ABSTRACT
This chapter demonstrates a high-resolution photoacoustic scanner based upon an optical ultrasound-mapping scheme. The system can provide three-dimensional (3D) images of vascular networks and other absorbing soft tissue structures with a spatial resolution of the order of tens of microns and penetration depths of several millimeters. There are several advantages of the concept over existing instruments, particularly those based on piezoelectric detection methods. The transparent nature of the sensor head, which enables it to be used in backward mode, is the most obvious. However the acoustic performance it offers is also advantageous, particularly for high-resolution imaging applications. Although the instrument in its current form is able to provide in vivo images of usefully high quality, there remains significant scope to improve its performance in terms of spatial resolution, penetration depth, and acquisition speed. In order to obtain a measure of the spatial resolution that the system can provide measurements of the instrument line spread function (LSF) were made.
