​Currently, most breast cancer screening involves imaging—a breast ultrasound—and, if anything suspicious is detected, a biopsy. However, a non-negligible percentage of breast biopsies turn out to be negative. In this research, which was part of the EU Solus project, the imaging step was enhanced with the goal of reducing the number of invasive and painful biopsies without increasing the risk of missing a malignant tumor.

The project involved adding time-resolved optical analysis capabilities to an existing ultrasound probe and testing the performance of the combined techniques. With time-resolved optical analysis, individual photons are emitted, and the time it takes for them to travel through the tissue being examined is used to determine the makeup of that tissue. CEA-Leti characterized the optical components, developed a semi-automated bench for the calibration of each probe's 1,408 parameters, and developed a user-friendly interface that was also used in the clinical trials.

The initial clinical trials on the dual-mode probe prototype produced encouraging results. The next step will be safety testing (laser emissions, thermal and acoustic testing, etc.) to obtain the CE marking and other certifications needed to be able to integrate the probe into machines, manufacture it, and roll it out in clinical settings. Until then, a prototype is being tested at a Milan hospital.