Abstract:
:For in vivo magnetic resonance imaging at high field (> or =3 T) it is essential to consider the homogeneity of the active B(1) field (B(1)+), particularly if surface coils are used for RF transmission. A new method is presented for highly rapid B(1)+ magnitude mapping. It combines the double angle method with a B(1)-insensitive magnetization-reset sequence such that the choice of repetition time (TR) is independent of T(1) and with a multislice segmented (spiral) acquisition to achieve volumetric coverage with adequate spatial resolution in a few seconds. Phantom experiments confirmed the accuracy of this technique even when TR < T(1), with the side effect being lowered SNR. The speed of this method enabled B(1)+ mapping in the chest and abdomen within a single breath-hold. In human cardiac imaging, the method enabled whole-heart coverage within a single 16-s breath-hold. Results from phantoms and healthy volunteers at 1.5 T and 3 T are presented.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Cunningham CH,Pauly JM,Nayak KSdoi
10.1002/mrm.20896subject
Has Abstractpub_date
2006-06-01 00:00:00pages
1326-33issue
6eissn
0740-3194issn
1522-2594journal_volume
55pub_type
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