Lifelike and Deformable Lung Phantoms for 4DCT Imaging: A Three-Dimensional Printing Approach

Area of Science:

• Medical Imaging
• Biomedical Engineering
• 3D Printing Technology

Background:

• Current respiratory motion phantoms lack realistic lung tissue structures, limiting their use in CT imaging evaluations.
• Advanced CT technologies, including motion artifact reduction and deformable image registration, require more lifelike phantoms for accurate testing.

Purpose of the Study:

• To present PixelPrint^4D, a method for 3D-printing deformable lung phantoms with realistic internal structures.
• To develop patient-specific CT phantoms for evaluating CT imaging technologies.
• To assess the accuracy of the developed phantom in mimicking patient lung motion.

Main Methods:

• Designed a deformable lung phantom using a patient's 4D CT data as a reference.
• Utilized an extended PixelPrint method and thermoplastic polyurethane (TPU) for 3D printing.
• Employed a linear compression device to simulate respiratory motion and scanned the phantom at various compression levels.
• Performed deformable image registration (DIR) to obtain motion vector fields.

Main Results:

• The 3D-printed phantom featured realistic internal lung structures and exhibited a Hounsfield unit range of -840 to -48 HU.
• Simulated respiratory motion using a compression device matched to patient diaphragm displacements.
• SI displacements of lung features in the phantom showed a mean error of 0.5 mm compared to patient data, less than the reconstructed slice thickness.

Conclusions:

• The developed deformable lung phantom accurately replicates realistic lung structures and deformation characteristics.
• This advancement holds significant potential for creating more lifelike respiratory motion phantoms for CT evaluations.
• PixelPrint^4D offers a promising approach for patient-specific CT phantom development and research.