Intrinsic optical signal imaging of normal and abnormal physiology in animals and humans--seeing the invisible.

Surgeons in general and neurosurgeons in particular are extremely dependent on their sense of vision. After the advances in antiseptic and anesthetic technique, which were critical to the establishment of surgery as a field in medicine, most recent advances in the field of neurosurgery have arisen from improvements in the surgeon¡¦s ability to see the relationship between normal and abnormal anatomy and to translate these images into the operating room as the basis for a therapeutic intervention. Although the microscope and endoscope allow us to see gross anatomic structures with finer detail, the implementation of image-based stereotaxy and intraoperative magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound permits us to anticipate anatomy that cannot be observed grossly.