Intraoperative imaging of the brain.

The development of computed imaging techniques has revolutionized contemporary neurosurgical procedures. In a 20-year interval, intraoperative imaging was used in more than 4,000 patients at our center. The selection of the appropriate intraoperative imaging tool was dependent on the neurosurgical procedure performed. In our dedicated operating room suite, intraoperative fluoroscopic imaging was used during transsphenoidal, spinal, and functional procedures, e.g. to treat percutaneous trigeminal neuralgia. A dedicated intraoperative computed tomography scanner was first available in 1981 and was used in more than 1,500 stereotactic or image-guided procedures. During radiosurgical procedures with the Gamma Knife (n = 1,560) a variety of intraoperative imaging tools (MRI, CT, angiography, and digital subtraction angiography) were used to define the target. The output of these imaging tools is currently transferred via fiberoptic ethernet to a wide variety of computer workstations designed to facilitate surgical or radiation dose planning. In addition, intraoperative imaging became increasingly important during vascular neurosurgery. Because of its superior patient accessibility and instrument compatibility. CT is likely to remain the most important imaging tool for conventional intraoperative image-guided stereotactic surgery. In contrast, intraoperative MRI proved to be the superior imaging tool for radiosurgery.