To investigate the feasibility of one-stop examination of aortic pulse wave velocity (PWV) , aortic distensibility (AD), and brachial artery flow-mediated dilation (FMD) in healthy volunteers by means of 3.0-T high-resolution magnetic resonance imaging (MRI).
A total of 32 healthy volunteers (24-37 years old; mean age, 29 years) underwent repeated high-resolution MRI to assess aortic PWV, ascending aorta (AA) AD, proximal descending aorta (PDA) AD, distal descending aorta (DDA) AD, and FMD of the brachial artery with an interval of 1 to 2 hours. Pulse wave velocity was evaluated by 2-dimensional (2D) phase contrast velocity-encoded MRI with a 4.7- to 7.8-millisecond (ms) temporal resolution. Fiesta-cine MRI was used to assess AD and FMD with a 18.75- to 31.25-ms temporal resolution. The image quality of repeated scans was evaluated with 4-point scores, and the agreement between the 2 scans was tested with kappa analysis. The reproducibility of the results from repeated measurements for PWV, AA-AD, PDA-AD, DDA-AD, and FMD was assessed with intraclass correlation coefficient (ICC) analysis. The method of Bland-Altman plot was also used to assess the agreement between repeated measurements.
Each examination including PWV, AD, and FMD were completed in approximately half an hour. The image quality between repeated scans showed good agreement (κ value, 0.776) with a mean score of 3.53 and 3.41, respectively. Reproducibility between repeated measurements was high for aortic PWV (4.33 ± 0.88 vs 4.36 ± 0.88 m/s; ICCPWV = 0.95; P < 0.01), AA-AD (8.60 ± 3.11 vs 8.59 ± 3.10 × 10−3 mm Hg−1; ICCAA-AD = 0.97; P < 0.01), PDA-AD (6.95 ± 2.44 vs 6.95 ± 2.42 × 10−3 mm Hg−1; ICCPDA-AD = 0.99; P < 0.01), DDA (10.54 ± 2.91 vs 10.55 ± 2.90 × 10−3mm Hg−1; ICCDDA-AD = 0.98, P < 0.01), and FMD (24.94 ± 12.55 vs 24.92 ± 12.38%; ICCFMD = 0.94, P < 0.01). Good agreement between repeated measurements was found for aortic PWV (confidence interval [CI], −0.55 to 0.50), AA-AD (CI, −0.11 to 0.12), PDA-AD (CI, −0.08 to 0.08), DDA-AD (CI, −0.23 to 0.21), and FMD (CI, −1.46 to 1.51).
Comprehensive assessment of aortic compliance and brachial endothelial function can be achieved in a single examination using 3.0-T high-resolution MRI with good reproducibility and within a reasonable amount of time.
From the Department of Diagnostic Radiology, Zhongshan Hospital, Shanghai Medical College, Fudan University; and Shanghai Medical Imaging Institute, Shanghai, China.
Received for publication February 13, 2012; accepted April 20, 2012.
Reprints: Jiang Lin, MD, 180 Fenglin Rd, Department of Diagnostic Radiology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China (e-mail: email@example.com).
This work was supported by a grant from Key Basic Research Project of Shanghai Science and Technology (No. 08JC1404500).