Aortic valve area assessment: Multidetector CT compared with cine MR imaging and transthoracic and transesophageal echocardiography

Purpose: To prospectively compare the accuracy of multidetector computed tomographic (CT) measurements of the aortic valve area (AVA) with transesophageal echocardiography (TEE) and cine magnetic resonance (MR) measurements of this area for preoperative examination of patients undergoing cardiac surgery, with transthoracic echocardiography (TTE) as the reference standard. Materials and Methods: After giving informed consent for the institutional review board-approved study protocol, 48 patients (33 men, 15 women; mean age, 62 years +/- 13 [standard deviation]) with (n = 27) or without (n = 21) aortic stenosis underwent multidetector CT, cine MR, TTE, and TEE before undergoing cardiac surgery. AVAs derived with manual planimetry by using cine short-axis multidetector CT, MR, and TEE images obtained through the aortic valve were compared among each other and with AVAs measured by using continuity equation TTE at regression and BlandAltman analyses. The diagnostic accuracy of multidetector CT for detection of aortic stenosis was compared with that operating characteristic curves. Results: Mulfidetector CT-derived AVA correlated highly with MR-derived (r 0.98, P < .001), TEE-derived (r = 0.98, P < .001). and TTE-derived (r = 0.96, P < .001) AVA. Multidetector CT planimetry AVAs (mean AVA +/- standard deviation, 2.5 cm(2) +/- 1.7) were not significantly different from MR planimetry (2.4 cm(2) +/- 1.8, P > .99) or TEE planimetery (2.5 cm(2) +/- 1.7, P = .21) AVAs, but they were significantly larger than TTE derived AVAs (2.0 +/- cm(2) +/- 1.5, P < .001). With TTE as the reference standard, multidetector CT correctly (kappa = 0.88, P < .001 depicted all 21 normal, six of eight mildly stenotic (AVA >= 1.2 cm(2) and < 2.0 cm(2)), seven of eight moderately stenotic (AVA >= 0.8 cm(2) and < 1.2 cm(2)), and 10 of 11 severely stenotic (AVA < 0.8 cm(2)) valves. It also correctly depicted all 14 bicuspid valves identified with TEE, eight of which were missed with TTE. Conclusion: Multidetector CT enables accurate noninvasive assessment of the AVA.