Quantitative imaging of iodine-124 with PET

Area of Science:

• Nuclear medicine
• Medical imaging
• Radiochemistry

Background:

• Positron emission tomography (PET) is valuable for in vivo quantitation of radiolabeled antibodies.
• Short half-lives of common positron emitters limit long-term quantitative studies.
• Iodine-124 (124I) offers a longer half-life (4.2 days) suitable for PET imaging.

Purpose of the Study:

• To evaluate the feasibility of quantitative PET imaging using Iodine-124 (124I).
• To assess the performance of 124I on various PET scanner configurations.

Main Methods:

• Utilized whole-body and head-optimized PET scanners with diverse detectors and correction schemes.
• Employed phantom studies to measure resolution, quantitative linearity, and sphere detectability.
• Investigated imaging under realistic conditions with varying background activities.

Main Results:

• Resolution and quantitation showed only slight degradation compared to conventional PET nuclides.
• Sphere detectability was minimally impacted when imaging time was extended to account for lower positron abundance.
• Satisfactory imaging and quantitative performance were demonstrated across different PET scanners.

Conclusions:

• Quantitative imaging with 124I is feasible under realistic conditions using various PET scanners.
• 124I is a viable option for long-term in vivo quantitation in PET studies.
• The complex decay of 124I does not preclude its effective use in PET.