scholarly journals Elastic AlignedSENSE for Dynamic MR Reconstruction: A Proof of Concept in Cardiac Cine

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 555
Author(s):  
Alejandro Godino-Moya ◽  
Rosa-María Menchón-Lara ◽  
Marcos Martín-Fernández ◽  
Claudia Prieto ◽  
Carlos Alberola-López
Keyword(s):  
Parallel Imaging ◽  
Subjective Assessment ◽  
Breath Hold ◽  
Extensive Literature ◽  
Cardiac Cine ◽  
Mri Reconstruction ◽  
Magnetic Resonance Imaging Mri ◽  
Temporal Redundancy ◽  
Mr Reconstruction ◽  
Dynamic Mr

Numerous methods in the extensive literature on magnetic resonance imaging (MRI) reconstruction exploit temporal redundancy to accelerate cardiac cine. Some of them include motion compensation, which involves high computational costs and long runtimes. In this work, we proposed a method—elastic alignedSENSE (EAS)—for the direct reconstruction of a motion-free image plus a set of nonrigid deformations to reconstruct a 2D cardiac sequence. The feasibility of the proposed approach was tested in 2D Cartesian and golden radial multi-coil breath-hold cardiac cine acquisitions. The proposed approach was compared against parallel imaging compressed sense (sPICS) and group-wise motion corrected compressed sense (GWCS) reconstructions. EAS provides better results on objective measures with considerable less runtime when an acceleration factor is higher than 10×. Subjective assessment of an expert, however, invited proposing the combination of EAS and GWCS as a preferable alternative to GWCS or EAS in isolation.

scholarly journals A review on deep learning MRI reconstruction without fully sampled k-space

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gushan Zeng ◽  
Yi Guo ◽  
Jiaying Zhan ◽  
Zi Wang ◽  
Zongying Lai ◽  
...  
Keyword(s):  
Deep Learning ◽  
Parallel Imaging ◽  
Prior Information ◽  
Clinical Medicine ◽  
Ground Truth ◽  
Acquisition Time ◽  
Sampled Data ◽  
Mri Reconstruction ◽  
Magnetic Resonance Imaging Mri ◽  
Space Data

Abstract Background Magnetic resonance imaging (MRI) is an effective auxiliary diagnostic method in clinical medicine, but it has always suffered from the problem of long acquisition time. Compressed sensing and parallel imaging are two common techniques to accelerate MRI reconstruction. Recently, deep learning provides a new direction for MRI, while most of them require a large number of data pairs for training. However, there are many scenarios where fully sampled k-space data cannot be obtained, which will seriously hinder the application of supervised learning. Therefore, deep learning without fully sampled data is indispensable. Main text In this review, we first introduce the forward model of MRI as a classic inverse problem, and briefly discuss the connection of traditional iterative methods to deep learning. Next, we will explain how to train reconstruction network without fully sampled data from the perspective of obtaining prior information. Conclusion Although the reviewed methods are used for MRI reconstruction, they can also be extended to other areas where ground-truth is not available. Furthermore, we may anticipate that the combination of traditional methods and deep learning will produce better reconstruction results.

Systematic Analysis and Review of Magnetic Resonance Imaging (MRI) Reconstruction Techniques

2021 ◽  
Vol 16 ◽  
Author(s):  
Penta Anil Kumar ◽  
R. Gunasundari ◽  
R. Aarthi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Optimization Technique ◽  
Motion Artifacts ◽  
Reconstruction Technique ◽  
Resonance Imaging ◽  
Research Gaps ◽  
Conventional Mri ◽  
Mri Reconstruction ◽  
Magnetic Resonance Imaging Mri

Background: Magnetic Resonance Imaging (MRI) plays an important role in the field of medical diagnostic imaging as it poses non-invasive acquisition and high soft-tissue contrast. However, the huge time is needed for the MRI scanning process that results in motion artifacts, degrades image quality, misinterpretation of data, and may cause uncomfortable to the patient. Thus, the main goal of MRI research is to accelerate data acquisition processing without affecting the quality of the image. Introduction: This paper presents a survey based on distinct conventional MRI reconstruction methodologies. In addition, a novel MRI reconstruction strategy is proposed based on weighted Compressive Sensing (CS), Penalty-aided minimization function, and Meta-heuristic optimization technique. Methods: An illustrative analysis is done concerning adapted methods, datasets used, execution tools, performance measures, and values of evaluation metrics. Moreover, the issues of existing methods and the research gaps considering conventional MRI reconstruction schemes are elaborated to obtain improved contribution for devising significant MRI reconstruction techniques. Results: The proposed method will reduce conventional aliasing artifacts problems, may attain lower Mean Square Error (MSE), higher Peak Signal-to-Noise Ratio (PSNR), and Structural SIMilarity (SSIM) index. Conclusion: The issues of existing methods and the research gaps considering conventional MRI reconstruction schemes are elaborated to devising an improved significant MRI reconstruction technique.

An Algorithm Combining Analysis-based Blind Compressed Sensing and Nonlocal Low-rank Constraints for MRI Reconstruction

2019 ◽  
Vol 15 (3) ◽  
pp. 281-291 ◽  
Author(s):  
Mei Sun ◽  
Jinxu Tao ◽  
Zhongfu Ye ◽  
Bensheng Qiu ◽  
Jinzhang Xu ◽  
...  
Keyword(s):  
Compressed Sensing ◽  
Signal Reconstruction ◽  
Low Rank ◽  
Mr Images ◽  
Scanning Time ◽  
Previous State ◽  
Rank Approximation ◽  
Mri Reconstruction ◽  
Magnetic Resonance Imaging Mri ◽  
Rank Constraints

Background: In order to overcome the limitation of long scanning time, compressive sensing (CS) technology exploits the sparsity of image in some transform domain to reduce the amount of acquired data. Therefore, CS has been widely used in magnetic resonance imaging (MRI) reconstruction. </P><P> Discussion: Blind compressed sensing enables to recover the image successfully from highly under- sampled measurements, because of the data-driven adaption of the unknown transform basis priori. Moreover, analysis-based blind compressed sensing often leads to more efficient signal reconstruction with less time than synthesis-based blind compressed sensing. Recently, some experiments have shown that nonlocal low-rank property has the ability to preserve the details of the image for MRI reconstruction. Methods: Here, we focus on analysis-based blind compressed sensing, and combine it with additional nonlocal low-rank constraint to achieve better MR images from fewer measurements. Instead of nuclear norm, we exploit non-convex Schatten p-functionals for the rank approximation. </P><P> Results & Conclusion: Simulation results indicate that the proposed approach performs better than the previous state-of-the-art algorithms.

scholarly journals Outracing Lung Signal Decay – Potential of Ultrashort Echo Time MRI

2018 ◽  
Vol 191 (05) ◽  
pp. 415-423 ◽  
Author(s):  
Mark Wielpütz ◽  
Simon Triphan ◽  
Yoshiharu Ohno ◽  
Bertram Jobst ◽  
Hans-Ulrich Kauczor
Keyword(s):  
Parallel Imaging ◽  
Proton Density ◽  
Ultrashort Echo Time ◽  
The Past ◽  
Signal Decay ◽  
Database Research ◽  
Pulmonary Parenchyma ◽  
Echo Time ◽  
Multiple Challenges ◽  
Magnetic Resonance Imaging Mri

Background Magnetic resonance imaging (MRI) of the pulmonary parenchyma is generally hampered by multiple challenges related to patient respiratory- and circulation-related motion, low proton density and extremely fast signal decay due to the structure of the lungs evolved for gas exchange. Methods Systematic literature database research as well as annual participation in conferences dedicated to pulmonary MRI for more than the past 20 years by at least one member of the author team. Results and Conclusion The problem of motion has been addressed in the past by developments such as triggering, gating and parallel imaging. The second problem has, in part, turned out to be an advantage in those diseases that lead to an increase in lung substance and thus an increase in signal relative to the background. To reduce signal decay, ultrashort echo time (UTE) methods were developed to minimize the time between excitation and readout. Having been postulated a while ago, improved hardware and software now open up the possibility of achieving echo times shorter than 200 µs, increasing lung signal significantly by forestalling signal decay and more effectively using the few protons available. Such UTE techniques may not only improve structural imaging of the lung but also enhance functional imaging, including ventilation and perfusion imaging as well as quantitative parameter mapping. Because of accelerating progress in this field of lung MRI, the review at hand seeks to introduce some technical properties as well as to summarize the growing data from applications in humans and disease, which promise that UTE MRI will play an important role in the morphological and functional assessment of the lung in the near future. Key Points:  Citation Format

Detection of Erosions in Sacroiliac Joints of Patients with Axial Spondyloarthritis Using the Magnetic Resonance Imaging Volumetric Interpolated Breath-hold Examination

2019 ◽  
Vol 46 (11) ◽  
pp. 1445-1449 ◽  
Author(s):  
Xenofon Baraliakos ◽  
Florian Hoffmann ◽  
Xiaohu Deng ◽  
Yan-Yan Wang ◽  
Feng Huang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Structural Changes ◽  
Axial Spondyloarthritis ◽  
Linear Regression Analysis ◽  
Cartilage Defects ◽  
Breath Hold ◽  
Resonance Imaging ◽  
Sacroiliac Joints ◽  
Magnetic Resonance Imaging Mri

Objective.The volumetric interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique can visualize erosive cartilage defects in peripheral joints. We evaluated the ability of VIBE to detect erosions in sacroiliac joints (SIJ) of patients with axial spondyloarthritis (axSpA) compared to the established T1-weighted MRI sequence and computed tomography (CT).Methods.MRI (T1-weighted and VIBE) and CT scans of SIJ of 109 patients with axSpA were evaluated by 2 blinded readers based on SIJ quadrants (SQ). Erosions were defined according to Assessment of Spondyloarthritis international Society (ASAS) definitions. Scores were recorded if readers were in agreement.Results.Erosions were less frequently detected by CT (153 SQ) than by T1-weighted MRI (182 SQ; p = 0.008) and VIBE-MRI (199 SQ; p < 0.001 vs CT and p = 0.031 vs T1-weighted MRI). Taking CT as the gold standard, the sensitivity of VIBE-MRI (71.2%) was higher than that for T1-weighted MRI (63.4%), with similar specificity (87.3% vs 88%, respectively). In linear regression analysis, younger age was significantly associated with occurrence of erosions independently in VIBE-MRI (β = 0.384, p < 0.001) and T1-weighted MRI (β = 0.369, p < 0.001) compared to CT.Conclusion.The VIBE-MRI sequence was more sensitive than T1-weighted MRI in identifying erosive damage in the SIJ, especially in younger patients. This might be due to the ability of VIBE-MRI to identify structural changes in the cartilage that have not yet extended to the underlying bone, where CT seems to be superior.

scholarly journals GrappaNet: Combining Parallel Imaging With Deep Learning for Multi-Coil MRI Reconstruction

2020 ◽  
Author(s):  
Anuroop Sriram ◽  
Jure Zbontar ◽  
Tullie Murrell ◽  
C. Lawrence Zitnick ◽  
Aaron Defazio ◽  
...  
Keyword(s):  
Deep Learning ◽  
Parallel Imaging ◽  
Mri Reconstruction

scholarly journals Cardiac cine with ART for radial parallel imaging reconstruction

2013 ◽  
Vol 15 (Suppl 1) ◽  
pp. E34
Author(s):  
Shu Li ◽  
Gigi Galiana ◽  
Leo Tam ◽  
Sebastian Kozerke ◽  
Jason P Stockmann ◽  
...  
Keyword(s):  
Parallel Imaging ◽  
Cardiac Cine ◽  
Imaging Reconstruction

A Cross-Sectional MRI T2* Study of Pancreatic and Pituitary Hemosiderosis in 180 Thalassemia Major Patients in Hong Kong.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2771-2771
Author(s):  
Wing Y. Au ◽  
Wynnie Lam ◽  
Winnie Chu ◽  
Hui-leung Yuen ◽  
S.C. Ling ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Iron Overload ◽  
Thalassemia Major ◽  
Carrier State ◽  
Breath Hold ◽  
Cross Sectional ◽  
Single Breath ◽  
Single Breath Hold ◽  
Organ Specific ◽  
Magnetic Resonance Imaging Mri

Abstract Background: The use of magnetic resonance imaging (MRI) for organ specific iron assessment has allowed better tailoring of chelation therapy. Since endocrine failure is common in thalassemia major (TM) patients, we explored the utility of rapid T2* MRI assessment of hemosiderosis in the pancreas and pituitary. The results were correlated with standard T2* heart and liver MRI assessments and clinical data. Material and methods: A total of 180 TM patients (M:F = 91:89, median age, range 12–48) were scanned on a 1.5 T scanner. (Sonata, Siemens Medical, Erlanger, Germany). T2* myocardium was assessed by a cardiac gated single breath hold 8-echo sequence (CMRtools; London, UK). The T2* liver, pancreas and pituitary were performed by a breath hold 20-echo sequence. Subcutaneous deferoxamine was used for chelation, except for addition of deferiprone in 24 cases for 1 year. Results: There was a high incidence of hemosiderosis of heart (severe T2*<12ms: 34%, mild-moderate <20ms, 15%) and liver (severe T2*<1.4ms, 14% mild-moderate <6.3ms, 63%). Iron overload above normal control was commonly found in the pancreas (T2*<23ms, 84%) and pituitary (T2*<5.9ms, 24%). Pancreatic T2* correlated with pituitary T2* (p=0.007, r=0.2), cardiac T2*(p<0.001, r=0.33), liver T2* (p<0.001, r=0.35), ferritin (p=0.004, r=−0.19) and age (p=0.033, r=0.16). Similarly pituitary T2* related to cardiac T2* (p<0.001, r=0.36) and liver T2* (p=0.026, r=0.17). On multivariate analysis, however, pancreatic T2* related to both heart T2* (p<0.001) and liver T2* (p=0.001), while pituitary T2* only related to heart T2* (p<0.001). Documented complications amongst the cases included heart failure (ejection fraction EF<55%, n=28, 16%), hypogonadism (n=84,47%), diabetes mellitus (n=44, 25%), hypoparathyroidism (n=16, 9%) and hypothyroidism (n=36, 20%), with hepatitis B and C carrier state in 2% and 25% respectively. On univariate and multivariate analysis, all 4 endocrine failures correlated with only cardiac T2* results (all p<0.001) and age (all p<0.001), but not with pituitary or pancreatic T2* results. The EF correlated with T2* of pituitary, pancreas and heart, but only MRI heart T2* correlation remained significant on multivariate analysis. Conclusions: MRI pituitary and pancreatic evaluation is viable in a cohort of poorly chelated Chinese thalassemia major patients on subcutaneous deferoxamine treatment. However, an abnormal cardiac T2* result is a good surrogate for endocrine iron overload and appeared more relevant in predicting endocrine complications.

scholarly journals Rank-One and Transformed Sparse Decomposition for Dynamic Cardiac MRI

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xianchao Xiu ◽  
Lingchen Kong
Keyword(s):  
Cardiac Mri ◽  
Low Rank ◽  
Cine Mri ◽  
Sparse Decomposition ◽  
Sparse Model ◽  
Cardiac Cine ◽  
Rank One ◽  
Magnetic Resonance Imaging Mri ◽  
Alternative Direction Method ◽  
Space Data

It is challenging and inspiring for us to achieve high spatiotemporal resolutions in dynamic cardiac magnetic resonance imaging (MRI). In this paper, we introduce two novel models and algorithms to reconstruct dynamic cardiac MRI data from under-sampledk-tspace data. In contrast to classical low-rank and sparse model, we use rank-one and transformed sparse model to exploit the correlations in the dataset. In addition, we propose projected alternative direction method (PADM) and alternative hard thresholding method (AHTM) to solve our proposed models. Numerical experiments of cardiac perfusion and cardiac cine MRI data demonstrate improvement in performance.

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