Optical fine-needle imaging biopsy of the brain.

We demonstrate optical fine-needle imaging biopsy (FNIB), combining a fine needle (22 gauge) and a high-resolution side-view probe (350-μm diameter) for minimally invasive interrogation of brain tissue in situ. We apply this technique to examine pathogenesis in murine models of neurodegeneration, brain metastasis of melanoma, and arterial occlusion, respectively. The demonstrated ability to obtain cellular images in the deep brain without craniotomy may be useful in the longitudinal studies of brain diseases.