Radiology, Vol 184, 401-404, Copyright © 1992 by Radiological Society of North America
Carotid arteries: evaluation with low-field-strength MR angiography
P Pavone, L Marsili, C Catalano, GA Petroni, E Aytan, GP Cardone and R Passariello
Department of Radiology, University of L'Aquila, Italy.
Magnetic resonance (MR) angiography of neck vessels was performed with a
0.2-T permanent magnet by using a two-dimensional, time-of-flight
technique. Thirty-one patients were included in the study. The imaging
parameters used included a repetition time of 60 msec, an echo time of 10
msec, a 90 degrees flip angle, and a 192 x 256 matrix; 40-50 sequential
two-dimensional sections were acquired through the neck. Stenosis was
graded on a scale of 1-5. Correlation of digital and MR angiography was
made in the clinically nonrelevant cases (stenoses of grades 1 and 2), with
overestimation to grade 3 in six cases. Two grade 3 stenoses were
overestimated as grade 4. Severe stenoses were correctly characterized in
all but one case, which was underestimated because of a segmental short
extension of the stenotic lesion. Obstructions were found in two cases.
Areas with a lack of signal were observed in four patients with severe
stenosis and in two with tortuous arteries. Correct diagnosis, however, was
achieved with analysis of the maximum intensity projection animation
display. Low-field-strength MR angiography has the same clinical value as
that performed with high field strengths.
