Radiopaque Three-dimensional Printing: A Method to Create Realistic CT Phantoms

Area of Science:

• Medical Imaging
• Radiology Physics
• Biomedical Engineering

Background:

• Accurate anthropomorphic phantoms are crucial for radiation therapy and diagnostic imaging quality assurance.
• Current phantom creation methods may lack patient-specific anatomical detail or precise radiation attenuation properties.

Purpose of the Study:

• To develop and validate a high-precision method for creating patient-specific 3D anthropomorphic phantoms.
• To ensure accurate reproduction of both anatomical structures and radiation attenuation characteristics.

Main Methods:

• Utilizing inkjet printing with potassium iodide solutions (600 mg/mL) on plain paper to create 1 cm thick 3D phantoms from CT scans.
• Developing a gray-scale correction procedure to align printed Hounsfield units (HU) with actual patient CT values.
• Validating the method by comparing phantom HU with patient CT HU using correlation and regression analyses.

Main Results:

• The method successfully created patient-specific phantoms with detailed anatomy.
• An exponential correlation between gray scale and iodine deposition was identified and corrected.
• Post-correction, highly linear correlations (r=0.9946 and r=0.9925) were achieved between phantom and patient Hounsfield units.

Conclusions:

• The developed inkjet printing method enables the creation of realistic, customizable, patient-specific phantoms.
• This technique significantly improves the accuracy of anatomical details and radiation attenuation properties in phantoms.
• The validated method holds promise for advancing diagnostic and therapeutic radiology applications.