Accelerated PET water activation acquisition with signal separation methodology

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Neuroscience

Background:

• Positron emission tomography (PET) water activation studies are crucial for understanding brain function.
• Reducing interinjection times in PET studies accelerates data acquisition.
• Shorter intervals (<10 min) lead to contaminating residual signals from previous injections.

Purpose of the Study:

• To develop and evaluate a signal separation methodology for PET water activation studies.
• To enable significantly shorter interinjection times (<10 min) without compromising data quality.
• To mitigate the impact of residual PET signals on quantitative analysis.

Main Methods:

• A signal separation technique was developed to estimate and subtract contaminating residual PET signals.
• The method involves extrapolating the decaying tail of the previous injection's signal.
• A biologically inspired function, based on the one-tissue compartmental model for [(15)O]H2O, was investigated and found to be optimal.

Main Results:

• The proposed signal separation method effectively removed bias caused by shorter interinjection times (<10 min).
• A biologically inspired extrapolation function yielded the best results among tested methods.
• While image variance slightly increased, activation maps remained visually similar to those from conventional longer scan times.

Conclusions:

• The developed method significantly reduces total PET scan time, potentially halving it for multiple injections.
• Realistic simulations demonstrate the method's efficacy, supporting future in vivo validation.
• This approach facilitates accelerated PET water activation studies, improving efficiency in neuroscience research.