Aortic Valve Area Assessment: Multidetector CT Compared with Cine MR Imaging and Tran

[ken]

http://radiology.rsnajnls.org/cgi/content/abstract/244/3/745

(Radiology 2007;244:745-754.)
© RSNA, 2007
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Cardiac Imaging

Aortic Valve Area Assessment: Multidetector CT Compared with Cine MR Imaging and Transthoracic and Transesophageal Echocardiography

Anne-Catherine Pouleur, MD , Jean-Benoît le Polain de Waroux, MD , Agnès Pasquet, MD , Jean-Louis J. Vanoverschelde, MD, FESC , and Bernhard L. Gerber, MD, FESC

From the Division of Cardiology, Department of Cardiovascular Diseases, Cliniques Universitaires St Luc, Université Catholique de Louvain, Av Hippocrate 10/2806, B-1200 Woluwe St Lambert, Belgium. Received June 29, 2006; revision requested August 31; revision received September 19; accepted October 26; final version accepted December 18. Supported by a grant from the Fondation Nationale de la Recherche Scientifique of the Belgian government (FRSM 3.4557.02). A.C.P. supported by a personal grant from the Fondation Nationale de la Recherche Scientifique of the Belgian government. Address correspondence to B.L.G. (e-mail: [email protected]).

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 Bland-Altman analyses. The diagnostic accuracy of multidetector CT for detection of aortic stenosis was compared with that of TTE by using statistics and receiver operating characteristic curves.

Results: Multidetector 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 cm2 ± 1.7) were not significantly different from MR planimetry (2.4 cm2 ± 1.8, P > .99) or TEE planimetery (2.5 cm2 ± 1.7, P = .21) AVAs, but they were significantly larger than TTE-derived AVAs (2.0 cm2 ± 1.5, P < .001). With TTE as the reference standard, multidetector CT correctly ( = 0.88, P < .001) depicted all 21 normal, six of eight mildly stenotic (AVA 1.2 cm2 and < 2.0 cm2), seven of eight moderately stenotic (AVA 0.8 cm2 and < 1.2 cm2), and 10 of 11 severely stenotic (AVA < 0.8 cm2) 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.

 

[Arlyss]

Important Comparison of Imaging Capabilities

Important Comparison of Imaging Capabilities

This paper is very interesting to me because of the capability of the "64 slice" (multidetector) CT that was demonstrated. In particular, there were 14 BAVs found by Transesophageal echo (TEE) and the 64 slice CT found them all also. A regular echo (TTE) missed 8 of them - over half! No doubt many BAVs have been missed in the past, when relying only on transthoracic echo.

The thing to remember is that there is significant exposure to x-rays from the 64 slice CT, so it is should be used wisely.

Best wishes,
Arlyss

 

[ALCapshaw2]

This paper is very interesting to me because of the capability of the "64 slice" (multidetector) CT that was demonstrated. In particular, there were 14 BAVs found by Transesophageal echo (TEE) and the 64 slice CT found them all also. A regular echo (TTE) missed 8 of them - over half! No doubt many BAVs have been missed in the past, when relying only on transthoracic echo.

The thing to remember is that there is significant exposure to x-rays from the 64 slice CT, so it is should be used wisely.

Best wishes,
Arlyss

Does anyone know How Much Radiation one receives from a 64 slice CT? MARTY - can you help with this one?

Is a 64 slice CT contraindicated for patients who have had Radiation Therapy (3000 Rads or 4000 Rads) for Cancer such as Hodgkins Disease?

'AL Capshaw'

 

[Marty]

64 slice CT radiation " significant"

64 slice CT radiation " significant"

Does anyone know How Much Radiation one receives from a 64 slice CT? MARTY - can you help with this one?

Is a 64 slice CT contraindicated for patients who have had Radiation Therapy (3000 Rads or 4000 Rads) for Cancer such as Hodgkins Disease?

'AL Capshaw'

Conventional wisdom says 64 slice CT roentgen dose is "significant" and potentially harmful particularly in younger adults and pediatric patients. It takes a skilled physicist to count roentgens and there is significant individual variation. Our cardiologists use echo and clinical evaluation once diagnosis of BAV established. There is no recommendation for routine annual CT studies. The only patients we CT at frequent intervals are those with lymphoma, Hodgkins, etc. So,Al, I would say its OK for you to have a 64 slice CT if it would help your doctors beyond what echo and auscultation can do.

 

[PJmomrunner]

When I have asked in the past if the CT being used on me is a 64-slice, I have been told something like, "it can do 64 slices." This leads me to think maybe it can be used in "lesser-slice" modes. If this is so, is it because they are trying to limit radiation exposure? I do have annual scans of my aneurysm. Is it important that x-slice images be taken?

 

[Arlyss]

For follow up of my aorta at regular intervals, my choice would be an MRI, not a CT of any kind. This would avoid ongoing exposure to x-ray, which I understand has cumulative affects in the body and potentially an increased risk of cancer. (Some people may have metal in their body which prevents them from having MRI, and would need a CT to see the entire aorta.)

However in an emergency setting, a CT is the fastest, most practical way to check the aorta - any CT would do, not just 64 slice. The great thing about 64 slice CT in the ER is it can also look for the other two things in the chest associated with pain besides the aorta - pulmonary embolism and coronary artery disease.

64 slice can also be great as a one-time look in a non-emergency setting - which is what was done for my husband prior to his last AVR.

Here is a link I found on Google re 64 slice CT

http://www.medicalimagingmag.com/issues/articles/2005-04_01.asp


Best wishes,
Arlyss