Motion detection and amelioration in a dedicated cardiac solid-state CZT SPECT device

Area of Science:

• Nuclear Medicine
• Medical Imaging Technology
• Cardiovascular Imaging

Background:

• Solid-state cadmium zinc tellurium (CZT) cameras offer simultaneous acquisition for myocardial SPECT.
• Patient motion during imaging can introduce artifacts, potentially affecting diagnostic accuracy.
• Existing methods for motion artifact detection and correction may not be optimized for CZT camera systems.

Purpose of the Study:

• To develop and validate a method for detecting and ameliorating patient motion artifacts in myocardial perfusion imaging (MPI) using a CZT cardiac camera.
• To assess the impact of motion artifacts on quantitative perfusion metrics.
• To improve the diagnostic accuracy of MPI studies acquired with CZT technology.

Main Methods:

• A myocardial phantom was moved to simulate patient motion, and artifactual perfusion defects were quantified using QPS software.
• List mode data were reframed into 10-second intervals.
• A motion index based on changes in the center of mass across projections was developed.
• Misregistered data were rejected to correct artifacts in phantom and clinical studies.

Main Results:

• Displacements of 1.5 cm or greater caused artifactual perfusion defects (TPD > 5%) in phantom studies.
• The motion detection method successfully identified motion in phantom and clinical scans.
• Artifact-free reconstructions were achieved in phantom scans after motion correction (TPD = 1.0 ± 0.8%).
• Clinical scans showed reduced blur and improved image quality after applying the motion correction method.

Conclusions:

• Motion during MPI with CZT cameras can lead to clinically significant artifacts.
• Reframing data into discrete time intervals allows for effective motion detection and correction.
• This method enhances diagnostic accuracy in myocardial perfusion imaging performed with CZT cameras.