Reproducibility of thoracic and abdominal aortic wall measurements with three‐dimensional, variable flip angle (SPACE) MRI. Issue 1 (31st December 2013)

• Record Type: Journal Article
• Authors: Mihai, Georgeta; Varghese, Juliet; Lu, Bo; Zhu, Hong; Simonetti, Orlando P.; Rajagopalan, Sanjay
• Is Part Of: Journal of magnetic resonance imaging. Volume 41:Issue 1(2015)
• Page Start: 202
• Page End: 212
• Publication Date: 2013-12-31
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.24545
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jmri24545-sec-0001" sec-type="section"> <title>Purpose</title> <p>To evaluate the reproducibility and repeatability of high‐resolution, isotropic thoracic and abdominal aortic wall measurements, and determine the implications they have on the number of subjects necessary for future clinical trials.</p> </sec> <sec id="jmri24545-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>Using a T1‐weighted three‐dimensional MRI SPACE sequence, we evaluated the interobserver, intraobserver, and scan–rescan variability of isotropic thoracic and abdominal aortic wall measurements in 15 cardiovascular diseased patients and 6 normal volunteers. Main outcome analyses were intracorrelation coefficient (ICC), mean relative error (mRE), and sample size calculation at 80% power to be used to compare placebo group and treatment group means in future two‐arm randomized clinical trials.</p> </sec> <sec id="jmri24545-sec-0003" sec-type="section"> <title>Results</title> <p>Excellent reliability, ICC > 0.8 (<italic>P</italic> < 0.001) and small mRE < 10% were demonstrated for the interobserver, intraobserver, and scan–rescan variability for all investigated measures: lumen area (LA), outer wall area (OWA), wall area (VWA), total wall volume (TWV), and percentage wall volume (%WV). Sample size calculation revealed slightly different sample size per treatment arm for thoracic and abdominal aorta segments (maximum number of subjects: 352 subjects for thoracic segment versus 421 subjects for abdominal segment for LA at 5% difference, and minimum of 3 thoracic versus 4 abdominal subjects needed for %WV evaluation at 25% difference).</p> </sec> <sec id="jmri24545-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Our study demonstrates the reproducibility and repeatability of SPACE aortic plaque measurements, and gives insight into the number of subjects needed for the design of therapeutic studies in aortic atherosclerosis. <bold>J. Magn. Reson. Imaging 2015;41:202–212.</bold> © <bold>2013 Wiley Periodicals, Inc</bold>.</p> </sec> </abstract>