TY - JOUR AU - Rodriguez-Alvarez, M. J. AU - Sanchez, F. AU - Soriano, A. AU - Iborra, A. PY - 2010 DA - 2010// TI - Sparse Givens resolution of large system of linear equations: Applications to image reconstruction T2 - Math. Comput. Model. JO - Mathematical and Computer Modelling SP - 1258 EP - 1264 VL - 52 IS - 7-8 PB - Pergamon-Elsevier Science Ltd KW - Givens rotations KW - QR-factorization KW - Computed tomography KW - Image reconstruction AB - In medicine, computed tomographic images are reconstructed from a large number of measurements of X-ray transmission through the patient (projection data). The mathematical model used to describe a computed tomography device is a large system of linear equations of the form AX = B. In this paper we propose the QR decomposition as a direct method to solve the linear system. QR decomposition can be a large computational procedure. However, once it has been calculated for a specific system, matrices Q and R are stored and used for any acquired projection on that system. Implementation of the QR decomposition in order to take more advantage of the sparsity of the system matrix is discussed. SN - 0895-7177 UR - https://doi.org/10.1016/j.mcm.2010.03.016 DO - 10.1016/j.mcm.2010.03.016 LA - English N1 - ISI:000280933700043 ID - Rodriguez-Alvarez_etal2010 ER -