Quantitative simultaneous In-111/Tc-99m planar imaging in a long-bone infection phantom

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiochemistry

Background:

• Osteomyelitis diagnosis often relies on dual-radionuclide imaging with Indium-111 white blood cells (In-111 WBC) and Technetium-99m sulfur colloid (Tc-99m SC).
• Accurate spatial registration and quantitative analysis are crucial for reliable interpretation of these scans.

Purpose of the Study:

• To develop and validate a quantitative planar imaging method for simultaneous In-111 and Tc-99m acquisition in accurate spatial registration.
• To assess the efficacy of Triple-Energy-Window (TEW) scatter correction and geometric mean attenuation compensation in improving quantitative accuracy.

Main Methods:

• Simultaneous acquisition of In-111 and Tc-99m scans using a novel quantitative planar imaging method.
• Optimization of TEW parameters for scatter and radionuclide crosstalk correction using synthesized energy spectra.
• Evaluation of In-111/Tc-99m count ratios in phantom studies with and without TEW correction and attenuation compensation.

Main Results:

• The quantitative method significantly improved the average bias of In-111/Tc-99m ratios from 17.2% to 5.3% with comparable precision.
• TEW corrections, even with non-optimized windows, reduced bias to 6.4%.
• Quantitation demonstrated potential for improved diagnostic accuracy over subjective visual assessment.

Conclusions:

• Quantitative analysis of In-111/Tc-99m ratios in dual-radionuclide imaging offers improved diagnostic accuracy for suspected osteomyelitis.
• This method may enable objective grading of osteomyelitis severity.
• The developed technique provides a more precise and reliable assessment compared to traditional visual interpretation.