Transducer Array-Based Photoacoustic Tomography: 2D, 3D, and 4-D Photoacoustic Imaging

In this chapter, we describe a transducer array-based photoacoustic tomography (PAT) system and demonstrate its ability for 2D, 3D, and 4-D photoacoustic imaging of biological tissue. Figures 4.1a and 4.1b present the photograph of an array-based PAT system. As shown in Figure 4.1a, a tunable Ti:Sapphire laser (part A) is used to provide 690 to 950 nm near-infrared (NIR) laser pulses with a pulse width of 8 to 25 ns and a repetition rate of 10 Hz. The photoacoustic signals generated by the laser are received by a full-ring array with 5 MHz frequency transducers (part B). Preamplifiers/amplifiers (part C) amplify the signals from the transducers and deliver the amplified signals to the A/D boards (part D), which are controlled by the computer (part E). The three key components of the system including the tunable laser, ultrasound transducer array, and data acquisition system are discussed in detail in Sections 4.1 to 4.3 below.