Some sources of artefact in computed tomography

Area of Science:

• Medical Imaging
• Radiology
• Image Reconstruction

Background:

• X-ray computed tomography (CT) is a vital diagnostic tool.
• Image quality in CT is susceptible to various error sources.
• Accurate image reconstruction is essential for reliable diagnosis.

Purpose of the Study:

• To analyze sources of error and artifact in X-ray computed tomography.
• To quantify the impact of these errors on reconstructed images and noise power.
• To highlight the relevance of these errors in specific CT scanner designs.

Main Methods:

• Analysis of temporal and spatial non-uniformities in X-ray tube output and detector sensitivity.
• Calculation of the effect of voltage supply changes, incomplete field of view, and scattered radiation.
• Utilizing computer simulation for object-dependent errors.

Main Results:

• Quantified the impact of non-uniformities and scattered radiation on image quality.
• Estimated the noise power introduced by various error sources.
• Demonstrated the significance of these artifacts in CT scanners with detector arrays.

Conclusions:

• Temporal and spatial non-uniformities significantly affect CT image quality.
• Scattered radiation and incomplete field of view are critical error sources.
• CT scanners using detector arrays require careful consideration of these potential errors.