PURPOSE: To describe a new method for performing dark blood (DB) magnetization preparation in TrueFISP (bSSFP) and apply the technique to high-resolution carotid artery imaging. MATERIALS AND METHODS: The developed method (HEFEWEIZEN) provides directional flow suppression, while preserving bSSFP contrast, by periodically applying spatial saturation in short repetition time (TR) TrueFISP. Steady-state free precession (SSFP) conditions are maintained throughout the acquisition for the imaging slice magnetization. HEFEWEIZEN was implemented on a 1.5 T scanner with standard receiver coils. Studies were performed in phantoms, eight asymptomatic volunteers, and two patients with low- and high-grade carotid artery stenosis. RESULTS: Average flow suppression was 88% +/- 4% (arterial) and 85% +/- 3% (venous) in a multislice study. Stationary signal, contrast, and fine details were maintained with only slight signal suppression (11% +/- 11%). Comparison to diffusion-prepared SSFP in the common carotid artery demonstrated significant improvement in wall-lumen contrast-to-noise ratio efficiency (P = 0.024). DB contrast was achieved with only 13% increased acquisition time (14.3 sec). Further acceleration was possible by confining the DB preparation to the central 60% of k-space. CONCLUSION: A fast, short TR, DB TrueFISP pulse sequence was developed and tested in the carotid arteries of asymptomatic volunteers and patients.
PURPOSE: To describe a new method for performing dark blood (DB) magnetization preparation in TrueFISP (bSSFP) and apply the technique to high-resolution carotid artery imaging. MATERIALS AND METHODS: The developed method (HEFEWEIZEN) provides directional flow suppression, while preserving bSSFP contrast, by periodically applying spatial saturation in short repetition time (TR) TrueFISP. Steady-state free precession (SSFP) conditions are maintained throughout the acquisition for the imaging slice magnetization. HEFEWEIZEN was implemented on a 1.5 T scanner with standard receiver coils. Studies were performed in phantoms, eight asymptomatic volunteers, and two patients with low- and high-grade carotid artery stenosis. RESULTS: Average flow suppression was 88% +/- 4% (arterial) and 85% +/- 3% (venous) in a multislice study. Stationary signal, contrast, and fine details were maintained with only slight signal suppression (11% +/- 11%). Comparison to diffusion-prepared SSFP in the common carotid artery demonstrated significant improvement in wall-lumen contrast-to-noise ratio efficiency (P = 0.024). DB contrast was achieved with only 13% increased acquisition time (14.3 sec). Further acceleration was possible by confining the DB preparation to the central 60% of k-space. CONCLUSION: A fast, short TR, DB TrueFISP pulse sequence was developed and tested in the carotid arteries of asymptomatic volunteers and patients.
Authors: Venkatesh Mani; Vitalii V Itskovich; Silvia H Aguiar; Gabor Mizsei; Juan Gilberto S Aguinaldo; Daniel D Samber; Frank M Macaluso; Zahi A Fayad Journal: J Magn Reson Imaging Date: 2005-11 Impact factor: 4.813