AJR:193, November 2009
Troy M. LaBounty, Prachi P. Agarwal, Aamer Chughtai, David S. Bach, Eric Wizauer, Ella A. Kazerooni
OBJECTIVE. The purpose of our study was to determine whether CT can accurately evaluate mechanical heart valve size and function.
MATERIALS AND METHODS. Sixty-two patients with mechanical valves (37 single-disc, 27 bileaflet; 59 aortic, 5 mitral) were evaluated with ECG-gated 64-MDCT and transthoracic echocardiography; a subset of 10 patients underwent cinefluoroscopy. Two readers independently interpreted each study.
RESULTS. The mean age of the patients was 46.4 ± 14.4 years; 50 were men and 12 were women. There was excellent correlation, and differences between CT readers were absent to small in measuring the opening angle (r = 0.96, p < 0.001; 76.7 ± 9.0¡ vs 76.8 ± 9.6¡, p = 0.73), annulus diameter (r = 0.96, p < 0.001; 25.9 ± 3.3 vs 25.9 ± 3.2 mm, p = 0.62), and geometric orifice area (r = 0.98, p < 0.001; 3.8 ± 0.9 vs 3.6 ± 0.8 cm2, p < 0.001). There was strong correlation without difference in opening angle between CT and cinefluoroscopy (r = 0.77, p < 0.001; 79.2¡ + 9.8¡ vs 77.2¡ ± 15.5¡, p = 0.45^. Compared with manufacturer specifications, CT reported opening angles that were smaller for single-disc valves (n = 36, 67.4¡ ± 5.7¡ vs 75f,p < 0.001) and similar for bileaflet valves (n = 42 for 21 valves, 83.8¡ + 3.9¡ vs 85¡, p = 0.05), valves, with small underestimation with CT versus specifications in annulus diameter (n = 41; r = 0.75, p < 0.001; 26.4 ± 3.0 vs 27.5 ± 3.3 mm, p = 0.003), and geometric orifice area (n = 35; r = 0.90,p < 0.001; 3.7 ±0.7 vs 3.8 ±0.8 cm2,/? = 0.04). Each disc closed fully on CT; none had more than mild regurgitation on echocardiography.
CONCLUSION. CT can measure the size and function of mechanical valves with high interobserver agreement and results similar to speci_fications. The opening angle with CT strongly correlates with cinefluoroscopy. CT is promising for the assessment of mechanical valves.