Title :
Regularized estimation of Bloch-Siegert |B1+| maps in MRI
Author :
Hao Sun ; Grissom, W.A. ; Fessler, J.A.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of Michigan-Ann Arbor, Ann Arbor, MI, USA
Abstract :
The Bloch-Siegert (BS) method is a fast method for finding RF transmit fields (|B1+| maps) in MRI based on the phase shift induced by an off-resonance pulse. The phase calculation can be very noisy in regions with low image magnitude, leading to inaccurate estimations using the conventional method. This paper proposes a penalized likelihood (PL) estimator of the |B1+| map in the image domain, and a fast optimization transfer algorithm for solving the problem. We validated our proposed method with both simulation and experimental data sets.
Keywords :
biomedical MRI; medical image processing; optimisation; BS method; Bloch-Siegert |B1+| maps regularized estimation; MRI; PL estimator; RF transmit fields; off-resonance pulse; optimization transfer algorithm; penalized likelihood estimator; phase calculation; phase shift; Algorithm design and analysis; Cost function; Estimation; Magnetic resonance imaging; Method of moments; Noise; Radio frequency;
Conference_Titel :
Image Processing (ICIP), 2014 IEEE International Conference on
Conference_Location :
Paris
DOI :
10.1109/ICIP.2014.7025740
