Nuclear Magnetic Resonance Imaging Data Research Articles

Intervention of Hepatocellular Carcinoma in Fibrosis Staging Based on Multi-Parameter Magnetic Resonance Image Depth Learning Method

This paper mainly discusses the deep learning solution for non-invasive evaluation of the differentiation degree of hepatocellular carcinoma based on multi-parameter nuclear magnetic resonance images, combined with the clinical diagnosis experience of radiologists and the characteristics of nuclear magnetic resonance images. The method of multimodal data fusion is studied based on multi-parameter nuclear magnetic resonance imaging data. Multi-channel three-dimensional convolution neural network and multi-scale depth residual network are proposed to extract the features of three-dimensional medical image data and two-dimensional fusion medical image data, and to solve the problem of insufficient cases in clinical image data of hepatocellular carcinoma (HCC). We examine the role of transition learning and metric learning in medical image classification. In this study, we use a method of data fusion, transition learning and multi scale feature extraction to construct a deep learning model for medical image aided diagnosis. Multiple modal fusion decisions for finding complementary modal data fusion for the complementarity of multimodal images in diagnostic decisions can effectively improve diagnostic effects. Although there is a clear difference between natural and medical images through experiments, a model trained with a natural image dataset as an initialization of the network can ensure and converge the training. At the same time, improve the performance of the model on the test set. The multi-scale feature extraction model proposed in this paper enhances the robustness of the model and further improves the effect of medical image classification.

Tirilazad inhibits surgically induced edema and interleukin-1 production: An experimental study in rats

The aim of this study was to evaluate the anti-inflammatory effect of tirilazad mesylate on edema and interleukin-1 (IL-1) levels in serum following standardized surgical procedures. Four groups, each containing eight rats, were randomized for treatment as follows: A) no medication, B) low-dose tirilazad, C) high-dose tirilazad, and D) corticosteroids. The animals were examined by nuclear magnetic resonance imaging (NMRI) 24 and 72 hours after surgery and the NMRI data were used in the determination of soft tissue edema. In addition, serum was obtained for analysis of IL-1 levels. Four other groups of animals were subjected to the same treatment regimen as groups A-D), respectively, and 24 hours after surgery the animals were killed, whereafter serum was obtained for analysis of IL-1 levels. The present study demonstrated that low-dose tirilazad significantly reduces soft tissue edema compared with all other treatment regimens 24 hours postoperatively. At 72 hours postoperatively significant reduction of soft tissue edema was achieved at low-dose tirilazad when compared to high-dose tirilazad and steroids. In addition, a significant suppression of the expression of IL-1 was observed at 24 and 72 hours when comparing low-dose tirilazad and the control group.

Estimation of porous media flow functions using NMR imaging data

Nuclear magnetic resonance (NMR) imaging data measured during two-phase displacement experiments on porous rock core samples are used in an inverse problem methodology to estimate the two-phase flow functions relative permeability and capillary pressure. Nuclear magnetic resonance imaging data contain valuable information about variation of fluid states within the core sample and are therefore important for accurate estimation of these properties. A precise agreement between measured data, which also includes pressure drop across the core samples, and the data simulated by using the estimated flow functions is found, indicating accurate flow function estimates.

Capillary penetration in fibrous matrices studied by dynamic spiral magnetic resonance imaging

The dynamic spiral nuclear magnetic resonance (NMR) imaging technique was used to investigate the water imbibition into cellulose fiber matrices. The advancing water boundary, water concentration distribution, and swelling degree within the fiber matrix samples were monitored as a function of time over the entire absorption process. A combined image that shows the time evolution of the absorbed water concentration distribution within the fiber matrix was synthesized from the dynamically acquired NMR image data set. The NMR imaging data clearly demonstrated that water imbibition into a fiber matrix consists of two different processes: water penetration into capillaries between fibers and water diffusion into the cellulose fibers. The advancing liquid front is primarily determined by the water capillary flow and can be quantitatively described by Washburn equation. The slower water diffusion process in fibers is mainly responsible for the fiber swelling. The time evolution of the absorbed water concentration distribution can be qualitatively interpreted in terms of steady capillary flow and concentration-gradient-driven diffusion into fibers with a constant permeability. The effects of pore morphology, tortuosity, and surface heterogeneity to the water absorption process are also discussed.

Diffusion of pyridine in Illinois No. 6 coal: measuring the swelling and deswelling characteristics by combined methods of nuclear magnetic resonance (NMR) and nuclear magnetic resonance imaging (NMRI)

The time-dependent swelling and deswelling of Illinois No. 6 coal by pyridine were measured by combined NMR and NMRI techniques. The results indicate that pyridine transport in this coal proceeds via Case II diffusion for swelling and via Fickian diffusion for deswelling. Once the relative pyridine concentrations reach values between 0.65 and 0.45, the coal's physical state changes from a glassy to a rubbery state. Transitions are well recorded by an inflection observed in the trend of spin-lattice relaxation or spin-spin relaxation of pyridine, as the coal swells and deswells. NMRI data indicate that the coal swelling is anisotropic, with swelling in a plane perpendicular to the coal bedding plane being 13% greater than that parallel to the coal bedding plane; however, the process of deswelling is almost isotropic. The differences between the swelling and deswelling characteristics are discussed from the viewpoint of coal's intrinsic structural properties and stored geologic pressure effects.

Shear-induced particle migration in Couette and parallel-plate viscometers: NMR imaging and stress measurements

Couette and parallel plate viscometers are two commonly used flow geometries to characterize shear viscosity of concentrated suspensions. In Couette flow, it is well documented that prolonged shearing causes a decrease in the apparent viscosity of concentrated suspensions due to shear-induced particle migration from the annulus region to the stagnant region under the bob. In this study, the technique of nuclear magnetic resonance imaging (NMRI) was used to measure the evolution of suspension concentration profiles in Couette and parallel-plate flow devices upon shearing. Neutrally buoyant suspensions of nearly monodisperse, non-Brownian spherical particles at a volume fraction of 0.5 in a Newtonian fluid were used. The same flow cells and suspensions were also used in a rheometer to measure the changes in shear stress under identical experimental conditions such that a direct comparison can be made between the stress and concentration data. For Couette flow, the NMRI data correlated very well with the stress measurements and directly confirmed the Leighton–Acrivos [J. Fluid. Mech. 181, 415 (1987)] shear-induced migration theory. In torsional flow between parallel plates, no detectable change was found in particle concentration in the radial direction, but some decrease in the apparent viscosity was observed. These results provide some important clues for developing and evaluating more general descriptions of particle migration for nonrectilinear shear flows.

JCAMP-DX for NMR

Following the development and publication of the JCAMP-DX protocol 4.24 and its successful implementation in the field of infrared spectroscopy, data exchange without loss of information, between systems of different origin and internal format, has become a reality. The benefits of this system-independent data transfer standard have been recognized by workers in other areas who have expressed a wish for an equivalent, compatible standard in their own fields. This publication details a protocol for the exchange of Nuclear Magnetic Resonance (NMR) spectral data without any loss of information and in a format that is compatible with all storage media and computer systems. The protocol detailed below is designed for spectral data transfer, and its use for NMR imaging data transfer has not as yet been investigated.