[Characterization of motion artifacts in multi-slice spiral CT].

Area of Science:

• Medical Imaging
• Radiology
• CT Technology

Background:

• Motion artifacts in multi-slice spiral CT (MSCT) can significantly impact image quality and interpretation.
• Object motion along the table feed (z-direction) is a common source of artifacts.
• Accurate interpretation of complex anatomy and cardiac imaging requires accounting for motion.

Purpose of the Study:

• To examine motion artifacts in MSCT caused by object movement in the z-direction using a spherical phantom.
• To assess the impact of motion on image quality and the detectability of structures.
• To evaluate the applicability of findings to ECG-gated cardiac imaging and stenosis detection.

Main Methods:

• Utilized a multi-slice spiral CT with a 500 ms rotation time and 4x1.0 mm/2x0.5 mm collimation.
• Employed a spherical phantom with embedded glass beads (1-3 mm) subjected to sinusoidal motion (5 mm amplitude, 60/90 min frequency).
• Investigated table feed compensation for object motion.

Main Results:

• Minor parameter changes led to significant variations in image quality.
• Moving objects (up to 3 mm) could completely vanish or appear hyperintense depending on motion phase.
• The model explained variations in calcium scoring reproducibility and absolute values.

Conclusions:

• Findings must be considered during image interpretation when object motion in the z-direction is present.
• Variations in stenosis degree or calcium score measurements can be attributed to vessel motion during diastole.
• The study provides insights into motion artifact management in CT imaging.