Halting the effects of flow enhancement with effective intermittent zeugmatographic encoding (HEFEWEIZEN) in SSFP.
OBJECTIVE
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.


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.


CONCLUSIONS
A fast, short TR, DB TrueFISP pulse sequence was developed and tested in the carotid arteries of asymptomatic volunteers and patients.
Derakhshan
Jamal J
JJ
Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
Griswold
Mark A
MA
Sunshine
Jeffrey L
JL
Duerk
Jeffrey L
JL
D000328:Adult; D000465:Algorithms; D016477:Artifacts; D001783:Blood Flow Velocity / Q000502:physiology*; D002339:Carotid Arteries / Q000033:anatomy & histology* / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity