bluuebunny/crossref_metadata_2025 huggingface dataset:
Overview of Complex-valued Image Reconstruction for CS-MRI Using Real-valued CNN with Symmetrical Signal Under-Sampling
Authors: Ouchi Shohei , Fukatsu Itona , Yamato Kazuki , Ito Satoshi
Published: August 2024

Complex-valued CNN based image reconstruction methods have been proposed to correspond to MR images with a spatial phase variation. However, using those CNN may lead to over-fitting because CNN layers for complex numbers are requires large number of parameters than real-valued CNN. We previously proposed a reconstruction method for complex-valued image using a real-valued DnCNN by introducing a symmetrical k-space under-sampling. In this study, we introduced this method to U-Net and ADMM-CSNet. Reconstruction experiments showed that a real-valued CNN has the possibility to have the same or better performance as a complex-valued CNN without perform complex calculations.
Knee MRI Using a Wireless and Passive Metasurface Coil
Authors: Yi Yi , Chi Zhonghai , Wang Yakui , Wu Maopeng , Wang Lixue , Jiang Deqing , He Li , Zhao Xihai , Meng Yonggang , Zhou Ji , Zhao Qian , Zheng Zhuozhao
Published: August 2024

Metasurface is an effective solution to enhance SNR of MRI images. Here, we propose a wireless and passive metasurface coil and evaluate its performance in knee MRI. Phantom studies suggest improved image uniformity compared to the conventional phased-array radio-frequency coils. In vivo knee MRI of volunteers suggests higher image quality scores and better contrast of knee cartilage in metasurface groups. When used in conjunction with the spine coil, the metasurface coil provides a favorable SNR between that of the 4- and 12-channel phased-array coil. It is more convenient, cost-effective, and applicable to 1.5T MRI systems from different manufacturers.
Towards Dense Flexible Transceive Coil Array: Comparison Study of Coaxial Dipoles for 7T Human Torso MRI.
Authors: Vliem Jules , Tomi-Tricot Raphael , Zivkovic Irena , Ipek Özlem
Published: August 2024

In this work, we explored properties of various coaxial dipole designs and compared them with the conventional dipole. Dipoles were fabricated of RG58 coaxial cable and the total length was 34cm. S-parameters and flip angle maps of individual elements and array configurations were measured on a torso phantom. Comparison of flip angle maps shows very similar performances of all examined dipoles with the coaxial dipole being slightly advantageous. When placed in densely populated array configuration, coaxial dipoles were sufficiently decoupled and produced expected B1+ maps. Coaxial dipole shows promising performances to be used in a densely populated flexible torso array.
Quantitative evaluation of two-dimensional flexible metasurfaces at 3.0 T
Authors: Lakshmanan Karthik , Schelokova Alena , Glybovski Stanislav , Bruno Mary , Collins Christopher
Published: August 2024

Quantitative evaluation of transmit efficiency and receive-specific SNR were performed for two different metasurfaces in a body-sized phantom for cases with 1) excitation and reception using the system body coil and 2) excitation with the system body coil and reception with a commercial 12-element array. Similar evaluations were performed for one of the metasurfaces in vivo with the receive array present, and for comparisons all measurements were also made with no metasurface present. Both metasurfaces were seen to significantly improve transmit efficiency in all cases, and to improve SNR when the body coil was used for reception, with effects being strong near the metasurface and extending toward the center of the phantom. The metasurfaces had minimal effects on receive SNR of the commercial Rx array.
Investigating the effect of ultra-High Dielectric Constant (uHDC) ceramic disk placement on RF coil performance for optimal MRI applications
Authors: Li Xin , Wiesner Hannes , Zhu Xiao-Hong , Chen Wei
Published: August 2024

It has been demonstrated that integrating ultra-High Dielectric Constant (uHDC) materials with a RF coil can achieve large improvement in RF magnetic field (B1) and imaging sensitivity. A typical configuration inserts the uHDC materials between the imaging object and the RF coil, resulting in a weak B1 from the coil due to the distance from the object. In this study, we explored different configuration options and found that the best arrangement was to place the uHDC materials outside the coil, leaving no gap between the RF coil and the object, for optimal imaging applications.
A coupled planar RF array for ultrahigh field MR imaging
Authors: Zhao Yunkun , Payne Komlan , YIng Leslie , Zhang Xiaoliang
Published: August 2024

This study proposes a coupled planar radio frequency (RF) array for spine imaging at 7T. Multiple identical loop coils are closely placed to achieve strong EM coupling in order to form a multimodal resonator. This coupled resonator can design large high-frequency RF coils for ultrahigh field imaging applications in humans.
Considerations for Accurate Active Detuning Measurements in Densely Parallel Array Coils
Authors: Shrestha Manisha , Mahmutovic Mirsad , Hansen Sam-Luca JD , Stockmann Jason , Keil Boris
Published: August 2024

Active detuning of receive array coil during transmit prevents large currents being induced in the coil which could damage sensitive electronic components and create SAR hotspots. The standard method of adjusting active detuning using a double probe shows an offset in the resonant frequency set at bench when tested in the presence of a scanner. Setting a high impedance at the input of loop using S11 measurement exactly at Larmor frequency has proven to be a better method to detune loops actively.
Therapeutic response assessment to IDH inhibitor using hyperpolarized [5-12C-1-13C]α-ketoglutarate MRSI in rat models of low-grade glioma
Authors: Hong Donghyun , Kim Yaewon , Mushti Chandrasekhar , Minami Noriaki , Wu Jing , Cherukuri Murali , Swenson Rolf , Vigneron Daniel , Ronen Sabrina
Published: August 2024

Hyperpolarized [1-13C]α-ketoglutarate is useful for monitoring 2HG and glutamate production but has limited SNR and the [5-13C]α-ketoglutarate natural abundance peak is within 0.1ppm of 2HG. To address these challenges, this study investigated the utility of HP [5-12C-1-13C]α-ketoglutarate to monitor 2HG and glutamate production as biomarkers of response to treatment with the mutant IDH inhibitor BAY-1436032 in an in vivo rat glioma model using an optimized acquisition strategy. We were able to clearly monitor the dynamic localized production of both 2HG and glutamate in vivo in real-time, and early metabolic changes predicted enhanced survival.
Agonism/antagonism on cannabinoid 1 receptor reveal opposite cerebral blood volume change: a simultaneous PET/fMRI study on primates
Authors: Yoo Chi-Hyeon , Wey Hsiao-Ying
Published: August 2024

The goal of this study was to detect the changes of cerebral blood volume (CBV) in the non-human primate brain induced by administration of agonist and antagonist of cannabinoid receptor 1 (CB1R) using simultaneous positron emission tomography (PET) and function magnetic resonance imaging (fMRI). After the antagonist injection, a bi-phasic response, fast increase and prolonged decrease of CBV, were identified throughout the brain, while CB1R agonist administration evoked elevation of CBV. Future studies integrating PET-derived receptor occupancy information with the CBV changes will provide deeper understanding on CB1R and brain response.
First neuroimaging experience at 11.7 Tesla on the anaesthetized non-human primate.
Authors: Boumezbeur Fawzi , Amadon Alexis , Gay Marion , Mauconduit Franck , Gras Vincent , Roustan Maxime , Lepretre Frederic , Massire Aurélien , Rabrait-Lerman Cécile , Mériaux Sebastien , Vignaud Alexandre , Boulant Nicolas
Published: August 2024

After more than 20 years of research and development, the 11.7T Iseult MRI scanner is in the last stage of its commissioning. However, authorization of Human MRI examination at this unprecedented magnetic field strength is still pending. In this context, MRI examinations of healthy anaesthetized non-human primates are being carried out to check on the absence of acute physiological effects following exposure and gain some insights into the opportunities and challenges ahead.
Exercise and Environmental Complexity Superintervention Improves Mechanical Property Recovery in FASD Rodents Measured via MRE
Authors: Williams L. , Smith Ian , Milbocker Katrina , Caban-Rivera Diego , Kurtz Samuel , McGarry Matthew , Van Houten Elijah , Klintsova Anna , Johnson Curtis
Published: August 2024

In this longitudinal study, we investigate the effects of fetal alcohol exposure on mechanical properties in the developing rodent brain using magnetic resonance elastography (MRE). Additionally, we test whether behavioral “superintervention,” consisting of combined exposure to wheel running followed by environmental complexity, can mitigate changes to property measures. We found that alcohol exposed rats exhibit lower stiffness than sham intubated rats at baseline but recover stiffness to near baseline levels after superintervention. Furthermore, we confirmed MRE is sensitive to small property variations in rodents which may reflect myelination and microstructural integrity.
Hyperpolarized [1-13C]pyruvate detects neuronal metabolic impairment in glucose transporter and pyruvate kinase deficient mice
Authors: Guglielmetti Caroline , Li Huihui , Sei Yoshitaka , Le Page Lydia , Schields Lauren , Tiret Brice , Gao Xiao , Lo Iris , Dayton Talya , Rathmell Jeffrey , Heiden Matthew Vander , Nakamura Ken , Chaumeil Myriam
Published: August 2024

We generated mice with deletion of the glucose transporter 3 (GLUT3cKO) or pyruvate kinase 1 (PKM1cKO) in CA1 hippocampal neurons. GLUT3cKO and PKM1cKO mice showed memory impairment. Hyperpolarized (HP) 13C magnetic resonance spectroscopic imaging showed that female, but not male, PKM1cKO mice had increased HP [1-13C]pyruvate-to-lactate conversion, while female GLUT3cKO mice had decreased conversion and brain volume, evaluated by T2-MRI. Fluorine-18-fluorodeoxyglucose ([18F]-FDG) positron emission tomography imaging did not detect changes, highlighting HP [1-13C]pyruvate’s potential to detect downstream alterations in brain glucose metabolism. Altogether, our findings demonstrated that neurons metabolize glucose through glycolysis in vivo, and require glycolysis for normal function.
Bias-Reduced LCModel Quantification of 1H Brain MRS with Baseline-and-MM Removal: Application in a Circulatory Arrest Study using Neonatal Pigs
Authors: Gu Meng , Hurd Ralph , Spielman Daniel
Published: August 2024

Quantification of in-vivo short-TE MRS using LCModel suffers from biases due to varying baseline and macro-molecule components, especially for metabolites with coupled resonances. This problem exacerbates at low SNR as the baseline estimated becomes less accurate. To improve quantification, baseline and macro-molecule components were estimated from a high SNR line-broadened spectrum and then subtracted from the original spectrum. Using the baseline and macro-molecule removed spectrum, significantly reduced biases for Gln/tCr and GABA/tCr were achieved at different SNRs. Using this method, LCModel quantification revealed a more prominent trend of increasing Gln/tCr and increased GABA/tCr during circulatory arrest in neonatal pig brain.
Development of a 2D MRSI sequence with Chemical-Shift Selective Adiabatic Pulses (2π-CSAP) using Pulseq at 7T
Authors: Nam Kyung Min , Weng Guodong , Lee Nam G , Versteeg Edwin , Jeon Yeong-Jae , Hendriks Arjan , Wijnen Jannie , Bhogal Alex , Klomp Dennis , Zaitsev Maxim , Slotboom Johannes
Published: August 2024

An MRSI sequence using a pair of chemically selective adiabatic 2 refocus pulses, referred to as 2-CSAP, was implemented using the open-source Pulseq framework. This sequence enables full coverage of the frequency spectrum of interest through a shift in carrier frequency, which has been a limitation in rapid MRSI sequences. In addition, this shifted frequency spectrum also minimizes signal contaminations from residual water signal after water suppression or unsuppressed water signal and strong lipid signals, possibly eliminating the need for additional water suppression pre-pulses. This base sequence can potentially be combined with accelerated acquisition techniques for better scan efficiency.
A Case Study Analysis on Monte Carlo-Simulated Uncertainty Propagation in Absolute Quantification for in vivo 1H-MRS of the Human Brain
Authors: Instrella Ronald , Juchem Christoph
Published: August 2024

The effect of uncertainty propagation for absolute quantification performed on individual single-voxel in vivo 1H-MRS experiments has yet to be examined. In this case study, we conduct an uncertainty analysis using Monte Carlo simulations on two previously published studies with reported absolute concentrations of metabolites and macromolecules, each employing different field strengths, relative linewidths and internal references (e.g. total creatine, tissue-specific water). The uncertainty from 8 in vivo spectra is simulated and compared to CRLBs from Linear Combination Modeling. A multifold uncertainty increase is observed in both metabolites and macromolecules across datasets, demonstrating that the CRLB systematically overestimates quantification precision.
Improved reproducibility of GABA measurement in short-TE 1H MRS by linewidth-matched basis sets
Authors: Xiao Ying , Lanz Bernard , Lim Songi , Xin Lijing
Published: August 2024

This study investigated the spectral linewidth effect on GABA quantification, as well as its correction approach in LCModel with both simulated and in vivo acquired 1H MR spectra. Using the same basis set to fit spectra with different linewidths results in elevated variations between measurements. An effective method to reduce the variability caused by the linewidth difference effect and more accurately quantify GABA is to use spectral-linewidth-matched basis sets. This study shows the validity of this approach for most of the Voigt-type spectra.
Long-term balance training enhances sensorimotor GABA levels in older adults: A 7 T longitudinal magnetic resonance spectroscopy study
Authors: Liu Xinyu , Scherrer Selin , Egger Sven , Lim Song-I , Lauber Benedikt , Taube Wolfgang , Xin Lijing
Published: August 2024

This study aims to examine the modulatory effect of long-term balance training on sensorimotor cortex GABA level in an older population. In-vivo GABA levels were accessed using in-vivo MR spectroscopy (MRS) at 7T. GABA level in sensorimotor cortex was measured in sixteen healthy older adults using MEGA-sSPECIAL sequence, and short echo time semi-sSPECIAL sequence was used for metabolite profiling, before and after a three-months period of balance training. Using edited MEGA-sSPECIAL we detected a significant increase in sensorimotor GABA level after training, indicating potentially enhanced motor inhibition by coordinative balance learning.
GABA spectroscopic imaging at 9.4T to localize the epileptogenic zone in an animal model of focal epilepsy
Authors: Plaindoux Alicia , Le Fur Yann , Guo Jia , Courivaud Clothilde , Valette Julien , Stupar Vasile , Fauvelle Florence
Published: August 2024

A surgical resection of the epileptogenic zone (EZ) can be proposed to drug-resistant epileptic patients, mainly suffering from focal epilepsy, in order to free them from their seizures. However, the mean efficiency of surgery is around 50 to 80%, indicating a possible miss-delimitation of the EZ. In recent studies, GABA was found to be a specific biomarker of the EZ in a mouse model of mesio-temporal lobe epilepsy (MTLE). Therefore, in this project, we propose a GABA-edited spectroscopic imaging method to improve the spatial localization of the EZ in this mouse model.
Black Blood Cardiac Diffusion Imaging using Second Order Motion Compensation and Double Inversion Recovery
Authors: Wang Yishi , Zhang Zhen , Wang Rui , Yue Xiuzheng , Wang Fang , Zhu Rongrong , Ha Ruoshui
Published: August 2024

Second-order motion-compensated diffusion imaging is a robust solution for cardiac diffusion imaging but prone to bright blood signals due to motion compensation itself. In this work, we incorporated black blood module into second-order motion-compensated sequence to achieve cardiac diffusion imaging with blood signal suppressed.
Investigation of motion probing gradient pulse for uniform collection of temporal and spatial diffusion information
Authors: Suzuki Yuichi , Murata Katsutoshi , Iwanaga Hideyuki , Abe Osamu
Published: August 2024

We examined the application order of MPG pulses (called reordered MPG) that can uniformly collect spatial diffusion information even if the examination is interrupted, compare it with the an electrostatic repulsion method (conventional method, called original MPG), and verify its usefulness. In conclusion, The reordered MPG, which was rearranged based on the MPG direction of the original, could collect diffusion information more uniformly than the original MPG even if the inspection examination was interrupted.
Volume isotropic thin-slice high-quality brain DWI with no fat-suppression pre-pulse
Authors: SAKAI Takayuki , Yoneyama Masami , Murayama Diachi , Ball Iain , MIYATI Tosiaki , Ochi Shigehiro , Watanabe Atsuya
Published: August 2024

We hypothesized that LIPO-only (LION) DWI might be one of the best solutions to improve the image quality of volumetric thin-slice DWI if it is further optimized to increase the robustness of fat suppression. We investigated the clinical usefulness of proposed LION fat suppression combined with thin-slice DWI for brain volumetric DWI in patients with acute stroke. LION-DWI has improved SNR compared to conventional DWI and has superior visual lesion detectability in patients with acute stroke. Therefore, it is possible to improve the image quality and shorten the imaging time of thin-slice DWI by changing the fat suppression to LION.
The Trouble with Free-Water Elimination using Single-Shell Diffusion MRI Data: A Case-Study in Ageing
Authors: Correia Marta M. , Winzeck Stefan , Golub Marc , Nunes Rita G.
Published: August 2024

Two different algorithms for free-water elimination (FWE) were applied to single-shell and multi-shell diffusion MRI data. Positive correlations were found between age and fractional anisotropy (FA) estimated with the FWE algorithm for single-shell, but this was not replicated with multi-shell diffusion data. Because only the multi-shell FWE algorithm is well-posed, we postulated that the positive correlations between age and FA must be a false positive finding, resulting from inappropriate fitting using single-shell data. FWE estimates from single-shell modelling have been shown to be biologically plausible, but this does not imply specificity, and more work is required to validate these approaches.
New Rapid 3D diffusion weighted imaging using 3D hybrid Radial-Echo Planar Imaging (RAZER) sequence
Authors: Kim Seong-Eun , Odeen Henrick , Roberts John , Parker Dennis
Published: August 2024

Non-Cartesian sampling schemes offer advantages over Cartesian schemes. Recently 2D radial and 3D hybrid radial-Cartesian approaches such as 3D stack of stars have gained popularity. Despite of many advantages, the current hybrid trajectory is presently limited by drawbacks including the degradation of sampling efficiency and the k-space coverage per unit time for diffusion application. For more flexible, rapid, and motion-robust 3D DWI, we implemented a 3D hybrid radial-EPI(RZAER) sequence and demonstrated the feasibility of 3D diffusion weighted RAZER sequence for carotid vessel wall.
Abnormal functional connectivity of the hippocampus and amygdala in plateau Tibetan with type 2 diabetes mellitus
Authors: Meng Jinli , Gao Yingxue , Li Hailong , Cao Lingxiao , He Wanlin , Feng Li , Guo Yongyue , Hu Xin , Li Hengyan , Zhang Chenghui , Wu Yunhong , Huang Xiaoqi
Published: August 2024

We performed a seed-based rsFC study to explore the hippocampus and the amygdala FC patterns in plateau Tibetan patients with T2DM. We found that, compared to plateau Tibetan HC, T2DM showed both increased rsFC between the right hippocampus and left DLPFC and left SFG, and between the left amygdala and right OFC as well as right DLPFC. Moreover, these rsFC abnormalities were significantly correlated with age, RBC and changes of visuospatial memory function in plateau Tibetan patients with T2DM. These findings of altered FC may provide important insights into the neural basis of diabetes-related cognitive decline in plateau Tibetan.
Role of tomoelastography in evaluation for pancreatic fistula after pancreaticoenteric anastomosis
Authors: Shi Siya , Wang Liqin , Yuan Jiaxin , Hu Xuefang , Xie Xingyan , Wen Tingting , Yu Jinhui , Luo Yanji
Published: August 2024

This prospective study enrolled the patients who underwent both preoperative tomoelastography and pancreaticoenteric anastomosis. Eighty-two patients were included (median age: 59.5 years, 40 men, 18 patients with POPF). Main pancreatic duct diameter (MPDD) (P=0.012), c (P<0.001) and φ (P=0.001) were relevant factors for POPF. The area under the curve (AUC) of c, φ and MPDD for predicting POPF was 0.880, 0.816 and 0.747. Fibrosis was the relevant factor of POPF (P=0.001). There was positive correlation between fibrosis and stiffness (r=0.681, P<0.001). Tomoelastography is a novel and robust multi-frequency MRE technique that can facilitate the prediction of POPF.
Novel method for quantifying pancreatic exocrine function from Secretin-MRCP
Authors: Guimaraes Alexander , Kim Joyce , Sharzehi Kaveh , Cote Gregory , Wang Lisa , Foster Bryan , Wyatt Cory
Published: August 2024

Chronic pancreatitis is a chronic fibro-inflammatory syndrome of the pancreas that often leads to exocrine pancreatic insufficiency EPI. Secretin MRCP provides an approach for quantifying function. Present interpretation of sMRCP lends itself to variability in interpretation. Further, previous approaches for quantitative assessment of sMRCP have been difficult to reproduce. We have developed a mathematical model for quantifying various features of dynamic sMRCP and have shown in a retrospective cohort, significant differences in one feature that correlates to delay of pancreatic production of fluid, to separate and correlate to ePFT and FE. 9
Application of natural language processing to post-structuring of rectal cancer MRI reports
Authors: Liu Wenjuan
Published: August 2024

We applied natural language processing (NLP) to the extraction of relevant information from MRI reports of rectal cancer written in Chinese. We used 358 MRI reports written between 2015 and 2021 to develop a rule-based NLP model to extract 11 key image features. The accuracy, precision, recall, and F1 score of our NLP model for correct extraction of values from reports were 93.82%, 95.63%, 87.06%, and 91.15% for pre-2015 reports, and 92.55%, 98.53%, 94.15%, and 96.29% for post-2021 reports. Our NLP system with rule-based pattern matching realized the rapid and accurate structured processing of rectal cancer MRI reports.
Multiparametric Cardiac Magnetic Resonance Reveals Persistent Myocardial injury in Patients with Exertional Heat illness
Authors: Luo Song , Zhang Jun , Dou Wei Qiang
Published: August 2024

To explore the clinical potential of multiparametric cardiac magnetic resonance (CMR) in evaluating myocardial injury in patients with exertional heat illness (EHI). This prospective study enrolled 28 male with EHI and 18 age-matched male healthy controls. All subjects underwent CMR, and 9 patients had follow-up CMR measurements 3 months after recovery from EHI. As shown in this study, EHI patients have left ventricular dysfunction, myocardial edema and fibrosis, and persistent myocardial injury at 3-month follow-up after the EHI episode. This knowledge has an important role in guiding patients recovering from EHI back to a return to work, play or duty, respectively.
Rapid Myocardial T1 Stress/Rest Reactivity Mapping in Ferumoxytol-enhanced Cardiac MRI: Initial Results
Authors: Unal Hazar Benan , Zeynali Shahriar , Han Fei , Anthony Gregory J. , Raman Subha , Tamarappoo Balaji , Dharmakumar Rohan , Sharif Behzad
Published: August 2024

Myocardial T1 reactivity, defined as the relative T1 change from rest to stress, has been proposed as a marker for detection of ischemic heart disease. SASHA-based T1 mapping provides higher accuracy than MOLLI, but the scan time can be prohibitive under stress. In this work, we investigated the feasibility of accelerated SASHA T1 mapping for ferumoxytol-enhanced dobutamine-stress T1 reactivity studies at 3T in a preclinical setting. We showed that a 2-fold accelerated SASHA T1 mapping can provide sufficiently accurate results compared to conventional SASHA.
Using Quantitative MR and Histology to Characterize Acute and Chronic DVT at 9.4T
Authors: Jordan Caroline , Sinha Kavya , Vela Deborah , Buja L. Maximillian , Karmonik Christof , Roy Trisha
Published: August 2024

Deep venous thrombosis (DVT) is common. Mechanical thrombectomy may offer advantages compared to medical therapy alone, but it can be challenging to determine the optimal treatment. Six patients underwent thrombectomy, and the ex vivo clot was scanned at 9.4T. We acquired T1, T2, and T2* maps, and histologic content of red blood cells, fibrin, and collagen. R2 between RBC content and each relaxation time was R2 = 0.58 for T1, R2 = 0.82 for T2, and R2 = 0.69 for T2*. T1, T2, and T2* mapping of ex vivo DVT clots at 9.4T may be feasible for determining clot components.
3D whole-heart joint T1/T1ρ mapping and water/fat imaging at low-field 0.55T scanner
Authors: Crabb Michael , Kunze Karl , Castillo-Passi Carlos , Munoz Camila , Velasco Carlos , Neji Radhouene , Prieto Claudia , Botnar Rene
Published: August 2024

Native T1 and T1ρ mapping has shown promising results for the detection of focal and diffuse myocardial fibrosis without requiring contrast agents. However, conventional myocardial maps are acquired sequentially in 2D at 1.5T/3T fields. 3D joint T1/T1ρ mapping has recently been proposed at 1.5T, but not demonstrated at lower field, which could potentially make cardiac MRI more accessible and affordable. Furthermore, lower T1 relaxation times, reduced SAR and fewer B0/B1 inhomogeneities make low-field MRI an attractive alternative for joint T1/T1ρ mapping. Here, we investigate the feasibility of novel 3D whole-heart joint T1/T1ρ mapping on the latest 0.55T MR scanner generation.
Texture analysis of area-at-risk based on T1-mapping associated with infarct characteristics following acute STEMI
Authors: Wang Jiali , Xu Kai , Hu Chunfeng , Meng Yankai , Han Shuguang , Wu Peng , Han Lu , Xu Yongzhou
Published: August 2024

To assess the potential of texture analysis (TA) of area-at-risk (AAR) based on native T1 mapping in predicting the severity of injury in ST-segment elevation myocardial infarction (STEMI) patients. Cine, T1 mapping, and late gadolinium enhancement (LGE) images were analyzed to evaluate cardiac function, and scar characteristics. The predictive value of TA for adverse LV remodeling (ALVR) and large final infarct size was evaluated. Entropy and uniformity (parameters of TA) in AAR of T1 mapping were highly correlated with convalescent infarct size, uniformity independently predicted large final infarct size, however, TA of AAR was not associated with convalescent ALVR.
The diagnostic value of multi-parameter CMR for early detection of light-chain amyloidosis from hypertension cardiomyopathy patients
Authors: Wang Fang , Yang Lili , Yang Yanbin , Ruan Xiaowei , Wang Rui , Yue Xiuzheng
Published: August 2024

The value of cardiac magnetic resonance imaging in diagnosing light chain amyloidosis has been confirmed, and its characteristic LGE manifestations are an important means to identify myocardial amyloidosis. However, early-stage light-chain amyloidosis patients always have the same symptoms as hypertensive cardiomyopathy in clinical practices. This study aimed to investigate the combined diagnostic efficacy of T1mapping, ECV, and myocardial strain techniques in early myocardial amyloidosis by comparing with healthy controls and patients with hypertensive cardiomyopathy that also caused uniform myocardial thickening.
Motion-corrected quantification of cerebral venous oxygenation in vulnerable populations: from neonates to older adults
Authors: Gou Yifan , Golden Christopher , Lin Zixuan , Shepard Jennifer , Tekes Aylin , Hu Zhiyi , Li Xin , Oishi Kumiko , Albert Marilyn , Lu Hanzhang , Liu Peiying , Jiang Dengrong
Published: August 2024

Cerebral venous oxygenation (Yv) is a biomarker in various brain diseases such as hypoxic-ischemic-encephalopathy in neonates and Alzheimer's disease in the elderly. T2-Relaxation-Under-Spin-Tagging (TRUST) MRI is a widely used technique to measure global Yv level. However, subject motion during TRUST scan can cause considerable errors in Yv quantification. This work developed an automatic algorithm for motion-corrected quantification of Yv, which showed improved precision of Yv estimation in both neonates and elderly adults.
Oxygen extraction fraction (OEF) mapping by using multi-delay arterial spin labeling based on QSM+qBOLD
Authors: Liu Xiaoyi , Yin Yayan , Wei Juan , Lu Jie
Published: August 2024

We aimed to improve the accuracy of OEF mapping by using multi-delay arterial spin labeling based on quantitative susceptibility mapping plus quantitative blood oxygen level-dependent magnitude (QSM+qBOLD, or QQ). 3D multi-echo gradient-echo and ASL sequence were performed in 7 healthy subjects. ROIs analysis and paired t-test compared QQ with single-delay ASL and QQ with multi-delay ASL. QQ with multi-delay ASL shows smaller OEFs than QQ with single-delay ASL method. Corresponding OEFs were 38.9±3.4% and 39.6±3.4% (P<0.01) in gray matter, 39.7±2.9% and 40.2±2.9% in whole brain(P<0.01), respectively. Our study suggests that QQ with multi-delay ASL provides more accurate OEF than QQ with single-delay ASL, which may have potential in the use of clinical diseases.
Pharmacological Inactivation of the Inhibitory Zona Incerta Decreased Resting-state Functional MRI Connectivity
Authors: Wen Junjian , Wang Xunda , Ma Teng , Xie Linshan , Leong Alex T. L. , Wu Ed X.
Published: August 2024

In the recent decade, resting-state functional MRI (rsfMRI) has emerged as the most invaluable, non-invasive imaging technique to map long-range, brain-wide functional connectivity networks. Despite the enormous potential inherent in this technique, our present knowledge of the neural underpinnings of rsfMRI connectivity remains generally incomplete given the lack of studies examining the role of the inhibitory neural population, which is the counterpart of the excitatory neurons. In this study, we directly examine the role of zona incerta, which is one of the major source of inhibitory drive to the cortex.
An improved data acquisition for robust oxygen extraction fraction (OEF) mapping using an integrative model of QSM and qBOLD (QSM+qBOLD=QQ)
Authors: Cho Junghun , Spincemaille Pascal , Nguyen Thanh , Wang Yi
Published: August 2024

Oxygen extraction fraction (OEF) is critical to evaluate brain tissue viability and function in neurologic disorders. An integrated model of QSM and qBOLD (QSM+qBOLD or QQ) has been developed to map OEF utilizing a routine multi-echo gradient echo (mGRE) acquisition without impractical vascular challenges. This study proposes a novel mGRE acquisition with logarithmic echo spacing that acquires more data points in short echo time regime, which is critical to decouple the model parameters in QQ. The proposed novel mGRE provided more accurate OEF in two simulations, compared to the conventional mGRE.
Exploring reproducibility in deep learning-based parallel imaging reconstruction
Authors: Oh Chungseok , An Hongjun , Lee Jongho
Published: August 2024

The performance of a deep neural network can be affected by software and hardware setups when training the network and, therefore, can vary from training to training. This issue of reproducibility, which can be referred to as an “intrinsic” reproducibility of deep learning, can be critical for academic research because reproducibility is a key requirement for journal papers. In this study, we explore this intrinsic reproducibility issue for deep learning-powered parallel imaging reconstruction by using a popular end-to-end variational network. This study may provide minimal requirements for reproducible research in network training.
Deep learning acceleration and reconstruction for single-channel signals
Authors: Ye Yongquan , Zhang Zhongqi , Chen Eric , Chen Xiao , Sun Shanhui , Xu Jian
Published: August 2024

The capacity of the deep learning ReconNet3D model for single-channel image reconstruction with highly under-sampled k-spaces is demonstrated. Without the need for coil sensitivity information, the proposed method can achieve an acceleration factor of 4 on a dual-channel VTC coil. Supporting high-factor acceleration with limited coil channels can be very beneficial for imaging with surface coils or preclinical animal scans.
Finding Optimal Regularization Parameter for Undersampled Reconstruction using Bayesian Optimization
Authors: Di Biase Alberto , Prieto Claudia , Botnar Rene
Published: August 2024

We present a Bayesian optimization approach to find the optimal regularization parameters for undersampled MRI reconstructions such as Compressed Sensing (CS). Bayesian optimization can find optimal points for expensive to evaluate functions by efficient sampling the next points to try by maximizing the expected improvement. Additionally, the use of pruning can speed up optimization by stopping early unpromising trials. We demonstrate the effectiveness of this optimization technique by finding optimal parameters for undersampled MRI using Total Variation and CS-Wavelet regularization. The parameters found with the proposed approach are comparable to does found by grid search but requiring shorter computational times.
Impact of Deep Learning-Based MR Image Reconstruction Algorithms on Abdominal MRI Radiomic Features
Authors: Li Hailong , Alves Vinicius Vieira , Pednekar Amol , Manhard Mary , Greer Joshua , Trout Andrew , He Lili , Dillman Jonathan
Published: August 2024

Deep learning (DL)-based techniques are increasingly being applied to assist with or improve image reconstruction. However, the impact of DL-based algorithms on radiomics is not well understood. This study aims to evaluate the impact of two commercially available DL-based reconstruction pipelines: (1) SmartSpeed (Philips Healthcare, U.S. FDA-cleared); and (2) SmartSpeed with Super Resolution (SmartSpeed+SuperRes, not U.S. FDA-cleared to date) on MRI radiomic features. Our analysis showed that compared to conventional image reconstruction technique, 42 out of 86 investigated radiomic features from SmartSpeed images were highly correlated whereas only 13 features from SmartSpeed+SuperRes images had high correlations with conventional image features.
Safeguarded Deep Unfolding Network for Parallel MR Imaging
Authors: Cui Zhuo-Xu , Jia Sen , Cheng Jing , Zhu Qingyong , Liang Dong
Published: August 2024

This study proposes a safeguarded methodology for network unrolling. Specifically, focusing on parallel MR imaging, we unroll a zeroth-order algorithm, of which the network module represents a regularizer itself so that the network output can still be covered by a regularization model. Furthermore, inspired by the idea of deep equilibrium models, before backpropagation, we carry out the unrolled network to converge to a fixed point and then prove that it can tightly approximate the real MR image. In a case where the measurement data contain noise, we prove that the proposed network is robust against noisy interferences.
Association Between Modic Change and Paraspinal Muscle Fat Infiltration Based on MRI
Authors: Fu Min , Li Ze , Yuan Xiaochun , Wei Xiaocheng , Chen Junrong
Published: August 2024

Paraspinal muscles play an important role in maintaining the stability of lumbar spine. The influencing factors of paraspinal muscle degeneration are still controversial. IDEAL-IQ MR sequence can provide quantitative fat fraction map to objectively and accurately evaluate the fat infiltration in paraspinal muscles. By using IDEAL-IQ MR sequence, this study investigated the influence of Modic change (MC) on quantitative propertied of paraspinal muscles in patients with low back pain (LBP). Our results showed that MC can aggravate the degeneration of paraspinal muscles, especially the multifidus, in LBP patients.
Evaluation of viscoelastic changes of the psoas major muscle after exercise using MR elastography
Authors: Habe Tetsushi , Numano Tomokazu , Ito Daiki , Takamoto Kouichi , Nishijo Hisao
Published: August 2024

The shear modulus of the psoas major muscle (PM) after exercise has been evaluated using magnetic resonance elastography (MRE) previously, however, a separate evaluation of elasticity and viscosity has not been performed. We evaluate storage modulus representing elasticity and loss modulus representing viscosity of the PM using MRE after exercise in this study. Comparing the before and immediately after exercise, the loss modulus showed a greater rate of decrease than the storage modulus, suggesting that the loss modulus, which reflects viscosity, is more useful for detecting changes of muscle tissue immediately after exercise.
Large coverage, high temporal and spatial resolution lower extremity blood oxygen level-dependent imaging
Authors: Qu Jianxun , Fan Xiaoyuan , Lin Tianye , Yu Xiaoxi , Feng Feng
Published: August 2024

Multi echo gradient echo (GRE) sequence is usually used in lower extremity BOLD experiments. This study replaced the GRE acquisition by SMS EPI and achieved broader coverage and higher temporal and spatial resolution. The minimum ischemia value (MIV) during the ischemia session and the R2* change rate (Grad) during the reperfusion session were calculated. Both MIV and Grad present muscle group-wise distribution. This study demonstrated the feasibility of the SMS GRE-EPI sampling strategy in the skeletal muscle BOLD experiment.
En Route to Body and Cardiac MRI at 21.0 T: Where does the RF power dissipate?
Authors: Nurzed Bilguun , Hieronymi Dennis , Eigentler Thomas , Niendorf Thoralf
Published: August 2024

Investigation of the power correlation matrix at 21.0 T is vital to elucidate the electrodynamics for human body and cardiac MR as well as the RF antenna performance. Recognizing this opportunity, this abstract assesses the power losses for multi-channel RF transceiver arrays for human body and cardiac MR using 32-channel pTx/Rx self-grounded bow-tie building block (SGBT). Losses were determined inside the tissue, lossy material of the antenna, lumped elements of the tuning and matching network and due to coupling and radiation.
Simultaneous multi-slice 23Na imaging using radial CAIPIRINHA
Authors: Wittrich Marco , Nagel Armin , Schmitter Sebastian , Bachert Peter , Ladd Mark , Kratzer Fabian
Published: August 2024

In this work, a simultaneous multi-slice (SMS) approach using radial CAIPIRINHA was implemented for sodium MRI. Initial experiments were confined to two simultaneously excited slices. Here, simulated and measured slice profiles agreed well with expectations. Further, the SNR of the acquired SMS images was analyzed and compared to reference measurements of the individual slices. An SNR increase of up to 38% when maintaining flip angle and up to 13% for constant SAR was observed. Lastly, in-vivo head images (2.9x2.9x12mm3) were obtained showing the feasibility of 23Na SMS MRI.
7T to 3T domain adaptation in white matter lesion segmentation on T2-weighted (T2-w) FLAIR images using deep learning
Authors: Li Jinghang , Diniz Eduardo , Forry Taylor , Ibrahim Tamer , Aizenstein Howard , Wu Minjie
Published: August 2024

In this work, we explored the domain adaptation problem in deep learning segmentation. Specifically, we applied the residual U-net [1] on 3T and 7T Fluid Attenuated Inverse Recovery (FLAIR) images to delineate the white matter hyperintensity (WMH) in a 2D fashion. We leveraged learning without forgetting [2] to regulate the network’s learning in the new domain to preserve the model’s performance on the old domain while still achieving satisfying results on the new domain images.
A Comparison of Cartesian MR Fingerprinting Maps acquired at 3T and 7T
Authors: Shirvani Saba , Ding Belinda , Rodgers Christopher T.
Published: August 2024

Abdominal 7T MRI is technically demanding but has great potential due to improved signal-to-noise ratio. One promising way to quantify tissue properties is to use MR Fingerprinting, since MRF rapidly quantifies T1 relaxation alongside other tissue properties such as T­2, B1+ and proton density. However, translating MRF measurements from high field to ultra-high field systems is challenging. Here we investigate a strategy to translate a Cartesian MRF sequence from 3T to 7T scanners, by optimising sequence parameters. We apply this approach to the brain and to the kidney and present comparable images from our 3T and 7T scanners.
Improved efficiency and quantitative accuracy in hyperpolarized 129Xe ventilation imaging using 2D spiral acquisition
Authors: Hussain Riaz , Plummer Joseph , Bdaiwi Abdullah , Willmering Matthew , Walkup Laura , Cleveland Zackary
Published: August 2024

Despite yielding high signal-to-noise ratio, conventional gradient recalled echo (GRE) sequence requires a relatively long breath-hold for 129Xe ventilation imaging. 2D-spiral sequence enables faster imaging and offers possibility to correct regional B1/flip-angle inhomogeneities and signal decay using keyhole reconstruction without making assumptions about bias texture that can obscure the physiology of interest. Here, GRE and 2D-spiral showed comparable image quality and revealed regional ventilation impairment in cystic fibrosis. Furthermore, flip-angle correction preserved signal variation due to underlying lung pathophysiology, including gravitation ventilation gradients and subtle defects. Thus, flip-angle corrections in 2D-spiral sequence may detect early and reversible disease-induced ventilation impairment.
3D Pulmonary Dynamic Ventilation Imaging with High Spatial and Temporal Resolution Using Hyperpolarized 129Xe MRI
Authors: Li Hongchuang , Li Haidong , Zhang Ming , Liu Xiaoling , Zhao Xiuchao , Han Yeqing , Ye Chaohui , Zhou Xin
Published: August 2024

The mutual restriction of temporal and spatial resolution is a challenge for hyperpolarized gas dynamic MRI, especially for 3D acquisition. Herein, we proposed a methodology to image the pulmonary dynamic ventilation with high temporal and spatial resolution using hyperpolarized gas MRI based on a 3D gradient echo sequence. Furthermore, we observed the difference of pulmonary dynamic ventilation in the posterior-anterior direction.
Effects of patch size on 3D patch-based super-resolution reconstruction of hyperpolarized 13C cardiac MRI
Authors: Lin Sung-Han , Ma Junjie , Park JaeMo
Published: August 2024

The volumetric patch-based super-resolution method can reconstruct a single-slice low-resolution hyperpolarized 13C MRI to multiple 13C slices with enhanced spatial resolution by exploiting the corresponding high-resolution structural 1H MRI. In this study, the overall performance of this method and the effects of patch size were evaluated using a simulated digital phantom and an anthropomorphic cardiac 13C MR phantom. The optimal patch size for this reconstruction method was also applied to in-vivo human 13C cardiac images acquired with an injection of hyperpolarized [1-13C]pyruvate.
Multiple-Slice, Multiple-Breath Washout Hyperpolarized 129Xe Ventilation Mapping of the Lung using Accelerated Data Acquisition
Authors: Alam Faiyza , Couch Marcus , Zanette Brandon , Li Daniel , Ratjen Felix , Santyr Giles
Published: August 2024

Multiple-breath washout hyperpolarized 129Xe MRI (MBW Xe-MRI) results in a regional map of fractional ventilation (FV), measuring percent gas clearance/breath. One limitation of previous work from our group is the single thick coronal slice (200mm) centered on the chest cavity results in significant partial volume effects. Acquiring multiple slices using parallel imaging adds spatial resolution in the slice direction. Feasibility of multiple-slice FV mapping using parallel acceleration is investigated in one adult. Median [IQR] FV was 0.35 [0.30 0.36]. Gravitational dependence was observed in posterior-anterior direction (-0.0122 cm-1). Multiple-slice MBW Xe-MRI is feasible in healthy adults using parallel image acquisition.
Highly accelerated 3D hyperpolarized MRI at ultra-high fields using Seiffert Spirals
Authors: Speidel Tobias , Knecht Stephan , Kolb Klaus , Gierse Martin , Rasche Volker
Published: August 2024

Isotropic 3D imaging of hyperpolarized media is generally challenging due to the extremely limited lifetime of the hyperpolarized phase. Fortunately, images of hyperpolarized media are often intrinsically sparse, resulting in an excellent precondition for non-linear reconstruction techniques such as Compressed Sensing. To preserve this condition, a 3D Seiffert Spiral trajectory was implemented at 11.7 T, yielding low-coherent sampling properties for an arbitrary number of excitations, until depletion of the hyperpolarized signal. We show that qualitative images with a resolution of <500 $$$\mu$$$m can be reconstructed from continuous data that was acquired in less than one second.
Three-dimensional radial echo-planar spectroscopic imaging for in vivo hyperpolarized 13C MRSI at 3 T
Authors: Awenius Marcel , Biegger Philipp , Glowa Christin , Müller Melanie , Bangert Renate , Abeln Helen , Ludwig Dominik , Kuder Tristan , Ladd Mark , Bachert Peter , Korzowski Andreas
Published: August 2024

In this study, a novel radially-sampled echo-planar spectroscopic imaging (rEPSI) sequence was implemented at a clinical 3T MR scanner to enable the non-invasive investigation of metabolic processes via hyperpolarized 13C substrates in real-time. Customized data analysis pipelines yielded high quality spectra and volumetric intensity maps for in vivo experiments using hyperpolarized [1-13C]pyruvate. Data extracted from k-space center points enabled a non-localized quantification of T1 values.
Value of BOLD MR in early evaluating the response and prognosis of esophageal squamous cell carcinoma treated with definitive chemoradiotherapy
Authors: Zheng Huanhuan , Zhang Hailong , Zhu Yan , Wei Xiaolei , Liu Song , Ren Wei
Published: August 2024

To confirm a quantitative imaging predictor for evaluation of early treatment response and prognosis to definitive chemoradiotherapy (dCRT) in patients with esophageal squamous cell carcinoma, using BOLD MR images. R2* values were obtained pre- and post-dCRT in 28 patients using BOLD MR. Independent samples t-test (normality) or Mann-Whitney U test (non-normality) was used to compare differences of R2*-related parameters between CR and non-CR groups. Diagnostic performance of parameters in predicting response was tested with receiver operating characteristic curve analysis. 3-years overall survival (OS) was evaluated using by Kaplan Meier curve, log rank test, and Cox proportional hazards regression analysis.
Reproducibility and image quality of diffusion weighted imaging in volunteers with pancreas using different respiratory schemes
Authors: Pei Yigang , Bai Yu , Liu Weiyin , Liu Wenguang , Li Wenzheng
Published: August 2024

DWI is essential in clinical diagnosis of pancreas. Image quality highly influence ADC measurements. Pancreases in abdomen easily suffers from artifact induced by abdominal and chest respiratory motion. A new diffusion-weighted imaging (DWI) sequence was explored to better delineate pancreas in our previous study (named FOCUS-MUSE DWI). In this study, we compared the clinical utility of FOCUS-MUSE DWI, MUSE DWI, FOCUS DWI and SS DWI using four different breathing schemes (RT, NT, BH and FB) for the repeatability of apparent diffusion coefficient (ADC) measurements and image quality. Our results suggested that RT‑DWI provided the best ADC reproducibility and image quality among four breathing schemes on 3.0 T MRI, making it as the recommended protocol for clinical DWI of the pancreas.