The interior structure of breast microcalcifications assessed with micro computed tomography

Background: Morphology microcalcification descriptors help stratify the risk of breast malignancy. Micro CT is feasible for visualization of the fine-structure of tissues and may be suitible for high resolution microcalcification analysis. Purpose: To analyze the interior structure of microcalcifications using a micro CT imaging system. Material and Methods: Core needle breast biopsy specimens from 16 women with clustered microcalcifications were examined with micro CT. The samples measured between 0.8 to 1.2 mm in diameter. Micro CT scans with an isotropic voxel size of 8.4 mu m were obtained to generate two- and three-dimensional images of the microcalcifications. The number of microcalcifications were counted on the magnified specimen radiogram and on micro CT. Attenuation values of microcalcifications were measured by drawing a region of interest (ROI) in the center of the microcalcifications. Two blinded observers assessed the morphology and the interior structure of microcalcifications. Results: Five patients had benign and 11 patients had malignant breast lesions. On micro CT, microcalcifications of benign tissue showed a coarse lamellar or trabecular interior structure, whereas microcalcifications of breast cancer tissue showed a more uniform granular interior structure. There was no correlation between attenuation values of benign compared with malignant microcalcifications. Conclusion: On micro CT, an interior structure of microcalcifications is detectable. Benign and malignant microcalcifications display different patterns of interior structure.