Development of a low-cost imaging performance evaluation phantom for a generic multi-detector CT scanner

Abstract

For quality assurance, an evaluation phantom is an important tool used to assess the imaging performance of a multi-detector CT (MDCT) scanner. In doing so, this would help to prevent the production of low-quality images that may lead to misdiagnosis and repeats of x-ray exposure. However, imaging performance test phantoms available commercially are too costly for resource-limited CT facilities to procure. This study aims to design an imaging performance evaluation phantom, fabricate a low-cost prototype of the design, and assess the suitability of use of the fabricated phantom under existing performance testing protocols. The phantom was designed according to recommended specifications from IAEA and AAPM and the prototype of the design was manufactured using engineering plastics and industrial metals through computer numerical controlled (CNC) machining and stereolithography (SLA) 3D printing. The fabricated phantom prototype was then tested with United Imaging 80-slice MDCT scanner and its usability was compared to Gammex ACR 464 phantom following the ACR QC assessment methods. This research was able to produce a three-module solid plastic phantom with a performance at par with the commercial phantom. Furthermore, the overall manufacturing cost for the fabrication of the phantom was 87% cheaper than the cost of acquiring a commercial phantom. Thus, local development of a quality assurance phantom for CT is a cost-effective solution for resource-limited facilities.