PixelPrint: a collection of three-dimensional printed CT phantoms of different respiratory diseases

Abstract

Imaging is often a first-line method for diagnostics and treatment. Radiological workflows increasingly mine medical images for quantifiable features. Variability in device/vendor, acquisition protocol, data processing, etc., can dramatically affect quantitative measures, including radiomics. We recently developed a method (PixelPrint) for 3D-printing lifelike computed tomography (CT) lung phantoms, paving the way for future diagnostic imaging standardization. PixelPrint generates phantoms with accurate attenuation profiles and textures by directly translating clinical images into printer instructions that control density on a voxel-by-voxel basis. The present study introduces a library of 3D printed lung phantoms covering a wide range of lung diseases, including usual interstitial pneumonia with advanced fibrosis, chronic hypersensitivity pneumonitis, secondary tuberculosis, cystic fibrosis, Kaposi sarcoma, and pulmonary edema. CT images of the patient-based phantom are qualitatively comparable to original CT images, both in texture, resolution and contrast levels allowing for clear visualization of even subtle imaging abnormalities. The variety of cases chosen for printing include both benign and malignant pathology causing a variety of alveolar and advanced interstitial abnormalities, both clearly visualized on the phantoms. A comparison of regions of interest revealed differences in attenuation below 6 HU. Identical features on the patient and the phantom have a high degree of geometrical correlation, with differences smaller than the intrinsic spatial resolution of the scans. Using PixelPrint, it is possible to generate CT phantoms that accurately represent different pulmonary diseases and their characteristic imaging features.

PixelPrint: generating patient-specific phantoms for spectral CT using dual filament 3D printing

“…Recently, we introduced a technique known as PixelPrint [1][2][3] , which demonstrates the capacity to fabricate patientspecific lung phantoms. These phantoms exhibit precise attenuation profiles and textural characteristics.…”

PixelPrint4D: A 3D printing method of fabricating patient-specific deformable CT phantoms for respiratory motion applications

“…The four dimensions refer to the three spatial dimensions plus one dimension of time. By leveraging components of the previously introduced PixelPrint method, which enables creating rigid lifelike patient-based phantoms [34][35][36][37][38][39][40][41] , PixelPrint 4D now fabricates deformable phantoms. PixelPrint converts the attenuation values, measured in Hounsfield Units (HU) from each voxel of patient CT imaging data into fused deposition modeling (FDM) 3D printer instructions called g-code.…”