Thermo/Opto-Acoustic Imaging
Thermo/opto-acoustic imaging provide a diagnostic imaging modality for breast cancer. The images generated by diffuse optical tomography are necessarily low resolution. As light bounces around inside the breast, small objects get blurred out. Thermo- or photo-acoustic imaging is a solution to this problem. When laser radiation or radio waves are absorbed by tissue, they slightly heat it. These kinds of radiation are not ionizing and thus don’t have a risk of causing cancer. If the tissue is heated rapidly, it will expand rapidly. This rapid expansion creates a sound wave which travels through the tissue and can be detected by an ordinary medical ultrasound transducer. Since the sound waves can travel through the tissue without scattering, fine details are not blurred out. This technique can generate high resolution maps of the blood vessels in a breast. Early studies (not yet on humans) have shown that this technique may be sensitive to microcalcifications. Regions with extra blood vessels are likely to be tumors. This technology has yet to be implemented in clinical settings.