Novel 3D printing technology for CT phantom coronary arteries with high geometrical accuracy for biomedical imaging applications

There is a growing interest in using Computed Tomography (CT) and Hounsfield Unit (HU) measurements in identifying and assessing non-calcified plaque; however, the complex geometry of the coronary arteries poses a challenge in achieving good image quality, which is crucial in providing patients with an accurate diagnosis. Minimizing artifacts associated with cardiac motion is also an important step in improving CT diagnostic accuracy of Coronary Artery Disease. Existing arterial phantoms are commonly straight, short tubular sections that are often rigid, and do not represent the geometry of the entire arterial network, with which image quality and Hounsfield Unit measurements vary and are dependent on. In this study, the process of manufacturing a plaque phantom with physiologically accurate geometry of the coronary arteries is demonstrated. A computer model is obtained by segmenting CTCA images, and several flexible commercially available materials are used to 3D print the model. The static and dynamic mechanical properties of the 3D printing materials are investigated under physiologically relevant loading and the CT numbers of contrast-enhanced tubular samples with 50%, 75%, and 90% concentric stenosis are characterized and compared with ranges for lipid-rich and fibrous plaque. The proposed plaque phantom design offers the possibility of investigating the effect of non-calcified plaque geometry and arterial motion on various parameters in CT optimization studies.