A comparison of two low-cost 3D printing techniques for constructing phantoms from MRI breast images

Background: This study aimed to test the possibility of using Magnetic Resonance (MR) images to create anthropomorphic breast phantoms for X-ray imaging and to compare the performance of fused deposition modeling (FDM) and 2D inkjet printing with radiopaque inks. Materials and Methods: Two physical phantoms were produced using either an inkjet printer on paper or an FDM technique, both based on clinical MR data. The paper phantom was printed with 1.2 g of KI dissolved in 20 ml of water. For the FDM phantom, the extrusion rate was adjusted according to clinical Hounsfield unit (HU) values. These phantoms underwent imaging using a clinical computed tomography (CT) device at two energy spectra, and their CT images were assessed in terms of HUs, histogram distributions, spectral and subjective analyses, as well as cost. Results: The objective CT analysis of the phantoms revealed that HU values and (3-values, indicating the anatomical complexity of the breast parenchyma, were in line with those expected, with an advantage for the FDM-based phantom. In both cases, the (3-values were close to those for clinical breast images acquired with high- resolution CT scanners. Subjective evaluation, however, indicated a need for refining the realism of the phantoms, particularly in terms of preserving the fine details. Conclusion: Breast MR Images offer the possibility of constructing breast phantoms. However, the method fails to replicate fine details in phantom CT images. Addressing this challenge requires improvement in segmentation processes and manufacturing accuracy.