Brain Biopsy Techniques

This chapter reviews closed stereotactic brain biopsy procedures, in which a stereotactic headframe is affixed to the animal's head prior to the performance of a diagnostic imaging scan such that the target lesion can be precisely localized and referenced to the external headframe or fiducials. The most common diseases diagnosed by brain biopsy in veterinary medicine are tumors and immune-mediated and infectious encephalitides, although theoretically any lesion that can be accurately targeted with imaging can be sampled. The initial diagnostic magnetic resonance (MR) imaging that identified the lesion that is intended to be biopsied should have been performed within two weeks of planned frame-based Stereotactic Brain Biopsy procedure to avoid registration errors that can be associated with lesion evolution or resolution. Fiducial markers are constructed of material visible to MR imaging or computed tomography. Biopsy samples can be used to make smear impressions for cytology and placed in formalin for histopathology and immunohistochemistry analysis.