gain could be used to increase resolution and/or reduce scan time. This study demonstrates that the DLR-reconstructed one-average (1NAQ) images have similar image quality to those acquired with 2NAQ and reconstructed with conventional reconstruction. As a result, approximately 2X scan time reduction is achieved with DLR.
RF Field Enhancement with Ultrahigh Dielectric Constant Material for Micro Imaging at 7T
Authors: Jayatilake Mohan , Sica Christopher , Karunanayaka Dhevin , Ekanayaka Anupa , Ahmed Biyar , Elyan Rommy , Karunanayaka Prasanna
Published: August 2024

In this study, we investigated the effects of ultra-high dielectric constant (uHDC) material for reducing noise and enhancing the B1 efficiency at 300 MHz for 1H nuclear applications at 7T. Using electromagnetic field simulations [CST Studio (2020) software] and imaging experiments, we estimated B1+ efficiency maps for a phantom mouse brain with and without uHDC material. Our results show significant enhancement of B1+ efficiency and Signal-to-Noise ratio (SNR) in the presence of the uHDC material.
A wireless unilateral Rx-only RF coil for dedicated MRI of a human breast at 1.5 T
Authors: Fedotov Aleksander , Tikhonov Pavel , Solomakha Georgiy , Puchnin Victor , Shchelokova Alena , Hurshkainen Anna
Published: August 2024

Wireless dedicated radiofrequency coils have recently proven to be a good alternative to conventional cable-connected coils due to compatibility with the scanners of different vendors. Due to significant increase of B1+ with respect to body coil manual calibration procedure needed often for operation of wireless coils. The goal of this work is to develop the first Rx-only wireless coil for dedicated breast MRI to overcome the aforementioned drawback. For that the passive detuning structure inserted to wireless Helmholtz resonator was designed and studied.
Characterization of the RF field for metamaterial-based structures constructed of conducting strips and a dielectric at 7T MRI
Authors: Maurya Santosh , Schmidt Rita
Published: August 2024

Metamaterial-based structures constructed of conducting strips and a dielectric have already been used to locally increase the RF transmit field. In this study we characterize the RF field of such structures at 7T MRI. Configurations included either long strips (representing electric dipoles), or a matrix of short strips (representing magnetic dipoles). The RF field dependence on strip density and distribution was analyzed, providing insights useful for efficiency and coverage optimization. The configuration based on a matrix of short strips provides higher RF transmit efficiency, while the use of a non-uniform concave distribution of strips is useful to lower SAR.
Disentangling coil coupling mechanisms through a Faraday equivalent model: application to the shielded-coaxial-cable (SCC) coil at 7T
Authors: Costa Giovanni , Paulides Margarethus , Zivkovic Irena
Published: August 2024

Minimizing coupling between coils constitutes a major challenge in the design of flexible arrays for UHF MRI. Recently, Shielded-coaxial-cable coils (SCC) were shown to be flexible and intrinsically highly decoupled: however, the decoupling mechanism of SCC remains unclear. In this work, we use an high frequency Faraday-equivalent model of the induced voltage to examine coupling between two SCCs in different geometrical configurations. We show that lower coupling in SCC derives from both lower magnitude of electric and magnetic fields as compared to a loop coil, and we discuss the implications in the design of coils for MRI.
MATCHING CIRCUIT CO-SIMULATION FOR MR RADIOFREQUENCY COIL SYSTEM OPTIMIZATION
Authors: Ajanovic Amer , Ogier Stephen , Tomi-Tricot Raphael , Hajnal Joseph , Malik Shaihan
Published: August 2024

We present a full closed form solution focusing on S-parameters to achieve tuning and matching of the coils by extending the circuit co-simulation (CCS) by enabling introduction of arbitrary matching networks into the CCS without requiring full RF simulation of the network. We validate the method against CCS and demonstrate its applicability to evaluate full-field solutions for 5 different coil model using MARIE.
Readout-segmented echo-planar imaging in the evaluation of anal fistula: Comparison with single-shot echo-planar diffusion-weighted imaging
Authors: Zhong Yuru , bai jiao , Shu Jian , Han Fugang , Li Jun , Zhao Dongmei , Wu Yunzhu
Published: August 2024

To assess the image quality of anal fistula by RESOLVE DWI compared to SS-EPI DWI, and explore the value of RESOLVE DWI for diagnosis and classification of anal fistula. Qualitative and quantitative evaluation of image quality showed that RESOLVE DWI group was superior than SS-EPI DWI group. The accuracy of RESOLVE DWI sequence in the diagnosis of the internal orifice, branch fistula, and classification was higher than in SS-EPI DWI for anal fistula. RESOLVE DWI can provide higher quality images of anal fistula than SS-EPI DWI.
Effect of Compressed SENSE on 3D T2-weighted sequence for Rectum Imaging with a deep learning constrained Compressed SENSE Reconstruction
Authors: Qiu Ying , Zhu Yi , Guo Dandan , Jiang Ke
Published: August 2024

Rectal MRI examination requires high resolution three-dimensional (3D) sequences to observe the morphology, structure and the location of the lesions. However, 3D sequences may lead to longer scan time ，patient discomfort and image quality problem. In this study, we investigated the use of a deep learning-based reconstruction algorithm (CS-AI) to highly accelerate 3D rectum MRI. The result showed that CS-AI reconstruction can use the same scan time with sufficient image quality compared to SENSE and might be clinically useful in assessment of rectum cancer.
Diagnostic performance of the vesical imaging-reporting and data system for detecting muscle-invasive bladder cancer based on tumor locations.
Authors: Wang Xiangyu , Lin Fan , Deng Kan
Published: August 2024

The VI-RADS criterion was reported to have limitations, particularly for tumors location. So we evaluated the diagnostic performance of Vesical Imaging-Reporting and Data System (VI-RADS) scoring and diagnostic accuracies based on tumor locations. VI-RADS had superior diagnostic performance for detecting MI, especially in tumors located at the bladder lateral, posterior walls and ureteric orifices.
Amide proton transfer values in testicular spermatogenic function evaluation: a preliminary study
Authors: Tang Guanglei , Fu Wenhao , Deng Kan , Guan Jian
Published: August 2024

In this study, we determined APT of normal testes possible variations with age, and to assess the feasibility of APT in testicular spermatogenic function evaluation. Our results showed that APT of normal testicular tissue decrease with advancing age, and could be promising in evaluation of male infertility.
Cardiac diffusion MRI using Connectom scanner
Authors: Afzali Maryam , Mueller Lars , Coveney Sam , Fasano Fabrizio , Evans John , Engel Maria , Szczepankiewicz Filip , Teh Irvin , Dall'Armellina Erica , Jones Derek , Schneider Jürgen
Published: August 2024

Cardiac diffusion Magnetic Resonance Imaging (cardiac dMRI) allows to non-invasively assess the microstructure of the heart. Cardiac motion typically necessitates the use of motion-compensated diffusion gradients. Here we report for the first time on the application of cardiac dMRI on a Connectom MR scanner with a gradient strength of 300 mT/m using a spin echo (SE) sequence with EPI readout and up to third order (M3) motion-compensated diffusion gradients. The results show the benefits of applying dMRI with higher order motion compensation in the human heart using a Connectom scanner.
Left Ventricular Vertical Run-Length Non-Uniformity Adds Prognostic Value to MACE in Patients with ESRD
Authors: Zhang Tian-yi , Wu Peng , Wu Lian-Ming , Mou Shan
Published: August 2024

Left ventricular vertical run-length non-uniformity (VRLN) represents heterogeneity within native T1 images and reflects the extent of cardiac fibrosis. In uremic cardiomyopathy, interstitial fibrosis was found to be the major histological alteration. The aim of this study was to evaluate the prognostic value of VRLN in patients with ESRD. The primary endpoint was major adverse cardiac events (MACE). Survival analysis was calculated by Kaplan-Meier curves with log-rank test. VRLN remained associated with MACE in the multivariable model. Adding VRLN to a model containing clinical and CMR parameters significantly improved the accuracy and reclassification of the predictive model.
Single-shot, Multi-TI Late Gadolinium Enhancement MRI using GRASP-Pro Reconstruction with View-Sharing and KWIC Filtering
Authors: Zhao Mingyue , Shen Daming , Fan Lexiaozi , Hong Kyungpyo , Feng Li , Allen Bradley , Lee Daniel , Kim Daniel
Published: August 2024

Late gadolinium enhancement (LGE) is the clinical standard for assessment of myocardial scarring. Current limitations of standard LGE are lengthy scan time, sensitivity to arrhythmia and/or dyspnea, and reliance of optimal inversion time (TI), which may be difficult to identify for patients with subendocardial scarring. We propose a free-breathing, single-short, multi-TI LGE approach to address the aforementioned challenges. Our results show that GRASP-Pro reconstruction with view-sharing (VS) and k-space weighted image contrast (KWIC) filtering produces multi-TI LGE images (i.e., no need for TI scout) with relatively high spatial resolution.
Twinkle, twinkle, T2*, still we wonder what you are
Authors: Storey Pippa , Novikov Dmitry
Published: August 2024

In the absence of macroscopic magnetic field inhomogeneity, the decay of gradient-echo signals is generally observed to be approximately monoexponential, with time constant $$$T_2^*$$$. The monoexponential behavior is typically attributed to diffusion, which averages out the dephasing of spins due to microstructural sources of magnetic susceptibility. The rationale is that, over times long enough for spins to have explored the microstructure, the cumulants of the spins’ phase distribution should increase linearly with time. By means of a simple counterexample, we demonstrate that this assumption is incorrect, thereby calling into question the mechanism underlying the monoexponential decay of gradient-echo signals.
On the practical influence of extra-axonal heterogeneity in a numerically informed model of extra-axonal water diffusion
Authors: Harkins Kevin , Xu Junzhong , Gore John , Does Mark
Published: August 2024

This study explores the role of extra-axonal environment on the time dependent diffusion coefficient of extra-axonal water in white matter. Monte Carlo simulations of water diffusion in geometries with varying extra-axonal heterogeneity were compared with a proposed analytic model. The results agree with previously published power-law relationships that depend on structural order, but also uncovers trends between model parameters with characteristics of extra-axonal space.
MULTI-SHELL DIFFUSION MRI TO INVESTIGATE THE EFFECTS OF HYPERTENSION ON RAT BRAIN
Authors: Wiskoski Haley , Do Loi , Zempare Marc , Carey Natalie , Delmendray Amy , Young Kimberly , Bohne Kimberly , Chawla Monica , Bharadwaj Pradyumna , Mitchell Kenneth , Alexander Gene , Barnes Carol , Trouard Theodore
Published: August 2024

Hypertension is associated with an increased risk of cardiovascular disease and cognitive decline in aging humans. This study investigated longitudinal effects of induced HTN in regional and microstructural neuroanatomy of F344 rats using noninvasive diffusion-weighted MRI and fixel-based analysis. Single-shot spin-echo EPI along 64 diffusion directions and three shells (b=1000, 2000, and 3000 s/mm2) was performed. Microstructural changes in the brain appeared in certain regions after 10 weeks of hypertension, yet, most regions remained unaffected, contrasting peripheral organs which showed dramatic fibrosis due to the HTN. This likely demonstrates a robust protective mechanism of the central nervous system.
ZTE segmentation of glenohumeral bone structure using deep learning
Authors: Carl Michael , Lall Kaustaub , Jamshidi Armin , Chang Eric , Statum Sheronda , Brau Anja , Chung Christine , Fung Maggie , Bae Won
Published: August 2024

Evaluation of 3D bone morphology of the glenohumeral joint is necessary for pre-surgical planning. Zero echo time (ZTE) MRI provides excellent bone contrast, and we developed a deep learning model to perform automated segmentation of major bones (i.e., humerus and others) from ZTE to aid evaluation. Axial ZTE images of normal shoulders (n=31) acquired at 3T were annotated for training with a 2D U-Net, and the trained model was validated with testing data (n=10 normal shoulder, n=6 symptomatic). Testing accuracy was around 80 to 90% (Dice score) for either cohort, except for a few failed cases with very low scores.
A Non-linear, Tissue-specific 3D Data Generative Framework for Deep Learning Segmentation Performance Enhancement
Authors: Ghose Soumya , Bhushan Chitresh , Shanbhag Dattesh , Yeo Desmond Teck Beng , Foo Thomas
Published: August 2024

Deep learning (DL) models have been successful in solving segmentation problems that involve large, balanced, and labeled datasets. However, in the medical imaging domain, it is rare to find manually annotated datasets that capture the entire spectrum of heterogeneity. Novel datasets with significantly different intensities than training datasets, may adversely affect DL model performance. In this work, we present a hybrid framework for tissue-specific, non-linear intensity transformation of pediatric T2w images similar to that of the adults training dataset and demonstrate an improved performance for vertebra segmentation of pediatric datasets without the need for DL network re-training/re-tuning.
Comparison of Combinations of MTR, FLAIR, and T1WCE MRI Images for Automatic Segmentation of Brain Metastases
Authors: Anand Ananya , Nussey Daniel , Sussman Dafna
Published: August 2024

This study presents an evaluation of utilizing MTR and FLAIR as compared to T1wCE and FLAIR images for automatic segmentation of brain metastases, due to the unknown consequences posed by accumulated contrast enhancement. Numerous combinations of FLAIR, T1wCE, and MTR MRI images were tested on three top-performing segmentation models (MS-FCN, U-NET, and SegresNet) to evaluate the feasibility of using MTR and FLAIR images for tumor segmentation. Overall, the U-Net produced the best similarity scores of 0.4±0.15 using MTR and FLAIR images. A future study will test the utility of 3D MTR images for tumor segmentation using convolutional and full-connected models.
Increased accuracy in relaxometry estimates through statistical determination of the noise floor
Authors: Hales Laurel , Goyal Ananya , Kogan Feliks
Published: August 2024

Including data below the noise floor in estimating relaxometry values leads to overestimation. It is possible to identify and remove data below the noise floor by considering the set of voxel data in an ROI at each echo time as a separate but related dataset, and then comparing the data from each echo time statistically. Removing data below the noise floor, reduces error in the estimates of relaxometry values.
Quantitative 3D Assessment of Meniscus in Patients with Posterior Root Tears and Healthy Controls Using T2* Mapping at 7T
Authors: Kajabi Abdul Wahed , Zbyn Stefan , Smith Jesse , Homan Morgan , Abbasguliyev Hasan , Rodriguez Ariel , Metzger Gregory , LaPrade Robert F. , Ellermann Jutta
Published: August 2024

Evaluating 3D T2* mapping of the meniscus at ultra-high field 7T provides necessary high resolution to better characterize tissue changes in the meniscus. This study was designed to measure the 3D structure of the meniscus with T2* mapping in a clinically acceptable scan time at 7T, and to evaluate meniscus degeneration in twelve patients with arthroscopically verified tears of the posterior horn of the medial meniscus and nine age, sex and body mass index matched healthy controls. T2* mapping at 7T provided comprehensive 3D evaluation of meniscus and detected degenerative alterations caused by the root tears in the patients.
Electric Dipole Based Metasurfaces Enhance Targeted RF Power Deposition of Thermal Magnetic Resonance at 7.0T, 9.4T and 10.5T
Authors: Saha Nandita , Schmidt Rita , Niendorf Thoralf
Published: August 2024

This work proposes the feasibility of passive metasurface (MS) to enhance the RF power deposition for Thermal Magnetic Resonance based treatment of brain tumors. An 8 channel hybrid RF applicator combining dipole antenna and passive MS is designed and evaluated at 7.0 T (300 MHz), 9.4 T (400 MHz) and 10.5 T (450 MHz). MS with metal strips inside waterbolus was designed which generates expected resonant modes of the thermal intervention frequency. The result demonstrated use of passive metamaterial surface in RF applicator enhances the RF power deposition inside target volume for targeted RF heating of deep seated brain tumor.
Implementation of Proposed Methods for MR-Guided Transperineal Prostate Interventions: Real Time Trajectory Calculation and Monitoring
Authors: Lilieholm Thomas , Woodrum David , Block Walter , Koepsel Erica Knavel
Published: August 2024

Utilizing MR guidance for minimally-invasive prostate interventions is known to improve the precision and accuracy of the procedure. Previous work has been done to develop and propose an integrated platform for conveniently providing this image guidance to clinicians for use with transperineal prostate interventions. Since then, the proposed methodology has been applied, in a limited capacity, to assist in an in-vivo prostate biopsy. It was found that the trajectory computation component of the platform was able to accurately guide needle placement to the clinician-selected anatomical regions with little need for correction.
Evaluation of MRI performance and PET compatibility of a 32 channel coil for the Siemens Biograph mMR PET/MRI scanner
Authors: Bidaman Harris , Dinelle Katie , Taylor Reggie , Tuominen Lauri
Published: August 2024

We evaluate MRI and PET performance of the novel Siemens 32 channel head coil for the Siemens Biograph mMR. Results are compared to the system standard 12 channel coil. MRI performance (SNR) was improved with the 32 channel coil. PET image uniformity was not impacted. ROI analysis of the PET data indicated a 5% underestimation of activity concentration in the 32 channel coil, however this difference was mitigated by the use of an image derived reference region. Any small differences in PET performance introduced by the 32 channel coil are far outweighed by the superior MRI performance of this coil.
Efficient Use of Specific Absorption Rate Limits Through Sub-Population Universal Pulses in Parallel Transmission
Authors: Tyshchenko Igor , Lévy Simon , Jin Jin , Tahayori Bahman , Johnston Leigh
Published: August 2024

Universal pulse (UP) design in parallel transmit (pTx) imaging is a calibration-free technique that can effectively mitigate the radiofrequency (RF) field inhomogeneity over a population in ultra-high field MRI. In this work, we explore a middle-ground approach of using sub-population UPs. Assuming the entire population is divided into sub-populations by grouping similar anatomical shapes and positions, UPs can thus be designed with reduced intersubject variability. In this preliminary study of head imaging, it is demonstrated that sub-populations of various sizes centred at the mean shape and position can reduce safety margins and improve UP’s performance.
Correction of field drifting for single shot spiral diffusion imaging
Authors: Chao Tzu Cheng , Borup Daniel , Pipe James
Published: August 2024

Diffusion MRI provides useful microstructural information of the soft tissue. Scans using a single-shot Spiral trajectory have demonstrated better geometric fidelity and SNR than those with a Cartesian EPI counterpart. This study shows that the field drifting during a diffusion scan can be a confounding factor to the image quality. A correction strategy exploiting the average off-resonance measurement before and after a scan was applied to mitigate the blurring artifact caused by field drifting.