
Photoacoustic Tomography and Ultrasound-Modulated Optical Tomography 439
21.10 Summary and Discussion on UOT
UOT is a novel hybrid bio-photonic imaging technique that can
supply strong optical contrast and high ultrasonic resolution.
By varying the ultrasonic parameters, the imaging depth and
the spatial resolution are scalable, within the reach of diu-
sive photons. e major challenge in UOT is the low SNR due
to uncorrelated speckle grains and low modulation eciency.
To overcome this problem, many detection techniques have
been developed including PRC-based detection, CFPI-based
detection, and SHB-based detection. Although the PRC-bas ...