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A Reconstruction Method of Blood Flow Velocity in Left Ventricle Using Color Flow Ultrasound
Jang, Jaeseong,Ahn, Chi Young,Jeon, Kiwan,Heo, Jung,Lee, DongHak,Joo, Chulmin,Choi, Jung-il,Seo, Jin Keun Hindawi Publishing Corporation 2015 Computational and mathematical methods in medicine Vol.2015 No.-
<P>Vortex flow imaging is a relatively new medical imaging method for the dynamic visualization of intracardiac blood flow, a potentially useful index of cardiac dysfunction. A reconstruction method is proposed here to quantify the distribution of blood flow velocity fields inside the left ventricle from color flow images compiled from ultrasound measurements. In this paper, a 2D incompressible Navier-Stokes equation with a mass source term is proposed to utilize the measurable color flow ultrasound data in a plane along with the moving boundary condition. The proposed model reflects out-of-plane blood flows on the imaging plane through the mass source term. The boundary conditions to solve the system of equations are derived from the dimensions of the ventricle extracted from 2D echocardiography data. The performance of the proposed method is evaluated numerically using synthetic flow data acquired from simulating left ventricle flows. The numerical simulations show the feasibility and potential usefulness of the proposed method of reconstructing the intracardiac flow fields. Of particular note is the finding that the mass source term in the proposed model improves the reconstruction performance.</P>
Jang, Jaeseong,Noh, Tae Hwan,Park, Jin Kyoon,Shim, Yoon‐,Bo,Jung, Ok‐,Sang WILEY‐VCH Verlag 2014 European journal of inorganic chemistry Vol.2014 No.32
<P><B>Abstract</B></P><P>Self‐assembly of AgX (X<SUP>–</SUP> = BF<SUB>4</SUB><SUP>–</SUP>, ClO<SUB>4</SUB><SUP>–</SUP>, and NO<SUB>3</SUB><SUP>–</SUP>) with <I>C</I><SUB>3</SUB>‐symmetric 1,3,5‐tris(isonicotinoyloxyethyl)cyanurate (<B>L</B>) yields 1D loop‐and‐chain strands. However, the formation of a super‐array of strands depends on the nature of the polyatomic anions: BF<SUB>4</SUB><SUP>–</SUP> and ClO<SUB>4</SUB><SUP>–</SUP> anions induce 1D polyrotaxaned loop‐and‐chain strands, whereas NO<SUB>3</SUB><SUP>–</SUP> anion leads to the formation of 2D‐like interdigitated loop‐and‐chain strands in the crystalline state. Calcination of [Ag<SUB>3</SUB>(<B>L</B>)<SUB>2</SUB>]3X (X<SUP>–</SUP> = BF<SUB>4</SUB><SUP>–</SUP> and NO<SUB>3</SUB><SUP>–</SUP>) crystals at 500 °C produces silver(0) particles, whereas the same treatment of [Ag<SUB>3</SUB>(<B>L</B>)<SUB>2</SUB>]3ClO<SUB>4</SUB> crystals affords a mixture of silver(0) and silver(I) chloride. The rates of formation of Ag<SUP>0</SUP> nanoparticles by reduction of crystalline products using ascorbic acid are in the order X<SUP>–</SUP> = ClO<SUB>4</SUB><SUP>–</SUP> > BF<SUB>4</SUB><SUP>–</SUP> > NO<SUB>3</SUB><SUP>–</SUP>, and their crystalline morphologies are dependent on the nature of the polyatomic anions.</P>
INDUSTRIAL MATHEMATICS IN ULTRASOUND IMAGING
JAESEONG JANG,CHI YOUNG AHN 한국산업응용수학회 2016 Journal of the Korean Society for Industrial and A Vol.20 No.3
Ultrasound imaging is a widely used tool for visualizing human body’s internal organs and quantifying clinical parameters. Due to its advantages such as safety, noninvasiveness, portability, low cost and real-time 2D/3D imaging, diagnostic ultrasound industry has steadily grown. Since the technology advancements such as digital beam-forming, Doppler ultrasound, real-time 3D imaging and automated diagnosis techniques, there are still a lot of demands for image quality improvement, faster and accurate imaging, 3D color Doppler imaging and advanced functional imaging modes. In order to satisfy those demands, mathematics should be used properly and effectively in ultrasound imaging. Mathematics has been used commonly as mathematical modelling, numerical solutions and visualization, combined with science and engineering. In this article, we describe a brief history of ultrasound imaging, its basic principle, its applications in obstetrics/gynecology, cardiology and radiology, domestic-industrial products, contributions of mathematics and challenging issues in ultrasound imaging.
Automatic Estimation of Fetal Abdominal Circumference From Ultrasound Images
Jang, Jaeseong,Park, Yejin,Kim, Bukweon,Lee, Sung Min,Kwon, Ja-Young,Seo, Jin Keun IEEE 2018 IEEE Journal of Biomedical and Health Informatics Vol.22 No.5
<P>Ultrasound diagnosis is routinely used in obstetrics and gynecology for fetal biometry, and owing to its time-consuming process, there has been a great demand for automatic estimation. However, the automated analysis of ultrasound images is complicated because they are patient specific, operator dependent, and machine specific. Among various types of fetal biometry, the accurate estimation of abdominal circumference (AC) is especially difficult to perform automatically because the abdomen has low contrast against surroundings, nonuniform contrast, and irregular shape compared to other parameters. We propose a method for the automatic estimation of the fetal AC from two-dimensional ultrasound data through a specially designed convolutional neural network (CNN), which takes account of doctors’ decision process, anatomical structure, and the characteristics of the ultrasound image. The proposed method uses CNN to classify ultrasound images (stomach bubble, amniotic fluid, and umbilical vein) and Hough transformation for measuring AC. We test the proposed method using clinical ultrasound data acquired from 56 pregnant women. Experimental results show that, with relatively small training samples, the proposed CNN provides sufficient classification results for AC estimation through the Hough transformation. The proposed method automatically estimates AC from ultrasound images. The method is quantitatively evaluated and shows stable performance in most cases and even for ultrasound images deteriorated by shadowing artifacts. As a result of experiments for our acceptance check, the accuracies are 0.809 and 0.771 with expert 1 and expert 2, respectively, whereas the accuracy between the two experts is 0.905. However, for cases of oversized fetus, when the amniotic fluid is not observed or the abdominal area is distorted, it could not correctly estimate AC.</P>
Inverse Problem for Color Doppler Ultrasound-Assisted Intracardiac Blood Flow Imaging
Jang, Jaeseong,Ahn, Chi Young,Choi, Jung-Il,Seo, Jin Keun Hindawi Publishing Corporation 2016 Computational and mathematical methods in medicine Vol.2016 No.-
<P>For the assessment of the left ventricle (LV), echocardiography has been widely used to visualize and quantify geometrical variations of LV. However, echocardiographic image itself is not sufficient to describe a swirling pattern which is a characteristic blood flow pattern inside LV without any treatment on the image. We propose a mathematical framework based on an inverse problem for three-dimensional (3D) LV blood flow reconstruction. The reconstruction model combines the incompressible Navier-Stokes equations with one-direction velocity component of the synthetic flow data (or color Doppler data) from the forward simulation (or measurement). Moreover, time-varying LV boundaries are extracted from the intensity data to determine boundary conditions of the reconstruction model. Forward simulations of intracardiac blood flow are performed using a fluid-structure interaction model in order to obtain synthetic flow data. The proposed model significantly reduces the local and global errors of the reconstructed flow fields. We demonstrate the feasibility and potential usefulness of the proposed reconstruction model in predicting dynamic swirling patterns inside the LV over a cardiac cycle.</P>