Improved MRI thermometry with multiple-echo spirals.
Magn Reson Med
; 76(3): 747-56, 2016 09.
Article
em En
| MEDLINE
| ID: mdl-26332512
ABSTRACT
PURPOSE:
Low-bandwidth PRF shift thermometry is used to guide HIFU ablation treatments. Low sampling bandwidth is needed for high signal-to-noise ratio with short acquisition times, but can lead to off-resonance artifacts. In this work, improved multiple-echo thermometry is presented that allows for high bandwidth and reduced artifacts. It is also demonstrated with spiral sampling, to improve the trade-off between resolution, speed, and measurement precision.METHODS:
Four multiple-echo thermometry sequences were tested in vivo, one using two-dimensional Fourier transform (2DFT) sampling and three using spirals. The spiral sequences were individually optimized for resolution, for speed, and for precision. Multifrequency reconstruction was used to correct for off-resonance spiral artifacts. Additionally, two different multiecho temperature reconstructions were compared.RESULTS:
Weighted combination of per-echo phase differences gave significantly better precision than least squares off-resonance estimation. Multiple-echo 2DFT sequence obtained precision similar to single-echo 2DFT, while greatly increasing sampling bandwidth. The multiecho spiral acquisitions achieved 2× better resolution, 2.9× better uncertainty, or 3.4× faster acquisition time, without negatively impacting the other two design parameters as compared to single-echo 2DFT.CONCLUSION:
Multiecho spiral thermometry greatly improves the capabilities of temperature monitoring, and could improve transcranial treatment monitoring capabilities. Magn Reson Med 76747-756, 2016. © 2015 Wiley Periodicals, Inc.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Algoritmos
/
Processamento de Sinais Assistido por Computador
/
Encéfalo
/
Imageamento por Ressonância Magnética
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Interpretação de Imagem Assistida por Computador
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Aumento da Imagem
/
Termografia
Tipo de estudo:
Diagnostic_studies
/
Evaluation_studies
Limite:
Humans
Idioma:
En
Revista:
Magn Reson Med
Assunto da revista:
DIAGNOSTICO POR IMAGEM
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos