Model for B1 Imaging in MRI Using the Rotating RF Field

• Main Authors: Adnan Trakic, Jin Jin, Ewald Weber, Stuart Crozier
• Format: Article
• Language: English
• Published: Hindawi Limited 2014-01-01
• Series: Computational and Mathematical Methods in Medicine
• Online Access: http://dx.doi.org/10.1155/2014/461647

Conventionally, magnetic resonance imaging (MRI) is performed by pulsing gradient coils, which invariably leads to strong acoustic noise, patient safety concerns due to induced currents, and costly power/space requirements. This modeling study investigates a new silent, gradient coil-free MR imaging method, in which a radiofrequency (RF) coil and its nonuniform field (B1+) are mechanically rotated about the patient. The advantage of the rotating B1+ field is that, for the first time, it provides a large number of degrees of freedom to aid a successful B1+ image encoding process. The mathematical modeling was performed using flip angle modulation as part of a finite-difference-based Bloch equation solver. Preliminary results suggest that representative MR images with intensity deviations of <5% from the original image can be obtained using rotating RF field approach. This method may open up new avenues towards anatomical and functional imaging in medicine.