5,359 results match your criteria Magnetic resonance imaging[Journal]


Diffusion MRI using two-dimensional single-shot radial imaging (2D ss-rDWI) with variable flip angle and random view ordering.

Magn Reson Imaging 2019 Apr 19. Epub 2019 Apr 19.

Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States of America; Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States of America. Electronic address:

Purpose: The main objective of this study is to develop a 2D single-shot radial-DWI (2D ss-rDWI) technique to reduce motion artifacts and geometric distortion in DW images.

Method: A diffusion-preparation module is developed and applied prior to the data acquisition. Because the diffusion-prepared longitudinal magnetization is measured over multiple RF excitations in each shot, 2D ss-rDWI is subject to low signal-to-noise ratio (SNR). Read More

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http://dx.doi.org/10.1016/j.mri.2019.04.008DOI Listing

Hepatic complications of oral contraceptive pills and estrogen on MRI: Controversies and update - Adenoma and beyond.

Magn Reson Imaging 2019 Apr 19. Epub 2019 Apr 19.

Wake Forest University and Baptist Health, Medical Center Boulevard, Winston-Salem, NC 27157, United States of America. Electronic address:

Hepatic complications of oral contraceptive pills and exogenous estrogens include intrahepatic canalicular cholestasis, neoplasm formation and vascular pathologies. While it remains controversial as to whether estrogen plays a role in focal nodular hyperplasia, hemangioma or hamartoma, exposure to oral contraceptive pills and estrogen has a strong association with hepatic adenomas. Four different subgroups of adenomas have been described: Inflammatory, HNF-1α-mutated, β-catenin-mutated and unclassified. Read More

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http://dx.doi.org/10.1016/j.mri.2019.04.010DOI Listing

Retrospective correction of intensity inhomogeneity with sparsity constraints in transform-domain: Application to brain MRI.

Magn Reson Imaging 2019 Apr 19. Epub 2019 Apr 19.

School of Electronics Engineering, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India. Electronic address:

An effective retrospective correction method is introduced in this paper for intensity inhomogeneity which is an inherent artifact in MR images. Intensity inhomogeneity problem is formulated as the decomposition of acquired image into true image and bias field which are expected to have sparse approximation in suitable transform domains based on their known properties. Piecewise constant nature of the true image lends itself to have a sparse approximation in framelet domain. Read More

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http://dx.doi.org/10.1016/j.mri.2019.04.011DOI Listing

Automated and accurate quantification of subcutaneous and visceral adipose tissue from magnetic resonance imaging based on machine learning.

Magn Reson Imaging 2019 Apr 17. Epub 2019 Apr 17.

Department of Radiology, the First Hospital of Jilin University, 130021 Changchun, China. Electronic address:

Accurate measuring of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) is vital for the research of many diseases. The localization and quantification of SAT and VAT by computed tomography (CT) expose patients to harmful ionizing radiation. Magnetic resonance imaging (MRI) is a safe and painless test. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S0730725X193004
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http://dx.doi.org/10.1016/j.mri.2019.04.007DOI Listing
April 2019
1 Read

Open-source pipeline for multi-class segmentation of the spinal cord with deep learning.

Magn Reson Imaging 2019 Apr 17. Epub 2019 Apr 17.

NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada.

This paper presents an open-source pipeline to train neural networks to segment structures of interest from MRI data. The pipeline is tailored towards homogeneous datasets and requires relatively low amounts of manual segmentations (few dozen, or less depending on the homogeneity of the dataset). Two use-case scenarios for segmenting the spinal cord white and grey matter are presented: one in marmosets with variable numbers of lesions, and the other in the publicly available human grey matter segmentation challenge (Prados et al. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S0730725X193000
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http://dx.doi.org/10.1016/j.mri.2019.04.009DOI Listing
April 2019
1 Read

Plaque components segmentation in carotid artery on simultaneous non-contrast angiography and intraplaque hemorrhage imaging using machine learning.

Magn Reson Imaging 2019 Apr 5. Epub 2019 Apr 5.

Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China. Electronic address:

Purpose: This study sought to determine the feasibility of using Simultaneous Non-contrast Angiography and intraPlaque Hemorrhage (SNAP) to detect the lipid-rich/necrotic core (LRNC), and develop a machine learning based algorithm to segment plaque components on SNAP images.

Methods: Sixty-eight patients (age: 58±9 years, 24 males) with carotid artery atherosclerotic plaque were imaged on a 3 T MR scanner with both traditional multi-contrast vessel wall MR sequences (TOF, T1W, and T2W) and 3D SNAP sequence. The manual segmentations of carotid plaque components including LRNC, intraplaque hemorrhage (IPH), calcification (CA) and fibrous tissue (FT) on traditional multi-contrast images were used as reference. Read More

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http://dx.doi.org/10.1016/j.mri.2019.04.001DOI Listing
April 2019
2 Reads

Differentiating platinum coated brachytherapy seeds and gold fiducial markers with varying off-resonant frequency offsets.

Magn Reson Imaging 2019 Apr 5;60:68-75. Epub 2019 Apr 5.

McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Radiology, McMaster University, Hamilton, Ontario, Canada; Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada. Electronic address:

Purpose: To develop an off-resonant frequency filtered method to selectively differentiate between implanted gold fiducial markers and platinum coated brachytherapy seeds.

Materials And Methods: The magnetic susceptibilities for gold fiducial markers and brachytherapy seeds differ in magnitude and also in their signs, resulting in B-field inhomogeneity patterns with opposite main lobes. A pulse sequence used to localize brachytherapy seeds with positive contrast, centre-out radial sampling with off-resonance reception (co-RASOR), was used to reconstruct images with a range of off-resonant frequency offsets. Read More

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http://dx.doi.org/10.1016/j.mri.2019.04.005DOI Listing
April 2019
1 Read

Clinical feasibility of brain quantitative susceptibility mapping.

Magn Reson Imaging 2019 Apr 4;60:44-51. Epub 2019 Apr 4.

Department of Radiology, Weill Cornell Medicine, New York, NY, USA; Department of Biomedical Engineering, Cornell University, Ithaca, NY, USA. Electronic address:

Purpose: To evaluate the quality of brain quantitative susceptibility mapping (QSM) that is fully automatically reconstructed in clinical MRI of various neurological diseases.

Methods: 393 consecutive patients in one month were recruited for this evaluation study. QSM was reconstructed using Morphology Enabled Dipole Inversion without zero reference regularization (MEDI) and using MEDI with cerebrospinal fluid automatic zero-reference regularization to generate susceptibility values (MEDI+0). Read More

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https://linkinghub.elsevier.com/retrieve/pii/S0730725X193001
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http://dx.doi.org/10.1016/j.mri.2019.04.003DOI Listing
April 2019
4 Reads

Synthesizing T1 weighted MPRAGE image from multi echo GRE images via deep neural network.

Magn Reson Imaging 2019 Apr 4. Epub 2019 Apr 4.

Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 065-591, Republic of Korea. Electronic address:

For quantitative neuroimaging studies using multi-echo gradient echo (mGRE) images, additional T-weighted magnetization prepared rapid gradient echo (MPRAGE) images are often acquired to supplement the insufficient morphometric information of mGRE for tissue segmentation which require lengthened scan time and additional processing such as image registration. This study investigated the feasibility of generating synthetic MPRAGE images from mGRE images using a deep convolutional neural network. Tissue segmentation results derived from the synthetic MPRAGE showed good agreement with those from actual MPRAGE (DSC = 0. Read More

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http://dx.doi.org/10.1016/j.mri.2019.04.002DOI Listing
April 2019
1 Read

Ultrafast multi-slice chemical exchange saturation transfer imaging scheme based on segmented spatiotemporal encoding.

Magn Reson Imaging 2019 Apr 3. Epub 2019 Apr 3.

Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, China. Electronic address:

Chemical exchange saturation transfer (CEST) imaging is an important magnetic resonance molecular imaging technology. However, long acquisition time limits its clinical application, especially when multi-slice CEST imaging is needed. Though single-shot EPI can be used to accelerate CEST imaging, images are often distorted under inhomogeneous magnetic fields. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S0730725X183062
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http://dx.doi.org/10.1016/j.mri.2019.04.004DOI Listing
April 2019
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Compressed sensing reconstruction of 7 Tesla Na multi-channel breast data using H MRI constraint.

Magn Reson Imaging 2019 Mar 31. Epub 2019 Mar 31.

Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Division of Medical Physics in Radiology, German Cancer Research Centre (DKFZ), Heidelberg, Germany; Institute of Medical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.

Purpose: To reduce acquisition time and to improve image quality in sodium magnetic resonance imaging (Na MRI) using an iterative reconstruction algorithm for multi-channel data sets based on compressed sensing (CS) with anatomical H prior knowledge.

Methods: An iterative reconstruction for Na MRI with multi-channel receiver coils is presented. Based on CS it utilizes a second order total variation (TV), adopted by anatomical weighting factors (AnaWeTV) obtained from a high-resolution H image. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.024DOI Listing
March 2019
3 Reads

Quantitative analysis of spatial averaging effect on chemical shift imaging SNR and noise coherence with k-space sampling schemes.

Magn Reson Imaging 2019 Mar 31. Epub 2019 Mar 31.

Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, MN, USA. Electronic address:

Spatial averaging of multiple voxels from high-resolution chemical shift imaging (hrCSI) is a common strategy for in vivo metabolic studies to achieve a better signal-to-noise ratio (SNR) for a region-of-interest. However, the mechanism about how the spatial averaging approach influences the respective spectral signal and noise and its relevance to the k-space sampling schemes remains unclear. Using three-dimension O CSI technique with the weighted k-space sampling method of Fourier series window, we performed quantitative SNR comparisons between a single low-resolution CSI (lrCSI) voxel (being 27 times larger than the hrCSI voxel size) and the spatially averaged hrCSI voxels with matched sampling volume and location. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.023DOI Listing
March 2019
3 Reads

Multivariate MR biomarkers better predict cognitive dysfunction in mouse models of Alzheimer's disease.

Magn Reson Imaging 2019 Mar 30;60:52-67. Epub 2019 Mar 30.

Department of Neurology, Duke University Medical Center, Durham, NC, USA.

To understand multifactorial conditions such as Alzheimer's disease (AD) we need brain signatures that predict the impact of multiple pathologies and their interactions. To help uncover the relationships between pathology affected brain circuits and cognitive markers we have used mouse models that represent, at least in part, the complex interactions altered in AD, while being raised in uniform environments and with known genotype alterations. In particular, we aimed to understand the relationship between vulnerable brain circuits and memory deficits measured in the Morris water maze, and we tested several predictive modeling approaches. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.022DOI Listing
March 2019
4 Reads

A two-step low rank matrices approach for constrained MR image reconstruction.

Magn Reson Imaging 2019 Mar 29;60:20-31. Epub 2019 Mar 29.

School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China. Electronic address:

Low-rank structure is a powerful priori characteristic that is exploited in constrained magnetic resonance imaging (MRI). In this paper, we build two low rank matrices T and T from weighted k-space data according to the duality between the sparsity in the difference image and the low-rankness of a reciprocal spectral domain. Then, we propose a two-step constrained MR image reconstruction method. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.019DOI Listing
March 2019
1 Read

Golden-angle radial sparse parallel (GRASP) MRI in clinical routine detection of pituitary microadenomas: First experience and feasibility.

Magn Reson Imaging 2019 Mar 27;60:38-43. Epub 2019 Mar 27.

Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Division of Diagnostic and Interventional Neuroradiology, Department of Radiology, University Hospital Basel, University of Basel, Basel, Switzerland.

Background and purpose To demonstrate the clinical feasibility of a novel MRI pulse sequence, Golden-angle radial sparse parallel MRI (GRASP) through comparison to the current imaging technique, dynamic T1- weighted contrast enhanced (DCE) imaging in terms of image quality and lesion depiction in the detection of microlesions (microadenomas and cysts) of the pituitary gland.

Materials And Methods: 16 patients (11 microadenomas, 5 cysts) underwent two MRI examinations (Siemens 1.5T and 3T) on separate dates, one using standard DCE (temporal resolution 30 s) and the other using GRASP (temporal resolution of 4. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.015DOI Listing

Reduced respiratory motion artefact in constant TR multi-slice MRI of the mouse.

Magn Reson Imaging 2019 Mar 27;60:1-6. Epub 2019 Mar 27.

Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, United Kingdom.

Purpose: Multi-slice scanning in the abdomen and thorax of small animals is compromised by the effects of respiration unless imaging and respiration are synchronised. To avoid the signal modulations that result from respiration motion and a variable TR, blocks of fully relaxed slices are typically acquired during inter-breath periods, at the cost of scan efficiency. This paper reports a conceptually simple yet effective prospective gating acquisition mode for multi-slice scanning in free breathing small animals at any fixed TR of choice with reduced sensitivity to respiratory motion. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.018DOI Listing
March 2019
1 Read

A deep learning approach to estimation of subject-level bias and variance in high angular resolution diffusion imaging.

Magn Reson Imaging 2019 Jun 26;59:130-136. Epub 2019 Mar 26.

Electrical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Psychiatry and Behavioral Sciences, Vanderbilt University School of Medicine, TN, USA.

The ability to evaluate empirical diffusion MRI acquisitions for quality and to correct the resulting imaging metrics allows for improved inference and increased replicability. Previous work has shown promise for estimation of bias and variance of generalized fractional anisotropy (GFA) but comes at the price of computational complexity. This paper aims to provide methods for estimating GFA, bias of GFA and standard deviation of GFA quickly and accurately. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.021DOI Listing

MEGA-PRESS and PRESS measure oxidation of glutathione in a phantom.

Magn Reson Imaging 2019 Mar 26;60:32-37. Epub 2019 Mar 26.

Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; NORMENT - Norwegian Center for Mental Disorders Research, University of Bergen, Bergen, Norway; Department of Clinical Engineering, Haukeland University Hospital, Bergen, Norway.

Purpose: Investigate the possibility of measuring changes in glutathione (GSH) concentration using the MRS PRESS and MEGA-PRESS sequences by tracking the natural oxidation of GSH, and to examine the accuracy of the two methods.

Methods: 122 GSH edited MEGA-PRESS and PRESS acquisitions were acquired on a "braino" based phantom +3.0 mM GSH during a period of 11 days. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.020DOI Listing
March 2019
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MRI-based texture analysis of the primary tumor for pre-treatment prediction of bone metastases in prostate cancer.

Magn Reson Imaging 2019 Mar 24;60:76-84. Epub 2019 Mar 24.

Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, PR China.

Purpose: To identify texture features of multiparametric MRI (mp-MRI) for pre-treatment prediction of bone metastases (BM) in patients with prostate cancer (PCa).

Patients And Methods: One-hundred and seventy-six patients with clinicopathologically confirmed PCa were enrolled,and the data was gathered from January 2008 to January 2018. A total of 976 texture features were extracted from T2-weighted (T2-w) and dynamic contrast-enhanced T1-weighted (DCE T1-w) MRI. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.007DOI Listing

MR fingerprinting with simultaneous T, T, and fat signal fraction estimation with integrated B correction reduces bias in water T and T estimates.

Magn Reson Imaging 2019 Mar 23;60:7-19. Epub 2019 Mar 23.

Vanderbilt University Institute of Imaging Science, Nashville, TN 37232, United States of America; Dept. of Radiology and Radiological Sciences, Vanderbilt University, United States of America; Dept. of Biomedical Engineering, Vanderbilt University, United States of America.

Purpose: MR fingerprinting (MRF) sequences permit efficient T and T estimation in cranial and extracranial regions, but these areas may include substantial fat signals that bias T and T estimates. MRI fat signal fraction estimation is also a topic of active research in itself, but may be complicated by B heterogeneity and blurring during spiral k-space acquisitions, which are commonly used for MRF. An MRF method is proposed that separates fat and water signals, estimates water T and T, and accounts for B effects with spiral blurring correction, in a single sequence. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.017DOI Listing

Compressed sensing MRI based on image decomposition model and group sparsity.

Magn Reson Imaging 2019 Mar 22. Epub 2019 Mar 22.

School of Information Science and Engineering, Yanshan University, Qinhuangdao 066004, China; Hebei Key Laboratory of Information Transmission and Signal Processing, Yanshan University, Qinhuangdao 066004, China.

The image representation plays an important role in compressed sensing magnetic resonance imaging (CSMRI). However, how to adaptive sparsely represent images is a challenge for accurately reconstructing magnetic resonance (MR) images from highly undersampled data with noise. In order to further improve the reconstruction quality of the MR image, this paper first proposes tight frame-based group sparsity (TFGS) regularization that can capture the structure information of images appropriately, then TFGS regularization is employed to the image cartoon-texture decomposition model to construct CSMRI algorithm, termed cartoon-texture decomposition CSMRI algorithm (CD-MRI). Read More

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https://linkinghub.elsevier.com/retrieve/pii/S0730725X183065
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http://dx.doi.org/10.1016/j.mri.2019.03.011DOI Listing
March 2019
10 Reads

Arterial spin-labeling magnetic resonance imaging of brain maturation in early childhood: Mathematical model fitting to assess age-dependent change of cerebral blood flow.

Magn Reson Imaging 2019 Jun 21;59:114-120. Epub 2019 Mar 21.

GE Healthcare, Taiwan.

Purpose: To determine the trajectory of age-dependent cerebral blood flow (CBF) change in infants and young children by fitting mathematical models to the imaging data.

Methods: In this retrospective study, we reviewed the arterial spin-labeling imaging studies of 49 typically developing infants and young children at postmenstrual age (PMA) ranging from 38 to 194 weeks. All patients had normal structural MR imaging. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.016DOI Listing

Demonstration of full tensor current density imaging using ultra-low field MRI.

Magn Reson Imaging 2019 Mar 18. Epub 2019 Mar 18.

Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.

Direct imaging of impressed dc currents inside the head can provide valuable conductivity information, possibly improving electro-magnetic neuroimaging. Ultra-low field magnetic resonance imaging (ULF MRI) at μT Larmor fields can be utilized for current density imaging (CDI). Here, a measurable impact of the magnetic field B, generated by the impressed current density J, on the MR signal is probed using specialized sequences. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.010DOI Listing

Feasibility study of a double resonant 8-channel H/ 8-channel Na receive-only head coil at 3 Tesla.

Magn Reson Imaging 2019 Jun 14;59:97-104. Epub 2019 Mar 14.

Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.

Sodium (Na) magnetic resonance imaging (MRI), especially brain applications are increasingly interesting since sodium MRI can provide additional information about tissue viability and vitality. In order to include sodium MRI in the clinical routine, a single RF setup is preferable which provides high sodium sensitivity and full proton performance in terms of signal-to-noise ratio (SNR) and parallel imaging performance. The aim of this work was to evaluate the feasibility of a double resonant receive (Rx) coil array for proton and sodium head MRI. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.013DOI Listing

Incorporating prior knowledge via volumetric deep residual network to optimize the reconstruction of sparsely sampled MRI.

Magn Reson Imaging 2019 Mar 14. Epub 2019 Mar 14.

Radiation Oncology Department, Stanford University, Stanford 94305, CA, USA. Electronic address:

For sparse sampling that accelerates magnetic resonance (MR) image acquisition, non-linear reconstruction algorithms have been developed, which incorporated patient specific a prior information. More generic a prior information could be acquired via deep learning and utilized for image reconstruction. In this study, we developed a volumetric hierarchical deep residual convolutional neural network, referred to as T-Net, to provide a data-driven end-to-end mapping from sparsely sampled MR images to fully sampled MR images, where cartilage MR images were acquired using an Ultra-short TE sequence and retrospectively undersampled using pseudo-random Cartesian and radial acquisition schemes. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.012DOI Listing

Registration-based image enhancement improves multi-atlas segmentation of the thalamic nuclei and hippocampal subfields.

Magn Reson Imaging 2019 Jun 15;59:143-152. Epub 2019 Mar 15.

Computer Science, Vanderbilt University, Nashville, TN, United States of America; Electrical Engineering, Vanderbilt University, Nashville, TN, United States of America; Biomedical Engineering, Vanderbilt University, Nashville, TN, United States of America; Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States of America.

Magnetic resonance imaging (MRI) is an important tool for analysis of deep brain grey matter structures. However, analysis of these structures is limited due to low intensity contrast typically found in whole brain imaging protocols. Herein, we propose a big data registration-enhancement (BDRE) technique to augment the contrast of deep brain structures using an efficient large-scale non-rigid registration strategy. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.014DOI Listing

7T CEST MRI: A potential imaging tool for the assessment of tumor grade and cell proliferation in breast cancer.

Magn Reson Imaging 2019 Jun 14;59:77-87. Epub 2019 Mar 14.

High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MRI, Christian Doppler Forschungsgesellschaft, Vienna, Austria.

Objectives: To investigate the feasibility of chemical exchange saturation transfer (CEST) MRI in patients with breast carcinomas and possible correlations between magnetization transfer asymmetry (MTR) values and histological features, such as tumor grade and the Ki-67 proliferation index.

Materials And Methods: Nine healthy subjects and 18 female patients were enrolled for this study. The imaging protocol for the patients consisted of diffusion-weighted imaging (DWI), CEST imaging, and T1-weighted, contrast-enhanced (CE)-MRI. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.004DOI Listing
June 2019
2.022 Impact Factor

3 T MR perfusion of solid pancreatic lesions using dynamic contrast-enhanced DISCO sequence: Usefulness of qualitative and quantitative analyses in a pilot study.

Magn Reson Imaging 2019 Jun 14;59:105-113. Epub 2019 Mar 14.

Diagnostic and Interventional Radiology, University of Pisa, Via Paradisa 2, 56124 Pisa, Italy. Electronic address:

Purpose: To assess the usefulness of qualitative and quantitative analyses of pancreatic focal diseases by using the dynamic contrast-enhanced Differential Subsampling with Cartesian Ordering (DISCO) sequence at 3 T MR device.

Materials And Methods: Ten patients without pancreatic diseases and twenty-five patients with pathologically confirmed pancreatic focal disease (ductal adenocarcinoma, n = 14; endocrine tumour, n = 8; focal chronic pancreatitis, n = 3), underwent MRI by 3 T-device. Multiphasic contrast-enhanced MR perfusion, consisting of a 3D axial navigator, based free-breathing T1-weighted DISCO sequence, was repeated for 5 min. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.001DOI Listing
June 2019
1 Read

Repeatability and reproducibility of longitudinal relaxation rate in 12 small-animal MRI systems.

Magn Reson Imaging 2019 Jun 12;59:121-129. Epub 2019 Mar 12.

Bayer AG, Research and Development, Pharmaceuticals, MR and CT Contrast Media Research, Müllerstraße 178, D-13353 Berlin, Germany. Electronic address:

Background: Many translational MR biomarkers derive from measurements of the water proton longitudinal relaxation rate R, but evidence for between-site reproducibility of R in small-animal MRI is lacking.

Objective: To assess R repeatability and multi-site reproducibility in phantoms for preclinical MRI.

Methods: R was measured by saturation recovery in 2% agarose phantoms with five nickel chloride concentrations in 12 magnets at 5 field strengths in 11 centres on two different occasions within 1-13 days. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.008DOI Listing
June 2019
2 Reads

Magnetic resonance elastography of the brain: A study of feasibility and reproducibility using an ergonomic pillow-like passive driver.

Magn Reson Imaging 2019 Jun 8;59:68-76. Epub 2019 Mar 8.

School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China. Electronic address:

Magnetic resonance elastography (MRE) can be used to noninvasively resolve the displacement pattern of induced mechanical waves propagating in tissue. The goal of this study is to establish an ergonomically flexible passive-driver design for brain MRE, to evaluate the reproducibility of MRE tissue-stiffness measurements, and to investigate the relationship between tissue-stiffness measurements and driver frequencies. An ergonomically flexible passive pillow-like driver was designed to induce mechanical waves in the brain. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.009DOI Listing
June 2019
1 Read

Comparison of compressed sensing reconstruction algorithms for P magnetic resonance spectroscopic imaging.

Magn Reson Imaging 2019 Jun 7;59:88-96. Epub 2019 Mar 7.

School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; Imaging Research Center, St. Joseph's Healthcare, Hamilton, Ontario, Canada; Electrical and Computing Engineering, McMaster University, Hamilton, Ontario, Canada. Electronic address:

Phosphorus MR spectroscopy and spectroscopic imaging (P-MRS/MRSI) provide information about energy metabolism, membrane degradation and pH in vivo. In spite of their proven utility, P-MRS/MRSI are not often used primarily because of the challenges imposed by the low sensitivity and low concentration of metabolites leading to low signal to noise ratio (SNR), coarse spatial resolution and prolonged acquisition time. More recently there has been considerable interest in compressed sensing as an acceleration method for MR signal acquisition. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.006DOI Listing

Analytical validation of single-kidney glomerular filtration rate and split renal function as measured with magnetic resonance renography.

Magn Reson Imaging 2019 Jun 6;59:53-60. Epub 2019 Mar 6.

Biomedical Imaging Sciences Department, LICAMM, University of Leeds, LIGHT Laboratories, Leeds LS2 9JT, UK.

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http://dx.doi.org/10.1016/j.mri.2019.03.005DOI Listing

Evaluation of cerebrovascular reserve in patients with cerebrovascular diseases using resting-state MRI: A feasibility study.

Magn Reson Imaging 2019 Jun 5;59:46-52. Epub 2019 Mar 5.

The Russell H. Morgan Department of Radiology & Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA. Electronic address:

Purpose: To demonstrate the feasibility of mapping cerebrovascular reactivity (CVR) using resting-state functional MRI (fMRI) data without gas or other challenges in patients with cerebrovascular diseases and to show that brain regions affected by the diseases have diminished vascular reactivity.

Materials And Methods: Two sub-studies were performed on patients with stroke and Moyamoya disease. In Study 1, 20 stroke patients (56. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.003DOI Listing

Assessing liver fibrosis in chronic hepatitis B using MR extracellular volume measurements: Comparison with serum fibrosis indices.

Magn Reson Imaging 2019 Jun 5;59:39-45. Epub 2019 Mar 5.

Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, No. 180 Fenglin Road, Xuhui District, Shanghai 20032, China. Electronic address:

Objectives: To evaluate the diagnostic value of liver extracellular volume (ECV) measurement by equilibrium MR in staging liver fibrosis in chronic hepatitis B (CHB) patients, and to compare its performance with serum fibrosis indices.

Materials And Methods: 91 CHB patients were included and underwent gadopentetate dimeglumine-enhanced MRI with T1 mapping sequence before and 15-min after contrast. ECV, aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis index based on the four factors (FIB-4) were calculated and compared between fibrosis subgroups, and the correlations between the three indices and fibrosis stage or inflammatory activity were measured by Spearman correlation analysis and stepwise multiple regression analysis. Read More

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http://dx.doi.org/10.1016/j.mri.2019.03.002DOI Listing
June 2019
2 Reads

Differentiation of spinal metastases originated from lung and other cancers using radiomics and deep learning based on DCE-MRI.

Magn Reson Imaging 2019 Feb 28. Epub 2019 Feb 28.

Department of Radiological Sciences, University of California, Irvine, CA, USA. Electronic address:

Purpose: To differentiate metastatic lesions in the spine originated from primary lung cancer and other cancers using radiomics and deep learning, compared to traditional hot-spot ROI analysis.

Methods: In a retrospective review of clinical spinal MRI database with a dynamic contrast enhanced (DCE) sequence, a total of 61 patients without prior cancer diagnosis and later confirmed to have metastases (30 lung; 31 non-lung cancers) were identified. For hot-spot analysis, a manual ROI was placed to calculate three heuristic parameters from the wash-in, maximum, and wash-out phases in the DCE kinetics. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.013DOI Listing
February 2019
1 Read

SWI processing using a local phase difference modulated venous enhancement filter with noise compensation.

Magn Reson Imaging 2019 Jun 26;59:17-30. Epub 2019 Feb 26.

Medical Image Computing and Signal Processing Laboratory, Indian Institute of Information Technology and Management-Kerala, India. Electronic address:

Susceptibility weighted imaging (SWI) involves post-processing of gradient echo images which are sensitive to the spatial variations in magnetic susceptibility. The aim of this study is to develop an automated filtering scheme to enhance the contrast-to-noise ratio (CNR) and blooming on SWI. Here, the high-pass filtering for SWI processing is designed by applying a weighting function to the neighboring phase differences to enhance the susceptibility-related (SuR) contrast. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.012DOI Listing

Feasibility of quantitative MR-perfusion imaging to monitor treatment response after uterine artery embolization (UAE) in symptomatic uterus fibroids.

Magn Reson Imaging 2019 Jun 23;59:31-38. Epub 2019 Feb 23.

Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer Ufer 1-3, 68167 Mannheim, Germany. Electronic address:

Introduction: In 25% of women, symptomatic uterus myomas are diagnosed with clinical and functional impairment ranging from abdominal and pelvic pain to dys- and hypermenorrhea, dyspareunia, pollakiuria and infertility. Women undergoing a treatment increasingly prefer nowadays minimal invasive, uterus preserving therapies like uterine artery embolization (UAE) over surgical hysterectomy, nowadays. To emphasize the efficacy of UAE as a uterus preserving treatment with targeted therapy of myomas only, analysis of tissue perfusion pre and post embolization is required. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.008DOI Listing
June 2019
3 Reads

Effect of labelling plane angulation and position on labelling efficiency and cerebral blood flow quantification in pseudo-continuous arterial spin labelling.

Magn Reson Imaging 2019 Jun 22;59:61-67. Epub 2019 Feb 22.

Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Queen Square Institute of Neurology, University College London, 8-11 Queen Square, London, UK; Leonard Wolfson Experimental Neurology Centre, UCL Queen Square Institute of Neurology, Queen Square, London, UK.

Pseudo-continuous arterial spin labelling (pCASL) is the MRI method of choice for non-invasive perfusion measurement in research and clinical practice. Knowledge of the labelling efficiency, α, is essential for accurate quantification of cerebral blood flow (CBF). Typically, a theoretical α value is used, based on an idealistic model and an assumption of spins flowing perpendicularly to the labelling plane. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.007DOI Listing

Reproducibility of multi-shell diffusion tractography on traveling subjects: A multicenter study prospective.

Magn Reson Imaging 2019 Jun 21;59:1-9. Epub 2019 Feb 21.

Center for Brain Imaging Science and Technology, Key Laboratory for Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrumental Science, Zhejiang University, Hangzhou, Zhejiang, China; Department of Imaging Sciences, University of Rochester, Rochester, NY, USA. Electronic address:

Reproducibility of multicenter diffusion magnetic resonance imaging has drawn more attention recently due to rapidly increasing need for large-size brain imaging studies. Advanced multi-shell diffusion models are recommended for their potentials to provide variety of physio-pathological information. While previous studies have investigated the consistency of single-shell diffusion acquisition from various hardware and protocols, a well-controlled study with multi-shell acquisition would be necessary to understand the inherent factors of reproducibility from new complexity of such acquisition protocol. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.011DOI Listing

Assessing image artifacts from radiotherapy electromagnetic transponders with metal-artifact reduction imaging.

Magn Reson Imaging 2019 Jun 17;59:137-142. Epub 2019 Feb 17.

Department of Physics & Astronomy, University of Manitoba, Canada; Medical Physics, CancerCare Manitoba, Canada.

Image artifacts due to 14 gauge radiotherapy electromagnetic (EM) transponders were assessed on conventional spin echo images, and corrected using metal artifact reduction techniques: high bandwidth, view angle tilting (VAT), and slice encoding for metal artifact correction (SEMAC). Large areas of signal loss and/or pile-up were produced in an area extending up to 15.3 mm in radius for 14G transponders in standard imaging. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.005DOI Listing
June 2019
2 Reads

Refractory diet-dependent changes in neural microstructure: Implications for microstructural endophenotypes of neurologic and psychiatric disease.

Magn Reson Imaging 2019 May 15;58:148-155. Epub 2019 Feb 15.

Department of Biomedical Engineering, College of Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA; Neuroscience Training Program, Wisconsin Institutes for Medical Research, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA. Electronic address:

Alterations in gut microbiome populations via dietary manipulation have been shown to induce diet-dependent changes in white matter microstructure. The purpose of this study is to examine the durability of these diet-induced microstructural alterations. We implemented a crossover experimental design where post-weaned male rats were assigned to one of four experimental diets. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.006DOI Listing

Evaluation of the sensitivity of Rρ MRI to pH and macromolecular density.

Magn Reson Imaging 2019 May 14;58:156-161. Epub 2019 Feb 14.

Department of Radiology, Box 218, University of Cambridge, Cambridge CB2 0QQ, United Kingdom; Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, United Kingdom, CB2 0QQ. Electronic address:

The tumor microenvironment is characteristically acidic and this extracellular acidosis is known to play a role in carcinogenesis and metastasis and can affect tumor chemosensitivity and radiosensitivity. Intracellular pH has been used as a possible biomarker of salvageable tissue in ischemic stroke. A non-invasive MRI-based approach for the determination and imaging of cerebral pH would be a powerful tool in cancer diagnosis and monitoring, as well as stroke treatment planning. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422633PMC
May 2019
2 Reads

Prostate cancer treated with irreversible electroporation: MRI-based volumetric analysis and oncological outcome.

Magn Reson Imaging 2019 May 12;58:143-147. Epub 2019 Feb 12.

Department of Radiology, University College London Hospital NHS Foundation Trust, London, UK; Centre for Medical Imaging, University College London, London, UK.

Background: To assess multiparametric magnetic resonance imaging (mpMRI) characteristics in prostate cancer (PCa) before and after irreversible electroporation (IRE) and to investigate their correlation with the presence of post-operative recurrence of PCa.

Methods: MpMRI was performed in 30 men with PCa prior to treatment, after 10 days and at 6 months. An additional scan at 1 year was available for 18 men. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.003DOI Listing
May 2019
5 Reads

T2 mapping with 3.0 T MRI of the temporomandibular joint disc of patients with disc dislocation.

Magn Reson Imaging 2019 May 10;58:125-134. Epub 2019 Feb 10.

High-Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna, Austria; CD Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Austrian Cluster for Tissue Regeneration, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Vienna, Austria. Electronic address:

Introduction: T2 mapping, as a quantitative biochemical MRI-technique that provides information on water and collagen fiber content and composition, was shown to be clinically feasible for the evaluation of healthy temporomandibular joints.

Objectives: The aim of our study was to compare the T2 values of whole discs in patients with and without disc dislocation, to evaluate the possible influence of morphological findings on T2 values and to assess the interrater agreement.

Methods: Sixty-six patients were included in the study. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.002DOI Listing
May 2019
6 Reads
2.022 Impact Factor

MRI estimates of brown adipose tissue in children - Associations to adiposity, osteocalcin, and thigh muscle volume.

Magn Reson Imaging 2019 May 8;58:135-142. Epub 2019 Feb 8.

Section of Radiology, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden; Antaros Medical, Mölndal, Sweden. Electronic address:

Context: Brown adipose tissue is of metabolic interest. The tissue is however poorly explored in children.

Methods: Sixty-three 7-year old subjects from the Swedish birth-cohort Halland Health and Growth Study were recruited. Read More

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http://dx.doi.org/10.1016/j.mri.2019.02.001DOI Listing

Automatic classification and removal of structured physiological noise for resting state functional connectivity MRI analysis.

Magn Reson Imaging 2019 May 26;58:97-107. Epub 2019 Jan 26.

Multimodal Functional Imaging Lab, Department of Biomedical Engineering, McGill University, Duff Medical Building, 3775 Rue University, Montreal, QC H3A 2B4, Canada; Montreal Neurological Institute, McGill University, 3801 Rue University, Montreal, QC H3A 2B4, Canada; Department of Physics and PERFORM Centre, Concordia University, 7200 Rue Sherbrooke St. W, Montreal, QC H4B 1R6, Canada.

Resting state functional magnetic resonance imaging is used to study how brain regions are functionally connected by measuring temporal correlation of the fMRI signals, when a subject is at rest. Sparse dictionary learning is used to estimate a dictionary of resting state networks by decomposing the whole brain signals into several temporal features (atoms), each being shared by a set of voxels associated to a network. Recently, we proposed and validated a new method entitled Sparsity-based Analysis of Reliable K-hubness (SPARK), suggesting that connector hubs of brain networks participating in inter-network communication can be identified by counting the number of atoms involved in each voxel (sparse number k). Read More

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https://linkinghub.elsevier.com/retrieve/pii/S0730725X183011
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http://dx.doi.org/10.1016/j.mri.2019.01.019DOI Listing
May 2019
3 Reads

Tissue sodium concentration and sodium T mapping of the human brain at 3 T using a Variable Flip Angle method.

Magn Reson Imaging 2019 May 26;58:116-124. Epub 2019 Jan 26.

Department of Neurology, RWTH Aachen University, Aachen, Germany. Electronic address:

Purpose: The state-of-the-art method to quantify sodium concentrations in vivo consists in a fully relaxed 3D spin-density (SD) weighted acquisition. Nevertheless, most sodium MRI clinical studies use short-TR SD acquisitions to reduce acquisition durations. We present a clinically viable implementation of the Variable Flip Angle (VFA) method for robust and clinically viable quantification of total sodium concentration (TSC) and longitudinal relaxation rates in vivo in human brain at 3 T. Read More

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http://dx.doi.org/10.1016/j.mri.2019.01.015DOI Listing
May 2019
1 Read

Eigenvector-based SPIRiT Parallel MR Imaging Reconstruction based on ℓ pseudo-norm Joint Total Variation.

Magn Reson Imaging 2019 May 25;58:108-115. Epub 2019 Jan 25.

School of Microelectronics, Tianjin University, Tianjin 300072, China. Electronic address:

Parallel Magnetic Resonance (MR) imaging is a well-established acceleration technique based on the spatial sensitivities of array receivers. Eigenvector-based SPIRiT (ESPIRiT) is a new parallel MR imaging reconstruction method that combines the advantages of the SENSE and GRAPPA methods. It estimates multiple sets of the sensitivity maps from the calibration matrix that is constructed from the auto-calibration data. Read More

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http://dx.doi.org/10.1016/j.mri.2019.01.014DOI Listing

NMR characterizing mixed wettability under intermediate-wet condition.

Magn Reson Imaging 2019 02 2;56:156-160. Epub 2018 Oct 2.

State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China.

Applying the concept of effective relaxivity to characterize wettability is based on the configuration of fluid distributions in porous media. However, in mixed-wet porous media with intermediate-wet patches (homogeneous wetting region), effective surface relaxivity cannot fully characterize wettability because fluid distributions are not directly corresponding to wetting patch distributions. Patches with different wettability interact with the same fluid differently, which leads to different surface relaxivity. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S0730725X183033
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http://dx.doi.org/10.1016/j.mri.2018.09.023DOI Listing
February 2019
18 Reads