Variability of MRI Aortic Stiffness Measurements in a Multicenter Clinical Trial Setting: Intraobserver, Interobserver, and Intracenter Variability of Pulse Wave Velocity and Aortic Strain Measurement

Maja Hrabak-Paar; Achim Kircher; Saeed Al Sayari; Sebastien Kopp; Francesco Santini; Roland E Schmieder; Nadjia Kachenoura; Denise Yates; Thomas Langenickel; Jens Bremerich; Tobias Heye

doi:10.1148/ryct.2020190090

Variability of MRI Aortic Stiffness Measurements in a Multicenter Clinical Trial Setting: Intraobserver, Interobserver, and Intracenter Variability of Pulse Wave Velocity and Aortic Strain Measurement

Radiol Cardiothorac Imaging. 2020 Apr 30;2(2):e190090. doi: 10.1148/ryct.2020190090. eCollection 2020 Apr.

Affiliation

¹ Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland (M.H.P., S.K., F.S., J.B., T.H.); Department of Diagnostic and Interventional Radiology, University Hospital Center Zagreb, University of Zagreb School of Medicine, Kispaticeva 12, HR-10000 Zagreb, Croatia (M.H.P.); Radiologie-Team Ortenau, Lahr, Germany (A.K.); Shaikh Khalifa Medical City, Abu Dhabi, United Arab Emirates (S.A.S.); Department of Biomedical Engineering, University of Basel, Switzerland (F.S.); Department of Nephrology and Hypertension, University Hospital Erlangen, Germany (R.E.S.); Cardiovascular Imaging Department, European Hospital Georges Pompidou, University of Paris, France (N.K.); and Novartis Institutes for Biomedical Research, Cambridge, Mass (D.Y., T.L.).

Abstract

Purpose: To assess intraobserver, interobserver, and scan-rescan variability of MRI aortic stiffness measurements in a multicenter trial setting.

Materials and methods: This study was a retrospective analysis of prospectively collected data in a multicenter prospective clinical trial (clinicaltrials.gov ID NCT01870739). Forty-five adult patients (31 men; mean age, 58 years ± 12 [standard deviation]; 15 patients per center; three centers) with arterial hypertension underwent standardized 3-T baseline MRI assessments between June and September 2014. Aortic strain was calculated from maximum and minimum aortic area measurements repeated three times by three readers at three aortic levels on three retrospectively gated axial gradient-echo (GRE) data sets. Pulse wave velocity (PWV) was assessed three times by five readers as Δx/Δt: Δx was measured on a parasagittal GRE image of the aortic arch, and Δt was extracted from ascending and descending aortic velocity curves created on three axial phase-contrast acquisitions. Intraobserver, interobserver, and scan-rescan variability was calculated using percentage coefficient of variation (COV).

Results: Aortic strain variability was lowest at the level of the distal descending aorta (DDA) with median COVs of 1.6% for intraobserver variability, 4.0% for interobserver variability, and 10.3% for scan-rescan variability. It was highest at the ascending aorta (AA) with COVs of 3.6% for intraobserver variability, 10.7% for interobserver variability, and 19.8% for scan-rescan variability. Variability of PWV was low: 0.7% for intraobserver variability, 1.5% for interobserver variability, and 8.1% for scan-rescan variability.

Conclusion: Low variability can be achieved for aortic strain and PWV measurements in a multicenter trial setting using standardized MRI protocols. Although COV was lower when measuring aortic strain at DDA compared with AA, variability was acceptable at both anatomic locations.Supplemental material is available for this article.© RSNA, 2020.

2020 by the Radiological Society of North America, Inc.

Associated data

ClinicalTrials.gov/NCT01870739