Rahul P Dewal1, Qing X Yang1. 1. Center for NMR Research, Department of Radiology, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania, USA.
Abstract
PURPOSE: Calculation of static magnetic field (B0 ) inhomogeneity maps of high-resolution susceptibility models by means of convolution with dipole kernels often encounters limitations in computer memory (RAM) for large input data matrices. In many applications, only a small portion of the full volume of the computer model is a volume of interest (VOI) or a susceptibility perturbation source. This work presents a VOI-based method to significantly reduce the computer memory usage for such applications. THEORY AND METHODS: The VOI-based method is presented and compared with the conventional method for calculation of the B0 field in the brain and heart of a human body model in terms of calculation speed, memory requirement, and calculation error relative to the full model results. RESULTS: Use of the VOI-based method significantly reduced memory usage in the human body model calculations over the conventional method without loss of accuracy and with comparable calculation speed. CONCLUSION: The proposed method can be valuable for rapid calculation of B0 distributions on standard computer hardware for applications such as subject-specific B0 field calculations derived from anatomic scans. Magn Reson Med 75:2473-2480, 2016.
PURPOSE: Calculation of static magnetic field (B0 ) inhomogeneity maps of high-resolution susceptibility models by means of convolution with dipole kernels often encounters limitations in computer memory (RAM) for large input data matrices. In many applications, only a small portion of the full volume of the computer model is a volume of interest (VOI) or a susceptibility perturbation source. This work presents a VOI-based method to significantly reduce the computer memory usage for such applications. THEORY AND METHODS: The VOI-based method is presented and compared with the conventional method for calculation of the B0 field in the brain and heart of a human body model in terms of calculation speed, memory requirement, and calculation error relative to the full model results. RESULTS: Use of the VOI-based method significantly reduced memory usage in the human body model calculations over the conventional method without loss of accuracy and with comparable calculation speed. CONCLUSION: The proposed method can be valuable for rapid calculation of B0 distributions on standard computer hardware for applications such as subject-specific B0 field calculations derived from anatomic scans. Magn Reson Med 75:2473-2480, 2016.
Authors: Maximilian N Diefenbach; Stefan Ruschke; Holger Eggers; Jakob Meineke; Ernst J Rummeny; Dimitrios C Karampinos Journal: Magn Reson Med Date: 2018-02-09 Impact factor: 4.668
Authors: Michael A Antonacci; Christian McHugh; Michele Kelley; Andrew McCallister; Simone Degan; Rosa T Branca Journal: Sci Rep Date: 2019-10-16 Impact factor: 4.379