Performance evaluation of computed tomography systems: Summary of AAPM Task Group 233.

Area of Science:

• Medical Imaging Physics
• Radiological Sciences
• Diagnostic Imaging Technology

Background:

• Rapid advancements in X-ray computed tomography (CT) technology necessitate updated performance evaluation methods.
• Optimizing image quality while managing radiation and contrast media dose is crucial for evidence-based practice.

Purpose of the Study:

• To provide updated guidelines for CT system testing, emphasizing operational performance.
• To incorporate advanced techniques such as iterative reconstruction and automatic exposure control (AEC).

Main Methods:

• Comprehensive literature review of best practices in CT performance evaluation.
• Assessment of CT noise (magnitude, texture, uniformity), resolution (task transfer function), task-based performance (detectability, estimability), and AEC performance.
• Utilized standardized testing protocols, phantoms, and metrology for quantitative comparisons and benchmarking.

Main Results:

• Developed robust methods reflecting operational CT system performance in clinical settings.
• Methods provide quantitative metrics for noise, resolution, and AEC, facilitating benchmarking.
• Recommendations for phantoms and image analysis are included.

Conclusions:

• Quantitative, operationally focused CT performance evaluation is more predictive of clinical outcomes than specification-based methods.
• These methods support both acceptance testing and system commissioning for optimal clinical use.
• The proposed procedures enable benchmarking and form a basis for future performance criteria in CT imaging.