Performance of steady-state free precession for imaging carotid artery disease
Anna E Zavodni1, Derek J Emery, Alan H Wilman
1Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
Purpose:
To evaluate steady-state free precession (SSFP) for diagnosing carotid artery disease.
Materials And Methods:
Following bilateral x-ray angiography, seven patients with suspected carotid artery disease were imaged with SSFP, black blood fast spin echo (BB FSE), and time-of-flight MR angiography (TOF MRA). The techniques were compared for characterizing the vessel lumen. Flow phantom experiments were also performed, using speeds of 0 to 40 cm/second, to further evaluate the merits of each MR technique.
Results:
In the patient studies, of the 14 arteries available, a correct grading of stenosis was possible with SSFP in 9 of 14, FSE in 12 of 14, and TOF in 13 of 14, assuming x-ray angiography as the gold standard. The SSFP technique was the least reliable and had severe artifacts in 5 of 14 arteries, making these images nondiagnostic. The flow phantom demonstrated that although the SSFP technique performs well under slow or no flow, it breaks down at higher flow levels.
Conclusion:
The continuous SSFP sequence used here was not reliable for imaging carotid artery disease owing to artifact in many cases. Nevertheless, the high speed of this SSFP technique does allow it to serve as a rapid scouting method prior to a more detailed evaluation with other MRI methods.
