A CZT-based blood counter for quantitative molecular imaging.

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Instrumentation

Background:

• Quantitative analysis in PET and SPECT requires blood activity time-activity curves for pharmacokinetic modeling.
• Accurate input functions are crucial for reliable tracer uptake analysis.
• Existing methods may lack the automation or portability needed for clinical settings.

Purpose of the Study:

• To develop and evaluate a novel, compact, automated gamma blood counter for real-time blood activity measurement.
• To assess the device's performance for use in Positron Emission Tomography (PET) and Single-Photon Emission Computed Tomography (SPECT) quantitative imaging.

Main Methods:

• The device utilizes a peristaltic pump for continuous blood withdrawal and a cadmium zinc telluride (CZT) detector for gamma detection.
• Custom electronics and FPGA-based signal processing enable automated data acquisition.
• A user-friendly graphical user interface (GUI) facilitates parameter selection and operation.

Main Results:

• The gamma counter achieved a sensitivity of 7.1 cps/(kBq/mL) and a minimum detectable activity of 2.5 kBq/mL for 18F.
• Excellent stability was demonstrated with count rate deviations <0.05% over 6 hours.
• An energy resolution of 8% at 662 keV was achieved.

Conclusions:

• The developed compact gamma blood counter meets the sensitivity and stability requirements for quantitative molecular imaging.
• The device is suitable for integration into PET and SPECT workflows, enhancing pharmacokinetic analysis.
• Patient studies confirmed the device's efficacy in supporting quantitative imaging.