The contrast definitions of opposite colors red-green and blue-yellow, which have been described in the CIELAB and YC r C b color spaces, respectively, and a method to accurately control chroma and color differences o...The contrast definitions of opposite colors red-green and blue-yellow, which have been described in the CIELAB and YC r C b color spaces, respectively, and a method to accurately control chroma and color differences on a cathode ray tube screen are presented according to the color display characteristics of cathode ray tubes. Using target gratings on a cathode ray tube screen, measurements of human vision contrast sensitivity to red-green and blue-yellow colors for 10 spatial frequencies (0.41, 0.82, 1.23, 1.97, 3.08, 3.79, 4.93, 7.04, 9.86 and 16.43 cpd) were carried out in 11 young observers in a dark environment. Contrast sensitivity functions of opposite colors were obtained, which can be used for practical applications in image technologies.展开更多
Diagnosis of chronic inflammatory bowel diseases (IBD) is based on a combination of clinical symptoms, laboratory tests and imaging data. Imaging of the morphological characteristics of IBD includes the assessment of ...Diagnosis of chronic inflammatory bowel diseases (IBD) is based on a combination of clinical symptoms, laboratory tests and imaging data. Imaging of the morphological characteristics of IBD includes the assessment of mucosal alterations, transmural involvement and extraintestinal manifestations. No single imaging technique serves as a diagnostic gold standard to encompass all disease manifestations. Ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) allow cross-sectional imaging of the transmural alterations and extraintestinal manifestations. While in the USA the technique of choice is CT, in Europe the focus is more on MRI and ultrasound (US). Most patients with chronic IBD are diagnosed at a young age. After baseline diagnosis many of these young patients have to undergo repetitive imaging procedures during the variable clinical course of the disease, characterized by alternate periods of remission and active disease, and in monitoring the response to treatment. US has the advantage of being noninvasive, less costly, and easily repeatable, and thus can be very useful in following up patients with IBD. In addition, rising concern about radiation exposure in young adults indicates the demand for radiation-sparing techniques like US and MRI. This article focuses on the current clinical practice of US in IBD, describing the current technologies used in transabdominal intestinal US and the characteristic sonographic findings in Crohn′s disease and ulcerative colitis.展开更多
基金supported by the National Natural Science Foundation of China (10447005)the Shaanxi Province Science Foundation of China (2009JM1012)the Scientific Research Plan Project of the Shaanxi Province Education Department of China (2010JK463 and 2010JK464)
文摘The contrast definitions of opposite colors red-green and blue-yellow, which have been described in the CIELAB and YC r C b color spaces, respectively, and a method to accurately control chroma and color differences on a cathode ray tube screen are presented according to the color display characteristics of cathode ray tubes. Using target gratings on a cathode ray tube screen, measurements of human vision contrast sensitivity to red-green and blue-yellow colors for 10 spatial frequencies (0.41, 0.82, 1.23, 1.97, 3.08, 3.79, 4.93, 7.04, 9.86 and 16.43 cpd) were carried out in 11 young observers in a dark environment. Contrast sensitivity functions of opposite colors were obtained, which can be used for practical applications in image technologies.
文摘Diagnosis of chronic inflammatory bowel diseases (IBD) is based on a combination of clinical symptoms, laboratory tests and imaging data. Imaging of the morphological characteristics of IBD includes the assessment of mucosal alterations, transmural involvement and extraintestinal manifestations. No single imaging technique serves as a diagnostic gold standard to encompass all disease manifestations. Ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) allow cross-sectional imaging of the transmural alterations and extraintestinal manifestations. While in the USA the technique of choice is CT, in Europe the focus is more on MRI and ultrasound (US). Most patients with chronic IBD are diagnosed at a young age. After baseline diagnosis many of these young patients have to undergo repetitive imaging procedures during the variable clinical course of the disease, characterized by alternate periods of remission and active disease, and in monitoring the response to treatment. US has the advantage of being noninvasive, less costly, and easily repeatable, and thus can be very useful in following up patients with IBD. In addition, rising concern about radiation exposure in young adults indicates the demand for radiation-sparing techniques like US and MRI. This article focuses on the current clinical practice of US in IBD, describing the current technologies used in transabdominal intestinal US and the characteristic sonographic findings in Crohn′s disease and ulcerative colitis.
