Abstract 17355: Multi-Modal Imaging Evaluation of the Aortic Root:ECG-gated and Non-ECG-Gated Computed Tomography versus Echocardiography
The main diagnostic imaging modalities currently used to image the aortic root and ascending aorta include transthoracic echocardiography (TTE) and either ECG-gated or non-ECG-gated computed tomography (CT), each with its respective advantages and disadvantages. This study aimed to examine the reproducibility and agreement of inter-reader measurements of the aortic root made on all three imaging modalities. The results of this study revealed that inter-cardiologist measurements of the aortic root performed on echocardiography lack reproducibility (mean difference of 2.9 ± 5.76 mm). Aortic root measurements made on ECG-gated CT studies more closely agree with measurements made on echocardiography than do those made on non-ECG-gated CT studies (mean differences of 0.4 ± 3.93 mm versus 0.9 ± 5.92 mm in the axial dimension and -0.2 ± 3.82 mm versus 1.1 ± 5.46 mm in the orthogonal dimension). When a single radiologist reviews a set of both ECG-gated and non-ECG-gated CTs, the mean difference of axial aortic root measurements is small (-0.6 ± 1.99 mm). However, when aortic root measurements are made by two different radiologists, there is a much greater increase in mean difference for non-ECG-gated CT studies (-2.4 ± 6.32 mm) as compared with ECG-gated CT studies (0.3 ± 3.06 mm), suggesting that ECG-gating, which produces higher resolution images, buffers the amount of bias and variation that are introduced by inter-radiologist differences in measurement methods. Finally, review of radiologists’ cardiac CT reports revealed poor standards and high non-uniformity in providing referring clinicians with relevant aortic measurements that have an important impact on patient care. A number of concluding recommendations are made and discussed to increase the value added by an institution’s cardiac radiology service.
- © 2012 by American Heart Association, Inc.