@TechReport{Petr-TR-2004-09, IS = { zkontrolovano 13 Jan 2005 }, UPDATE = { 2004-08-13 }, author = {Petr, Jan and Kybic, Jan and Hlav{\'a}{\v c}, V{\'a}clav}, title = {Parallel {MRI} Reconstruction using {B}-splines}, institution = {Center for Machine Perception, K13133 FEE Czech Technical University}, address = {Prague, Czech Republic}, year = {2004}, month = {July}, type = {Research Report}, number = {{K333--19/04}, {CTU--CMP--2004--09}}, issn = {1213-2365}, pages = {12}, figures = {5}, authorship = {33-33-34}, psurl = {[Petr-TR-2004-09.pdf]}, project = {STINT Dur IG2003-2 062, CONEX GZ 45.535, IST-2001-32184, LN00B096}, annote = {Parallel MRI (pMRI) is a way to use the data obtained simultaneously from several receiver coils with distinct spatial sensitivities to increase the speed of the MRI acquisition. The idea is to sample more sparsely during the acquisition and compensate the decrease of the data amount by the use of several coils. The total acquisition time is thus reduced. The key contribution of this work is a design of a reconstruction algorithm with emphasis on the speed of the reconstruction and the suppression of artifacts. The reconstruction minimizes the square difference error. The currently available methods (SENSE, mSENSE) estimate the reconstruction transformation independently in each image point. We propose an algorithm that uses the fact that the coil sensitivities are smooth in space. A grid of B-splines is used to represent the coefficients of the reconstruction transformation. This reduces the number of estimated variables and thus speeds up the estimation. It also makes the method robust to noise during the estimation. The B-spline representation is continuous. It has the advantages of scalability and differentiability, which is useful for computing and minimizing of the reconstruction error. The method was tested on a synthetic and real data. No major artifacts were observed and the square difference error is also small. The results are comparable in quality to the results of the other available methods. Our method was found to be comparable or faster.}, keywords = {Medical Imaging, MRI, B-splines, parallel MRI}, }