bluuebunny/crossref_metadata_2025 huggingface dataset:
Spiral-GRASP-UTE: 4D Real-Time MRI of the Lung with Sub-Second Temporal Resolution
Authors: Xia Ding , Tian Ye , Benkert Thomas , Feng Li
Published: August 2024

The purpose of this work was to develop a dynamic lung MRI framework, called Spiral-GRASP-UTE, for 4D real-time imaging of the lung with sub-second temporal resolution. Spiral-GRASP-UTE combines continuous ultra-short echo time (UTE) variable-density stack-of-spirals acquisition with a recently developed GRASP-Pro reconstruction technique that is based on a low-rank subspace model. Compared to other state-of-the-art lung MRI methods using 3D radial Kooshball sampling, Spiral-GRASP-UTE enables fast free-breathing dynamic lung imaging (2-3 minutes) and a high temporal resolution of less than one second per volume. This eliminates the need for respiratory motion detection and compensation, which is often challenging in lung MRI.
Motion-resolved pulmonary imaging for simultaneous fractional ventilation and T1 mapping using MR Multitasking
Authors: Wu Chaowei , Lee Hsu-Lei , Wang Nan , Han Fei , Deshpande Vibhas , Voskrebenzev Andreas , Vogel-Claussen Jens , Christodoulou Anthony , Xie Yibin , Li Debiao
Published: August 2024

Pulmonary imaging has taken on greater importance during the COVID-19 pandemic. Regional fractional ventilation (FV) and T1 from MR imaging are potential biomarkers for pulmonary tissue and functional abnormality. However, FV imaging is limited to 2-D acquisition or 3-D with low spatial resolution, and T1 imaging typically requires long breath-holding that is not practical in many scenarios. Furthermore, there is no existing technique for simultaneous acquisition of both pieces of information. To address these limitations, we propose a novel motion-resolved pulmonary imaging technique for simultaneous FV and T1 mapping using MR Multitasking, and demonstrate its feasibility in 7 healthy volunteers.
CMR Myocardial Strain Analysis in Discriminating Obstructive Sleep Apnea-Hypopnea Syndrome Induced Heart Failure and Dilated Cardiomyopathy
Authors: Du Xiao , Wang Jian , Yao Jian , Wang Ruopeng , Han Mengyue , Yang Tiantian , Zhu YingCui , Xu Chenglin , Jing Zheng , Yan Deyue , Li Baijie , Yue Xiuzheng
Published: August 2024

The obstructive sleep apnea-hypopnea syndrome (OSAHS) patients with heart failure and dilated cardiomyopathy (DCM) patients all show left ventricular dilatation and systolic dysfunction as the main phenomenon. Still, there are very few reports on identifying the two diseases. Herein cardiac magnetic resonance (CMR) myocardial strain technology was used to evaluate the cardiac function and myocardial structure of the OSAHS and DCM patients. The results showed that the global peak circumferential and longitudinal strains and the left ventricular myocardial mass of the DCM group were lower than the OSAHS group. This research provides reference for the identification of these two diseases.
Cardiovascular MRI combined with catheterization for objective assessment of cardiac function: data- and model-derived pressure-volume loops
Authors: Gusseva Maria , Castellanos Daniel , Hussain Tarique , Chapelle Dominique , Chabiniok Radomír
Published: August 2024

Clinical pressure-volume data are often subjected to measurement noise. In the present work we explore the potential of a biomechanical model of the heart as a data-filtering tool. We use cardiovascular MRI volume data either simultaneously or sequentially acquired with catherization. We use time-varying elastance metrics for a quantitative comparison of data- and model-derived pressure-volume loops (PV loops). Our results demonstrate that the biomechanical model provides high quality PV loops that could be used to replace noisy data signals. In addition, this work contributes to the increased understanding of cardiovascular MRI results.
Probing Mitochondrial Dysfunction in Mouse Hearts with Doxorubicin-Induced Cardiotoxicity Using Ungated 4D Oxy-wavelet MRI
Authors: Cortes Devin Raine , Stapleton Margaret , Schwab Kristina , Coulson Noah , Mazzella Elizabeth , West Dalton , Becker-Szurszewski Thomas , Hartwick Sean , Christodoulou Anthony , Wu Yijen
Published: August 2024

Cardiomyopathy caused by anti-cancer anthracyclines, such as Doxorubicin (Dox), is one major cause for long-term morbidity and mortality among cancer survivors. Patients can develop cardiomyopathy leading to heart failure decades after successful cancer treatment with Dox. There is an urgent need for early detection of sub-clinical pathogenesis of Dox-induced cardiotoxicity for early intervention before irreversible cardiac tissue damage occurs. Cellular mechanistic investigations showed that mitochondrial dysfunctions are central to the Dox-induced cardiotoxicity. We have developed a time-and-motion-resolved 4D Oxy-wavelet MRI capable of detecting early Dox-induced mitochondrial dysfunction in the heart before irreversible myocardial damage occurred.
Reverse Remodeling of Left Atrium Assessed by Cardiac MR Feature Tracking in Hypertrophic Obstructive Cardiomyopathy after Septal Myectomy
Authors: Yang Shujuan , Zhao Shihua
Published: August 2024

Eighty-eight patients with hypertrophic obstructive cardiomyopathy(HOCM) who received CMR before and after myectomy were retrospectively studied. Thier Pre- and postmyectomy left atrial (LA) parameters derived from CMR-feature tracking were compared. Patients with HOCM after septal myectomy showed LA reverse remodeling with a reduction in LA size and restoration in LA reservoir and booster function but unchanged LA conduit function. Among volumetric and functional changes, booster function had the greatest improvement postoperatively. Besides, preoperative LAVmin index and ΔLVOT might be potential factors associated with the degree of improvement in εa.
Cardiac PET-MRI to measure cardiac efficiency access Alginate intramyocardial injections in a porcine heart failure model
Authors: Tartibi Mehrzad , Shrestha Uttam , Deo Youngho , Gullberg Grant , Nguyen Christopher , Ravanfar Vahid , Fang Qizhi , Lee Randall
Published: August 2024

Nearly 70% of heart attacks (myocardial infarctions, MI) cases lead to a condition known as heart failure (HF), where the left ventricle (LV) remodels. Previous alginate and stem cell intramyocardial injection studies reported mixed outcomes using the LV global volumetric function and local myocardium mechanical response (strains and stresses)1,2. Such measures involve unvalidated assumptions yielding erroneous results3. We conducted a swine HF study treated with a particular alginate intramyocardial injection; however, instead of using the mechanical response, we directly measured the metabolic energy consumed by the myocardium before and after treatment using Positron emission tomography–magnetic resonance images (PET-MRI)4.
Endogenous contrast T1ρ CMR: a novel technology for differential diagnosis between cardiac amyloidosis and hypertrophic cardiomyopathy
Authors: Wang Keyan , Zheng Jie , An Jing , Cheng Jingliang
Published: August 2024

This study evaluated a cardiac T1ρdispersion mapping technique, termed as myocardial fibrosis index (mFI), to distinguish cardiac amyloidosis (CA) from hypertrophic cardiomyopathy (HCM). Our data showed that mFI is significantly superior to native T1 and contrasts medium-derived extracellular volume in the differential diagnosis of CA and HCM.
7-T 39K/23Na MRI for assessment of ionic balance in patients exhibiting hypokalemic periodic paralysis
Authors: Mathy Claudius , Nagel Armin , Türk Matthias , Uder Michael , Heiß Rafael , Weber Marc-André , Gast Lena
Published: August 2024

Combined 39K/23Na MRI at 7T has become feasible recently after technical advances of 39K MRI. Here we assessed ion homeostasis alterations, especially tissue potassium and sodium concentrations (TPC/TSC) in a small pilot cohort of patients of hypokalemic periodic paralysis (HypoPP). Depending on the severity of fatty involvement of muscles, TSC was elevated in slightly to moderately involved muscles and TPC showed a tendency to decrease in an inverse correlated fashion. Almost entirely fatty infiltrated muscle showed a decrease of TSC and TPC. Therefore, combined 39K/23Na MRI could help to examine the pathophysiological processes in HypoPP and other muscular channelopathies.
23Na MRI at 21.1T reveals the Impact of Estrogen Deprivation in Preclinical Migraine
Authors: Richter Dayna , Holder Samuel , Grant Samuel
Published: August 2024

Migraine disproportionately affects women in part due to menstrual migraine, linked to 17β-estradiol deprivation. This study implements 23Na MRI at 21.1 T in female Sprague-Dawley rats to evaluate the impact of estradiol deprivation on widespread sodium increases previously reported in the male model. Ovariectomy was implemented, and animals dosed with controlled estradiol to mimic the natural estrus cycle. It was found that females at physiological estradiol concentrations are resilient to sodium increases in the brainstem and CSF, while estradiol deprivation removes this resiliency. This interaction may play a role in menstrual migraine, and the clinical migraine gap between sexes.
Quantitative sodium MRI of the human kidneys at 7T – Before, during and after water load via sliding window evaluation
Authors: Scheipers Anna , Nagel Armin , Ruck Laurent , Gast Lena , Ladd Mark , Platt Tanja
Published: August 2024

23Na-MRI is a non-invasive tool for the in-vivo quantification of the tissue sodium concentration (TSC); however, it suffers from low in-vivo signals and short relaxation times. High magnetic field strengths, dedicated hardware and pulse sequences as well as various correction methods contribute to obtaining reliable TSCs. In the presented work we employ a custom-built coil and reference vial setup and perform T1, B1+ and B1- corrections that were validated in phantom measurements. We use a sliding window reconstruction for the quantitative 23Na-images to investigate the changes in the TSC before, during and after a water load in two healthy volunteers.
Conventional χ-separation compared to self calibrated method (BIOPHYSICSS-DL) with histological validation
Authors: Benslimane Ilyes , Grabner Günther , Hametner Simon , Jochmann Thomas , Zivadinov Robert , Schweser Ferdinand
Published: August 2024

The χ-separation method determines para- and diamagnetic susceptibility tissue compartments correlating to iron and myelin in the brain respectively. The method presupposes subject invariant relaxometry coefficients and compartments disregarding the changes in those parameters in disease or postmortem cases. We implement a biophysically informed autoencoder network developed for single subject use (BIOPHYSICSS-DL) to determine underlying biophysical model coefficients from individual datasets. We expand the current model with different combinations of relaxometry and susceptibility data to produce a self-calibrated χ separation method finding the network comparable to standard methods for iron and predicts myelin distribution more closely to ground truth histology.
A Fat-suppression, Image-subtraction Method Using Deep Learning for the Detection of Knee Abnormalities on MRI
Authors: Inaoka Tsutomu , Wada Akihiko , Nakatsuka Tomoya , Sugeta Masayuki , Yamamoto Akinori , Tomobe Hisanori , Sakai Ryousuke , Nakazawa Hiroyuki , Sonoda Masaru , Ishikawa Rumiko , Kasuya Shusuke , Terada Hitoshi
Published: August 2024

This fat-suppression subtraction-image method using a DL model with 2D CNNs may be useful for the detection and classification of abnormalities on knee MRI.
A Deep Learning Nomogram Based on Gd-EOB-DTPA MRI for Predicting Early Recurrence in Hepatocellular Carcinoma after Hepatectomy
Authors: Yan Meng , Zhang Xiao , Zhang Bin , Qi Zhendong , Liang Xiaoyun , Huang Feng , Zhang Shuixing , Li Xinming , Wang Shutong , Quan Xianyue
Published: August 2024

Prognostic risk assessment after hepatectomy for patients with hepatocellular carcinoma (HCC) remains difficult. Previous studies have shown that Gd-EOB-DTPA MRI is sensitive and accurate for HCC detection, but studies in predicting early recurrence after hepatectomy based on deep learning (DL) are still lacking. This study investigated the performance of a Gd-EOB-DTPA MRI-based DL approach, and then evaluated the DL nomogram incorporating deep features and significant clinical indicators. DL nomogram outperformed the clinical nomogram (validation AUC: 0.909 vs. 0.715). The proposed DL nomogram could provide a noninvasive and comprehensive tool for predicting early recurrence of HCC after curative resection.
Multi-parametric MRI Radiomics Combined with Clinical Factors to Predict the Response to Neoadjuvant Chemotherapy in Nasopharyngeal Carcinoma
Authors: Wang Zhuo , Chen Zhiqiang , Chen Xiaohua , Zhang Shaoru , Zhou Yunshu , Zhang Ruodi , Liu Shili , Xiong Yuhui , chen Bing
Published: August 2024

This study aims to evaluate the predictive performance of the nomogram integrating multi-parametric MRI-based radiomics and clinical characteristics in detecting therapeutic response to neoadjuvant chemotherapy (NAC) in nasopharyngeal carcinoma (NPC) patients. Least absolute shrinkage and selection operator (LASSO) regression was performed to select radiomics features. A nomogram was constructed using multivariable logistic regression. The receiver operating characteristic (ROC) curves, calibration, and decision curves were performed to assess the discriminative performance of the clinical, radiomics, and the combined models. The nomograms developed by integrating radiomics score (Rad-Score) with clinical factors outperformed the clinical model alone.
HYPOTHALAMIC VOLUME IS ASSOCIATED WITH BODY MASS INDEX
Authors: Brown Stephanie , Westwater Margaret , Seidlitz Jakob , Ziauddeen Hisham , Fletcher Paul
Published: August 2024

The hypothalamus plays a major role in appetite regulation via well-defined orexigenic and anorexigenic pathways. Perturbation of these pathways is known to alter feeding behaviour and body mass. Using an automated technique, we segmented the hypothalamus in 1299 young adults with variation in body mass index (BMI). We showed that in participants who were overweight or obese, the hypothalamus and constituent nuclei were significantly increased in volume compared to those of a healthy weight. Further, these volume increases are predominantly localised to the arcuate and paraventricular nuclei, which form the core of the neuroendocrine appetite maintenance system.
Improved Clinical Diffusion Weighted Imaging by Combining Deep Learning Reconstruction, Partial Fourier, and Super Resolution
Authors: Benkert Thomas , Weiland Elisabeth , Arberet Simon , Helo Majd , Gadjimuradov Fasil , Engelhard Karl , Thoermer Gregor , Nickel Dominik
Published: August 2024

Diffusion weighted imaging (DWI) has found widespread use in daily clinical routine but can still be limited by long acquisition times and low spatial resolution. In this work, combining deep learning-based k-space to image reconstruction with super resolution processing tailored to support partial Fourier acquisitions is demonstrated to efficiently mitigate these obstacles. The approach is shown for various applications, including liver, breast, prostate, and brain DWI at 0.55T, 1.5T, and 3T.
Stochastic optimization of 3D non-Cartesian sampling trajectory (SNOPY)
Authors: Wang Guanhua , Nielsen Jon-Fredrik , Fessler Jeffrey , Noll Douglas
Published: August 2024

Efficient k-space trajectories are crucial for accelerated MRI. SNOPY proposes a generalized gradient-based method for optimizing 3D non-Cartesian sampling patterns. The algorithm can simultaneously tune multiple properties of sampling patterns, including image quality, hardware constraints (maximum slew rate and gradient strength), reduced peripheral nerve stimulation (PNS), and parameter-weighted contrast. The proposed method applies to various scenarios, such as optimizing gradient waveforms or optimizing rotation angles of radial/spiral trajectories. We adopted several computational strategies to address this non-convex and large-scale problem. Various simulated and in-vivo experiments demonstrated the effectiveness of SNOPY.
Cartesian Spiral acquisitions for radiotherapy on an MR-Linac
Authors: Lecoeur Bastien , Nair Prashant , Goodburn Rosie , Bruijnen Tom , Oelfke Uwe , Luk Wayne , Wetscherek Andreas
Published: August 2024

Respiratory-resolved 4D-MRIs could measure the extent of respiratory motion for online MR-guided radiotherapy on MR-Linacs. Cartesian spiral (CASPR) trajectories are an alternative to radial sampling for self-gated 4D-MRIs, because they could avoid prohibitively long image reconstruction times related to the non-uniform Fourier Transform. We studied the effect of different sampling parameters on image quality for CASPR-based sequences on an MR-Linac and reconstructed abdominal 4D-MRI, we found that increasing the number of points per spiral arm improved the reconstructed image quality, creating a trade-off between spatial and temporal resolutions.
Evaluation of perfusion on Golden-Angle Radial Sparse Parallel (GRASP) MRI in discriminating benign and malignant liver tumors
Authors: Wang Yu , Duan Xiaohui , Wang Mengzhu , Yang Lingjie , Yan Zhuoheng , Hu Huijun
Published: August 2024

This study investigated the utility of quantitative parameters of golden-angle radial sparse parallel (GRASP) dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for evaluation of perfusion and differentiation of benign and malignant liver tumors. The results showed the quantitative parameters in GRASP DCE-MRI can effectively evaluate the perfusion characteristics and differentiation in liver tumors with good diagnostic performance. This indicated that the GRASP quantitative parameters may be useful to evaluate and predict the pathological stage of liver lesions.
Repeatability and reproducibility of oxygen-enhanced MRI of the lung at 3 tesla: cross-center, cross-vendor evaluation
Authors: Kim Mina , Needleman Sarah , Naish Josephine , Taylor Yohn , Tibiletti Marta , O’Connor James , Parker Geoff
Published: August 2024

A recently developed protocol with a dual echo RF-spoiled gradient echo acquisition enabled simultaneous measurement of dynamic OE signal change and the substantial ∆R2* effect at 3 tesla. To progress towards clinical translation, we evaluated repeatability and reproducibility across two sites, vendors and time points. Our results demonstrate good repeatability for the quantitative and semi-quantitative indices across time points, consistent signal behaviour and repeatable ∆R2* across two sites and vendors, suggesting potential utility in multi-centre clinical studies. However, echo time dependence should be considered when interpreting percentage signal enhancement.
Evaluation of a Patient with Interstitial Lung Disease Using 3D Perfusion Maps Based on 3D Ultrashort Echo-time Imaging
Authors: Kim Hyeonha , Lee Seokwon , Park Jinil , Choe Jooae , Bak So Hyeon , Kim Ho Cheol , Park Jang-Yeon
Published: August 2024

Since vascular abnormalities are common features of interstitial lung disease, not only structural images but also functional images such as perfusion maps are required to accurately evaluate vascular abnormalities including pulmonary hypertension. In this preliminary study, we proposed a method of evaluating an interstitial lung disease (ILD) patient particularly with idiopathic interstitial pneumonia (IIP) using 3D perfusion maps as well as high-resolution 3D structural images, both of which were obtained from 3D ultrashort echo-time imaging. Fibrotic areas were well identified in the structural UTE images as well as in the perfusion maps showing increased perfusion signals in the corresponding lesions.
Tracking lipid and macromolecular changes in Ex-vivo hearts using NOEMTR and rNOE at 7T
Authors: Benyard Blake , Swago Sophia , Wilson Neil , Jacobs Paul , Witschey Walter , Harris Mohammed , Reddy Ravinder
Published: August 2024

Two ex-vivo animal hearts were scanned at 7T to track lipid and macromolecular changes using NOEMTR and rNOE. Data was acquired on a fresh lamb heart and a healthy Yorkshire swine with an anteroseptal infarct by occlusion of the left anterior descending (LAD) coronary artery. After performing a multi-pool analysis, it is demonstrated that the NOEMTR and rNOE signal decreases in the infarcted region of the swine heart compared to the normal tissue and lamb heart.
Improved self-navigation of respiratory motion in XD-GRASP reconstruction using exploratory factor analysis on 3D late gadolinium enhancement
Authors: Bishara Dima , Hong Kyungpyo , Gunasekaran Suvai , Lee Daniel , Allen Bradley , Markl Michael , Passman Rod , Kim Daniel
Published: August 2024

Signal processing of self-navigation in 3D late gadolinium enhancement (LGE) with XD-GRASP reconstruction often leads to variable results due to a variety of factors including arrhythmia (variations in inversion-recovery of self-navigated signal) and bright signals around the body that are projected onto the edge profile used for tracking respiratory motion. Principal component analysis (PCA) is the conventional approach to process navigation signal. We hypothesize that exploratory factor analysis (EFA) produces better extraction of respiratory motion. Our results show that EFA improves respiratory motion tracking in 3D LA LGE obtained b-SSFP readout, but not in gradient echo [GRE] readout.
Left Atrial Circumferential Strain for Evaluation of Mitral Regurgitation: A Feasibility and Reproducibility Study
Authors: Sreedhar Siva , Gupta Aakash , Chitiboi Teodora , Pradella Maurice , Elbaz Mohammed
Published: August 2024

Short-axis CMR left atrial (LA) circumferential strain has not yet been investigated as a cardiac biomarker. This study assessed feasibility and reproducibility of LA circumferential strain in a healthy cohort, examined changes in strain within mitral regurgitation (MR) patients, and assessed correlations between reproducible strain measures and MR severity and cardiac function. Reservoir strain globally and at superior and mid LA regions was found to be reproducible, was significantly different between healthy volunteers and MR patients, and was correlated with cardiac function. CMR LA circumferential strain is reproducible with potential utility in evaluating impaired LA mechanics in MR patients.
Radiomics-Based Classification of Patients with Repaired Tetralogy of Fallot by Cardiac Magnetic Resonance
Authors: Peng Jo-Hua , Wu Ming-Ting , Pan Nai-Yu , Huang Teng-Yi , Liu Yi-Jui , Weng Ken-Pen , Peng Hsu-Hsia
Published: August 2024

Radiomics is a novel technique of advanced cardiac magnetic resonance (CMR) phenotyping by analyzing a couple of variables of cardiac shape and tissue texture. This study aimed to develop the radiomics-based classification model to differentiate rTOF patients from normal controls and evaluate the representative features of ventricular and myocardial abnormalities in rTOF patients. In conclusion, the radiomics-based classification model can successfully differentiate rTOF patients from normal controls with routine CMR cine images. The selected features underlined the right ventricular remodeling and left ventricular myocardium fibrosis in rTOF patients.
A Novel Iron-oxide-based T1 Contrast Agent outperforms Gd-DOTA for Magnetic Resonance Lymphography
Authors: Chae Yeon Ji , Kim Mi-hyun , Woo Chul-Woong , Kim Sang-Tae , Lee Do-Wan , Heo Hwon , Choi Monica Young , Choi Yoonseok , Kim Kyung Won , Woo Dong-Cheol
Published: August 2024

The novel iron-oxide-based T1 contrast agent may be an optimal contrast agent for MR lymphangiography, because it enhances the lymphatics only without venous contamination for more than 1 hour. It can overcome the limitations of gadolinium-based contrast agents such as venous contamination and rapid washout.
HiFNet: Hierarchical feature sharing network for multi-echo GRE denoising
Authors: Park Juhyung , Oh Chungseok , Ji Sooyeon , Youn Jonghyo , Lee Jongho
Published: August 2024

A new denoising network, HiFNet, for complex valued multi-echo GRE image denoising, is proposed. This network shared network features hierarchically from the first echo image to the last echo image, utilizing the redundancy in multi-echo GRE images along the echo dimension. When tested with synthetic noise denoising and real-world denoising experiments, the proposed network shows better performance than a network with no featuring or feature sharing in reverse order, demonstrating the effectiveness of the proposed feature sharing.
Automatic Fetal Orientation Detection Algorithm in Fetal MRI
Authors: Eisenstat Joshua , Wagner Matthias , Vidarsson Logi , Ertl-Wagner Birgit , Sussman Dafna
Published: August 2024

Fetal orientation determines the mode of delivery. It is also important for sequence planning in fetal MRI. This abstract proposes Fet-Net, a deep-learning algorithm, which uses a novel convolutional neural network (CNN) architecture, to automatically detect fetal orientation from a 2-dimensional (2D) magnetic resonance imaging (MRI) slice. 6,120 2D MRI slices displaying vertex, breech, oblique and transverse fetal orientations were used for training, validation and testing. Fet-Net achieved an average accuracy and F1 score of 97.68%, and a loss of 0.06828. Fet-Net was able to detect and classify fetal orientation, which may serve to accelerate fetal MRI acquisition.
Multimodal MRI radiomics for identifying true tumor recurrence and treatment-related effects in postoperative glioma patients
Authors: Ren Jinfa , Han Dongming , Zhai Xiaoyang , Yin Huijia , Yan Ruifang , Wang Kaiyu
Published: August 2024

Detecting true tumor recurrence and treatment-related effects in glioma after treatment is crucial for patient managements and challenging via conventional MRI for differentiation. Radiomics can be used to access the details in the images in an objective way. We constructed models based on multiple modalities by using radiomics features of the postoperative enhanced and edematous regions to find key features for identifying true tumor recurrence. Features from CE-T1WI and enhanced regions have excellent classification performance, and the model of multimodality with whole regions is the best, which may aid clinicians in developing individualized treatment strategies.
Modified Homodyne reconstruction using a high-resolution phase in magnetic resonance images
Authors: Wang Xinzeng , Litwiller Daniel , Guidon Arnaud , Sprenger Tim , Lebel Robert
Published: August 2024

A partial Fourier acquisition has been widely used for fast MR imaging. To reduce the truncation artifacts in partial Fourier image, Homodyne reconstruction is often used, and it exploits the conjugate symmetry in real-valued signal to recover the full k-space. However, the MR signal is complex-valued. Artifacts are commonly observed in Homodyne images in the regions of rapid phase change due to the interference of imaginary components of adjacent pixels. In this work, we proposed a modified Homodyne reconstruction to reduce the conventional Homodyne artifacts and truncation artifacts by using a high-resolution phase from a pre-trained deep-learning network.
Quantification and evaluation of cardiac motion correction methods for hybrid PET/MRI
Authors: Lim Heeseung , Wilk Benjamin , Moran Gerald , Biernaski Heather , Thiessen Jonathan , Prato Frank
Published: August 2024

Different motion correction methods for cardiac imaging were compared with no motion correction and free-motion images on a hybrid PET/MRI platform. These data were acquired in eight large animals five days after induction of myocardial infarction. PET/MRI images were acquired under different conditions of cardiac and respiratory motion: BodyCompass™, XD-GRASP, ECG gated. Upon completion of in vivo imaging, the animal was immediately euthanized within the scanner, and motion-free images were acquired. Initial quantitative evaluation of the cardiac images showed variation in mean and standard deviation values between the region of interest and different motion correction methods.
Ultrahigh Field CMR for the Assessment of Cardiac Function – Scan Rescan Reproducibility and Shim Limitations
Authors: Lohr David , Schlötelburg Wiebke , Terekhov Maxim , Schreiber Laura
Published: August 2024

In this study we aim to analyze blood tissue contrast (BTC), SNR, and reproducibility in measurements of cardiac function at 7T. Furthermore, we assess shim quality and its impact on image quality as well as T2*. Measurements are performed in n=7 healthy volunteers using a 7T system. Diastolic BTC and SNR in scan1 and scan2 were 2.14±0.24 and 2.22±0.33 as well as 96±35 and 105±29, respectively. Reproducibility assessed via intra class correlation coefficient was found to be excellent for ejection fraction (0.93), myocardial mass (0.99), stroke volume (0.91), end-systolic volume (0.94), and end-diastolic volume (0.93).
A novel streamline representation to reduce redundancy in tractography
Authors: Gabusi Ilaria , Battocchio Matteo , Bosticardo Sara , Schiavi Simona , Daducci Alessandro
Published: August 2024

Diffusion MRI tractography allows one to characterize brain connectivity in vivo, and it is common practice to reconstruct millions of streamlines and filter them a posteriori. However, redundancy among streamlines leads to collinearity in the linear operators used by existing filtering algorithms. To solve this problem, we propose a novel streamline representation which uses a combination of clustering and spatial blur to reduce redundancy. This representation is as accurate as state-of-the-art filtering methods and more robust to noise/perturbations in the input, but requires only ≈5% of the input streamlines thus decreasing both storage requirements and computational complexity.
Improving in vivo MR g-ratio mapping via calibration of linearly transformed MR markers from in situ to ex vivo
Authors: Oeschger Jan Malte , Fritz Francisco , Ashtarayeh Mohammad , Morozova Maria , Streubel Tobias , Rusch Henriette , Morawski Markus , Weiskopf Nikolaus , Mohammadi Siawoosh
Published: August 2024

In vivo MR g-ratio mapping relies on a calibrated method that relates myelin and axon MR markers to volume fractions. To estimate the calibration parameter, fixed ex vivo tissue measured with MRI and histology is used. The so-determined calibration parameter is then applied in vivo, neglecting the difference in the MR markers due to fixation. Here, we proposed a new calibration method accounting for this difference. The new calibration reduced the variability across MR g-ratios based on different myelin and axon markers, indicating that it can improve the accuracy of MR g-ratios.
Myelination differences between cerebrum and cerebellum at early-stage schizophrenia detected by macromolecular proton fraction MRI.
Authors: Krupina Ekaterina , Manzhurtsev Andrei , Ublinskiy Maxim , Bozhko Olga , Mamedova Galina , Ushakov Vadim , Zakharova Natalia , Yarnykh Vasiliy , Andreyuk Denis , Shlyapnikov Maxim , Kostiuk Georgiy , Akhadov Tolib
Published: August 2024

The purpose of this study is to identify quantitative alterations of the myelin content using the macromolecular proton fraction (MPF) method. Forty-five subjects, 22 controls and 23 schizophrenia patients participated in the study. A significant decrease in myelination in schizophrenia was observed in the left and right cerebral cortex and in the left and right cerebral white matter. No myelination alterations in the entire cerebellum (not separated into regions) were detected. The differences found in the regional and global myelination at an early stage of schizophrenia may provide additional information for understanding the biological mechanisms of the disease.
In vivo primary sensorimotor cortex glutathione does not differ in autistic children
Authors: Song Yulu , Hupfeld Kathleen , Davies-Jenkins Christopher , Zöllner Helge , Crocetti Deana , Hui Steve , Yedavalli Vivek , Oeltzschner Georg , Alessi Natalie , Batschelett Mitchell , Puts Nicolaas , Mostofsky Stewart , Edden Richard
Published: August 2024

Redox imbalance has been suggested as a pathophysiological factor in autism spectrum disorder (ASD). Edited MRS can be used to measure levels of glutathione, the most abundant redox compound in the brain. This study aims to compare glutathione levels in autistic children and typically developing children (TDC). Edited data were collected from the primary sensorimotor cortex (SM1) in 34 children with ASD and 31 TDC and quantified using Osprey. No difference was found in GSH levels in the SM1 between these two groups.
Reconfigurable Coaxial Receive Dipoles for Dynamic Parallel Imaging of Human Brain at 9.4T
Authors: Solomakha Georgiy , Glang Felix , Steffen Theodor , Scheffler Klaus , Avdievich Nikolai
Published: August 2024

Recently developed dynamic parallel imaging, i.e. rapid modulation of element's sensitivities during acquisition, greatly improved the performance of the method. In this work, sensitivity profiles of dipole elements were electronically reconfigured by varying impedances of lumped element circuits connected in series with the dipoles. This required a large number of DC wires directly connected to the dipoles. In the present work, we developed, constructed, and evaluated a dynamically reconfigurable 8-element coaxial dipole array for brain imaging at 9.4T. Our design eliminates the DC wires directly connected to the dipoles and, hence, substantially simplifies further increasing the number of receive channels.
Wearable and stretchable RF coils using self-decoupling technology
Authors: Chai Shuyang , Gore John , Yan Xinqiang
Published: August 2024

A novel flexible and stretchable coil based on the self-decoupling technology is proposed. It can be stretched and bent to match the shape of the human anatomy of interest, exhibiting high SNR. A 4 coil array was built and tested at different stretching (horizontally and vertically), and on different anatomies (torse, thigh, head), showing a strong robustness.
Increasing the repeatability of DESS 3D brain T2 mapping with optimized k-space sampling order
Authors: Kadalie Emile , Trotier Aurélien , Corbin Nadège , Miraux Sylvain , Ribot Emeline
Published: August 2024

While recent works have determined that the DESS sequence has the ability to produce 3D T2 mapping of the brain, it remains sensitive to B0-related variation due to respiration. Multiple encoding strategies, using cartesian-spiral trajectories with different lengths combined with a variable density Poisson undersampling mask and Compressed-Sensing reconstruction, were consequently employed and compared in order to suppress respiration artifacts as well as to establish accurate and repeatable 3D T2 maps of the brain at 3T.
Validation of the Single Reference Variable Flip Angle T1 mapping method in an innovative phantom
Authors: Malmberg Michael , Odéen Henrik , Parker Dennis
Published: August 2024

An innovative cylindrical phantom is used to mimic a dynamic acquisition with temperature-induced changes in T1. Single reference (SR) variable flip angle (VFA) T1 maps are acquired at several rotational positions of this phantom, and are compared to corresponding T1 values acquired with the dual-angle variable flip angle and inversion recovery T1 mapping methods. The SR-VFA method of T1 mapping is shown to produce T1 accuracy within 4-10% of both inversion recovery and dual-angle VFA T1 measurements.
Slice-selective Zero Echo Time imaging of ultra-short 𝛵2 tissues
Authors: Borreguero Jose , Galve Fernando , Algarín Jose Miguel , Benlloch Jose María , Alonso Joseba
Published: August 2024

Here we provide an MRI sequence which allows slice selection and 2D-imaging of hard tissues with T2 as short as 275 μs within clinically acceptable scan times even at fields as low as 260 mT. Our proposed sequence combines slice selection through spin-locking, which suffers a much more benign decay (T1ρ>>T2), and the fastest imaging sequence (ZTE), providing a new and robust tool for slice selection of the shortest-lived tissue signals in the body.
Deep-learning-based super-resolution technique for cine cardiac magnetic resonance
Authors: Tsuneta Satonori , Aono Satoru , Kimura Rina , Kwon Jihun , Aoike Takuya , Yoneyama Masami , Ishizaka Kinya , Fujima Noriyuki , Kudo Kohsuke
Published: August 2024

Cine cardiac magnetic resonance (CMR) imaging is an optimal cardiac volumetric analysis method because of its high contrast resolution. However, its spatial resolution is limited owing to prolonged scanning and breath-holding. Although compressed sensing–sensitivity encoding (Compressed SENSE; CS) and its deep-learning-based advancement (SmartSpeed AI; SSAI) can reduce the scan time, the spatial resolutions remain unchanged. Herein, we investigated the effect of a deep-learning-based super-resolution technique (SmartSpeed Precise Image; SSPI) on the cine CMR visual image quality in comparison with CS and SSAI with conventional zero-filling interpolation; resultantly, the SSPI significantly improved the visual image quality scores.
Unsupervised deep learning with variational autoencoder for image quality improvement in ultrafast cardiac cine MRI: Initial results
Authors: Zhang Yajing , Ruan Guohui , Han Tianyu , Kuhl Christiane , Yoneyama Masami , Truhn Daniel , Zhang Shuo
Published: August 2024

Ultrafast imaging with high acceleration in cardiac MRI is of great clinical interest, but so far often results in inferior image quality that prevents its use in routine diagnosis. In this work, we aim to establish an unsupervised deep learning neural network based on vector quantized variational autoencoder for noise reduction and image quality improvement. Initial results on both public and clinical data promise a new approach to the existing methods. Further investigations with focus on its effectiveness of performance in real world applications are warranted.
Diffusion imaging on a 0.35 T MRI-guided linear accelerator providing accurate ­in vivo ­apparent diffusion coefficient maps
Authors: Weygand Joseph , Armstrong Tess , Bryant J.M. , Andreozzi Jacqueline , Oraiqat Ibrahim , Liveringhouse Casey , Latifi Kujtim , Yamoah Kosj , Costello James , Moros Eduardo , El Naqa Issam , Naghavi Arash , Rosenberg Stephen , Redler Gage
Published: August 2024

Diffusion weighted imaging (DWI) allows for the evaluation of tumor cellularity. Its application on a 0.35 T MRI-guided linear accelerator (MRL) would facilitate integration of this information into radiotherapy planning and potentially allow for online biologically-guided plan adaption. This study demonstrates the capability of a DWI protocol both in phantom and in vivo. In particular, it is demonstrated that quantitively accurate, repeatable, and geometrically precise ADC maps can be produced in phantom on the 0.35 T MRL. Additionally, this technique was applied in vivo on one sarcoma patient receiving same-day diagnostic diffusion scans before, during, and after radiotherapy.
Deep Learning Quantification of Magnetic Resonance Spectroscopy Based on Basis set and Exponential Priors
Authors: Chen Dicheng , Liu Huiting , Zhou Yirong , Chen Xi , Tu Zhangren , Lin Liangjie , Wu Zhigang , Wang Jiazheng , Guo Di , Lin Jianzhong , Qu Xiaobo
Published: August 2024

Quantification of 1H-MRS is difficult because of the overlapping of individual metabolite signals, non-ideal acquisition conditions, and strong background signal interference. We introduced Deep Learning (DL) method to learn these effects to improve the accuracy of the quantification. Results indicate that, compared with the conventional method LCModel, the proposed Qnet (Quantification deep learning network) shows better quantification for both simulated and in vivo acquired MRS data with lower fitting errors and enhanced stability.
Quantitative MRI Parameter Estimation using Neural Controlled Differential Equations: Proof-of-Concept in Intra-voxel Incoherent Motion
Authors: Kuppens Daan , van den Berg Daisy , Barbieri Sebastiano , Nederveen Aart , Gurney-Champion Oliver
Published: August 2024

In quantitative MRI, tissue properties are estimated from MRI data using bio-physical models that relate the MRI signal to the underlying tissue properties via model parameters. Deep learning can improve parameter estimation, but is conventionally dependent on the input being either a fixed set of input signals or a series of regularly sampled signals. Neural controlled differential equations (NCDEs) are models that are independent of the configuration of input data. NCDEs have similar performance to state-of-the-art acquisition-specific deep learning methods in estimating intra-voxel incoherent motion parameters. Therefore, NCDEs are a generic purpose tool for parameter estimation in quantitative MRI.
A multicenter external validation study of the role of AI algorithm in detecting and localizing clinically significant prostate cancer on mpMRI
Authors: Sun Zhaonan , Wang Xiaoying , Wang Kexin
Published: August 2024

A total of 557 mpMRI data were retrospectively collected from three hospitals to build an external validation dataset, with 245 csPCa cases and 312 non-csPCa cases. The csPCa lesions were annotated based on pathology records by two experienced radiologists. AI algorithms were used to automatically detect and localize the suspicious csPCa areas on the T2WI and ADC maps. The metrics of sensitivity, specificity, and accuracy were used to evaluate the diagnostic efficacy of the AI algorithms at the lesion level, the sextant level, and the patient level.
Development of a realistic human spine phantom to mimic static B0 field inhomogeneity in the cervical spinal cord
Authors: Ponsi Brunnhilde , Beghini Laura , Sandbu Sebastian , Schmidt Annelen Dogger , Vannesjo S. Johanna
Published: August 2024

Anthropomorphic phantoms could facilitate testing of novel MRI methods. This is especially important for spinal cord imaging at 7T, which is severely affected by local B0 field inhomogeneity due to susceptibility differences between tissues, particularly between bone and soft tissues. Here we built a 3D-printed model of vertebrae C3-C5, which was included in a spherical phantom. Measured field maps of the phantom were compared with simulations, showing similar features in the field distortion. The phantom also exhibited a spatially periodic pattern of signal drop-out around the intervertebral junctions in multi-echo GRE, similar to what is commonly observed in in-vivo data.
Clinical application of the Myocardial Transit-time (MyoTT) for patients with cardiac disease from a single center in China
Authors: Yan Fei , Li Tao , Jin Xin , Cui Jianing , Zhao Yanan , Yue Xiuzheng
Published: August 2024

Myocardial microvascular disease is widespread in cardiovascular disease and is associated with an increased risk of adverse events. Assessment of myocardial microcirculation is of great help in clinical diagnosis and treatment. Myocardial transit-time (MyoTT), as a relatively novel, non-invasive, non-radiation, and easy-to-perform CMR parameter, played an important role in the diagnosis and monitoring of disease prognosis. In this study, the CMR resting-state first-pass perfusion imaging sequence was used to measure the change of signal intensities from the coronary ostium to the coronary sinus to calculate the blood circulation time, as MyoTT. The study aims to observe the differences in myocardial microcirculation time of different diseases in the Chinese population. Keywords: CMR, cardiomyopathies, MyoTT,
Indirectly Prediction of Cardiac Adverse Events Based on Hemodynamics Change Induced by Exercise Using 4D flow MRI
Authors: Li Jiali , Liu Qian , Tang Min , Qi Wanying , Luo Qianfeng , Liu Tao , Zhang Xiaoyong , Chen Jing
Published: August 2024

In this study, we aimed to implement and evaluate methods for indirectly prediction of cardiac adverse events inside athletes based on hemodynamic changes in heart and aorta of four-dimensional (4D) flow MRI. The results showed that advanced parameters such as wall shear stress, energy loss and relative differential pressure were increased in athletes' hearts with late gadolinium enhancement and/or cardiac remodeling compared to controls, and the probability of remodeling in the exercising heart could be predicted by predictive models. This suggests that exercise-induced hemodynamic changes could be detected by 4D flow, which could predict the occurrence of adverse cardiovascular events.
Radiologist validation of a multi-tissue breast segmentation convolutional neural net ensemble
Authors: Weitz Michelle , Pfeiffer John , Pekis Arda , Earnest Tyler , Peterson Joseph , Antony Anuja , Zamora Kathryn , Woodard Stefanie
Published: August 2024

We developed and validated (with the expertise of two breast-specialized radiologists) an ensembled suite of convolutional neural network models that accurately segment tumor, chest wall, adipose, gland, vasculature, and skin from a patient's T1-weighted DCE breast MRI.
The relationship of brain areal activity with the entire brain’s activity
Authors: Huang Jie
Published: August 2024

The relationship between the activity of brain areas and that of the entire brain remains unknown. The temporal correlation of the BOLD time signal of an area with that of every point in the brain yields a full spatial map that characterizes the entire brain’s functional co-activity (FC) relative to that area’s activity. Analyzing the temporal correlation of the signal time courses of two areas and the spatial correlation of their corresponding two FC maps for all pairwise areas revealed a quantitative relationship between the activity of brain areas and that of the entire brain.
Intra-plaque hemorrhage of the basilar artery is a risk factor for recurrent pontine infarction
Authors: Shi Chuanying , Wu Peng , Zhao Xiance
Published: August 2024

Compared with the first episode of pontine acute infarction, the risk factors of the basilar artery (BA) wall of recurrent pontine acute infarction have not been fully defined. In this study, high-resolution magnetic resonance vessel wall imaging (HRMR-VWI) was used to compare the changes of BA wall in patients with first-onset and recurrent pontine acute infarction, to find the risk factors of the BA wall in patients with recurrent pontine acute infarction. The result showed intra-plaque hemorrhage (IPH) of the BA wall identified on HRMR-VWI is associated with recurrent ischemic stroke.
Predictive models for early recurrence of hepatocellular carcinoma without microvascular invasion in patients after hepatectomy
Authors: Qu Qi , Zhang Tao , Zhang Xue-Qin , Lu Meng-Tian , Xu Lei , Zhao Xian-Ce
Published: August 2024

To assess the predictive value of preoperative gadoxetic acid (GA)-enhanced magnetic resonance imaging (MRI) features and postoperative histopathological grading for early recurrence of hepatocellular carcinoma (HCC) without microvascular invasion (MVI) after curative hepatectomy. The results of the present demonstrated that our predictive model incorporating postoperative Edmondson-Steiner grade and preoperative imaging features including peritumoral hypointensity on HBP and RIR on HBP (Model-2) represents a promising model to assess the risk of early recurrence after resection of MVI-negative HCC. This predictive model may help clinicians formulate more aggressive and personalised treatment plans way earlier to improve patient prognosis and reduce early recurrence.
Imaging features and differential diagnosis of Zinner's syndrome: what radiologists should know
Authors: Zhao Yue , Guan Xiuhong , Xu Yongzhou , Jiang Xinqing , Yang Ruimeng
Published: August 2024

Zinner's syndrome is a rare congenital urogenital abnormality. Since this disease is rare, knowledge about its imaging manifestations by clinical surgeons and radiologists is inadequate. In this study, data of 11 cases of Zinner's syndrome were retrospectively analyzed, and their morphological characteristics on imaging changes were investigated, aiming to improve the knowledge and differential diagnosis of this disease. The relevant images of Zinner's syndrome show characteristic manifestations, so the seminal vesicle cysts and isolateral kidney development must be carefully observed. Comprehensive judgement should be made according to urogenital mutation or deformity and systemic development situation.