Abstract T P108: MRI Measurements of Intracranial Atherosclerosis in the ARIC Neurocognitive Study: Methods, Reliability and Descriptive Statistics
Introduction: A 3D high resolution MRI (HRMRI) vascular protocol was designed to measure intracranial atherosclerosis in a biracial population from the multicenter ARIC Neurocognitive (ARIC-NCS) study.
Hypothesis: HRMRI provides reliable intracranial vessel wall measurements in a population-based study.
Methods: 1980 ARIC-NCS participants (mean age, 77.2±5.3 years; 40% male; 71% white, 28% black) underwent a brain HRMRI protocol designed to identify atherosclerosis in major intracranial arteries, that included 3D time-of-flight MRA and 3D black blood MRI (both acquired at 0.5-mm3 resolution). Among 1980 participants, 102 were recruited for repeat MRI exams to estimate scan and reader variability. Participants were selected based on identification of at least one intracranial plaque on the baseline MRI scan with adequate or excellent image quality. Exam pairs were read by the same reader to exclude inter-reader variation. Presence of plaque by vessel segment was recorded. Quantitative MRI measurements included lumen size and stenosis, wall/plaque thickness, area, and volume, normalized wall index over each vessel segment, and the largest plaque identified for each vascular territory (Table 1). Reliability was assessed by percent of agreement, kappa statistics and intraclass correlations (ICC).
Results: There were 272 pairs of repeated interpretations. Percent agreement, of plaque identification per participant was 87.0% (inter-reader), 89.2% (intra-reader), and 89.9% (between scans). The reliability for plaque identification was not impacted by the vessel segment. Repeat scan and repeat reader reliability (ICC) for quantitative measurements ranged from 0.69 to 0.98 (Table 1).
Conclusion: HRMRI provides reliable MRI measurements of intracranial vessels, and reliability was not impacted by plaque location.
Author Disclosures: Y. Qiao: None. L. Liu: None. Y. Zhang: None. Z. Anwar: None. S. Mirbagheri: None. Y. Xie: None. N. Nezami: None. J. Intrapiromkul: None. S. Zhang: None. E. Guallar: None. F. Suri: None. B.A. Wasserman: None.
- © 2015 by American Heart Association, Inc.