title: Evaluation of aortic root for definition of prosthesis size by magnetic resonance imaging and cardiac computed tomography: implications for transcatheter aortic valve implantation.
abstract: BACKGROUND
  This study sought to compare cardiac magnetic resonance imaging (CMR) with dual source computed tomography (DSCT) for analysis of aortic root dimensions prior to transcatheter aortic valve implantation (TAVI). In addition, the potential impact of CMR and DSCT measurements on TAVI strategy defined by 2D-transesophageal echocardiography (TEE) was evaluated.
  
  
  METHODS
  Aortic root dimensions were measured using CMR and DSCT in 58 patients referred for evaluation of TAVI. The TAVI strategy (choice of prosthesis size and decision to implant) was based on 2D-TEE annulus measurements.
  
  
  RESULTS
  CMR and DSCT aortic root measurements showed an overall good correlation (r=0.86, p<0.001 for coronal aortic annulus diameters). There was also a good correlation between TEE and CMR as well as between TEE and DSCT for measurement of sagittal aortic annulus diameters (r=0.69, p<0.001). However, annulus diameters assessed by TEE (22.1±2.3mm) were significantly smaller than coronal aortic annulus diameters assessed by CMR (23.4±1.8mm, p<0.001) or DSCT (23.6±1.8, p<0.001). Regarding TAVI strategy, the agreement between TEE and sagittal CMR (kappa=0.89) as well as sagittal DSCT measurements (kappa=0.87) was statistically perfect. However, decision based on coronal CMR- or MSCT measurements would have modified TAVI strategy as compared to a TEE based choice in a significant number of patients (22% to 24%).
  
  
  CONCLUSIONS
  In patients referred for TAVI, CMR measurements of aortic root dimensions show a good correlation with DSCT measurements and thus CMR may be an alternative 3D-imaging modality. Aortic annulus measurements using TEE, CMR and DSCT were close but not identical and the method used has important potential implications on TAVI strategy.
authors.affiliation: Department of Cardiology, University Hospital RWTH Aachen, RWTH University Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany. rkoos@ukaachen.de
authors.forename: Ralf
authors.initials: R
authors.lastname: Koos
authors.forename: Ertunc
authors.initials: E
authors.lastname: Altiok
authors.forename: Andreas Horst
authors.initials: AH
authors.lastname: Mahnken
authors.forename: Mirja
authors.initials: M
authors.lastname: Neizel
authors.forename: Guido
authors.initials: G
authors.lastname: Dohmen
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Marx
authors.forename: Harald
authors.initials: H
authors.lastname: Kühl
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000033:anatomy & histology*; D001024:Aortic Valve Stenosis / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods* / Q000706:statistics & numerical data; D006328:Cardiac Catheterization; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D015588:Observer Variation; D009929:Organ Size; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000150:complications; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000706:statistics & numerical data; D014463:Ultrasonography