Comparison between echocardiographic and non‐ECG‐gated CT measurements in dogs

Abstract

The aim of this study was to compare echocardiographic measurements with non-ECG-gated contrast-enhanced cardiac CT measurements in dogs. Fifty-seven dogs were included in the study. The following echocardiographic parameters were measured: M-mode interventricular septum in diastole and systole, left ventricular internal diameter in diastole and systole, left ventricular free wall in diastole and systole, 2D left atrial maximal diameter, 2D left atrium to aorta ratio in diastole, 2D aortic annulus in systole and 2D pulmonary annulus in diastole and systole. CT measurements were obtained from multiplanar reconstruction images, replicating the imaging planes used for 2D measurements on echocardiography. It was not possible to discriminate between systole and diastole. The results showed moderate Lin's concordance correlation coefficients between the left ventricular internal diameter in systole (0.77), the aortic annuli (0.84) and the pulmonary annuli in diastole (0.78) and systole (0.80). Low coefficients were obtained between the other parameters. Bland-Altman plots for the parameters with highest concordance correlation coefficients were calculated. They suggested equivalence between the measurements of the aortic annuli. Equivalence was not seen between the remaining echocardiographic and CT measurements. Therefore, non-ECG-gated CT is not a reliable way of quantitatively assessing cardiac size.

Non‐electrocardiographic‐gated computed tomographic angiography can be used to diagnose coronary artery anomalies in Bulldogs with pulmonary valve stenosis

“…When acquired in diastole, this results in improved cardiac image quality . However, electrocardiographic‐gating is not widely available in veterinary practice . Imaging the cardiac structures with CT angiography, but without electrocardiographic gating, is often challenging due to motion artifact.…”

“…A recent study found that echocardiographic and non‐electrocardiographic‐gated CT angiography measurements of the aortic valve annulus were moderately correlated and correlated better than all other measured parameters. This was thought to be due to decreased motion of the aorta during systole and diastole, relative to the other cardiac structures . The decreased motion of the aorta may also mean that the coronary ostia that arise from the aorta exhibit decreased motion throughout the cardiac cycle.…”

“…11 However, electrocardiographic-gating is not widely available in veterinary practice. 15 Imaging the cardiac structures with CT angiography, but without electrocardiographic gating, is often challenging due to motion artifact. Although no peer reviewed data exists, a published thesis revealed a significant decrease in the percent motion demonstrated between electrocardiographic-gated and non-gated studies, respectively.…”

“…This was thought to be due to decreased motion of the aorta during systole and diastole, relative to the other cardiac structures. 15 The decreased motion of the aorta may also mean that the coronary ostia that arise from the aorta exhibit decreased motion throughout the cardiac cycle.…”

Electrocardiography‐gated cardiac CT angiography can differentiate brachycephalic dogs with and without pulmonary valve stenosis and findings differ from transthoracic echocardiography

“…The data demonstrate that timing during the cardiac cycle need not be a critical consideration. However, high motion anatomy like the pulmonary valve leaflets can introduce difficulty when measuring landmarks leading to inaccurate measurements if gating is not employed . A lack of ECG‐gating can be overcome with a high‐pitch technique using a dual‐source scanner; however, the scanners with dual‐source technology are commonly cost prohibitive in clinical veterinary medicine .…”