New in-vivo calibration phantoms and their performance

Area of Science:

• Medical Physics
• Radiological Imaging
• Biomedical Engineering

Background:

• Development of accurate in-vivo calibration phantoms is crucial for standardizing nuclear medicine and medical imaging procedures.
• Existing calibration phantoms may not adequately represent diverse anthropometric characteristics, particularly for specific populations like the Japanese.
• The need for adaptable phantoms that can be used in various positions and geometries is recognized.

Purpose of the Study:

• To develop and evaluate novel in-vivo anthropometric phantoms tailored to Japanese body size data.
• To assess the performance of these new phantoms regarding body size accuracy, activity distribution, and counting efficiency.
• To compare the anthropometric phantoms with traditional block phantoms for calibration applications.

Main Methods:

• Anthropometric phantoms were designed using Japanese population body size survey data.
• Phantom dimensions were compared against survey data for accuracy assessment.
• Performance was evaluated by measuring activity distribution along the phantom axis.
• Counting efficiency was measured and compared between anthropometric and block phantoms.

Main Results:

• The adult anthropometric phantom demonstrated good agreement with Japanese survey data for most dimensions (31 of 47 items).
• Gaps in phantom joints did not significantly impact the overall accuracy of measurements.
• Counting efficiency differences between anthropometric and block phantoms were within 6% for comparable age groups.

Conclusions:

• The developed Japanese anthropometric phantoms are suitable for in-vivo calibration, offering improved anthropometric accuracy.
• These phantoms provide a reliable alternative to block phantoms, with minimal impact on measurement accuracy despite joint gaps.
• The adaptability and accuracy of these phantoms support their use in standardizing radiological measurements for the Japanese population.