Simple recipe for accurate T(2) quantification with multi spin-echo acquisitions.
MAGMA
; 27(6): 567-77, 2014 Dec.
Article
em En
| MEDLINE
| ID: mdl-24643838
ABSTRACT
OBJECTIVE:
The quantification of magnetic resonance relaxation parameters T 1 and T 2 have the potential for improved disease detection and classification over standard clinical weighted imaging. Performing a mono-exponential fit on multi spin-echo (MSE) data provides quantitative T 2 values in a clinically acceptable scan-time. However, due to technical imperfections of refocusing pulses, stimulated echo contributions to the signals lead to significant deviations in the resulting T 2 values. In this work, a simple auto-calibrating correction procedure is presented, allowing the accurate estimation of T 2 from MSE acquisitions. MATERIALS ANDMETHODS:
Correction factors for T 2 values obtained from MSE acquisitions with a mono-exponential fit are derived from simulations following the extended phase graph formulation. A closed formula is given for the calculation of the required correction factors directly from the measured data itself.RESULTS:
Simulations and phantom experiments show high accuracy of corrected T 2 values for a wide range of clinically relevant T 2 values and for different nominal refocusing flip angles. In addition, corrected T 2 maps of the human brain are presented.CONCLUSION:
A simple recipe is provided to correct T 2 values obtained from MSE acquisitions via a mono-exponential fit for the influence of stimulated echoes. Since all required parameters are extracted from the data themselves, no additional acquisitions are required.
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Base de dados:
MEDLINE
Assunto principal:
Algoritmos
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Processamento de Sinais Assistido por Computador
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Encéfalo
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Interpretação de Imagem Assistida por Computador
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Aumento da Imagem
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Artefatos
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Imagem Ecoplanar
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article