bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in Aspartate Metabolism in the medial-prefrontal cortex of Nicotine Addicts Based on J-edited Magnetic resonance spectroscopy
Authors: Yu Miaomiao , Lin Liangjie , Xu Ke , Xu Man , Ren Jianxin , Niu Xiaoyu , Gao Xinyu , Zhang Mengzhe , Yang Zhengui , Dang Jinghan , Tao Qiuying , Han Shaoqiang , Wang Weijian , Cheng Jingliang , zhang yong
Published: August 2024

Cigarette smoking harms nearly every organ of the body, causes many diseases, and reduces the health of smokers in general. Our study aims to explore the changes of aspartate (Asp) levels in the medial prefrontal cortex of patients with nicotine addiction using the J-edited 1H MRS technique. Results showed that the Asp level in medial prefrontal of nicotine addicts is relatively increased, suggesting that the metabolism of aspartate may play a key role in nicotine dependence.
Altered cortical metabolism contributes to cognitive deficits in a healthy military cohort
Authors: Joyce Julie , Heaton Kristin , Liao Huijun , Lin Alexander
Published: August 2024

The selection of control groups is of increasing interest in military research. Here, we used single voxel magnetic resonance spectroscopy (MRS) to probe cortical metabolism in the anterior and posterior cingulate gyri, temporal lobe and parietal white matter in healthy military service members and civilian controls. Computerized neuropsychological tests were administered to evaluate neurocognitive abilities. We identified higher incidence of cognitive deficits in military service members relative to civilian controls as well as associations between neurometabolite levels and poor cognitive performance.
In situ determination of pH in brain tissue using postmortem 1H-MRS
Authors: Frese Sabina , Gascho Dominic , Thali Michael , Kozerke Sebastian , Zölch Niklaus
Published: August 2024

Postmortem, relatively low pH values have been described and reported to be dependent on the cause of death and the duration of the agonal phase. Using 1H-MRS on decedents and subsequent control pH measurements in collected samples, we investigated to what extent the pH dependence of peak positions of acetate and lactate are suitable to detect such low pH values non-invasively. We found that the measured chemical shift of acetate and corresponding pH value follow a simulated titration curve. Hence, acetate is a promising candidate to detect low postmortem brain pH for forensic investigations.
Cerebral glucose quantification using 1H short-TE STEAM spectroscopy at 7T: Influence of macromolecule signals
Authors: Kuribayashi Hideto , Urushibata Yuta , Dinh Thuy , Imai Hirohiko , Ahn Sinyeob , Seethamraju Ravi , Isa Tadashi , Okada Tomohisa
Published: August 2024

The ability of conventional 1H short-TE STEAM spectroscopy at 7T was investigated to quantitate cerebral glucose. Spectra were analyzed using LCModel with the standard 7T STEAM basis set and with that plus macromolecule basis set. With the evaluation of Cramér-Rao lower bounds, the precision of glucose quantification reduced with the macromolecule basis set. Moreover, estimated glucose and taurine concentrations were shown to correlate for both analytical conditions. Thus, the quantification is not improved using the macromolecule basis set and may be more precise via detecting H1-α-glucose, which is free from spectral overlap.
Deuterium oxide MRI to image the water inflow in the bovine lens of the eye
Authors: Pan Xingzheng , MacFarlane Emily , Donaldson Paul
Published: August 2024

In the absence of a blood supply the lens operates an internal microcirculation to deliver nutrients, remove metabolic wastes, and controll the lens volume, which together to maintain the optical properties of the lens. While this microcirculation is generated by circulating fluxes of ions and water, visualising water flow throughout the whole lens and especially into the central of lens in real time has proven challenging. To address this, we developed and optimised new deuterium oxide (D2O) MRI protocols to image water flow within multiple organ-cultured bovine lenses that can be routinely performed using 3T clinical MRI.
Rejecting or retaining motion corrupted transients in diffusion-weighted MRS: high b-values and multiple directions
Authors: Ligneul Clémence , Andersson Jesper , Jbabdi Saad , Lerch Jason , Clarke William
Published: August 2024

Robust processing is crucial for a reliable microstructural interpretation of advanced diffusion-weighted magnetic resonance spectroscopy (DW-MRS) methods. The spectral signal intensity depends on the direction when using strong diffusion-gradients and multiple directions, even more if the voxel content is very anisotropic (e.g. contains a white matter tract). In this study we propose a model-based way of identifying motion corrupted averages that accounts for the voxel anisotropy.
Correlations of 31P-containing metabolites in human brain at 3 and 7 Tesla
Authors: Hong Sungtak , Shen Jun
Published: August 2024

Numerical Monte Carlo analysis was performed to quantify metabolite-metabolite correlations of spectral origin in 31P MRS spectra acquired from human brain at both 3 and 7 Tesla without any confounding biological correlations. Significant correlations were found for many 31P-containing metabolite pairs. In particular, the 3 and 7 Tesla NAD+-NADH correlations are significantly different because of the field strength difference. These results demonstrate that it is necessary to incorporate metabolite-metabolite correlations originating from spectral overlap into statistical models that correlate MRS measurements with clinical parameters when overlapping 31P signals are of clinical interest.
Two Dimensional MRSI of Human Calf Muscle at 3T: Decoupling and NOE effects on PDE and total NAD
Authors: Nagarajan Rajakumar , Kent Jane , Layec Gwenael
Published: August 2024

Using two-dimensional 31-phosphorus spectroscopic imaging (2D-MRSI) in human skeletal muscle, we have demonstrated that proton decoupling and nuclear Overhauser effect sequences improve the coefficient of variation and enhance the resolution of key metabolites in vivo.
Modified reduced FOV diffusion-weighted MRI using tilted 2D RF excitation pulses in patients with pancreatic ductal adenocarcinoma
Authors: Tanabe Masahiro , Higashi Mayumi , Hideura Keiko , Ihara Kenichiro , Benkert Thomas , Imai Hiroshi , Yamane Masatoshi , Yamaguchi Takahiro , Inoue Atsuo , Ito Katsuyoshi
Published: August 2024

This study evaluated the image quality of modified reduced field-of-view (FOV) DWI using 2D spatially-selective RF pulses with tilted excitation plane (tilted r-DWI) for pancreatic ductal adenocarcinomas (PDACs) compared with conventional full-FOV DWI (f-DWI). Two radiologists evaluated the MR image quality, and SNR, CNR, and ADC values of the pancreatic lesions were quantitatively assessed. Image quality scores and CNR of tilted r-DWI were significantly higher than that of f-DWI. The ADC values of PDACs showed no significant deference between them. Tilted r-DWI provides better image quality with less artifacts and higher pancreatic lesion conspicuity than f-DWI.
MR Elastography of the affected mesenteric fat in active Crohn’s Disease: a feasibility study
Authors: van Schelt Anne-Sophie , Beek Kim , Wassenaar Nienke , Schrauben Eric , Runge Jurgen , Nederveen Aart , Stoker Jaap
Published: August 2024

Crohn’s Disease (CD) is a chronic inflammatory bowel disease. Mesentery of afflicted bowel loops often is involved. MR-Elastography allows assessment of its underlying mechanical properties and gives more insight in the role of the mesentery. Feasibility was first shown in 15 healthy volunteers. Seven patients with active CD (aCD) scheduled for surgical intervention underwent pre-operative MR-Elastography acquisition and histopathological analysis. Seven age- and sex matched volunteers were also scanned. Significantly higher shear wave speed, shear stiffness and phase angle were found in aCD patients, possibly related to increased fibrotic tissue in or inflammation of the mesentery.
Amide Proton Transfer MRI for Treatment Response of Locally Advanced Rectal Cancer Following Neoadjuvant Chemotherapy and Radiation Therapy
Authors: Zhang Lan , Li Xin , Sun Peng , Yang Fan
Published: August 2024

We conducted this prospective study to determine whether APTw imaging is precise in evaluating treatment response of LARC after NCRT, by comparing the accuracy of evaluation using APTw imaging to that of T2-weighted imaging and DWI, which is value for the selection of organ preservation candidates.
Diffusion-weighted MRI of rectal cancers: Utility of reduced FOV single-shot EPI with tilted 2D RF excitation pulses
Authors: Inoue Atsuo , Tanabe Masahiro , Ihara Kenichiro , Hideura Keiko , Benkert Thomas , Imai Hiroshi , Yamane Masatoshi , Yamaguchi Takahiro , Higashi Mayumi , Ito Katsuyoshi
Published: August 2024

This study evaluated the image quality of reduced FOV DWI using 2D spatially-selective RF pulses with tilted excitation plane (tilted r-DWI) for rectal cancer compared with full-FOV DWI (f-DWI) using readout segmented echo-planar imaging (RS-EPI). Two radiologists evaluated the MR images, and SNR, CNR, and ADC values of the rectal lesions were quantitatively evaluated. All image quality scores and CNR were significantly higher in tilted r-DWI than in f-DWI with RS-EPI. SNR and ADC values showed no significant deference between them. Tilted r-DWI provides better image quality with less artifacts and higher rectal lesion conspicuity than f-DWI with RS-EPI.
Multiparametric 3D cardiac MR for simultaneous bright- and black-blood imaging and joint T1/T2 myocardial tissue mapping
Authors: Kokhanovskyi Ivan , Crabb Michael , Kunze Karl , Neji Radhouene , Ganter Carl , Tripp Donovan , Castillo-Passi Carlos , Karampinos Dimitrios , Prieto Claudia , Botnar Rene
Published: August 2024

Accurate diagnosis of cardiac disease requires imaging with high spatial resolution and whole-heart coverage. Current clinical protocols acquire contrasts sequentially, in different 2D orientations during several breath-holds leading to long examination times and misregistration artifacts. To address these limitations, we present a novel free-breathing four-heartbeat sequence for simultaneous 3D whole-heart Assessment of Cardiovascular anaTomy via bright- and black-blood Imaging and T1/T2 myocardial tissue quantificatiON (ACTION). Sequence parameters are optimized with Bloch simulations to enhance the mapping sensitivity and to improve the quality of anatomical images. Primarily results in a standardized phantom and in-vivo show potential for comprehensive heart disease detection.
Optimization of spin-lock preparation pulses for B1 and B0 insensitive cardiac T1ρ mapping
Authors: Qi Haikun , Lv Zhenfeng , Xu Jian , Hu Peng
Published: August 2024

Cardiac T1ρ mapping is a promising technique for assessment of myocardial fibrosis without exogenous contrast agent. However, its wide application is hindered by the sensitivity of T1ρ preparation to B1 and B0 inhomogeneities. In this study, the state-of-the-art constant spin-lock methods including the composite and adiabatic excitation continuous-wave spin-lock methods were investigated using numerical simulations to assess their robustness to field inhomogeneities, and validated in phantoms and a preliminary subject. Two T1ρ preparation modules were found to generate superior T1ρ mapping quality in the presences of B0 and B1 inhomogeneities, indicating the potential of clinical application of cardiac T1ρ MRI.
Rapid multiple-breath-holds myocardial CINE T2-mapping with dynamic multiple trigger delay acquisition
Authors: Kato Mana , Yoneyama Masami , Nagao Michinobu , Kodaira Kazuo , Ogawa Takumi , Hamatani Yutaka , Shiina Isao , Goto Yasuhiro , Sakai Shuji
Published: August 2024

T2-mapping is generally obtained only in diastole. However, because myocardial edema can affect both diastole and systole, acquisition of T2-mapping of different cardiac phases is desirable, but it prolongs examination time and increases patient stress. To overcome this limitation, we report a new T2-mapping technique using dynamic trigger delay which enables quantitative mapping at multiple cardiac phases in one scan. In this study, we demonstrate the feasibility of this approach in healthy volunteer examination.
Deep Learning Based Reconstruction Improved Image Quality for rectum T2-weighted imaging
Authors: Feng Weiming , Zhu Lan , Xia Yihan , Wang Kangning , Zhang Yong , Dai Jiankun , Fu Guifeng , Zhang Huan
Published: August 2024

High-resolution MRI is of much significance in preoperatively staging rectal cancer. However, the motion artifact from intestinal peristalsis inevitably affects image quality then the accuracy of staging. Deep learning reconstruction (DLRecon) that uses artificial neural networks to extract patterns and makes predictions from large data sets, has been verified in related studies for improving image quality and reducing scanning time. In this study, rectum T2-weighted imaging (T2WI) reconstructed with DLRecon and conventional reconstruction were evaluated, and the results indicate that DLRecon could be employed for better image quality without extra scanning time in clinical practice.
Monitoring changes of the muscles around the knee joint in amateur marathon athletes using synthetic MRI: a preliminary study
Authors: Zhu Dantian , Wu Wenhao , Li Shaolin , Qian Long , Ma Yajun , Fang Yijie
Published: August 2024

To investigate the value of synthetic MRI sequences for quantitative detection of the muscles around the knee joints before and after a marathon. Marathon runners were examined with Synthetic MRI sequences of both knees. Quantitative profiles of T1, T2, and PD were obtained after scanning. The differences in T1, T2, and PD values of each muscle were analyzed. Most muscle subregions had elevated T1, T2, and PD values 48 hours after the marathon compared to pre-race, and decreased after 1 month of post-race rest. The synthetic MRI sequences can be useful for detecting dynamic changes in the knee muscles.
Automatic Segmentation of Rotator Cuff Muscles on MR Images Using Deep Learning
Authors: Alipour Ehsan , Chalian Majid , Jahanian Hesamoddin
Published: August 2024

Rotator cuff (RC) injuries are a common occurrence affecting millions of people across the globe. Quantitative MRI-based evaluation of RC injuries can aid in early diagnosis and improve the treatment outcome. A crucial step towards developing a quantitative, clinically relevant methods for these patients, is developing reliable automatic techniques for segmentation of RC muscles. In this study, we developed a deep convolutional neural network model to automatically segment RC muscles on T1-weighted MR images. We showed that the proposed deep learning method provides rapid and reliable automatic segmentation of RC muscles, with an accuracy comparable with that of human raters.
Measuring cellular-interstitial water exchange time in patients with head and neck cancer using time-dependent diffusion experiments
Authors: Solomon Eddy , Lemberskiy Gregory , Baete Steven , Hu Kenneth , Malyarenko Dariya , Swanson Scott , Shukla-Dave Amita , Russek Stephen , Zan Elcin , Kim Sungheon
Published: August 2024

Cellular-interstitial water exchange time has been suggested to be associated with a number of important cellular properties such as membrane permeability, tumor aggressiveness and treatment response. In this study we investigated the reliability of measuring water exchange times based on diffusivity and diffusional kurtosis at long diffusion times. We used two well-established diffusion phantoms and found that diffusion and kurtosis show stable values over a wide range of diffusion times. In head and neck cancer patients, we found that the Kärger model is a valid model for measuring water exchange time in metastatic lymph node voxels.
Feasibility and Preliminary Evaluation of Breath Hold and Free Breathing Quantitative Susceptibility Mapping of the Liver
Authors: Velikina Julia , Buelo Collin , Wu Yan , Alley Marcus , Nazeef Moniba , Jeng Michael , Samsonov Alexey , Reeder Scott , Vasanawala Shreyas , Hernando Diego
Published: August 2024

Quantitative susceptibility mapping (QSM) is a promising non-invasive technique for quantification of liver iron concentration. Abdominal QSM typically requires a breath-hold acquisition since respiration induces liver motion, which leads to blurring artifacts. However, some patients have trouble even with a short breath-hold, which necessitates development of free-breathing approaches. In this work, we report initial results on the feasibility of using the modified “butterfly” navigator approach in multi-echo imaging in conjunction with compressed sensing reconstruction to enable free-breathing liver QSM.
Pseudo COSMOS: Efficient deep learning quantitative susceptibility mapping based on local field transformation
Authors: Huang De-Rong , Cheng Jhih-Shan , Chung Hsiao-Wen , Wu Ming-Long
Published: August 2024

A deep learning framework termed pCOSMOS for quantitative susceptibility mapping (QSM) was proposed, which employed a local-field-to-local-field transformation to generate multiple orientation local field maps from single orientation data, followed by COSMOS reconstruction using physical model. 3T multi-orientation data from 10 healthy subjects (7 for training, 3 for testing) were used to investigate performance. Quantitative results compared with MEDI, SFCR, QSMnet, and LPCNN demonstrated superior performance of pCOSMOS comparable to the amongst best algorithms using single orientation data, while showing drastically reduced training time from tens of hours to 3.2 hours.
Knowledge Distillation Enables Efficient Neural Network for Better Generalizability in MR Image Denoising and Super Resolution
Authors: Shou Qinyang , Zhou Zechen , Blansit Kevin , Gulaka Praveen , Gong Enhao , Zaharchuk Greg , Shankaranarayanan Ajit
Published: August 2024

In this work, knowledge distillation (KD) is investigated to improve model generalizability for image enhancement tasks. KD can allow a 35× faster convolutional network to achieve similar performance as a Transformer based model in image denoising tasks. In addition, KD can enable a single image enhancement model for both denoising and super-resolution tasks that outperforms the conventional multi-task model trained with mixed data. KD potentially allows efficient image enhancement models to achieve better generalization performance for clinical translation.
Diffusion Tensor Imaging parameters predict quadriceps strength in younger and older healthy adults
Authors: Vainberg Yael , Asay Jessica , Schmidt Andrew , Muccini Julie , Gold Garry , Kogan Feliks , Mazzoli Valentina
Published: August 2024

The loss of muscle strength was previously thought to be primarily impacted by the loss of muscle volume due to sarcopenia during aging, however, this did not explain why strength declined more rapidly than muscle volume. To better understand this, our study aimed to explore Diffusion Tensor Imaging parameters and their correlations to muscle strength in addition to volume. As expected, volume had a strong positive correlation with all functional strength tests. However, we also observed that radial diffusivity had a significant negative correlation with eccentric functional strength tests, but no correlation was found with the concentric tests.
Identification of Imaging Marker for Tumor Tissue Composition in Rectal Carcinoma Using Dynamic Contrast-Enhance MRI
Authors: YUAN Jie , Liu Mengxiao , Zhan Songhua , Tan Wenli
Published: August 2024

Dynamic contrast-enhanced (DCE) MRI incorporates arterial input function and pharmacokinetic models to assess tissue perfusion, vasculature, capillary permeability, and interstitial space volume. It can be used to assess tumor vascularization, which can help determine tumor aggressiveness and the degree of angiogenesis and monitor therapy. However, the relationship between pathological characteristics of rectal cancer and the quantitative analysis of DCE remains unclear.
Structural alterations in right ventricle of hypoxic pulmonary hypertensive rats assessed by high-resolution DTI
Authors: El Hamrani Dounia , Le Nezet Emma , Campagnac Marilyne , Ayez Céline , Pere Benjamin , Guibert Christelle , Benoist David , Quesson Bruno
Published: August 2024

Transgenic rats with Bmpr2 mutation is a model of heritable pulmonary arterial hypertension. This study aims to evaluate structural alterations of Bmpr2-mutants associated with a risk factor (chronic hypoxia) by high-resolution diffusion tensor imaging (DTI). Chronic increases of pressure-loading conditions appears to be poorly tolerated by the right ventricle (RV). Indeed, chronic hypoxia groups showed a hypertrophy in RV. Moreover, DTI analysis showed disturbances in RV (myofibers and sheetlets) and this more prominently at basal level in transgenic rats. Consequently, hypoxic pulmonary hypertension can induce microstructural changes and electrophysiological remodeling, which are potentiated by Bmpr2 mutation.
Fast reconstruction of SMS bSSFP myocardial perfusion images using a combination of parallel imaging and AI-based denoising
Authors: Adam Naledi , Grzegorz Kowalik , Tyler Andrew , Mooiweer Ronald , Neofytou Alexander , McElroy Sarah , Kunze Karl , Speier Peter , Stäb Daniel , Neji Radhouene , Nazir Muhummad , Razavi Reza , Chiribiri Amedeo , Roujol Sébastien
Published: August 2024

Simultaneous multi-slice (SMS) imaging enables high spatial coverage and resolution for myocardial perfusion imaging. We developed and evaluated a fast, noise-removing and signal-preserving SMS reconstruction approach combining parallel imaging and deep-learning and evaluated its benefit for myocardial perfusion imaging. In comparison to conventional parallel imaging reconstruction, the proposed SMS reconstruction provides improved perceived SNR and image quality (p<0.008), preserved sharpness and signal fidelity (p>0.05) in a short computation time (+20s for an entire dataset).
Evidence of axon beading and loss of extracellular fluid following perfusion and fixation of the marmoset brain
Authors: Santini Tales , Rahman Naila , Shim Alyson , Budde Matthew , Everling Stefan , Baron Corey
Published: August 2024

Previous work showed that advanced diffusion metrics (OGSE and μFA) are sensitive to microstructural changes between in vivo and ex vivo marmoset brain tissues. Here, we utilized Monte Carlo simulations to investigate potential microstructure changes that could be occurring during tissue perfusion and fixation. A comparison between simulations and experiments showed that beading and decreased extracellular space are in agreement with the experimental trends observed. Changing microstructural properties during these processes has implications for studies that compare ex vivo tissue samples with in vivo findings.
Characterization of white matter myelinated and unmyelinated axons from diffusion MRI perspective
Authors: Abdollahzadeh Ali , Coronado-Leija Ricardo , Mehrin Subah , Lee Hong-Hsi , Sierra Alejandra , Fieremans Els , Novikov Dmitry
Published: August 2024

We segment all myelinated and unmyelinated axons from electron microscopy (EM) images of brain white matter (WM) of a mouse and a rat and quantify their cross-sectional morphology. We provide the exact relation between the long-time limit of the along-axon diffusion coefficients and the geometry of segmented intra-axonal spaces (IAS). By performing Monte Carlo (MC) simulations of diffusion in the IASs at varying diffusion times, we establish the time-dependence of diffusion along segmented myelinated and unmyelinated axons and validate the relation between axonal geometry and the long-time behavior of the longitudinal diffusion coefficient.
Fractional-order total variation penalised hyperpolarized metabolic model fitting in the human heart
Authors: Miller Jack , Lau Justin , Lewis Andrew , Laustsen Christoffer
Published: August 2024

Fractional-order derivatives represent the smooth analytic continuation of differentiation by a non-integer order. Their use for total-variation spatial regularisation has been proposed as they effectively smoothly interpolate data from the entirety of the image domain, and are reported to avoid ``blocky'' artefacts and better capture edges. Here, we show that their use permits the rapid and parsimonious optimisation of a piecewise metabolic model in the human heart, able to reconstruct terms representing perfusion delay and apparent metabolic rate constants of interconversion.
3D nnU-Net with Multi Loss Ensembles for Automated Segmentation of Intracranial Aneurysm
Authors: Orouskhani Maysam , Xia Shaojun , Mossa-Basha Mahmud , Zhu Chengcheng
Published: August 2024

In the segmentation of intracranial aneurysm, deep neural networks are equipped with modified loss functions to penalize the training weights for aneurysm false predictions and conduct unbiased learning. In this paper, we used a new compound loss function to capture the different aspects of embedding as well as diverse features. The proposed loss was given to a 3D full resolution nnU-Net to segment imbalanced TOF-MRA images from ADAM dataset. The proposed loss outperformed commonly used losses in terms of Dice, Sensitivity, and Precision.
Design of a well decoupled 4-channel catheter Radio Frequency coil array for endovascular MR imaging at 3T
Authors: PAYNE KOMLAN , Zhao Yunkun , Ying Leslie , Zhang Xiaoliang
Published: August 2024

Catheter-based radio frequency (RF) coils for interventional MRI are proposed as a means of obtaining high resolution images with significant advantages over conventional external signal detecting RF coils. A 4-channel catheter array coil was designed to improve the power transmission and SNR using parallel imaging and ultra-sensitive imaging with maximum proximity inside a blood vessel phantom. This design can be scaled to smaller/larger form to fit in tiny/wide vascular structure to provide the required B1 fields and sufficient decoupling among the resonant elements. Numerical simulation was employed to validate the performance and the feasibility of the proposed design.
Comparison of the transmit performance and Local SAR for multi-row parallel transmit coil arrays at 3 Tesla human brain MRI
Authors: Karadeniz Nejat , Hajnal Jo , Ipek Özlem
Published: August 2024

MRI multi-row array coils can offer increased flexibility to control and tailor the RF field distribution through RF Shimming. The performance of various multi-row configurations of parallel-transmit (pTx) RF coil array for brain imaging at 3T is investigated using electromagnetic field simulations with digital human computational model for overlapping and non-overlapping loop coil elements in 16- to 24-channel single, double, triple-row arrays. We found that triple-row coil arrays improve the transmit field homogeneity in the entire volume of the head. The double-row coil array offers the best SAR efficiency among other investigated coils.
Quasi-Damped Newton’s Method for Large Flip Angle Universal Pulse Design Using Parallel Transmission at 9.4T
Authors: Boga Celik , Geldschlager Ole , Henning Anke
Published: August 2024

The Universal Pulse (UP) concept to parallel transmission radiofrequency (RF) pulse design was introduced to avoid time consuming B1+ and ΔB0 data acquisition before each clinical scan. Introduced large flip angle design methods utilize kT-point trajectories and small tip angle approximation. In this work, new quasi damping scheme for Newton's methods method is introduced for large flip angle universal pulse design using numerical solution of the Bloch equation. Introduced quasi-damping scheme can be utilized in large flip angle Universal Pulse design for all flip angles including 180o pulses, without the loss of performance.
Experimental and theoretical investigation of eddy current heating of RF shield in a high-performance gradient system
Authors: Kang Daehun , Lee Seung-Kyun , Gray Erin , Fiveland Eric , Shu Yunhong , Foo Thomas , Bernstein Matt
Published: August 2024

With a high-performance gradient system, gradient-induced eddy current in the RF shield can cause a substantial temperature rise in the patient bore. Especially, a multi-echo EPI sequence involving intense gradient switching and long echo trains, usually lasts for >10 minutes in many resting-state functional MRI studies. The temperature change caused by RF shield heating can jeopardize patient safety and hardware reliability. Based on theoretical and experimental investigation, we demonstrated two main factors that could contribute to the RF shield heating in a high-performance compact 3T scanner, namely the shield surface conductivity and mean-square slew rate of the gradient waveform.
Eddy-current characterization and pre-emphasis on a compact inside-out nonlinear gradient
Authors: Fettahoglu Ates , Zhang Zhehong , Elsaid Nahla , Dewdney Andrew , Galiana Gigi
Published: August 2024

Diffusion-weighted imaging requires strong sensitizing gradients, resulting in eddy currents that create image distortions and hinder the reliability of measured diffusion parameters. In this study, we characterize and and compensate for eddy currents on a compact inside-out nonlinear gradient using a 2D phase encoded FLASH sequence. Time series of the effective waveform was calculated from PCA of the field maps, which was then used to calculate a gradient impulse response function (GIRF). The GIRF was validated by comparing the output waveform of a simple vs pre-emphasized trapezoid. Results showed clear improvement of the pre-emphasized waveform.
Application of Metabolic Imaging of Hyperpolarized [1-13C]Pyruvate to a Genetic Mouse Model of Nonalcoholic Steatohepatitis
Authors: Jhajharia Aditya , Elsaid Salaheldeen , Zhu Minjie , Rogers Joshua , Choi Youngshim , Yu Liqing , Tee Sui Seng , Mayer Dirk
Published: August 2024

This study applied metabolic imaging of hyperpolarized [1-13C]pyruvate to a genetic mouse model of nonalcoholic steatohepatitis (NASH). Histology of the NASH (livKO) mice showed different levels of liver injury that were categorized into mild, moderate, and severe. NASH mice with severe liver injury had significantly higher Lac-to-Pyr and Ala-to-Pyr ratios in liver ROIs than that in control animals. These results suggest that hyperpolarized MRSI can be a promising method to differentiate liver injury based on severity in NASH. We also discussed several sources for variability of the MR data and how to potentially address them.
Evaluation of a vendor-agnostic scan-specific quality control acquisition for clinical whole-body MRI (WB-MRI) protocols
Authors: Keaveney Sam , Hopkinson Georgina , Markus Julia , Priest Andrew N , Scurr Erica , Hughes Julie , Richardson Cheryl , Doran Simon J , Collins David J , Messiou Christina , Koh Dow-Mu , Winfield Jessica
Published: August 2024

A short quality control (QC) acquisition and analysis process was developed previously to detect faulty RF coil elements and coil positioning errors in whole-body (WB) MRI. This work demonstrates the feasibility of this process on systems from three manufacturers and reports on the evaluation of this approach following its addition to the clinical WB-MRI protocol for all examinations over a period of six months on six scanners, providing on-going monitoring of image quality across 450 examinations. Two previously unidentified broken RF coil elements were detected, which were affecting clinical image quality, demonstrating the value of this active detection approach.
The Brain-Heart-Placenta Connection: Multimodal Investigation of Neurodevelopment in Mice with Congenital Heart Disease
Authors: Stapleton Margaret , Cortes Devin , Wyman Samuel , Ruck Cody , Manzoor Shanim , Saladino Gabriella , Gabriel George , Tan Tuan Tuan , Lin Jiuann-Huey , Ho Sebastian , Bharathi Sivakama , Goetzman Eric , Lo Cecilia , Christodoulou Anthony , Wu Yijen
Published: August 2024

Neurodevelopmental deficits (NDD) are a prevalent debilitating factor in patients with congenital heart disease (CHD) even after successful surgical palliation, but the etiology for NDD is not understood. Our study in a transgenic mouse model carrying causative genetic mutations found that NDD associated with CHD is not merely the consequence of compromised fetal hemodynamics, but primarily driven by intrinsic genetic factors and modulated by the placenta. Our study suggests that placental functions might potentially be a possible intervention strategy to overcome intrinsic genetic disadvantages.
Cardiac magnetic resonance T2 mapping for evaluating the degree of myocardial edema in patients with chronic kidney disease
Authors: Zhang Jingyu , Tian Di , Xiong Ziqi , He Yifan , Li Zhiyong
Published: August 2024

T2 mapping is used to assess the degree of myocardial damage in CKD patients, and T2 values increase as the glomerular filtration rate decreases in CKD patients.
Diffusion spectrum imaging at 7T for probing Restricted compartment of Textile-based Phantom
Authors: Pathak Sudhir , Wu Yijen , Zuccolotto Tony , Schneider Walter
Published: August 2024

Validating mathematical models that describe the diffusion in the restricted compartment in biological tissue is an active research area. Techniques like NODDI, SMT, and CHARMED models claim to quantify restricted, hindered, and free water compartment but lacks validation on a typical clinical scanner. We present a 3D-printed phantom that uses (non)-water-filled textile-based hollow fiber with a 0.9μ diameter to validate restricted and hindered compartments. This study used a DSI-based scanning protocol and reconstruction method (GDSI and RDI) to probe the restricted compartment at a 2-6μ length scale. Scalar metrics derived from reconstruction methods show a significant difference between water-(un)filled taxons.
T1 Relaxation Anisotropy in White Matter is Directly Linked to the Axon Fibre Orientation in the Magnetic Field
Authors: Kauppinen Risto , Thotland Jeromy , Leskinen Henri , Pisharady Pramod , Manninen Eppu , Kettunen Mikko , Lenglet Christophe , Grohn Olli , Garwood Michael , Nissi Mikko
Published: August 2024

Interrelationships between T1 relaxation time and axon fibre orientation in midsagittal corpus callosum (CC) were studied in human brain in vivo at 3T and 7T as well as in a rat brain ex vivo at 9.4T. It was observed that in the same CC tracts in vivo the change in T1 results from altered fibre orientation with respect to B0. In the rat brain, ex vivo rotation of a given midsagittal CC ROI produced angular T1 plots that match those observed in vivo. Thus, axon fibre orientation is directly linked to T1 relaxation anisotropy.
Hyperpolarized 129Xe Magnetic Resonance Dual Signal Probe Based on CB[6] Nanoparticles for Precise Drug Delivery Monitoring
Authors: Yuan Chenlu , Guo Qianni , Zeng Qingbin , Yuan Yaping , Jiang Weiping , Ye Chaohui , Zhou Xin
Published: August 2024

We synthesized an ultrasensitive 129Xe NMR probe with dual signals. It is a hollow nanoparticle composed of water-soluble CB[6]. It has two different hydrophobic cavities. Two 129Xe NMR signals with different chemical shifts can appear in a single detection, effectively avoiding the occurrence of false positive and false negative in complex biological environment detection, improving the accuracy and sensitivity of single detection, and has broad application prospects.
Improved segmentation of neuromelanin region for low SNR short scan sandwichNM imaging
Authors: Yoon Joonhyeok , Park Juhyung , Nam Yoonho , Sohn Chul-Ho , Kang Junghwa , Youn Jonghyo , Ji Sooyeon , Oh Chungseok , Lee Jongho
Published: August 2024

Neuromelanin (NM) has been considered an associated biomarker of Parkinson’s disease (PD). Conventional NM visualizeing techniques requires about 5~10min which is sub-optimal for scanning PD patient with movement disorders. Recently, SandwichNM is reduced scan time to 5m 30s, but it is still may not enough. In this research, we approach this issue in the viewpoint of image post processing with denoising techniques to reduce scan time. After 162 NM MRI data acquisition with short scan time, we demonstrated that using denoising technique can improve the distinguishability for NM segmentation.
Reduced input combination study for the Simultaneous Multi-Tissue Segmentation and Multi-Parameter Quantification Network (MSMQ-Net) of Knee
Authors: Lu Xing , Ma Yajun , Athertya Jiyo , Hsu Chun-Nan , Chang Eric , Gentili Amilcare , Chung Christine , Du Jiang
Published: August 2024

To accelerate ultrashort echo time (UTE) based multi-parameter quantitative MRI (qMRI), we performed comparison studies on the input MRI image numbers and the effects on the prediction quality of the MSMQ-Net. The MSMQ-net was modified and trained accordingly with different combinations of inputs. Both image similarity and regional analysis were evaluated. The results demonstrate that 90% accuracy can be achieved for both UTE-T1 and UTE-T1rho mapping when the scan time is reduced by 75%.
Intelligent volume rendering of ZTE MR Bone images
Authors: Mehta Vineet , Sundaran Deepthi , Dholakia Jignesh , Fung Maggie , Carl Michael
Published: August 2024

This study presents a new Deep-Learning (DL) based processing pipeline to enable one-click volume rendering of MR Bone Zero TE (ZTE) images. It comprises of DL based background subtraction followed by histogram adjustment. A comparison with existing algorithms demonstrates that the proposed method prevails in accuracy of background subtraction (DICE = 0.97) and eliminates the tedious, error-prone manual steps of segmentation and histogram adjustment required to prepare the data for usable volume rendering. It can also be used universally across anatomies as opposed to other methods requiring anatomy-specific tuning.
Toward an Imaging Biomarker for Proximal Femur Fracture Risk Using 3T Chemical Shift-Encoded MRI Radiomic Of Bone Marrow
Authors: Martel Dimitri , Leporq Benjamin , Monga Anmol , Honig Stephen , Chang Gregory
Published: August 2024

Recent studies using Chemical Shift Encoded-MRI have used textural analysis to assess vertebral marrow heterogeneities in postmenopausal women and in paraspinal muscle to predict its strength. Radiomics provide another means to quantify bone marrow on MR images, specifically by analyzing texture, shape, and intensity distribution in the region of interest. Our aim was to investigate whether radiomic features in fatty acid composition maps of the proximal femur bone marrow improve the prediction of osteoporotic fracture.
Reproducibility of field from an easily installed insert gradient coil for prostate DWI
Authors: Zhang Zhehong , Elsaid Nahla , Nixon Terry , Dewdney Andrew , Galiana Gigi
Published: August 2024

A compact, lightweight device that generates a strong nonlinear gradient was recently developed for prostate DWI. In principle this hardware can be installed/removed for individual scans, but an additional question is whether the gradient field would need to be mapped and characterized with each installation. This work shows high reproducibility of the field after different installations, implying a single high quality field map can be reused. This result paves the way for practical clinical use of this insert gradient.
Parallel transmission of cardiac imaging using statistical initial phase optimization at 5T
Authors: Li Jiaxu , Zhou Liqiang , Liu Bin , Li Nan , Shen Zhenhua , Zhang Xiaoliang , Li Ye
Published: August 2024

High-field magnetic resonance imaging is one of the main development directions of magnetic resonance cardiac imaging because of its high signal-to-noise ratio and more anatomical details. However, with the increase of field strength, the homogeneity of B1 field is a serious challenge, and parallel transmission is one of the important methods to solve this problem. In this work, we proposed a clinically applicable radiofrequency shimming method to improve the imaging quality of cardiac imaging at 5T MRI. Statistical methods were employed to find out a better initial phase of an eight-channel coil and enhance the stability of cardiac imaging.
A dual multi-dimensional integration (dMDI) method for reliable noise masking
Authors: Ye Yongquan
Published: August 2024

A dual multi-dimensional integration (dMDI) method was proposed for reliable image noise masking. By adopting a state-of-the-art MDI method, a signal ratio and a reciprocal signal ratio were constructed in the proposed dMDI method. The product of the two signal ratios display a highly reliable dependency of the intrinsic SNR of the signals, which can serve as a voxel-wise noise mask.
A Simple Analytical Model of B1+ for MRI Measurement of RF Currents in Wire-like Medical Devices
Authors: Hartmann Chiara , Bouldi Mélina , Warnking Jan
Published: August 2024

Safe access to MRI for patients with active implants may be possible by measuring RF currents in implants in individual patients with low-SAR sequences. We present a simple theoretical model of the B1+-field close to a locally straight wire at any angle to B0. MRI signals fitted by our model closely match magnitude and complex signals from electromagnetic simulations with a wire parallel to B0 or tilted at 45° and magnitude experimental signals with parallel wire. RF currents reconstructed from simulated data match ground-truth values to within 6% and current profiles reconstructed from experimental signals follow simulated currents in shape.
Research on Denoising of Magnetic Resonance Spectrum Based on Exponential Decomposition Constraint
Authors: Wu Jinyu , Qiu Tianyu , Tu Zhangren , Guo Di , Qu Xiaobo
Published: August 2024

Nuclear Magnetic Resonance (NMR) has been a frequently-used analytical tool in many areas of modern biology, chemistry and medicine for decades. However, it is usually limited by a low Signal-to-Noise ratio (SNR). In practical applications, Signal Averaging (SA) with repeated samplings is required to improve the signal-to-noise ratio, which greatly increases the scanning time. In this paper, based on the characteristic that NMR time-domain signals can be decomposed exponentially, a model for denoising NMR spectroscopy based on exponential decomposition constraints is proposed. It can effectively improve the denoising ability and therefore save the scanning time.
Concatenated multi-contrast wavelet-based compressed sensing reconstruction.
Authors: Varela-Mattatall Gabriel , Cho Jaejin , Oran Omer , Baron Corey , Bilgic Berkin , Menon Ravi
Published: August 2024

There is a family of multi-contrast sequences such as MEGRE, MP2RAGE and 3D-QALAS which produce a limited number of contrasts, and their corresponding reconstructions in highly accelerated acquisitions are not optimally represented by either compressed sensing, low rank, or both reconstruction styles together. In this work, we explore a novel way to perform compressed sensing for simultaneous multi-contrast reconstruction. By using a concatenation operator in the regularization term, we can perform a single compressed sensing reconstruction with automatic parameter selection to reconstruct all contrasts at once and provide an implicit form of parallelization for multi-contrast reconstruction.
Standardization of Containerized “MRD Apps” for Reproducible and Deployable Research
Authors: Chow Kelvin , Wallace Tess , Fyrdahl Alexander , Kellman Peter , Xue Hui , Knoll Florian , Campbell-Washburn Adrienne
Published: August 2024

Reproducibility and translation of advancements in MR image reconstruction and analysis algorithms have been limited by incompatibilities between heterogeneous software environments. Containerization of “MRD Apps” packages software together with all dependent libraries into a single ready-to-use container. Standardization of the container format enables broad inter-compatibility and source code examples are provided for Python, MATLAB, and C++ through Gadgetron. A neural network was implemented in the MRD Apps format using Python and run directly on the scanner with vendor-provided integration. MRD Apps can be published alongside manuscripts as reference implementations or used to streamline image reconstruction and analysis challenge contests.
The Impact of Acceleration Factors of Compressed Sensing on the Image Quality of the Fast Spin Echo Diffusion Weighted Imaging for the Skull Base
Authors: Zhang Haonan , Song Qingwei , Wang Jiazheng , Liu Ailian
Published: August 2024

Compared with echo planar imaging diffusion weighted iamging (EPI-DWI), turbo spin echo diffusion weighted imaging (TSE-DWI) can significantly reduce magnetic sensitivity artifacts in skull base imaging. However, the longer scan time limits its clinical promotion. The purpose of this study is to investigate the effect of the compression sensing acceleration factor on the image quality of TSE-DWI in the skull base area.
Highly accelerated acquisition of MP2RAGE using Compressed SENSE
Authors: Zhao Yang , Wang Yishi , Wang Guangbin , Chen Weibo
Published: August 2024

The magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) sequence provides morphological T1-weighted images and quantitative T1 maps. Compressed sensing (CS) acceleration technique has been drawing extensive attention with its high acquisition efficiency for MRI sequence. In this study, volume measurement and ROI analysis were used to assess the images obtained from CS-MP2RAGE sequence under different acceleration factors. We find that CS-MP2RAGE show high similarity in brain structure volumes measurement and ROI analysis with traditional SENSE-MP2RAGE. Those findings prove that CS-MP2RAGE can be considered as an alternative to the SENSE-MP2RAGE, though the specific acceleration factor still needs to be further studied.
Comparison of Compressed Sensing Accelerated Rosette UTE and Conventional 31P 3D MRSI at 3T in Leg Muscle
Authors: Bozymski Brian , Shen Xin , Ozen Ali , Ilbey Serhat , Thomas Albert , Chiew Mark , Clarke William , Dydak Ulrike , Emir Uzay
Published: August 2024

Quantitative comparison of novel, rosette trajectory UTE (70 μs) and conventional weighted Cartesian 3D 31P MRSI sequences is performed at 3T in quadriceps muscle. After previous validation, five healthy volunteers were scanned by both sequences without interruption. Fitted metabolite maps and SNR calculations of PCr and ATP signals across selected slices and voxels displayed competitive performance between each acquisition. Retrospective compressed sensing (CS) acceleration results suggest this UTE MRSI may enable faster, higher resolution 31P metabolite mapping in leg muscle and other organs of interest.
In-vivo image acceleration with an 8-channel local B0 coil array and parallel imaging in a 9.4T human MR scanner
Authors: Tian Rui , Steffen Theodor , Scheffler Klaus
Published: August 2024

We further developed a recent idea called spread spectrum MRI to reduce the sampling time by rapidly modulating spins with localized magnetic fields during signal readout. Given phantom experiments tested and safety evaluation for human subjects performed, this time, we started in-vivo measurements of human head with multi-slice FLASH sequence accelerated by local B0 coil modulations, and examined the reconstructed image quality. Sinusoidal modulation schemes in various phase offset patterns and frequencies given different scanner bandwidth were tested and compared, which were shown to boost the image acceleration from 6-fold (i.e., SENSE only) to about 8-fold in one phase-encoded dimension.
Improved Fast Whole-Brain High Resolution Diffusion Imaging on 7 Tesla MRI
Authors: Mani Merry , Wang Xinzeng , Yang Baolian
Published: August 2024

Achieving high resolution in diffusion MRI is challenging due to its inherently low SNR, vulnerability to motion and other EPI-related artifacts. On higher field-strengths, the SNR advantage can be exploited to push the resolution if the echo-time can be effectively reduced and the increased number of slices can be efficiently acquired. Combining acceleration techniques such as multi-band and parallel imaging is critical for this approach. Here we combine two deep-learned reconstruction priors, one pertaining to the q-space and another pertaining to image artifact removal, into a model-based iterative reconstruction framework to improve the quality of highly accelerated high-resolution 7T DWIs.