A Micro CT Study in Patients with Breast Microcalcifications Using a Mathematical Algorithm to Assess 3D Structure

The aim of this study was to evaluate the relevance of the three-dimensional (3D) structure of breast microcalcifications (MC) as a predictor of malignancy using highly resolved micro-computed tomography (micro-CT) datasets of biopsy samples.

The study included 28 women with suspicious MC in their mammogram undergoing vacuum-assisted biopsy. Directly after the intervention, the specimens were scanned in a micro-CT with an isometric spatial resolution of 9 μm. Datasets were analysed regarding the number, volume and morphology of suspicious non-monomorphic MC (fl-fine linear, fp-fine pleomorphic, ch-coarse heterogeneous) and the structure model index (SMI). Histological evaluation was performed according to the B-classification: normal tissue or benign (group A: B1, B2), unclear malignant potential or suspicious of malignancy (group B: B3, B4) and malignant lesions (group C: B5).

In all groups, suspicious non-monomorphic MC were found: group A exhibited fp MC in 38.5% of samples, no fl/ch; group B: fl 14.3%, fp 28.6%, ch 14.3%; group C always had at least one type of suspicious non-monomorphic MC (fl (57.1%) or fp (57.1%)) in each sample. The different histologic groups showed a similar mean SMI (benign: 2.97 ± 0.31, malignant: 3.02 ± 0.10, unclear: 2.90 ± 0.28). Between the three groups, no significant differences were found regarding number, volume or SMI value of MC.

3D structure based on the SMI of MC analysed with highest spatial resolution is not significantly associated with the B-classification of breast lesions. Thus, magnification views of MC may be omitted in the analysis of MC detected in mammograms.