Inversion recovery prepared turbo spin echo sequences with reduced SAR using smooth transitions between pseudo steady states
Autor: | Matthias Weigel, Maxim Zaitsev, Juergen Hennig |
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Rok vydání: | 2007 |
Předmět: |
Adult
Male Brain Mapping Pulse (signal processing) Chemistry Echo time RF power amplifier Specific absorption rate Inversion recovery Fluid-attenuated inversion recovery Fast spin echo Image Enhancement Magnetic Resonance Imaging Image contrast Nuclear magnetic resonance Image Processing Computer-Assisted Feasibility Studies Humans Female Radiology Nuclear Medicine and imaging |
Zdroj: | Magnetic Resonance in Medicine. 57:631-637 |
ISSN: | 1522-2594 0740-3194 |
Popis: | This study investigates the contrast behavior of 2D inversion recovery (IR) prepared turbo spin echo (TSE) sequences that use RF pulse schemes with variable low flip angles (hyperTSE) to reduce RF power deposition. A framework of equations and calculations for adapting the sequence parameters is presented by which equivalent image contrast is achieved compared to conventional IR-TSE imaging. Although the inversion time (TI) and repetition time (TR) do not need to be changed, the echo time (TE) has to be prolonged such that the effective TE (TE(eff)) is preserved. Measurements in healthy volunteers confirmed this finding for IR-TSE sequences using different TIs: fluid attenuated inversion recovery (FLAIR), gray matter (GM)-white matter (WM)-IR, and short tau IR (STIR). The results demonstrate that hyperTSE sequences enable high-quality IR-prepared imaging with a considerably reduced specific absorption rate (SAR). |
Databáze: | OpenAIRE |
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