Figure 2: A 39-year-old woman who presented for assessment of function after undergoing SJM mitral valve replacement (valve size, 29 mm) for infective endocarditis. In the mitral valve, the GOA determined by MDCT was 3.35 cm2 and the manufacturer's value was 3.5 cm2. The valve length determined by MDCT was 28.6 mm and the manufacturer's value was 29 mm. The opening angle determined by MDCT was 11.2° and the manufacturer's value was 10°, and the closing angle determined by MDCT was 132.1° and the manufacturer's value was 130°. A: a vertical reformatted image of the valve shows the SJM mitral valve (#29) with symmetric opening of mechanical components. The valve is intact, based on measurement of the GOA and the length. B: a parallel reformatted image of valve shows the SJM mitral valve (#29). The valve is intact based on measurement of the opening and closing (not shown) angles. SJM: St. Jude Medical, GOA: geometric orifice area, MDCT: multidetector computed tomography.

Mentions: The images were analyzed using an Image-Pro Plus Image analyzer (Media Cybernetics, Bethesda, MD, USA) and the values determined for the geometric orifice area (GOA) and valve length by 64-slice MDCT were compared with the manufacturer's values. The open and closing angles were measured with a protractor. The manufacturer's values were approximately 10° for the open angle and 120-130° for the closing angle (Fig. 1). Figs. 2 and 3 give examples of the morphologic and functional assessment by MDCT after undergoing valve replacement.

Lee DH, Youn HJ, Shim SB, Lee SH, Jung JI, Jung SE, Choi YS, Park CS, Oh YS, Chung WS, Kim JH - Korean Circ J (2009)

Bottom Line: The OA and length of the mechanical valves were compared with the manufacturer's values.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 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.MDCT is an accurate modality with which to assess the function and morphology of bileaflet mechanical valves.

Affiliation: Division of Cardiology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.

Abstract: The aim of this study was to assess mechanical valve function using 64-slice multidetector computed tomography (MDCT).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.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.MDCT is an accurate modality with which to assess the function and morphology of bileaflet mechanical valves.