Imaging small absorbing and scattering objects in turbid media using diffuse optical tomography structurally guided by reconstructive ultrasound tomography

We describe an imaging technique that combines near-infrared diffuse optical tomography and reconstructive ultrasound tomography (RUT). In this technique, both absorption and scattering images of turbid media are reconstructed by use of the a priori structural information obtained from computational based ultrasound tomography. Under the guidance of a RUT, the absorption and scattering images with high spatial resolution are obtained using a finite element based reconstruction algorithm. With the combined approach, we experimentally demonstrate that 2-3 mm size targets embedded in a 5 cm diameter background can be reconstructed quantitatively in terms of the absorption and reduced scattering coefficients of the target, whereas it is impossible to quantitatively resolve the targets without the ultrasonic guidance.