Steady-state double-angle method for rapid B1 mapping.
Magn Reson Med
; 82(1): 189-201, 2019 07.
Article
em En
| MEDLINE
| ID: mdl-30828871
ABSTRACT
PURPOSE:
To introduce an accurate, rapid, and practical method for active B1 field mapping based on the double-angle method (DAM) in the steady-state (SS) signal regime.METHODS:
We introduced and evaluated the performance of the SS-DAM approach to map the B1 field and compared the results to those calculated from the conventional DAM approach. Similar to DAM, SS-DAM uses the signal intensity ratio of 2 magnitude images acquired with different flip angles using the spoiled gradient recalled echo sequence. However, unlike DAM, in SS-DAM, these 2 spoiled gradient recalled echo images are acquired with very short TR, which allows substantially reduced acquisition time. Numerical, phantom, and in vivo brain imaging analyses, representing a wide range of T1 s and large B1 variation, were conducted. Methods for further accelerating acquisition were also investigated.RESULTS:
Our results demonstrate the potential of the SS-DAM approach to be applied widely in the clinical setting. B1 maps derived from SS-DAM were demonstrated to be quantitatively comparable to those derived from DAM but were derived much more rapidly. Large-volume B1 maps were obtained at a field strength of 3 tesla within clinically acceptable acquisition times.CONCLUSION:
SS-DAM permits accurate B1 mapping in the clinical setting, with whole-brain coverage in less than 1 min.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Processamento de Imagem Assistida por Computador
/
Imageamento por Ressonância Magnética
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article