Wide-field two-dimensional multifocal optical-resolution photoacoustic-computed microscopy

• Published in: Optics letters 2013-12, Vol.38 (24), p.5236-5239
• Main Authors: Xia, Jun, Li, Guo, Wang, Lidai, Nasiriavanaki, Mohammadreza, Maslov, Konstantin, Engelbach, John A, Garbow, Joel R, Wang, Lihong V
• Format: Article
• Language: English
• Subjects: Animals; Arrays; Brain - cytology; Female; Field of view; Focal plane; Imaging; Mice; Microscopy; Microscopy - instrumentation; Microscopy - methods; Optical Phenomena; Photoacoustic Techniques - instrumentation; Photoacoustic Techniques - methods; Pregnancy; Transducers; Two dimensional; Uterus - cytology
• ISSN: 0146-9592; 1539-4794
• DOI: 10.1364/OL.38.005236

Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technique that directly images optical absorption in tissue at high spatial resolution. To date, the majority of OR-PAM systems are based on single-focused optical excitation and ultrasonic detection, limiting the wide-field imaging speed. While 1D multifocal OR-PAM (1D-MFOR-PAM) has been developed, the potential of microlens and transducer arrays has not been fully realized. Here we present the development of 2D multifocal optical-resolution photoacoustic-computed microscopy (2D-MFOR-PACM), using a 2D microlens array and a full-ring ultrasonic transducer array. The 10 mm×10 mm microlens array generates 1800 optical foci within the focal plane of the 512-element transducer array, and raster scanning the microlens array yields optical-resolution photoacoustic images. The system has improved the in-plane resolution of a full-ring transducer array from ≥100 to 29 μm and achieved an imaging time of 36 s over a 10 mm×10 mm field of view. In comparison, the 1D-MFOR-PAM would take more than 4 min to image over the same field of view. The imaging capability of the system was demonstrated on phantoms and animals both ex vivo and in vivo.