Fast T2 mapping with multiple echo, Caesar cipher acquisition and model-based reconstruction.
Magn Reson Med
; 73(3): 1065-74, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-24753216
ABSTRACT
PURPOSE:
Fast, quantitative T2 mapping is of value to both clinical and research environments. However, many protocols utilizing fast spin echo (FSE) pulse sequences contain acceleration-induced artifacts that are compounded when fitting parameter maps, especially in the presence of imperfect refocusing. This work presents a B1 -corrected, model-based reconstruction and associated Cartesian FSE phase-encode ordering that provides enhanced accuracy in T2 estimates compared with other common accelerated protocols. THEORY ANDMETHODS:
The method, known as multiple echo, Caesar cipher acquisition and model-based reconstruction (ME-CAMBREC), directly fitted T2 , flip angle, and proton density maps on a row-by-row basis to k-space data using the extended phase graph model. Regularization was enforced in order to minimize noise amplification effects. ME-CAMBREC was evaluated in computational and physical phantoms, as well as human brain, and compared with other FSE-based T2 mapping protocols, DESPOT2, and parallel imaging acceleration.RESULTS:
In computational, phantom, and human experiments, ME-CAMBREC provided T2 maps with fewer artifacts and less or similar error compared with other methods tested at moderate-to-high acceleration factors. In vivo, ME-CAMBREC provided error rates approximately one-half those of other methods.CONCLUSION:
Directly fitting multi-echo data to k-space using the extended phase graph can increase fidelity of T2 maps significantly, especially when using an appropriate phase-encode ordering.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Algoritmos
/
Encéfalo
/
Imageamento por Ressonância Magnética
/
Interpretação de Imagem Assistida por Computador
/
Aumento da Imagem
/
Artefatos
Tipo de estudo:
Diagnostic_studies
/
Guideline
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Magn Reson Med
Assunto da revista:
DIAGNOSTICO POR IMAGEM
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Estados Unidos