A feasibility study of the optoacoustic imaging of microcalcification for early breast cancer detection

In this study, the feasibility of visualization of microcalcification using optoacoustic (photoacoustic) imaging (PAI) technique is investigated. The non-ionizing radiation and speckle-free characteristic makes the PAI a potential diagnostic tool for early breast cancer detection. To verify this idea, a custom-made laser illumination probe integrated with commercial ultrasound imaging system was established. The artificial phantom imbedded with granulated calcium hydroxyapatite (HA), the major chemical composition of the microcalcification associated with ductal carcinoma in situ (DCIS), was used for imaging. Relationships of PA signal amplitude versus various light wavelengths were also studied. The results showed that given an optimal near-infrared (NIR) wavelength of 750nm, the dimension of 500~1000 μm HA at ~3cm-depth in phantom can be clearly observed via B-mode and projected C-mode scan images. The proposed approach provides another diagnostic tool for screening early stage of breast cancer.