Three-Dimensional Optical-Resolution Photoacoustic Microscopy - Biomedical Optical Imaging Technologies: Design and Applications - page 74

Fig. 2.11 Optical-resolution photoacoustic microscopy (OR-PAM) of the healing process of
a laser-induced microvascular lesion (A) before laser destruction, (B) immediately after laser
destruction, and (C) on each of the subsequent 12 days. The left image in each panel is the
photograph taken by a commercial transmission-mode optical microscope; the middle image is
the front view of the 3-D microvascular morphology acquired by OR-PAM at 57 nm; the right
image is the maximum-amplitude projection image overlaid by the hemoglobin oxygen saturation
map of the laser-damaged region

2.10 Perspectives

OR-PAM has potentially broad applications in biomedical imaging, yet much effort
still needs to be invested to mature this technology. Four potential directions of
future OR-PAM development are anticipated:

￿ Fast scanning over a large FOV. The current fast scanning strategy (i.e., optical

scanning) limits the FOV to less than 6 mm, which is inadequate in many
applications. One possible solution is to increase the speed of mechanical
scanning by using specific scanners [ 33 ].

￿ Optical detection of photoacoustic waves. Current acoustic detection in OR-PAM

is based on piezoelectric transducers, which require good tissue contact and