Author + information
- Christoph Rodewald,
- Jochen Spieß,
- Horst Brunner,
- Andreas Kuemmel,
- Thomas Walcher,
- Jochen Woehrle,
- Wolfgang Rottbauer and
- Peter Bernhardt
For successful transcatheter aortic valve replacement (TAVR) correct sizing of the aortic annulus and root in aortic valve stenosis is crucial. With multislice computed tomography (MSCT) 3D volume data sets of the aorta could be acquired in high spatial resolution, but the comorbid patients are exposed to nephrotoxic contrast agents leading to kidney injury in many cases. The purpose of this study was to establish a useful method for aortic root sizing without the use of contrast media. With MSCT serving as a the reference standard, we compared measurements of a non-contrast 3D steady-state free-precession (SSFP) magnetic resonance (MRI) and a contrast-enhanced magnetic resonance angiography
We examined 42 patients previous to TAVR with MSCT with a 256-MSCT and a 1.5 Tesla whole-body MRI scanner, respectively. MRI examination included a 3D SSFP sequence covering the entire ascending aorta and contrast-enhanced MRA. The 3D images were reconstructed for correct orthogonal view of the aortic annulus. Minimal and maximal aortic root diameters of all three imaging modalities were analyzed by two blinded and readers in consensus. Decision for valve size was based on the median of these diameters.
Minimal aortic annulus diameter as measured by MSCT was 24.6 ± 3.4 mm; maximal diameter was 24.4 ± 3.5 mm. MRA yielded a minimal and maximal diameter of 25.0 ± 4.3 mm and 26. ± 3.4, respectively. Each diameter showed good correlation to MSCT (r=0.66, p<0.0001 and r=0.39, p=0.02). Annulus diameters on SSFP images were 24.6 ± 3.5 mm and 24.5 ± 3.5 mm with good correlation to MSCTdiameters (r=0.95, p<0.0001 for minimal and r= 0.83, p<0.0001 for maximal diameter). Decision for valve size showed good correlation between MSCT and MRA (?=0.57, p=0.0002), and better correlation between MSCT and SSFP (?=0.81, p<0.0001).
In conclusion, both MRI techniques, MRA and SSFP show good correlation to MSCT in the assessment of the aortic root and valve sizing. However, the SSFP MRI showed better correlation to MSCT resulting in better concordance of valve sizing. SSFP MRI might be a reasonable alternative for aortic root sizing before TAVR without the use of nephrotoxic contrast agents.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Imaging: MRI IV CMR in Valve Disease and Imaging Intracardiac and Vascular Flows
Abstract Category: 19. Imaging: MRI
Presentation Number: 1224-317
- 2013 American College of Cardiology Foundation