Reproducibility of aortic annulus measurements by computed tomography.
OBJECTIVE
To evaluate a systematic approach for measurement of aortic annulus dimensions by cardiac computed tomography.


METHODS
CT data sets of 64 patients were evaluated. An oblique cross-section aligned with the aortic root was created by systematically identifying the caudal insertion points of the three aortic cusps and sequentially aligning them in a double oblique plane. Aortic annulus dimensions, distances of coronary ostia and a suitable fluoroscopic projection angle were independently determined by two observers.


RESULTS
Interobserver intraclass correlation coefficients (ICC) for aortic annulus diameters were excellent (ICC 0.89-0.93). Agreement for prosthesis size selection was excellent (ĸ = 0.86 for mean, ĸ = 0.84 for area-derived and ĸ = 0.91 for circumference-derived diameter). Mean distances of the left/right coronary ostium were 13.4 ± 2.4/14.4 ± 2.8 mm for observer 1 and 13.2 ± 2.7/13.5 ± 3.2 mm for observer 2 (p = 0.30 and p = 0.0001, respectively; ICC 0.76/0.77 for left/right coronary artery). A difference of less than 10° for fluoroscopic projection angle was achieved in 84.3% of patients.


CONCLUSIONS
A systematic approach to generate a double oblique imaging plane exactly aligned with the aortic annulus demonstrates high interobserver and intraobserver agreements for derived measurements which are not influenced by aortic root calcification.


CONCLUSIONS
• Systematic approach to generate a double oblique imaging plane for TAVI evaluation. • This method is straightforward and software independent. • An approach with high reproducibility, not influenced by aortic root calcification.
Department of Cardiology, University of Erlangen, Ulmenweg 18, 91054, Erlangen, Germany, annika.schuhbaeck@uk-erlangen.de.
Annika
A
Schuhbaeck
Stephan
S
Achenbach
Tobias
T
Pflederer
Mohamed
M
Marwan
Jasmin
J
Schmid
Holger
H
Nef
Johannes
J
Rixe
Franziska
F
Hecker
Christian
C
Schneider
Michael
M
Lell
Michael
M
Uder
Martin
M
Arnold
D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery; D002114:Calcinosis / Q000000981:diagnostic imaging*; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D061330:Multidetector Computed Tomography / Q000379:methods*; D012372:ROC Curve; D015203:Reproducibility of Results