Respiratory average CT for attenuation correction in myocardial perfusion SPECT/CT

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiology

Background:

• Attenuation correction (AC) is crucial for accurate SPECT/CT imaging.
• Respiratory motion introduces artifacts in myocardial perfusion SPECT.
• Cine average CT (CACT) and interpolated average CT (IACT) are advanced AC techniques.

Purpose of the Study:

• To evaluate the effectiveness of CACT and IACT for attenuation correction in myocardial perfusion SPECT/CT.
• To compare CACT and IACT with standard helical CT (HCT) based AC.
• To assess the impact of these methods on quantitative accuracy and radiation dose.

Main Methods:

• Computer simulations using the XCAT phantom with varying respiratory motion amplitudes.
• Physical phantom experiments with a clinical SPECT/CT scanner.
• Generation of IACT by averaging interpolated CT phases.
• Reconstruction of SPECT/CT data with AC using CACT, IACT, and HCT.

Main Results:

• CACT and IACT-AC significantly reduced respiratory artifacts and improved quantitative accuracy compared to HCT-AC.
• SPECT reconstructed with CACT showed the highest similarity to the original phantom data (RDmax <8%).
• SPECT reconstructed with IACT also demonstrated good accuracy (RDmax <10%) and reduced radiation dose.
• HCT-AC resulted in greater deviations (RDmax up to 19.76%) and fluctuating results with increased motion.

Conclusions:

• CACT and IACT-AC are effective in reducing artifacts and enhancing quantitation in myocardial perfusion SPECT/CT.
• IACT offers the additional benefit of reduced radiation exposure.
• These advanced AC methods provide superior diagnostic accuracy over traditional HCT-AC.