Development of a minipig physical phantom from CT data.

Area of Science:

• Medical physics
• Radiological research
• Animal modeling

Background:

• Accurate quantification of radiation-induced injury is crucial for developing effective treatments.
• Minipigs are valuable animal models due to their anatomical and pathological similarities to humans.
• A validated physical phantom is essential for precise radiological and medical studies.

Purpose of the Study:

• To develop a minipig physical phantom using computed tomography (CT) data for radiation dosimetry.
• To assess the suitability of tissue-equivalent (TE) substitutes for constructing the phantom.
• To ensure the phantom accurately represents human tissues for radiation studies.

Main Methods:

• A minipig physical phantom was constructed slice-by-slice from CT data.
• The phantom incorporated holes for dosimeter placement for accurate dosimetry.
• Tissue-equivalent materials for bone, lung, and soft tissue were analyzed for atomic composition and Hounsfield units (HUs).

Main Results:

• The phantom was constructed with distinct bone, lung, and soft tissue components on 20-mm-thick axial slices.
• Tissue-equivalent substitutes exhibited densities of 1.4, 0.5, and 1.0 g/cm³ for bone, lung, and soft tissue, respectively.
• Effective atomic numbers for TE substitutes were 7.9 (bone), 10.0 (lung), and 5.9 (soft tissue), with HU values within the range of real tissues.

Conclusions:

• The developed minipig physical phantom is acceptable for radiation dosimetry applications.
• The phantom's tissue-equivalent materials, despite slight property variations, provide a reliable representation of human tissues.
• This phantom serves as a valuable tool for studying radiation-induced injuries in a human-relevant animal model.