Design of a 3D printed coronary artery model for CT optimization. Issue 2 (May 2022)

• Record Type: Journal Article
• Authors: Mørup, S.D.; Stowe, J.; Precht, H.; Gervig, M.H.; Foley, S.
• Is Part Of: Radiography. Volume 28:Issue 2(2022)
• Page Start: 426
• Page End: 432
• Publication Date: 2022-05
• Subjects: Computed tomography -- Phantom -- Three-dimensional printing -- Iterative reconstruction -- Image quality -- Patient safety; Diagnostic imaging -- Periodicals; Radiotherapy -- Periodicals; Cancer -- Radiotherapy -- Periodicals; Diagnostic Imaging -- Periodicals; Neoplasms -- Periodicals; Radiotherapy -- Periodicals; Imagerie pour le diagnostic -- Périodiques; Radiothérapie -- Périodiques; Cancer -- Radiothérapie -- Périodiques; Electronic journals; 616.0757
• DOI: 10.1016/j.radi.2021.09.001
• Languages: English
• ISSNs: 1078-8174

Abstract

Abstract: Introduction: To design a custom phantom of the coronary arteries to optimize CT coronary angiography (CCTA) protocols. Methods: Characteristics of the left and right coronary arteries (mean Hounsfield Unit (HU) values and diameters) were collected from consecutive CCTA examinations (n = 43). Four different materials (two mixtures of glycerine, gelatine and water, pig hearts, Ecoflex™ silicone) were scanned inside a Lungman phantom using the CCTA protocol to find the closest model to in vivo data. A 3D printed model of the coronary artery tree was created using CCTA data by exporting a CT volume rendering into Autodesk Meshmixer™ software. The model was placed in an acid bath for 5 h, then covered in Ecoflex™, which was removed after drying. Both the Ecoflex™ and pig heart were later filled with a mixture of contrast (Visipaque 320 mg I/ml), NaCl and gelatin and scanned with different levels of tube current and iterative reconstruction (ASiR-V). Objective (HU, noise and size (vessel diameter) and subjective analysis were performed on all scans. Results: The gelatine mixtures had HU values of 130 and 129, Ecoflex™ 65 and the pig heart 56. At the different mA/ASiR-V levels the contrast filled Ecoflex™ had a mean HU 318 ± 4, noise 47±7HU and diameter of 4.4 mm. The pig heart had a mean HU of 209 ± 5, noise 38±4HU and a diameter of 4.4 mm. With increasing iterative reconstruction level the visualisation of the pig heart arteries decreased so no measurements could be performed. Conclusion: The use of a 3D printed model of the arteries and casting with the Ecoflex™ silicone is the most suitable solution for a custom-designed phantom. Implications for practice: Custom designed phantoms using 3D printing technology enable cost effective optimisation of CT protocols.