Calibration of a cadmium IVNAA system

Area of Science:

• Medical Physics
• Nuclear Medicine
• Toxicology

Background:

• Cadmium accumulation in human organs like the liver and kidney is a significant health concern.
• Accurate measurement of cadmium levels is crucial for assessing exposure and potential health risks.
• In vivo neutron activation analysis (IVNAA) offers a non-invasive method for quantifying elemental concentrations in organs.

Purpose of the Study:

• To calibrate an in vivo neutron activation analysis (IVNAA) system for measuring cadmium (Cd) in the human liver and kidney.
• To assess the impact of organ position and inter-organ interference on cadmium detection accuracy.
• To compare the performance of the developed IVNAA system against other existing methods.

Main Methods:

• Calibration of the IVNAA system using cadmium-doped liver and kidney phantoms immersed in a water tank.
• Assessment of the influence of organ depth and cross-organ interference on detected cadmium gamma rays.
• Performance evaluation using a composite index considering equipment specifications and radiation dose.

Main Results:

• The system achieved lower detection limits of 12 mg for kidney cadmium and 7 ppm for liver cadmium.
• Organ depth was identified as a critical factor significantly affecting measurement accuracy.
• The IVNAA system ranked second best for liver cadmium measurements and second worst for kidney measurements when compared to five other systems.

Conclusions:

• The developed IVNAA system provides a viable method for non-invasive cadmium measurement in the liver and kidney.
• Accurate calibration and consideration of organ depth are essential for reliable IVNAA results.
• Differences in calibration geometry can explain performance variations between different IVNAA systems.