Measurement of iodine-123 thyroid uptake using a gamma camera with LEAP collimator

Area of Science:

• Nuclear medicine
• Radiopharmacology
• Medical imaging

Background:

• Thyroid uptake measurements are crucial for diagnosing and managing thyroid disorders.
• Traditional methods using uptake probes have limitations in spatial resolution and quantification.
• Gamma cameras offer improved imaging capabilities but require appropriate collimator selection for thyroid uptake studies.

Purpose of the Study:

• To compare Iodine-123 (123I) thyroid uptake measurements obtained with a gamma camera using a low-energy all-purpose (LEAP) collimator against those from a standard thyroid uptake probe.
• To evaluate the performance of a gamma camera with a LEAP collimator versus a pinhole (PH) collimator for 123I thyroid uptake assessment.

Main Methods:

• Thirty-one patients underwent 123I thyroid uptake measurements using both a probe and a gamma camera with LEAP collimators.
• Twenty-five patients were assessed using gamma cameras with LEAP and PH collimators.
• 123I uptake was measured at 5 and 24 hours post-administration of oral 123I capsules.

Main Results:

• Excellent correlation (0.912-0.988) was observed between gamma camera (LEAP) and probe measurements.
• The probe system showed slightly higher uptake ratios compared to the gamma camera with LEAP collimator.
• High correlation coefficients (0.979 at 5h, 0.931 at 24h) were found when comparing LEAP and PH collimator data.

Conclusions:

• Gamma camera-based 123I thyroid uptake measurements using a LEAP collimator are accurate and consistent.
• Proper selection and application of regions of interest (ROIs) are essential for reliable quantification.
• LEAP collimators provide a viable alternative for accurate thyroid uptake assessment with gamma cameras.