Comprehensive assessment of aortic compliance and brachial endothelial function using 3.0 T highresolution MRI:a feasibility study / 中华放射学杂志

ABSTRACT

ObjectiveTo investigate the feasibility of examining aortic pulse wave velocity (PWV),aortic distensibility (AD) and brachial artery flow-mediated dilation (FMD) by means of highresolution 3.0 T MRI.MethodsA total of 32 healthy volunteers underwent high-resolution MRI to assess aortic PWV,and AD in ascending aorta (AA),proximal descending aorta (DA),distal descending aorta (DDA) and FMD of the brachial artery with repeat examination performed in 1-2 hours.PWV was evaluated by 2D Phase Contrast (PC) velocity-encoded MRI with a 4.7-7.8 ms temporal resolution.Fiesta-cine MRI was used to assess AD and FMD with a 18.75-31.25 ms temporal resolution.The image quality of these two scans was scored and the agreement between them was tested with Kappa analysis.The reproducibility of the results between repeated measurements of PWV,AA-AD,DA-AD,DDA-AD and FMD was assessed with intra-class correlation coefficient (ICC) analysis.The method of Bland-Altman plot was used to assess the agreement between results of repeated studies.Results Each examination including PWV,AD and FMD were completed in about half an hour.The image quality between repeated scans showed good agreement ( Kappa value 0.776 ) with the score of ( 3.53 ± 0.62 ) and ( 3.41 ± 0.67 ) respectively.Reproducibility between repeated measurements was high for aortic PWV [ (4.33 ± 0.88 ) vs ( 4.36 ±0.88) m/s],AA-AD [(8.60±3.11) × 10-3 vs (8.59 ± 3.10) × l0-3/mm Hg(1 mm Hg =0.133 kPa) ],DA-AD[ (6.95 ±2.44) × 10-3 vs (6.95 ±2.42) × 10-3/mm Hg],DDA [(10.54 ±2.91) ×l0-3 vs (10.55 ±2.90) × 10-3/mm Hg] and FMD [(24.94 ± 12.55)％ vs (24.92 ±1 2.38 ) ％ ].ICC were 0.95,0.97,0.99,0.98 and 0.94,P ＜ 0.01.Excellent agreement between repeated measurements was found for aortic PWV [ confidence interval (CI) between - 0.55 and 0.50 ],AA-AD ( CI between - 0.11 and 0.12 ),DA-AD ( CI between - 0.08 and 0.08 ),DDA-AD ( CI between - 0.23 and 0.21 ) and FMD (CI between - 1.46 and 1.51 ).The maximum difference percentage in minimum average for aortic PWV,AA-AD,DA-AD,DDA-AD and FMD was 38.53％,9.65％,3.86％,5.68％,42.37％,respectively,all less than 50％.Conclusion Comprehensive assessment of aortic compliance and brachial endothelial function can be achieved using 3.0 T high-resolution MRI with excellent reproducibility and within a reasonable amount of time.