Reproducibility of CT Measurements of Aortic Valve Calcification, Mitral Annulus Calcification, and Aortic Wall Calcification in the Multi-Ethnic Study of Atherosclerosis

University of Washington Seattle, Seattle, Washington, United States
Academic Radiology (Impact Factor: 1.75). 03/2006; 13(2):166-72. DOI: 10.1016/j.acra.2005.09.090
Source: PubMed


Extracoronary calcifications may have clinical significance. The error in extracoronary calcification measurements is still unknown. Accurate quantification of calcifications of the aortic valve (AVC), mitral annulus (MAC), and aortic wall (AWC) may be possible by using cardiac computed tomography (CT). We sought to establish the interscan, interobserver, and intraobserver reproducibility of these measures in all cardiac CT scans in the Multi-Ethnic Study of Atherosclerosis.
We measured extracoronary calcifications in 100 randomly selected participants to assess interobserver, interscan, and intraobserver variability. Two scans were available for analysis in 99 of these participants, and we quantified thoracic aorta and valvular calcifications.
Mean interscan variability of AVC was 9.7% +/- 11.4% and 8% +/- 10.3% for Agatston and volume scores, with variability of the median at 6.4% and 5.5%, respectively (P > .05). MAC inter-reader variability was 8.2% and 8.9%, with interscan variability of 28% and 33% and intrareader variability of 4% and 4.1%, respectively. For AWC, inter-reader variability was 3%-7.1%, interscan variability was 17%-18%, and intrareader variability was 0.4%-1.4%.
AVC, MAC, and AWC measurements are sufficiently reproducible to allow serial investigations over a time suitable for clinical studies.

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    • "This presumption and the feasibility of our scale were shown valid in the present study, and the five steps turned out to be intuitive and easy to apply for echocardiographers and surgeons. Our reproducibility with ultrasound scoring was very good and comparable to studies using computed tomography and the Agatston score to assess AVC (Koos et al., 2004; Messika-Zeitoun et al., 2004; Budoff et al., 2006). Although the prevalence of bicuspid aortic valves in the general population is only 1–2%, bicuspid valves are much more common, around 20–50%, in patients subjected to aortic valve surgery (Turina et al., 1986; Bauer et al., 2007; Jackson et al., 2011). "
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    ABSTRACT: Aortic valve calcification (AVC), even without haemodynamic significance, may be prognostically import as an expression of generalized atherosclerosis, but techniques for echocardiographic assessment are essentially unexplored. Two-dimensional (2D) echocardiographic recordings (Philips IE33) of the aortic valve in short-axis and long-axis views were performed in 185 consecutive patients within 1 week before surgery for aortic stenosis (n = 109, AS), aortic regurgitation (n = 61, AR), their combination (n = 8) or dilation of the ascending aorta (n = 7). The grey scale mean (GSMn) of the aortic valve in an end-diastolic short-axis still frame was measured. The same frame was scored visually 1-5 as indicating that the aortic valve was normal, thick, or had mild, moderate or severe calcification. The visual echodensity of each leaflet was determined real time applying the same 5-grade scoring system for each leaflet, and the average for the whole valve was calculated. Finally, a similar calcification score for the whole valve based on inspection and palpation by the surgeon was noted. Visual assessment of real-time images using the proposed scoring system showed better correlation with the surgical evaluation of the degree of valve calcification (r = 0·83, P<0·001) compared to evaluation of stop frames by visual assessment (r = 0·66, P<0·001) or the GSMn score (r = 0·64, P<0·001). High inter- and intra-observer correlations were observed for real-time visual score (both intraclass correlation coefficient = 0·93). Real-time evaluation of the level of AVC is superior to using stop frames assessed either visually or by dedicated computer grey scale measurement software.
    Clinical Physiology and Functional Imaging 11/2012; 32(6):470-5. DOI:10.1111/j.1475-097X.2012.01153.x · 1.44 Impact Factor
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    • "All multidetector CT scans were reviewed on an external workstation (Wizard Medical Solutions, Mount Waverley, Australia) by a radiologist with expertise in chest CT. Mitral valve calcifications were subjectively characterized by the following criteria: presence, location (annulus or leaflet), Agatston score, and length in millimeters.13,14 For measuring the length of calcification, multiplanar reconstruction was used to obtain the longest diameter, and if calcification was extending from the annulus to the leaflet, we measured them together as one unit. "
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    ABSTRACT: Mitral valve calcification is often incidentally detected on chest computed tomography (CT) scans obtained for a variety of noncardiac indications. In this study, we evaluated the association between mitral valve calcification incidentally detected on chest CT and the presence and severity of mitral valve disease on echocardiography. Of 760 patients undergoing 64-row multidetector CT of the chest, 50 with mitral valve calcification and 100 controls were referred on for echocardiography. Calcifications of the mitral valve leaflet and annulus were assessed for length, Agatston score, and site, and were compared with echocardiographic findings. Mitral valve calcification was noted in 59 (7.7%) patients on multidetector CT. Fifty of these patients were assessed by echocardiography, and 32 (64%) were found to have mitral annular calcification. Nine patients (18%) had posterior mitral valve leaflet calcification, and both mitral valve leaflet and annular calcification were detected in nine (18%) cases. Nine (18%) patients had mild, three (6%) had moderate, and one (2%) had severe mitral stenosis. None of the patients with isolated mitral annular calcification had mitral stenosis; however, all the patients with mitral stenosis showed mitral valve leaflet calcification with or without mitral annular calcification (P < 0.001). Moreover, patients with mitral stenosis had a larger mitral calcification length and greater Agatston scores in comparison with those without mitral stenosis (P = 0.001). While 31 patients (62%) with mitral calcification had mitral regurgitation on echocardiography, 21 (21%) in the control group showed mitral regurgitation (P = 0.001). Mitral valve leaflet calcification, with or without annular calcification, may be an indicator of mitral stenosis. Mitral calcification can also be considered as an indicator for mitral regurgitation in general. Therefore, patients with mitral valve calcification detected incidentally on chest CT scan may benefit from functional assessment of the valve using echocardiography.
    International Journal of General Medicine 10/2012; 5:839-43. DOI:10.2147/IJGM.S33665
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    ABSTRACT: Valvular heart disease (VHD) affects 2.5% of US adults and predominantly involves the left-sided cardiac structures. Regurgitant lesions are more common than stenoses, and mitral regurgitation (MR) is the most prevalent abnormality [1]. Doppler echocardiography is the initial imaging modality of choice, allowing for a complete diagnosis in the majority of patients [2]. In cases of poor acoustic window and/or disparate results regarding disease severity, additional tests may be required. Cardiac catheterization is a time-honored modality, but limited by its invasive nature. Magnetic resonance imaging (MRI) has become an excellent noninvasive alternative for both valvular insufficiency and stenosis [3]. Due to the need for radiation and contrast, computed tomography (CT) has a limited role for the evaluation of VHD as the primary indication. It may occasionally be employed as such when echocardiographic results are inconclusive and the patient is not a good candidate for MRI. However, CT is increasingly used for noninvasive coronary angiography, and useful information on valve anatomy and function can simultaneously be obtained from a coronary examination. Also, in patients with primary valve diseases, ruling out obstructive coronary artery disease is deemed a highly appropriate indication and may allow patients to forgo invasive coronary angiography.
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