bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of DWI with Deep Learning-based Reconstruction in the Differentiation of Benign and Malignant Breast Lesions
Authors: Meng Tiebao , Liu Huiming , Xie Chuanmiao , Zhang Jialu , Qian Long
Published: August 2024

As the most common malignant tumor in women, the differentiation of benign lesion from malignant breast tumors is the most essential step in early diagnosis. Recent study demonstrated that DWI could offer great help in differential diagnosis of breast tumors. The novel deep learning-based reconstruction (DLR) technique is able to increase SNR of MRI images. Using DLR, DWI images can be acquired with less NEX (fast DWI) and still maintain the image quality. This study indicated the feasibility of fast DWI protocol with DLR in the differentiation of breast benign lesions and malignant tumors.
Radial-RIM: accelerated radial 4D MRI using the recurrent inference machine
Authors: Zhang Chaoping , Caan Matthan , Navest Robin , Teuwen Jonas , Sonke Jan-Jakob
Published: August 2024

To accelerate the acquisition and reconstruction of the respiratory correlated (4D) radial MRI for image guided radiotherapy guidance, we propose a 3D radial-RIM network by adapting the forward model for Cartesian k-space in the regular RIM to radial k-space. Experiments show that the radial-RIM reconstructs images with better quality than the XD-GRASP compressed sensing for 3-4 times accelerated 4D radial free-breathing lung/liver acquisitions, with reconstruction time per slice reduced from 2 minutes to 1.9 seconds. Signal correlation exploited by the radial-RIM over the extra motion-state dimension contributes substantially to the image quality.
Navistar: Golden-Angle Stack-of-Stars Sampling with Embedded 2D Navigators for Highly-Accelerated 4D Dynamic MRI
Authors: Xia Ding , Saju Sera , Block Kai Tobias , Feng Li
Published: August 2024

This work proposes a new radial sampling scheme called Navistar for highly-accelerated 4D dynamic MRI. Navistar periodically inserts 2D navigators into a golden-angle radial stack-of-stars acquisition. The embedded 2D navigators provide spatially-resolved information that can be used for different purposes, such as improved temporal-basis estimation for image reconstruction or respiratory-motion estimation. In our experiments, we have shown that Navistar sampling can be combined with low-rank subspace-constrained image reconstruction for highly-accelerated free-breathing 4D DCE-MRI of the liver with sub-second temporal resolution, which helps reduce intraframe respiratory blurring and eliminates the need for explicit respiratory-motion compensation.
Electric Potential Energy Optimized 3D Radial Trajectories
Authors: Huynh Christopher , Goolaub Datta Singh , Macgowan Christopher
Published: August 2024

The commonly used golden angle trajectory for 3D radial dynamic MRI suffers from spiral-shaped sample clustering around the z-axis, often resulting in image streaking artifact. We develop a method that corrects for this for center-out 3D radial trajectories. The electric potential energy of the trajectory is minimized through the use of repulsive forces, producing a spherically uniform distribution while maintaining the quasirandom quality of the golden angle trajectory. ELECTRic potential energy Optimized (ELECTRO) trajectories are relatively inexpensive to obtain and can produce images with lower MSE compared to the golden angle counterpart.
A Physics-informed Conditional Wasserstein Autoencoder to Quantify Uncertainties in Accelerated 2D Dynamic Radial MRI
Authors: Brahma Sherine , Schaeffter Tobias , Kolbitsch Christoph , Kofler Andreas
Published: August 2024

Uncertainty quantification (UQ) can provide important information about deep learning algorithms and help interpret the obtained results. UQ for multi-coil dynamic MRI is challenging due to the large scale of the problem and scarce training data. We approach these issues by learning distributions in a lower dimensional latent space using a conditional Wasserstein autoencoder while utilizing the MR data acquisition model and by exploiting spatio-temporal correlations of the cine MR images. Our results indicate excellent image quality accompanied with uncertainty maps that correlate well with estimation errors.
Mitigation of water-fat swap caused by off-resonance effects in Dixon-based non-contrast-enhanced MR angiography
Authors: Nolte Teresa , Kwon Jihun , Terwolbeck Mark , Yoneyama Masami , Kuhl Christiane , Zhang Shuo
Published: August 2024

Recently introduced Dixon-based MR angiographic techniques have shown promise for non-contrast enhanced vascular imaging, though off-resonance effects induced by B0 inhomogeneities may result in water-fat separation errors (i.e., swaps) during Dixon water fat separation, typically seen in a large field of view at high field strength. In this work, we investigate possible swaps via numeric simulations and in vivo measurements with various shimming techniques as well as reconstruction options for B0 demodulation. Initial results may suggest practical methods to mitigate water-fat swaps and improve technical robustness even in challenging applications.
Predictive value of total ischemic time and T1 mapping after emergency PCI in acute ST-segment elevation myocardial infarction
Authors: Wang Jiali , Xu Kai , Hu Chunfeng , Meng Yankai , Han Shuguang , Lu Yuan , Wu Peng , Han Lu , Xu Yongzhou
Published: August 2024

ST-segment elevation myocardial infarction (STEMI) remains a major cause of morbidity and mortality worldwide, effective risk stratification is crucial for the management of STEMI. This study sought to investigate the predictive value of total ischemic time (symptom onset to balloon, S2B), native T1 and extracellular volume (ECV) in STEMI patients undergoing primary percutaneous coronary intervention (PCI). We found regardless of microvascular obstruction (MVO) or not, ECV in myocardial infarction (ECVMI) was significantly correlated with S2B time, while native T1 was not. In the 4-month follow-up, ECVMI was independently associated with final larger infarct size in multivariable regression analysis.
Radiomics of non-contrast bSSFP cine short axis images performs better with end-systolic images in distinguishing infarct and control subjects
Authors: Dresselaers Tom , Berg Baptiste Vande , Tilborghs Sofie , Cernicanu Alexandru , Bogaert Jan
Published: August 2024

Several studies suggest that radiomics of non-contrast cine balanced steady-state free precession (bSSFP) images allows to detect myocardial infarct patients. Relevant radiomic features vary however without clear knowledge of the underlying causes. Most studies rely on time consuming manual contouring on use end-diastolic images while it was shown that features vary through the heart cycle. In this study we show that radiomics of end-systolic images result in a higher classification accuracy than for end-diastolic images and produce the same result when relying on commercial automated contouring.
Delays in first medical contact to primary interventional therapy and left ventricular remodeling in myocardial infarction
Authors: Wang Jiali , Xu Kai , Hu Chunfeng , Meng Yankai , Han Shuguang , Lu Yuan , Wu Peng , Han Lu , Xu Yongzhou
Published: August 2024

Early reperfusion and early evaluation of cardiac adverse left ventricular remodeling (ALVR) have become important aspects of treatment for ST-segment elevation myocardial infarction (STEMI) post-percutaneous coronary intervention (PCI). The aim of this study was to investigate the predictive value of emergency medical service (EMS) delays on the severity of myocardial injury in STEMI patients after PCI. Cardiac magnetic resonance (CMR) cine, myocardial strain, and scar characteristics were analyzed. The first medical contact to balloon (FMC2B) time was recorded. FMC2B time > 90 min led to poor recovery of cardiac function and was an independent predictor of ALVR.
New Tagging MRI Method is More Sensitive than Ejection Fraction for Assessment of Contractile Function Recovery in Infarcted Pig Hearts
Authors: Naumova Anna , Kerwin William
Published: August 2024

A new tagging method has been proved as a sensitive approach for assessment of regional deformation in the infarcted pig’s heart. The linear tags were placed in 60-degree pattern offsets and aligned with the AHA segments. The tagging analysis algorithm uses local Fourier transformation of the isolated spectral peaks. We have shown the temporal changes in circumferential strain of the infarcted segments of myocardium and faster recovery of myocardial strain followed by 60-min ischemia-reperfusion injury in comparison with 90-min. Circumferential strain was a more sensitive parameter for earlier detection of regional contractile dysfunction in comparison with ejection fraction.
T1rho was used to monitor myocardial changes in patients with CAD
Authors: Yang Yanbing , YUE Xiuzheng , Wang Fang , Wang Yishi
Published: August 2024

The current reference standard for detection of myocardial scar tissue is late gadolinium enhancement(LGE). Cardiac magnetic resonance T 1 mapping is a technique that enables quantification of extracellular volume fraction (ECV). Calculating ECV mapping need to inject gadolinium contrast agent, which may be contraindicated in some patients. For those patients, T1rho contrast may help them find the changes in myocardial because T1rho MRI has been used to detect early myocardial infraction in swine model. In this study, we used T1rho to assess myocardial changes in patients with early CHD with a view to finding Grey zone of LGE positive patients.
Cardiac magnetic resonance imaging for preprocedural planning of percutaneous left atrial appendage closure
Authors: Bertsche Dagmar , Metze Patrick , Luo Erfei , Dahme Tillman , Gonzka Birgit , Rottbauer Wolfgang , Vernikouskaya Ina , Schneider Leonhard , Rasche Volker
Published: August 2024

An isotropic 2D six-point Dixon method was applied for assessment of the left arterial appendix (LAA) morphology prior to LAA closure intervention. Sufficient image quality was achieved even in highly arrhythmic patients allowing for the preinterventional quantification of the LAA dimensions as required for proper closure device selection. MR derived diameters were compared to periprocedurally TEE and XR derived values, which were in good agreement. Further, optimal XR angulation providing projections perpendicular to the envisaged landing zone could be identified.
Cardiac magnetic resonance imaging with feature tracking to evaluate left atrial strain for patients with systemic lupus erythematosus
Authors: wei huang , song luo , jun zhang , yan zhang , qiang dou
Published: August 2024

This study aimed to detect left atrial (LA) strain and left ventricular (LV) stain by cardiac magnetic resonance imaging feature tracking (CMR-FT) in patients with systemic lupus erythematosus (SLE). SLE patients showed lower LVEF and multiple LV strain data than control group. Furthermore, significantly different LA reservoir, conduit and bump function were found in SLE patients than healthy controls. With these findings, CMR-FT has proven as an effective method in the diagnosis of cardiac injury in SLE patients.
DRA-CMR based layer-specific right ventricle strain predicts pulmonary arterial hypertension prognosis: results from a Chinese registry study
Authors: Li Wen , Zhang Xianchang , Zhou Xiaoyue , Wetzl Jens , Gu Qing , He Jianguo
Published: August 2024

This is the first study to demonstrate that right ventricle (RV) layer-specific strain rate measured by deformation registration algorithm based cardiovascular magnetic resonance had the long-term and 3-year mortality predictive values in pulmonary arterial hypertension (PAH) patients. Our findings indicated that RV layer-specific strain rate may be sensitive indicators of RV dysfunction in PAH.
Analysis of Biventricular and Biatrial Strain by Cardiovascular Magnetic Resonance in Dilated Cardiomyopathy
Authors: Liu Shengliang , Li Yunling , Lian Jianxiu , Wang Guokun , Wang Xueying , Li Ye , Zhao Yanming , Yu Bo
Published: August 2024

Dilated cardiomyopathy (DCM) remains to attract worldwide attention for its poor prognosis and high mortality. The interaction of biatrial and biventricular deformation capacity in DCM patients is unclear. In this study, feature tracking and fast long-axis method were used to evaluate myocardial strain. We found that biventricular and biatrial strain were significantly impaired in DCM group than control group. LV GLS was obviously impaired in event group than no event group, and it showed significantly prognostic value in predicting cardiovascular events. Comprehensive CMR analysis should be performed to improve the diagnosis ability for DCM patients.
Imaging arterial and venous vessels using Iron Dextran enhanced multi-echo susceptibility weighted imaging (SWI) MRI at 7T
Authors: Li Yinghao , Paez Adrian , Cao Di , Gu Chunming , Zhang Kaihua , Miao Xinyuan , Pillai Jay , van Zijl Peter , Earley Christopher , Li Xu , Hua Jun
Published: August 2024

Iron Dextran is a widely used FDA-approved ultra-small-superparamagnetic-iron-oxides (USPIO) to treat iron deficiency anemia in patients. Here, we evaluate the feasibility of using Iron Dextran as an MRI contrast agent for imaging arterial and venous blood vessels using multi-echo susceptibility weighted imaging (SWI) MRI at 7T. Phantom experiments were performed to measure relaxivity values (r1 and r2) for Iron Dextran in blood. Pre- and post-infusion MRI images were acquired in human subjects from which maps of arteries and veins were extracted. The post-contrast SWI images showed enhanced susceptibility difference between blood and the surrounding tissue in both arteries and veins.
A new class of easily synthesized manganese contrast agents for liver MRI
Authors: McRae Sean , Cleary Michael , Martinez Francisco , Xia Ying , Caravan Peter , Gale Eric , Ronald John , Scholl Timothy
Published: August 2024

This work investigated the performance of a novel class of Mn(II) T1 contrast agents made from a commercially available chelator with various lipophilic targeting moieties added to promote uptake through the human derived OATP1B1 and OATP1B3 transporters. Agent performance was assessed in vitro using cells engineered to express the human OATPs, and in vivo by assessing liver uptake in mice where other OATP isoforms are present. In vitro measurements suggested targeting of agents to human OATPs where in vivo imaging revealed strong contrast enhancement in murine livers, with no evident toxicity at a 0.1 mmol/kg dose.
MULTIPLEX with water-fat imaging (WFI) capacity for body imaging
Authors: Ye Yongquan , Zhang Zhongqi , Xu Jian
Published: August 2024

A multi-parametric method with WFI imaging capacity, i.e. MULTIPLEX-WFI, was developed and demonstrated. Routine two-point Dixon WFI images are additionally achieved, and a fat-suppression mask is extracted for use on the MULTIPLEX images to improve the overall image quality for body imaging. The cost of adding the WFI capacity to the MULTIPLEX method was negligible. The MULTIPLEX-WFI method was tested on phantom and in vivo knee and pelvis scans, showing much improved imaging quality for body imaging.
Characterizing the Temperature Dependence of T2 in Phantoms using an Ethylene Glycol Reference
Authors: Siu Adrienne , Ivanov Boyan , Smith Alex , Robson Matthew , Salvati Roberto
Published: August 2024

Phantom vials of varying T2 were calibrated as a function of temperature, where the temperature was measured via multi-echo gradient echo imaging of ethylene glycol in a phantom vial. The temperature calibrations were used to adjust T2 to a reference temperature, achieving T2 deviations to within [-3.2, 2.0] ms [-3.1%, 2.9%] on Siemens 3T (16.7ºC – 25.1ºC) and [-3.5, 1.4] ms [-3.4%, 0.8%] on GE 1.5T (16.5ºC – 23.7ºC). This demonstrates that corrections for T2 due to temperature can be performed while measuring temperature from gradient-echo imaging of ethylene glycol.
Quantitative MR T1 Value of Arterial Plaque using 3D Black-blood MP2RAGE：A Feasibility Study
Authors: Ruan Qizeng , He Zehe , Liu Zeping , Nie Yuhui , Liao Liping , Li Qingchun , Tan Mingxia , Huang Lanbin , Xie Guoxi , Wang YuanLi , Zhou Minglu
Published: August 2024

Carotid plaque is an important cause of stroke. The T1 value of the plaque could provide potential information for the diagnosis. In this work, we compared the performance of T1 mapping of BB-MP2RAGE and conventional MP2RAGE in carotid plaque. Experiments demonstrated BB-MP2RAGE could achieve more accurate measurement of T1 value for diagnosis of carotid plaque.
Monte Carlo simulations of transverse relaxation for assessing physico-chemical properties of novel superparamagnetic iron oxide particles
Authors: Klünder Lauritz , Maus Bastian , Aiello Maria Belen Rivas , Kirse Thomas , Strassert Cristian , Faber Cornelius
Published: August 2024

Physico-chemical properties of superparamagnetic iron oxide nanoparticles (IONP) strongly affect their impact on transverse relaxation and their efficiency as MR contrast agents. Monte Carlo simulations were developed to model relaxation in silico for two novel IONPs with distinct physico-chemical properties. The IONPs comprised an identical magnetite core but differed in preparation strategy, defining their coating and size. Simulations were compared to in vitro relaxometry measurements and reproduced experimentally measured relaxation times. Using lognormally distributed particle radii in the simulations was required to obtain correct R2* values. Together, simulations and measurements unveiled additional particle aggregation in the MR samples.
Optimisation of T1 measurement sensitivity for Oxygen-Enhanced MRI assessment of hypoxia in patients with head and neck cancers
Authors: Tariq Maira , Macdonald Alison , Orton Mathew , Dubec Michael , Collins David , Winfield Jessica , O’Connor James
Published: August 2024

Hypoxia is an important prognostic factor for head and neck cancers (HNC). Oxygen-Enhanced MRI (OE-MRI) can map hypoxia, by quantifying change in longitudinal relaxation time, T1, but the technique suffers from low signal-to-noise ratio (SNR), which reduces the sensitivity of hypoxia detection. We optimised standard T1 mapping methods on a 1.5T scanner, to select an accurate, precise, and high SNR sequence, derived in a phantom and in healthy volunteers. 3D Variable Flip Angle spoiled gradient-echo acquisition with view-sharing, flip angles 2o and 8-10o and with B1 correction applied provided suitable protocol for clinical application.
Brain R2 dependence on field strength
Authors: Wang Yicun , van Gelderen Peter , de Zwart Jacco , Duyn Jeff
Published: August 2024

Gradient Echo Sampling of Spin Echo signal was used to obtain R2 maps in nine adults at 3 T and 7 T. These were analyzed using anatomically defined ROIs, across most of the brain. Comparison between the two field strengths shows in most brain regions the R2 increases by about a factor of 1.62, with the notable exception of regions high in iron. Linear fits of R2 versus estimated iron concentration yielded 50.6 and 132 1/s/(mg/g) for 3 T and 7 T respectively, in line with prior reports at lower fields for the field dependence of iron related relaxation.
B1 and B0 insensitive R1σ preparation pulses can reduce sensitivity to R1σ dispersion
Authors: Harkins Kevin , Ostenson Jason , Adelnia Fatemeh , Wang Feng , Zu Zhongliang , Gore John
Published: August 2024

R1σ dispersion imaging can be used to uncover specific relaxation mechanisms in soft tissues, but is sensitive to B0 and B1 inhomogeneity. Several varieties of R1σ preparation pulses have been developed to reduce sensitivity to B0 and B1, typically by introducing a spin echo or double spin echo as part of the preparation pulse. This simulation study shows that such pulses can actually reduce the sensitivity to R1σ dispersion.
Automatic localization of metal artifacts regions on MRI scout images
Authors: Anand Deepa , Shanbhag Dattesh , Bhushan Chitresh , Manickam Kavitha , Madhavan RAdhika
Published: August 2024

In MRI, presence of metal can cause blooming artifacts on MRI images. Automatically detecting the presence of metal and localizing it on the scout images itself can help streamline the MRI imaging workflow decisions downstream. In this work, we demonstrate a DL framework for hot spotting of metal/metal affected regions based on 2D three-plane MRI scout images of spine. The results indicate that the solution not only detects metal regions well on spine images (on which it was trained), but also is generalizable enough to work on other anatomies such as knee which was not part of the training data.
Classification of Plaque Composition in Peripheral Arterial Disease with Multi-Contrast Histology using 7 Tesla and a Variational AutoEncoder
Authors: Karmonik Christof , Buckner Lily , Wilhoit Kayla , Roy Trisha
Published: August 2024

To differentiate soft versus hard peripheral arterial disease (PAD) plaques, a dedicated ultra-high field magnetic resonance imaging (MRI) histology protocol using three different image contrast (ultra-short TE, T1-weighted and T2-weighted) was used to scan on a clinical 7 Tesla human MRI scanner six amputated legs immediately after surgery that were harboring PAD lesions. A 2D convolutional network (CNN) variational autoencoder (VAE) was created. For each lesion, average classification values along the long axis of the artery were determined from latent space and ranged from partially occluded to patent (three lesions), soft-plaque occluded (two) and hard-plaque occluded (one).
Automated Motion Artifact Detection in Early Pediatric Diffusion MRI Using a Convolutional Neural Network
Authors: Weaver Jayse , DiPiero Marissa , Rodrigues Patrik Goncalves , Cordash Hassan , Dean Douglas
Published: August 2024

A three-dimensional convolutional neural network was trained to detect motion artifacts on a volume level for two pediatric diffusion MRI datasets acquired between 1 month and 3 years of age. Accuracies of 95% and 98% were achieved between the two datasets. Additionally, the effects of motion-corrupted volumes on quantitative parameter estimation was examined. Data was processed without quality control and with quality control performed by the neural network. DTI and NODDI metrics were calculated and compared between methods. Significant differences were found for both individual and group results.
Region of Interest Prediction by Intra-stack Attention Neural Network
Authors: Lei Ke , Syed Ali , Zhu Xucheng , Pauly John , Vasanawala Shreyas
Published: August 2024

Manual prescription of the field of view (FOV) by MRI technologists is variable and prolongs the scanning process. Often, the FOV is too large or crops critical anatomy. We propose a deep-learning framework, trained by radiologists’ supervision, for predicting region of interest (ROI) and automating FOV prescription. The proposed ROI prediction model achieves an average IoU of 0.867, significantly better (P<0.05) than two baseline models and not significantly different from a radiologist (P>0.12). The FOV prescribed by the proposed framework achieves an acceptance rate of 92% from an experienced radiologist.
Transformer-based image quality improvement of radial undersampled lung MRI data from post-COVID-19 patients
Authors: Zubke Maximilian , Müller Robin , Wernz Marius , Klimeš Filip , Wacker Frank , Vogel-Claussen Jens
Published: August 2024

Currently, MR-based ventilation imaging relying on radial 3D-stack-of-stars spoiled gradient echo sequence requires a fairly long acquisition time of 8 minutes, which may impact clinical translation. Therefore, a shorter acquisition time is desired. In this study, a novel deep learning approach called transformer was evaluated for image restauration of radial undersampled lung images from 16 post-COVID-19 patients. For each patient, images resulting from 4- and 8 minutes acquisitions were provided. A transformer was trained to translate the 4-minute-version to the corresponding 8-minute-version and led to a significant image quality improvement, demonstrated by three complementary image similarity metrics.
Association between myosteatosis and impaired glucose metabolism: A deep learning whole-body MRI population phenotyping approach
Authors: Jung Matthias , Reisert Marco , Rospleszcz Susanne , Peters Annette , Nattenmüller Johanna , Schlett Christopher , Bamberg Fabian , Weiss Jakob
Published: August 2024

Diabetes remains a major challenge for healthcare systems, making screening and early detection desirable. We used deep learning to quantify myosteatosis as 1) skeletal muscle fat fraction (SMFF) and 2) intramuscular adipose tissue (IMAT) normalized for SM mass and assessed their association with impaired glucose metabolism. SMFF had a higher discriminatory capacity for impaired glucose metabolism than IMAT. In multivariable logistic regression adjusted for baseline demographics and cardiometabolic risk factors, only SMFF remained an independent predictor of impaired glucose metabolism. Deep learning-based MR phenotyping enables opportunistic screening of myosteatosis and may identify individuals at high risk for impaired glucose metabolism.
Alterations of the structural covariance network in the thalamic subnuclei of non-comorbid treatment-naïve patients with major depressive disorder
Authors: Hu xinyue , Zhang lianqing , Li hailong , Tang Mengyue , Qiu Hui , Hu Yongbo , Gao Yingxue , Kuang Weihong , Gong Qiyong , Huang Xiaoqi
Published: August 2024

The thalamus is one of the key structures involved in the pathophysiology of major depressive disorder (MDD). Most previous neuroimaging studies on MDD measured the volume of thalamus as a whole, however, the thalamus consists of multiple subnucleus with distinct function and connectivity. Recent advances in structural MRI segmentation techniques have enabled the measurement of the volumes of thalamic subnucleus with a robust, automatic approach using a Bayesian inference-based atlas-building algorithm. Using this algorithm, we aimed to investigate the alternations in volume and structural covariance networks in thalamic subnucleus in a relatively large sample of non-comorbid treatment-naïve patients with MDD.
Left DLPFC - left ACC resting state functional connectivity association with response to rTMS therapy of major depressive disorder
Authors: Bhattacharyya Pallab , Anand Amit , Huang Xuemei , Lowe Mark , Altinay Murat
Published: August 2024

High frequency repetitive transcranial magnetic stimulation (rTMS) targeted at left dorsolateral prefrontal cortex (lDLPFC) is an increasingly popular therapy of patients with major depressive disorder, who are inadequately responsive to medication treatment. There is evidence of resting state functional connectivity (fcMRI) between lDLPFC and left anterior cingulate cortex (lACC) playing a role in rTMS efficacy. We performed a longitudinal study by scanning patients before and after 6-week long 10-Hz rTMS therapy. Patients with lower resting state low frequency blood oxygen level dependent fluctuation correlation and anticorrelation between lDLPFC and lACC responded better to rTMS therapy.
White matter alterations in patients with major depressive disorder: A Quantitative synthetic MRI Study
Authors: Wen Junyan , Yang Shanshan , Lin Xuecong , Cui Wei , Qian Long , Chen Zhimin , Gao Liaoming , Gao Qian , Huang Weikang , Cheng Dongliang , Wen Ge
Published: August 2024

Major depressive disorder (MDD) is a severe mental disorder with unclear pathophysiology mechanism. The present study aimed explore white matter (WM) microstructure alterations in MDD patients using synthetic MRI technique. The results showed shorter T1 relaxation time in several deep WM regions, while extensive myeline content was found in left anterior limb of internal capsule in patients with MDD. Thus, we concluded that WM alterations caused by MDD can be revealed by quantitative MRI parameters.
Modulation of left anterior cingulate glutathione in Lithium treatment of bipolar disorder
Authors: Bhattacharyya Pallab , Hu Bo , Lowe Mark , Anand Amit
Published: August 2024

Changes in total glutathione (GSH) level in left anterior cingulate cortex (ACC) following lithium monotherapy of bipolar disorder in depressed state were studied at7T. Patients were scanned with a semi-LASER sequence at baseline and 2, 8 and 26 weeks from onset of therapy. Healthy controls were also scanned at those 4 time points. An increase in GSH level at left dorsal/rostral ACC was observed in patients, and the increase took place between 8 and 26 weeks after the start of therapy.
Neurochemical effects of intrusive thinking in pathological and non-pathological worriers: A combined MRS, functional connectivity study
Authors: Napolitano Antonio , Schettino Martino , Parrillo Chiara , Baldassari Giulia , Cairone Luca , Gazzellini Salvatore , Giove Federico , Ottaviani Cristina
Published: August 2024

The present study combined magnetic resonance spectroscopy, resting state functional connectivity and ecological momentary assessment to support the view that intrusive thinking may be pathologically maintained via negative reinforcement, namely a reduction in autonomic arousal that prevents the transition from a relaxed state to a spike of activation.
Retrospective and prospective accelerated T1ρ/T2 mapping with Compressed Sensing: high resolution T1ρ mapping and simultaneous T1ρ/T2 mapping
Authors: Kim Jeehun , Zhang Zhiyuan , Liu Ruiying , Eck Brendan , Yang Mingrui , Li Hongyu , Li Mei , Lartey Richard , Winalski Carl , Ying Leslie , Li Xiaojuan
Published: August 2024

Quantitative MR T1rho T2 imaging shows promising results on detecting early-stage osteoarthritis, but long scan time limits the spatial resolution, making it vulnerable to partial volume averaging. Such effect reduces the sensitivity to small focal degeneration. In this study, compressed sensing reconstruction with spatio-temporal finite difference regularization was used to accelerate high-resolution (slice thickness < 2mm) T1rho imaging and standard-resolution simultaneous T1rho and T2 imaging, and evaluated the result comparing with reference imaging, retrospective and prospective reconstruction, and scan-rescan repeatability.
Low Rank Subspace-Constrained Compressed Sensing Reconstruction of Highly Accelerated Phase-Cycled bSSFP MRI for Fat Fraction Quantification
Authors: Peper Eva , Mackowiak Adèle , Açıkgöz Berk , Plähn Nils , Safarkhanlo Yasaman , Feng Li , Bastiaansen Jessica
Published: August 2024

Fat fraction (FF) maps can be estimated from phase-cycled (PC) balanced steady-state free precession (bSSFP) imaging using a dictionary fitting approach (SPARCQ). Three-dimensional PC bSSFP imaging, however, is time consuming, since around 16 PCs must be sampled to fully describe a voxels’ PC profile. Compressed sensing (CS) has been proven to accelerate MRI scans. This study has two aims 1) to evaluate the performance of two CS algorithms (total variation (TV)- vs. subspace-constrained) taking regularisation along the PC dimension into account and 2) to investigate the upper limits of acceleration using these techniques on FF quantification using SPARCQ.
Joint K-TE reconstruction for T2 mapping with the weighted linear regression fitting
Authors: Dai Yan , Deng Jie , Jia Xun
Published: August 2024

We developed a joint quantitative imaging reconstruction algorithm to reconstruct T2-weighted (T2W) images and T2 mapping simultaneously through an iterative optimization process, which integrated the weighted linear regression fitting. The proposed method achieved accurate T2 measurements and improved signal-to-noise (SNR) of both T2W images and the T2 map.
Mapping cardiac |B1+| field with B1+ prepared imaging
Authors: Siuryte Paulina , Henningsson Markus , van de Steeg-Henzen Christal , Weingärtner Sebastian
Published: August 2024

Cardiac MRI at 3T offers gains in SNR, but is strongly affected by field inhomogeneities, including the transmit field B1+. Mapping |B1+| field around the heart is particularly challenging due to the presence of motion, and few techniques exist for robust imaging. Recently, Bloch-Siegert shift mapping was proposed for motion robust cardiac |B1+| mapping, however, it requires long echo times making it more susceptible to artifacts. Here, we introduce a new preparation module for efficient |B1+| mapping. The method shows 0.06% / 0.35% reduced noise variability in phantom and 0.61±0.35% / 0.89±0.63% in-vivo imaging, and visually improved map quality.
Cardiac MRI at 3.0T in the presence of implantable cardioverter defibrillators (ICDs)
Authors: Reiter Theresa , Weber Oliver , Weiss Ingo , Bauer Wolfgang
Published: August 2024

Performing a cardiac MRI in the presence of active cardiac implants remains a challenge due to the extensive artifact burden caused by the implant. Sequence solutions established at 1.5 T have yet to be transferred to a clinical use at 3T. In this work, we use phantom and volunteer measurements in order to establish an adapted 3T protocol for CINE with TFE and wideband LGE-PSIR sequences that sufficiently suppress image artifacts caused by active implants. The first clinical data show the feasibility of this protocol and its ability to detect scar tissue in patients with implanted ICD.
Real-time Automatic Passive Catheter Tracking During MR-guided Cardiac Catheterization
Authors: Shankar Rohini Vidya , Huang Li , Neji Radhouene , Kowalik Grzegorz , Neofytou Alexander , Mooiweer Ronald , Moon Tracy , Mellor Nina , Razavi Reza , Pushparajah Kuberan , Roujol Sébastien
Published: August 2024

MR-guided cardiac catheterization procedures currently employ passive tracking approaches to follow the gadolinium-filled catheter balloon during catheter navigation. This requires frequent manual tracking and repositioning of the imaging slice, especially when the catheter moves out-of-plane during the procedure. In this study, we developed a novel MRI guidance approach that enables automatic real-time tracking of the catheter balloon and repositioning of the imaging slice for continuous visualization of the balloon during catheter navigation. We first demonstrate the proposed approach in a phantom and subsequently present an initial evaluation in patients.
Patient specific respiratory motion correction for cardiac MRI
Authors: Diao Jiameng , Liu Yang , Liu Wenjian , Tao Yiming , Geng Jianing , Cao Shang , Zhu Jiayu , Hu Junpu , Xu Jian , Zhou Zijian , Qi Haikun , Hu Peng
Published: August 2024

Magnetic resonance imaging (MRI) is susceptible to respiratory motion-induced artifacts due to the relatively slow data acquisition. These artifacts remain an impediment to clinical application and are further amplified in cardiovascular MRI. Respiratory motion model is an effectively method to reduce motion artifacts. In this study, we proposed a novel patient-specific respiratory motion correction method with more reliable training data and capability to perform spoke-wise correction. Combined with compressed sensing, parallel imaging, image registration and model fitting, this method greatly reduces respiratory motion artifacts.
Off-resonance encoded fat suppression methods for 5D whole-heart free-running cardiac MRI at 1.5T
Authors: Safarkhanlo Yasaman , Yerly Jerome , Falcao Mariana , Mackowiak Adèle , Piccini Davide , Stuber Matthias , Jung Bernd , Gräni Christoph , Bastiaansen Jessica
Published: August 2024

The presence of fat signals around the heart can affect the diagnostic quality of cardiovascular MR images. There are multiple fat-suppression pulses, such as FISS, and off-resonance water-excitation (WE) pulses, such as BORR, LIBRE, and LIBOR, that have been developed for the free-running balanced Steady-State Free-Precession (bSSFP) sequences at low-field MRI (1.5T). These fat-suppression pulses have never been thoroughly compared to each other, therefore, in this work, we implemented four different fat-suppression pulses and validated their performance on phantoms and healthy volunteers. Our results indicated LIBOR provided better fat suppression compared to BORR and LIBRE, while having fast acquisition time.
Dynamic 3D Stack-of-Radial Multi-Baseline PRF MR Thermometry using Compressed Sensing Reconstruction and Image-Based Navigation
Authors: Dai Qing , Shih Shu-Fu , Zhou Jiaqi , Zhang Le , Wu Holden
Published: August 2024

Multi-baseline proton resonance frequency-shift (PRF) MR thermometry can reduce motion-induced temperature errors in moving organs during MR-guided thermal therapy. However, previous methods had to compromise the spatial coverage to increase the temporal resolution for resolving motion. This work developed a dynamic 3D stack-of-radial MRI method using compressed sensing reconstruction and image-based navigation to enable motion-resolved multi-baseline PRF thermometry with 1.4-sec true temporal resolution. The proposed method achieved stable thermometry with volumetric coverage in free-breathing liver MRI without heating.
Applicability of Magnetic Resonance Fingerprinting for Proton Resonance Frequency Shift based Temperature Monitoring of Microwave Ablation
Authors: Gutt Moritz , Caballero Josef Löning , Horstmann Dominik , Wacker Frank , Hensen Bennet , Gutberlet Marcel
Published: August 2024

MRI offers the unique ability of measuring the temperature inside of the patient during minimally invasive tumor ablation. In this proof-of-concept approach MR Fingerprinting was used in order to get an accurate thermometry with potential for real-time application. The method was validated by performing a microwave ablation in a bioprotein phantom. The temperature accuracy was 1.54 °C ± 0.85 °C and the dice score between the calculated and the ground truth denaturation zone was 90.02 %. The mean standard deviation of the non-heated area was 0.19 °C.
Sparse regression-based delineation of air-motion artifacts for real-time correction of PRFS thermometry
Authors: Nouwens Sven , Paulides Maarten , Heemels Maurice
Published: August 2024

Proton resonance frequency shift-based MR thermometry is widely used to non-invasively monitor thermal therapies in vivo. However, further clinical integration in deep hyperthermia is hampered by intestinal air-motion induced susceptibility artifacts. We developed a sparse regression approach to delineate susceptibility artifact sources. The resulting mask is then used to correct the artifact using existing methods from quantative susceptibility mapping. We verified our approach by a heated phantom experiment equipped with a moveable air volume and temperature probes. Here, we found a reduction in the mean absolute error from 1.6 degrees Celsius to 0.4 degrees Celsius, near the air-motion artifact.
Validation of an MR Thermometry Motion Compensation Algorithm for Periodic Motion During MR guided High Intensity Focused Ultrasound (MRgHIFU)
Authors: Wong Suzanne , Macsemchuk Craig , Headrick Andrew , Luo Phoebe , Akbulatov Arthur , Drake James , Waspe Adam
Published: August 2024

Magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) can noninvasively administer controlled hyperthermia as an adjuvant cancer therapy. For clinical translation, one of the main challenges is the sensitivity of MR thermometry to motion artifacts. This work aims to validate a real-time hybrid principal component analysis and projection onto dipole fields (PCA-PDF) motion compensation algorithm on a clinical MRgHIFU system during reproducible motion profiles. The real-time PCA-PDF algorithm maintained a temperature standard deviation of < 1°C in a phantom while the periodic motion was induced on a phantom using an MR-compatible robot.
Deep Learning based drift field correction for MR Thermometry in the upper leg at 7T
Authors: Meliadò E.F. , Kikken M.W.I. , Steensma B.R. , van den Berg C.A.T , Raaijmakers A.J.E.
Published: August 2024

PRFS-based MR Thermometry (MRT) bears strong potential for RF safety assessment. However, PRFS-MRT is impaired by external sources of frequency shift. It is hypothesized that deep learning will be able to separate the PRFS signal from these other sources of frequency shift. This study has tested this concept on drift field correction for MRT in the human thigh at 7T. A convolutional neural network is trained using synthetic phase difference images based on measured drift fields and simulated temperature distributions. Results show that the proposed deep-learning approach is able to correctly predict both simulated and measured temperature rise distributions.
Evaluating Various Phase Drift Correction Methods in PRFS-based Thermometry in the Pelvic Region of Free-Breathing Volunteers
Authors: Belker Othmar , Hensen Bennet , Wacker Frank , Gutberlet Marcel
Published: August 2024

Proton Resonance Frequency Shift Thermometry relies on a homogeneous B0-field as the B0-field significantly influences the resonance frequency. A multitude of phase drift correction methods have been proposed. The temperature accuracy and computing time of reference-less phase estimation, prospective, and fat-based phase correction have been evaluated in a manually segmented dorsal muscle ROI in the pelvic region of free-breathing volunteers. The evaluated phase drift correction methods correct phase drift comparably regarding temperature accuracy. Fat-based and prospective phase correction are almost ten times faster than reference-less phase estimation but require a reliable baseline acquisition.
Optimization of EPI based PRF thermometry at 0.5 T
Authors: Harris Chad , Wiens Curtis , Martinez Diego , Curtis Andrew , Chronik Blaine
Published: August 2024

Echo planar imaging (EPI) is well-suited for temperature mapping in the mid-field (0.5T) thanks to longer T2* values that can be leveraged without prohibitively slow update rates. In this work, we optimize EPI based PRF thermometry acquisitions for mid-field MRI. Digital simulations and in-vivo temperature stabilities were computed over echo times ranging from 50ms – 100ms. The optimal mean temperature uncertainty over the entire acquisition volume was measured to be approximately 1⁰C demonstrating that EPI based thermometry provides clinically viable sensitivity at 0.5T with sufficient image resolution and extremely fast update rates (1.3-2 s).
PRF thermometry at 0.55T using multi-contrast segmented EPI approach
Authors: Majeed Waqas , Odéen Henrik , Parker Dennis , Maier Florian , Pang Jianing , Krafft Axel
Published: August 2024

MR thermometry based on the proton resonance frequency (PRF) shift is a widely used tool to monitor changes in tissue temperature in response to MR-guided thermal interventions. However, MR temperature mapping at low field (< 1T) is challenging because of reduced signal to noise ratio (SNR) and intrinsically low temperature-sensitivity of the PRF shift. In this work, we present a multi-contrast segmented EPI sequence for PRF thermometry at low field. The proposed sequence provides high sampling efficiency and improves temperature quantification via echo combination. The performance of the sequence was tested in healthy volunteer measurements in the absence of heating.
Minimally invasive measurement of arterial and brain temperature in the mouse
Authors: Gazdzinski Lisa , Chung Luke , Spring Shoshana , Botelho Owen , Stefanovic Bojana , Nieman Brian , Heyn Chinthaka , Sled John
Published: August 2024

Brain temperature is an important physiological parameter that both reflects and modulates brain activity, but current in vivo thermometry methods are invasive and/or impractical for small animals. We present a minimally invasive method for measuring blood and brain temperature in mice using Tm-DOTMA and characterize the relationship between brain and blood temperature under isoflurane anesthesia. Brain temperature was strongly correlated and approximately equal to the temperature of the inflowing arterial blood, possibly reflecting the vasodilatory and metabolic suppressive effects of isoflurane. Application of this method with alternative anesthesia approaches would provide insight into brain temperature regulation in health and disease.
Accelerated MRI thermometry guidance for transurethral ultrasound ablation of the prostate using locally low rank reconstruction
Authors: Leung Ben , Staruch Robert , Chiew Mark
Published: August 2024

MRI-guided transurethral ultrasound ablation of the prostate (TULSA) is controlled based on dynamic proton resonance frequency shift MR temperature imaging. Given the localized, but spatio-temporally coherent heating pattern, locally low rank (LLR) reconstruction could facilitate accelerated thermometry. Images acquired during TULSA in a phantom were retrospectively under-sampled by acceleration factors of R=3,4,6 by randomly sub-sampling EPI segments, and reconstructed using LLR constraints with non-overlapping 4D patches and cycle-spinning patch shifts. LLR reconstruction demonstrated lower variance than GRAPPA reconstructions in unheated regions, but increasing measurement bias at R≥4. In vivo investigation of LLR reconstruction of MR thermometry for TULSA is warranted.
Novel light-sheet scattering microscopy for voxel-wise validation of 3D-fibre orientations in murine white matter
Authors: Corral-Bolaños Mario , Nguyen Tram , Kjer Hans , Pizzolato Marco , Salinas Casper Gravesen , Perens Johanna , Frisvad Jeppe Revall , Colombelli Julien , Dyrby Tim
Published: August 2024

This work develops a novel 3D validation technique that reveals the white matter orientation with micron resolution in cleared murine brains. Light-sheet elastic scattering microscopy (LSSM) can be used to exploit the scattering signal exhibited by white matter fibres, which is dependent on their orientation. The rotation and imaging of the sample yield a scattering profile, which corresponds to that of infinitely long cylinders. Our work combines two orthogonal acquisitions to voxel-wise reconstruct 3D-fibre orientations in large brain volumes. LSSM could be the definitive validation method for diffusion MRI orientation methods.
Voxel-level denoising of diffusion MRI using a rank-1 decomposition
Authors: Leysen Siebe , Sunaert Stefan , Maes Frederik , Christiaens Daan
Published: August 2024

A voxel-wise rank-1 decomposition in spherical harmonics of the dMRI signal allows for a denoising method with minimal assumptions on signal and noise distributions. A voxel-wise denoising strategy is compared to MP-PCA on in vivo data and simulated data. The rank-1 decomposition and MP-PCA show visually similar results on the in vivo data, indicating that a voxel-level denoising approach has potential. However, results on the simulations differ. This may have various explanations; further investigation is necessary to strengthen the credibility of a rank-1 decomposition as a denoising approach.
Multiexponential analysis of diffusion exchange times reveals a distinct exchange process associated with metabolic activity
Authors: Cai Teddy , Williamson Nathan , Ravin Rea , Basser Peter
Published: August 2024

Contrary to prevailing views, recent work suggests that steady-state water exchange between the intra- and extracellular space is driven, in part, by active metabolic processes. To support these findings, we investigate whether exchange exhibits multiexponential behavior consistent with distinct exchange processes. We find a bimodal distribution of exchange times in live neural tissue, with only the faster peak being reduced upon the introduction of a sodium-potassium pump inhibitor, thus supporting the existence of active exchange. Furthermore, we describe a time-efficient method of isolating exchange and fitting multiexponential exchange times using diffusion exchange spectroscopy, paving the way for future studies.
Deep learning-based APT imaging using synthetically generated training data
Authors: Viswanathan Malvika , Yin Leqi , Kurmi Yashwant , Zu Zhongliang
Published: August 2024

Machine learning is increasingly applied to address challenges in specifically quantifying APT effect. The models are usually trained on measured data, which, however are usually lack of ground truth and sufficient training data. Synthetically generated data from both measurements and simulations can create training data which mimic tissues better than full simulations, cover all possible variations in sample parameters, and provide the ground truth. We evaluated the feasibility to use synthetic data to train models for predicting APT effect. Results show that the machine learning predicted APT is more close to the ground truth than the conventional multiple-pool Lorentzian fit.