Abstract
Purpose
To determine whether pulsed arterial spin‐labeled (pulsed ASL) balanced steady‐state free precession (bSSFP) imaging allows for rapid projective depiction of the carotid arteries without electrocardiographic (ECG) gating.
Materials and Methods
The carotid arteries of six volunteers were scanned at 1.5 T using an ASL two‐dimensional bSSFP sequence. Three configurations were tested, with and without ECG gating: (a) full field‐of‐view (FOV) acquisition (scan time = 48 s), (b) full‐FOV acquisition with parallel acceleration of 2 (24 s), and sequence C (half‐FOV acquisition (24 s). Vessel‐to‐background contrast‐to‐noise ratios (CNRs) and vessel lengths were compared between sequence configurations. Vessel caliber measurements were compared with those obtained from three‐dimensional time‐of‐flight (TOF) angiography.
Results
The carotid arteries were seen over extensive lengths with ASL two‐dimensional bSSFP. Projected vessel length and vessel‐to‐background CNR did not differ with ECG gating (P = NS). Nonaccelerated full‐FOV and half‐FOV scans provided larger apparent vessel‐to‐background CNR and slightly longer vessel lengths than the parallel‐accelerated scans (P < 0.01). Carotid diameter measurements were in agreement with those obtained from three‐dimensional TOF (intraclass correlation coefficient = 0.810; P < 0.001).
Conclusion
pulsed ASL bSSFP is a fast technique for projective carotid angiography that may not require ECG gating. Acquisition time may be decreased with reduced FOV or parallel imaging strategies. J. Magn. Reson. Imaging 2008;28:778–782. © 2008 Wiley‐Liss, Inc.