WCN 2013 No: 1860 Topic: 36 — Other Topic A fast method for determination of the parameters of pulsed-CEST MRI G. Xiao, Z. Dai, P.Z. Sun, R. Wu. Department of Mathematics and Applied Mathematics, Hanshan Normal University, Chaozhou, China; Department of Radiology, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, China; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA Objective: The object of the research is to demonstrate a fast method for simultaneous determination of labile proton fraction ratio and exchange rate and other parameters of pulsed chemical exchange saturation transfer (pulsed-CEST) MRI. Methods: Mathematical models have been developed to describe pulsed-CEST contrast. We simulated pulsed-CEST MRI in MatLab (MathWorks, Natick, MA) for Z-spectra and asymmetry spectra using matrix exponential algorithm. The number of repetition of the sequence is 256. Each Gaussian-shaped pulse was divided into 101 steps, and the evolution within each step was modeled assuming a constant amplitude. We also calculated the above spectra by using the fourth/fifth-order RKF(ode45 in MatLab; MathWorks, Natick, MA, USA) with an absolute error tolerance for each integration step of 10−6, and compared with the results obtained by our method. Calculations were performed using MatLab on Pentium® Dual-Core CPU (2.2 GHz) with 2-GB RAM. There was a good agreement between them, and this method was much faster than the RKF method (by a factor of approximately 1000 in this study). We simulated that the error of the labile proton fraction ratio, exchange rate and other parameters less than 5%. Results: This method will be useful for determination of labile proton fraction ratio and exchange rate and other parameters, and for analyzing the pulsed-CEST contrast mechanism and/or investigating the optimal RF pulse parameters such as the RF pulse duration or pulse flip angle. doi:10.1016/j.jns.2013.07.2242 Abstract — WCN 2013 No: 1859 Topic: 36 — Other Topic Association between obstructive pulmonary function abnormalities and brain cortical thickness WCN 2013 No: 1859 Topic: 36 — Other Topic Association between obstructive pulmonary function abnormalities and brain cortical thickness J. Cho, J. Sohn, S.-K. Cho, H. Kim, C. Kim, D.-C. Shin, S. Seo. Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea; Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul,