Open-source, customizable phantom for low-field magnetic resonance imaging.

Abstract

Objective: This study aimed to describe important criteria for phantom design, while designing an open-source phantom that uses accessible materials and fabrication processes, and that can be easily reproduced and modified by others in the MRI research community.

Materials and methods: We enumerate considerations related to designing a phantom based on literature and previous experience. We design and use an open-source phantom on a low-field MRI system. The phantom was 3D printed and assembled, and the imaged samples were made from commonly available materials. T1-weighted and T2-weighted axial and coronal images were acquired at 64 mT, and signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and geometric distortion along one dimension were assessed for each image.

Results: Two iterations of the phantom design were made to improve the construction materials and overall form factor for imaging. T1-weighted and T2-weighted images showed contrast between samples and background. T2-weighted images had an 8-10× increase in SNR and CNR compared to T1-weighted images. Geometric distortion measurements were within one-pixel spacing for all scans.

Discussion: An open-source phantom was created to assess MRI scans at low-field. Future users may modify the phantom to suit their needs. User-designed inserts can be added, allowing for validation of many MRI-related measurements.