Novel phantom for performance evaluation of contrast-enhanced 3D rotational angiography

Abstract

Purpose: This technical note presents an in-house phantom with a specially designed contrast-object module constructed to address the need for three-dimensional rotational angiography (3DRA) testing.

Methods: The initial part of the study was a brief evaluation on the commercially available phantom used for 3DRA and computed tomography angiography (CTA) to confirm the need for a special phantom for 3D angiography. Once confirmed, an in-house phantom was constructed. The novel phantom was tested to evaluate the basic image performance metrics, i.e., unsharpness (MTF) and noise characterization (NPS), as well as to show its capability for vessel contrast visibility study.

Results: The low contrast objects in the commercially available tools dedicated for CT is found to yield significantly lower signal difference to noise ratio (SDNR) when used for 3DRA, therefore deemed inadequate for 3DRA contrast evaluation. The constructed in-house phantom demonstrates a capability to serve for basic imaging performance check (MTF, NPS, and low contrast evaluation) for 3DRA and CTA. With higher and potentially adjustable visibility of contrast objects as artificial vessels, the in-house phantom also makes more clinically relevant tests, e.g., human- or model observer study and task-based optimization, possible.

Conclusion: The novel phantom with special contrast object module shows higher visibility in 3DRA compared to the currently available commercial phantom and, therefore, is recommended for use in 3D angiography.

Keywords: 3D angiography; Imaging performance; Phantom; Quality control.