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Comparison of native high-resolution 3D and contrast-enhanced MR angiography for assessing the thoracic aorta

Authors

  • F. von Knobelsdorff-Brenkenhoff
  • H. Gruettner
  • R.F. Trauzeddel
  • A. Greiser
  • J. Schulz-Menger

Journal

  • European Heart Journal - Cardiovascular Imaging

Citation

  • Eur Heart J Cardiovasc Imaging 15 (6): 651-658

Abstract

  • AIMS: To omit risks of contrast agent administration, native magnetic resonance angiography (MRA) is desired for assessing the thoracic aorta. The aim was to evaluate a native steady-state free precession (SSFP) three-dimensional (3D) MRA in comparison with contrast-enhanced MRA as the gold standard. METHODS AND RESULTS: Seventy-six prospective patients with known or suspicion of thoracic aortic disease underwent MRA at 1.5 T using (i) native 3D SSFP MRA with ECG and navigator gating and high isotropic spatial resolution (1.3 x 1.3 x 1.3 mm3) and (ii) conventional contrast-enhanced ECG-gated gradient-echo 3D MRA (1.3 x 0.8 x 1.8 mm3). Datasets were compared at nine aortic levels regarding image quality (score 0-3: 0 = poor, 3 = excellent) and aortic diameters, as well as observer dependency and final diagnosis. Statistical tests included paired t-test, correlation analysis, and Bland-Altman analysis. Native 3D MRA was acquired successfully in 70 of 76 subjects (mean acquisition time 8.6 +/- 2.7 min), while irregular breathing excluded 6 of 76 subjects. Aortic diameters agreed close between both methods at all aortic levels (r = 0.99; bias +/- SD -0.12 +/- 1.2 mm) with low intra- and inter-observer dependency (intraclass correlation coefficient 0.99). Native MRA studies resulted in the same final diagnosis as the contrast-enhanced MRA. The mean image quality score was superior with native compared with contrast-enhanced MRA (2.4 +/- 0.6 vs. 1.6 +/- 0.5; P < 0.001). CONCLUSION: Accuracy of aortic size measurements, certainty in defining the diagnosis and benefits in image quality at the aortic root, underscore the use of the tested high-resolution native 3D SSFP MRA as an appropriate alternative to contrast-enhanced MRA to assess the thoracic aorta.


DOI

doi:10.1093/ehjci/jet263