A detector response function design in pinhole SPECT including geometrical calibration

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biomedical Engineering

Background:

• Clinical single photon emission computed tomography (SPECT) with pinhole collimators offers high spatial resolution for small animal imaging.
• Monte Carlo simulations integrated into iterative reconstruction enhance image quality (SNR, contrast, resolution).
• Pinhole SPECT systems are highly susceptible to geometric misalignments during collimator changes.

Purpose of the Study:

• To develop a flexible detector response function table (DRFT) to account for geometric misalignments in SPECT.
• To avoid repetitive Monte Carlo simulations for each study's system matrix calculation.
• To accelerate the computation of the system matrix for SPECT imaging.

Main Methods:

• A novel flexible detector response function table (DRFT) design was developed.
• The DRFT was integrated to calculate the system matrix, incorporating geometric misalignments.
• The computational time for system matrix calculation was evaluated.

Main Results:

• The DRFT effectively accounts for geometric misalignments in pinhole SPECT.
• System matrix computation time was reduced by two orders of magnitude.
• The method proved acceptable for both preclinical and clinical SPECT applications.

Conclusions:

• The flexible DRFT design is a significant advancement for SPECT imaging.
• This approach enhances efficiency and accuracy in SPECT image reconstruction.
• The DRFT facilitates wider adoption of high-resolution SPECT in research and clinical settings.