Assessment and reproducibility of aortic atherosclerosis magnetic resonance imaging: impact of 3-Tesla field strength and parallel imaging.
OBJECTIVE
To investigate image quality and interstudy reproducibility of aortic atherosclerosis imaging at 1.5 T, and to explore the impact of parallel imaging techniques at 3 T.


METHODS
Institutional review board approval and informed consent were obtained. Thirty-two subjects (20 normal, 12 patients with impaired cardiac function) underwent 4 black-blood T2-weighted imaging studies of the abdominal aorta: 2 conventional studies at 1.5 T, a conventional study at 3 T, and an accelerated 3-T study with parallel imaging (SENSE). Contrast-to-noise ratio and image quality score (1-5 scale, 5 = highest quality) were determined for each study. Studies were analyzed for mean wall thickness and area plaque burden as endpoints for aortic atherosclerosis. Bland-Altman analyses were performed to determine interstudy reproducibility between imaging methods. Wilcoxon signed-rank tests were used to identify significant differences between methods (P < 0.05).


RESULTS
Image quality scores were comparable between 1.5 T and 3 T with SENSE (4.0 +/- 0.6 vs. 4.2 +/- 0.6, P = 0.21). Bland-Altman reproducibility for mean wall thickness was -0.03 mm +/- 0.15 (1.5 T vs. 1.5 T), 0.01 mm +/- 0.17 (1.5 T vs. 3 T without SENSE), and -0.01 mm +/- 0.18 (1.5 T vs. 3 T with SENSE), P = 0.83. Detection of the presence or absence of plaque was comparable. Bland-Altman reproducibility for area plaque burden was -0.02% +/- 0.32% (1.5 T vs. 1.5 T), 0.06% +/- 0.41% (1.5 T vs. 3 T without SENSE), and 0.11% +/- 0.33% (1.5 T vs. 3 T with SENSE), P = 0.41.


CONCLUSIONS
Black-blood MR imaging of aortic atherosclerosis is very reproducible. Parallel imaging at 3 T permits shorter scan time compared with conventional 1.5-T imaging with comparable measures of atherosclerosis extent.
Maroules
Christopher D
CD
Department of Radiology, Division of Cardiology, Donald W. Reynolds Cardiovascular Clinical Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8896, USA.
McColl
Roderick
R
Khera
Amit
A
Peshock
Ronald M
RM
D001012:Aorta, Abdominal / Q000473:pathology*; D001018:Aortic Diseases / Q000175:diagnosis*; D050197:Atherosclerosis / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity