High-resolution spiral CT of the breast at very low dose: concept and feasibility considerations.

OBJECTIVE

Mammography, today's standard imaging approach, has deficits with respect to the superimposition of anatomical structures. Dedicated CT of the breast so far indicated that it can provide superior soft-tissue imaging, but that it still has significant limitations with respect to spatial resolution and dose. We have assessed novel dedicated breast CT technology.

METHODS

Based on simulations and measurements we developed novel technology which uses direct-conversion CdTe material and photon-counting electronics with 100 μm detector element size for close to 100% dose efficiency. We assessed the potential for the imaging of microcalcifications of 100 to 200 μm diameter and soft-tissue lesions of 1 to 5 mm diameter by simulations at dose levels between 1 and 6 mGy.

RESULTS

Microcalcifications of 150 μm and soft-tissue lesions of 2 mm diameter were found to be clearly detectable at an average glandular dose of 3 mGy. Separate displays are required for high-resolution microcalcification and for low-resolution soft-tissue analysis. Total CT data acquisition time will be below 10 s.

CONCLUSION

Dedicated breast CT may eventually provide comprehensive diagnostic assessment of microcalcifications and soft-tissue structures at dose levels equivalent to or below those of two-view screening mammography.