Fig. 1: 3D-PACT synchronized with ECG for cardiac imaging.
From: Non-invasive photoacoustic computed tomography of rat heart anatomy and function
a Representative sketch of the 3D-PACT platform with a close-up view of the imaging aperture. b Experimental setup for the rat heart imaging. The rat was mounted in a prone position, and the expanded light beam was directed towards the rat’s chest from the bottom. c Example of the signal synchronization between the 3D-PACT (top) and ECG (bottom) measurements. The 3D-PACT signal was collected from one transducer element on one array at multiple scanning positions (i.e., on the same latitude). In the photoacoustic signal diagram, the horizontal axis represents the scanning steps (i.e., time), and the vertical axis stands for the time-of-flight signal (data acquisition sampling at 20 MHz). The P, R, and T waves in the ECG signals correspond to atrial contraction, ventricular contraction, and ventricular relaxation, respectively. d The rat heart images reconstructed with different ultrasonic apertures, showing the impact of a sizeable ultrasonic detection aperture on image reconstruction. The red arcs on the top right corner of each image represent the cross-sectional view of the ultrasonic detection aperture
