What is CT Resolution?

CT resolution refers to the ability of the CT system to image small structures as separable features. The topic is a methodological foundation for reliable CT data, because it directly affects detection limits, measurement capability and reproducibility.

Scientific background

The scientific basis is rooted in the physical interaction of X-ray radiation with matter and in the mathematical data processing of projections. Particularly relevant is the interplay between focal-spot unsharpness, detector pixel pitch and reconstruction filter. For technical decisions, these relationships must be understood as a quantifiable measurement chain.

Relevant key metrics

Spatial resolution, contrast-to-noise ratio and measurement uncertainty are the central parameters.
Systematic effects are controlled via calibration, reference standards and repeat measurements.
Parameter changes must be evaluated for robustness and transferability to series production conditions.

Standards and thresholds

Standards: ISO 15708-2:2025 and ISO 15708-4:2025 as well as VDI/VDE 2630 Part 1.2:2018-06.
Typical thresholds (in practice): Target feature should be imaged with at least 2-3 voxels; for robust defect detection typically at least 3 voxels per smallest relevant defect.
Validity: Required resolution derives from functional risk, tolerance allocation and inspection task.

Application in industrial practice

Design of valid scan parameters for defect and measurement tasks.
Objective interpretation of CT findings in development and series production.
Comparability of results across systems, batches and time points.

Sources and reference date

ISO 15708-2:2025 and ISO 15708-4:2025.
VDI/VDE 2630 Part 1.2:2018-06.
Reference date: February 2026.