Interpolated CT for attenuation correction on respiratory gating cardiac SPECT/CT - A simulation study.

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Cardiovascular Imaging

Background:

• Respiratory motion causes artifacts in cardiac SPECT imaging.
• Accurate attenuation correction (AC) is crucial for quantitative SPECT analysis.
• Four-dimensional (4D) imaging techniques aim to mitigate motion-related artifacts.

Purpose of the Study:

• To develop and evaluate an interpolated CT (ICT) method for improved AC in respiratory-gated cardiac SPECT.
• To assess the effectiveness of ICT in reducing artifacts compared to conventional CT methods using simulations.

Main Methods:

• Simulated 4D XCAT phantom data representing diverse patient populations.
• Generated interpolated CT (ICT) from end-inspiration and end-expiration helical CT (HCT) data.
• Reconstructed SPECT projections using OS-EM with AC from GCT, ICT, and HCTs.

Main Results:

• ICT-based AC demonstrated a significantly lower relative difference (2.14 ± 0.56%) compared to HCTs (up to 7.93%).
• ICT resulted in defect size measurements closest to the reference GCT, with HCT differences exceeding 40%.

Conclusions:

• The interpolated CT (ICT) method achieves performance comparable to gated CT (GCT) for cardiac SPECT AC.
• ICT significantly enhances image quality and quantitative accuracy over conventional HCT.
• ICT offers a potential method to reduce radiation dose associated with GCT.