Recent Advances in Neuroimaging and Neurosurgery

Several imaging techniques are now available to clinicians caring for patients with neurological disorders. These techniques include computed tomography (CT), CT angiography (CTA), perfusion CT (pCT), magnetic resonance imaging (MRI), MR angiography (MRA), functional MRI (fMRI), MR spectroscopy, perfusion MRI (pMRI), and MR Neurography. Other interventional techniques such as angiography, embolization and stenting of vascular structures, spine interventions such as discography, selective nerve root injection, and epidural injections are also available. In general, MRI is more sensitive than CT for detection of lesions affecting the central nervous system (CNS), particularly those of the cranial nerves, brain structures, and spinal cord, while CT is more sensitive than MRI for visualizing fine osseous details and lesions affecting the skull base. However, CT is the pragmatic choice for the initial evaluation of patients with suspected acute stroke, hemorrhage, and intracranial or spinal trauma because it is widely available and can be quickly obtained. In recent years, the advent of computer-based technology and the development of new digital scanning techniques have resulted in medical images of exquisite anatomical and pathological details. The integration of these anatomic and functional imaging techniques with neuronavigation technology has revolutionized the practice of neurosurgery. Neuronavigation, also called frameless stereotaxy, has improved the ability of neurosurgeons, neurologists, radiologists, oncologists, other clinicians, and neuroscientists to understand and apply medical images and imaging systems in the treatment of patients with brain disorders, especially brain tumors. Neuronavigation technology allows multi-modality-based images to be merged into a single model in which anatomic and pathologic changes are at once distinguished and integrated into the same framework. Thus, the technology helps neurosurgeons to use multimodality imaging data in a rational and quantitative fashion for purposes of surgical localization and operation. The key elements of neuronavigation technology include model-based image understanding, visualization and display platforms and related software for information and display, the use of computing clusters to increase the speed of computation and at the time optimize performance, and advanced devices and systems for 3-dimensional (3-D) device tracking and navigation. Neuronavigation, which displays 3-D reconstructions of brain lesions, vessels, nerves, and fiber tracts during surgery and makes use of image fusion techniques, is an important tool in the neurosurgical management of brain lesions.