Figure 11.

Printed 3D model versus image measurements of the aortic valve. A, Caliper measurements performed on a 3D printed model of the aortic valve and radiologist measurements performed on source CT angiograms (CTA) demonstrate individual differences in coronary artery heights and aortic annulus diameters between the model and angiograms. B, Graph data show that in 10 patients, mean absolute differences in these measurements were within the range of interobserver variability in CT angiographic measurements. C, Graph data show that the use of mean signed differences led to an overestimation of the accuracy of the 3D printing process, as the positive and negative differences for different patients canceled each other. Error bars indicate the maximal differences across the 10 patients. LM = left main coronary artery, RCA = right coronary artery, R1 = reader 1, R2 = reader 2.