Because of its similar genetic makeup with humans, zebrafish are an available and well-established osteoporosis model in vivo for anti-osteoporosis drug development as well as the drug safety-evaluation process. However, few optical imaging methods could effectively visualize the bone of adult zebrafish due to their limited penetration depth. In this paper, in vivo high-resolution and long-term characterization of a prednisolone-induced osteoporotic zebrafish model was achieved with spectral-domain optical coherence tomography (SD-OCT). The capability of three-dimensional SD-OCT imaging was also demonstrated in this study. With SD-OCT images, we could non-destructively monitor the deforming process of adult zebrafish skull from several directions at any time. There is good correlation and agreement between SD-OCT and histology. Valuable phenomenon such as bone defects could be quantitatively evaluated using the SD-OCT images at different time points during a period of 21 days.

A novel numerical iterative approach is proposed to effectively eliminate the zero-order term and to improve the signal-to-noise ratio of the reconstructed image in off-axis digital holography. The iterations are conducted in the spatial domain, resulting in considerable reduction in the computational time and avoiding the subjectivity involved in selecting a filter window in spectral domain. These advantages promote the application of this approach in real-time detection processes. The feasibility of this approach is confirmed by mathematical deductions and numerical simulations, and the robustness of the proposed approach is tested by means of an experimentally obtained hologram.

We developed a simple and compact laser-scanning photoacoustic microscopy (PAM) for imaging large areas of subcutaneous microvasculature in vivo. The reflection-mode PAM not only retains the advantage of high scanning speed for optical scanning, but also offers an imaging field-of-view (FOV) up to 20 × 20 mm2, which is the largest FOV available in laser-scanning models so far. The lateral resolution of the PAM system was measured to be 17.5 µm. Image experiments on subcutaneous microvasculature in in vivo mouse ears and abdomen demonstrate the system's potential for fast and high-resolution imaging for injuries and diseases of large tissues and organs.

In this paper, an approach for expanding the sampled area of a dynamic process by digital holography is reported, where angular, polarization and wavelength multiplexing are applied to record different regions of the sample on a series of sub-holograms overlapped in a single frame of the charge-coupled device. This approach based on a single exposure has special potential for the digital holographic recording of dynamic processes.