Three-dimensional registration of cardiac positron emission tomography attenuation scans

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Image Processing

Background:

• Accurate attenuation correction is vital for quantitative cardiac Positron Emission Tomography (PET).
• Subject motion between sequential PET scans can degrade image quality and quantification.
• Existing methods for aligning cardiac PET scans acquired at different times can be complex and time-consuming.

Purpose of the Study:

• To develop and validate a novel three-dimensional (3D) registration method for cardiac PET attenuation scans.
• To assess the accuracy and utility of this alignment method for improving cardiac PET imaging.

Main Methods:

• A novel alignment method based on maximizing the cross-correlation coefficient between cardiac PET attenuation scan slices was developed.
• The method was tested by realigning deliberately misaligned attenuation scans.
• The validated method was used to correct fluorodeoxyglucose (FDG) emission scan data.

Main Results:

• The 3D registration method achieved accuracy better than 1 mm in spatial dimensions (x, y, z).
• Rotational accuracy was better than 1.5 degrees in all three angles.
• Reconstructed FDG emission data using realigned attenuation scans showed no significant difference compared to original data.

Conclusions:

• The developed 3D registration method provides accurate and reliable alignment of cardiac PET attenuation scans.
• This technique is valuable for correcting subject motion, especially in longitudinal studies or during multiple interventions.
• The method facilitates improved cardiac PET data analysis and may allow for breaks during long imaging sessions.