The measurement of opening angle and orifice area of a bileaflet mechanical valve using multidetector computed tomography.
OBJECTIVE
The aim of this study was to assess mechanical valve function using 64-slice multidetector computed tomography (MDCT).


METHODS
In 20 patients (mean age, 50+/-12 years; male-to-female ratio, 10:10), 30 St. Jude bileaflet mechanical valves (15 aortic and 15 mitral valves) were evaluated using MDCT. We selected images vertical and parallel to the mechanical valve. The valve orifice area (OA) and valve length were determined by manual tracing and the opening and closing angles were measured using a protractor. The OA and length of the mechanical valves were compared with the manufacturer's values.


RESULTS
The geometric orifice areas (GOAs) based on the manufacturer's values and the OAs determined by MDCT were 3.4+/-0.2 cm(2) and 3.4+/-0.3 cm(2) for the mitral valves and 2.1+/-0.3 cm(2) and 2.1+/-0.4 cm(2) for the aortic valves, respectively. The correlation coefficients between the OA measures were 0.433 for the mitral valves and 0.874 for the aortic valves (both p<0.001). The lengths based on the manufacturer's values and determined by MDCT were 29.3+/-1.99 mm and 29.6+/-1.65 mm for the mitral valves and 21.5+/-2.1 mm and 20.7+/-2.3 mm for the aortic valves, respectively. The correlation coefficients between the measures were 0.651 for the mitral valve and 0.846 for the aortic valve (both p<0.001). The opening and closing angles determined by MDCT were 10.9+/-0.6 degrees and 131.1+/-3.2 degrees for the mitral valves and 11.1+/-0.9 degrees and 120.6+/-1.7 degrees for the aortic valves, respectively.


CONCLUSIONS
MDCT is an accurate modality with which to assess the function and morphology of bileaflet mechanical valves.
Lee
Dong-Hyeon
DH
Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Youn
Ho-Joong
HJ
Shim
Sung-Bo
SB
Lee
Sun-Hee
SH
Jung
Jung-Im
JI
Jung
Seung-Eun
SE
Choi
Yun-Seok
YS
Park
Chul-Soo
CS
Oh
Yong-Seog
YS
Chung
Wook-Sung
WS
Kim
Jae-Hyung
JH