We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
B<sub>1</sub> Mapping with Selective Pulses.
- Authors
Bouhrara, Mustapha; Bonny, Jean-Marie
- Abstract
Knowledge of B1+ distribution is crucial for many applications, such as quantitative MRI. A novel method has been developed to improve the accuracy of the conventionally applied doubleangle method for B +1 mapping. It solves the remaining issues raised by the use of selective pulses for slice selection to accelerate the acquisition process. A general approach for reconstructing B1+ maps is presented first. It takes B1+ -induced slice profile distortions over off-resonance frequencies into account. It is then shown how the ratio between the prescribed flip angles can be adjusted to reach a compromise between the level of noise propagated onto B1+ maps and the width of the range in which the field can be mapped. Lastly, several solutions are proposed for reducing the B1+ -dependent pollution of regions distal to the image slice which participates significantly in the inaccuracy of B1+ mapping. These methods were experimentally tested by comparison with gold standard B1+ maps obtained on a phantom using a non-selective and thus much slower technique. As they are independent and lead to significant improvements, these solutions can be combined to achieve high precision and fast B1+ mapping using spin-echo DAM.
- Publication
Magnetic Resonance in Medicine, 2012, Vol 68, Issue 5, p1472
- ISSN
0740-3194
- Publication type
Article
- DOI
10.1002/mrm.24146