CT-analyser (CTAn) and CT-volume (CTVol) are the analysis and visualization components of Bruker's SkyScan micro-CT software suite, forming a connected pipeline from reconstructed cross-section slices to quantified morphometric parameters and rendered 3D models. The two applications are linked — a 3D object model segmented and measured in CTAn can be exported directly to CTVol for surface rendering — but each addresses a distinct stage of the micro-CT workflow. Together with the CT-voxel (CTVox) volume renderer included in the bundle, they provide the complete computational chain that converts grayscale voxel data into the structural parameters — porosity percentage, trabecular thickness distribution, degree of anisotropy — that are the actual deliverables of a micro-CT experiment.

What morphometric parameters does CTAn measure?

CTAn computes a comprehensive set of 2D and 3D morphometric indices within user-defined regions of interest (ROIs) and volumes of interest (VOIs). For bone microarchitecture — the most common application — the software measures bone volume fraction (BV/TV), bone surface-to-volume ratio (BS/BV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), and trabecular number (Tb.N), with parameter naming switchable between general scientific nomenclature and the ASBMR bone morphometry standard. Structure model index (SMI) quantifies whether the tissue is plate-like (SMI → 0), rod-like (SMI → 3), or intermediate. Degree of anisotropy is computed via mean intercept length (MIL) with eigenvalues and eigenvectors, characterising the directional dependence of the structure. Fractal dimension (Kolmogorov) captures surface complexity. Density can be calibrated to Hounsfield units (HU), bone mineral density (BMD, mg HA/cm³), or linear attenuation coefficient (cm⁻¹) using co-scanned reference phantoms. For materials science applications — foam characterisation, composite porosity analysis, particle size distribution — the same parameter set applies, with the software treating any binarised phase as the object of interest.

How does the batch automation work?

CTAn implements a programmable task list: the user stacks image-processing and measurement functions — thresholding, despeckling, ROI definition, 2D analysis, 3D analysis — into a script, then applies that script to an entire directory of datasets. A single batch run can process hundreds of reconstructed volumes overnight, outputting CSV-format morphometric tables ready for statistical analysis. This is the workflow that makes high-throughput pre-clinical bone studies and quality-control porosity measurements on production parts practical — the operator sets up the analysis protocol once on a representative dataset, validates the segmentation against a few manually analysed slices, then applies the protocol to the entire study cohort. Measurement accuracy is validated against both physical phantoms of known geometry and virtual phantoms of known digital parameters.