Papers by Keyword: Magnetic Resonance Imaging

Abstract: This study observed the properties of gelatin as tissue-mimicking materials for quality assessment of image quality in the quantitative T2 MRI method. Images for spin-spin relaxation time (T2) measurement were acquired using MRI 3 Tesla system. T2 values were measured by acquiring T2 images from gelatin samples as tissue-mimicking materials with five different concentrations: 10%, 15%, 20%, 25%, and 30%. The decay rate of signal intensity values over various echo-time (TE) was used to plot an exponential graph for T2 values, with spin-spin relaxation rate (R2) as the reciprocal of T2. The signal intensities and T2 values were observed to determine the relation between gelatin concentration and those parameters. The gelatin concentration is inversely proportional to T2 value, but no relation is found between gelatin concentration and signal intensity. The result shows that gelatin concentration of 30% has potential for tissue-mimicking materials for white matter and spinal cord. This study is potentially developed for further studies of tissue-mimicking materials for phantom development in quantitative MRI.

Abstract: Positron annihilation spectroscopy (PAS) offers a transformative approach to medical imaging, providing detailed insights into molecular structures. Although PAS has been extensively applied in studying defects in semiconductors and synthetic materials—yielding quantitative data on their microscopic properties—its potential in medical imaging could significantly enhance diagnostic methodologies. The application of positrons and other forms of radiation in analyzing living tissues necessitates careful consideration of potential damage. In this work, a model method designed to determine the optimal dose for experimental measurements is introduced. While Positron Emission Tomography (PET) has been instrumental in clinical diagnostics using radiopharmaceuticals to visualize metabolic processes, PAS presents a cutting-edge tool for improving the specificity and accuracy of biological imaging. Its capability to non-destructively explore structural transformations and micro-environmental changes in biological samples positions it as a promising innovation in diagnostics, paving the way for enhanced healthcare outcomes globally.

Abstract: A magnetic resonance imaging contrast agent is proposed using iron oxide nanoparticles (IONPs) synthesized by a pulsed laser ablation technique. Experimentally, an Nd: YAG laser (1064 nm, 7 ns, 30 mJ) was directed and focused on a high-purity iron plate immersed in a liquid solution of deionized water and polyvinylpyrrolidone (PVP). After a few minutes of laser bombardment, iron oxide nanoparticles dispersed in the liquid were homogeneously produced. A reddish yellow color-colloidal IONPs are produced in the water, while its color changes to dark brown for the PVP solution. The characterization results demonstrated that IONPs in the form of Fe₂O₃ and Fe₃O₄ made in the PVP have an excellent dispersibility with a spherical shape that is significantly smaller than that of IONPs made in the deionized water at the same laser repetition rate. The produced IONPs are further applied as a contrast agent for the magnetic resonance imaging (MRI) modality by varying concentrations from 0.05 mM to 2.31 mM. The results demonstrated that images of the IONPs sample with a concentration of 2.31 mM showed the highest contrast enhancement (Cenh), with an enhancement factor of 221.875 % for T₁-weighted images and 91.227 % for T₂-weighted images. IONPs with a concentration of 2.31 mM had the highest signal-to-noise ratio (SNR) for a T₁-weighted picture of 52.92, while IONPs with a concentration of 0.05 mM had the highest SNR for a T₂-weighted image of 179.117.

Abstract: This paper presents an approach to investigate the influence of metamaterial to radio-frequency (RF) magnetic field in magnetic resonance imaging (MRI) at 3T. The variety of magnetic fields of RF receiving coil was calculated using the commercial electromagnetic simulation software (CST). The simulation results demonstrate that the transmitting and receiving magnetic field (B₁+ and B₁-) can be enhanced when the metamaterial is inserted into the RF coil, suggesting that the metamaterial has potential in MRI applications at 3T.

Abstract: The ultimate goal of quantum calculation is to build high performance practical quantum computers. With quantum mechanics model of computer information coding and computational principle, it is proved in theory to be able to simulate the classical computer is currently completely, and with more classical computer, quantum computation is one of the most popular fields in physics research in recent ten years, has formed a set of quantum physics, mathematics. This paper to electronic spin doped fullerene quantum aided calculation scheme, we through the comprehensive use of logic based network and based on the overall control of the two kinds of quantum computing model, solve the addressing problem of nuclear spin, avoids the technical difficulties of pre-existing. We expect the final realization of the quantum computer will depend on the integrated use of in a variety of quantum computing model and physical realization system, and our primary work shows this feature..