Computer-assisted craniotomy is a craniotomy that is guided by computers. The computers are used by the surgeons to gather, store, and reformat images from the patient's MRI or CT scan. These are rendered in three dimensional volumetric information that allow definition of an intracranial lesion with respect to the surgical field. Most importantly, this information is displayed to the surgeon intraoperatively and scaled to the actual size and location of the surgical field.

With this technique, a surgeon can plan and simulate the surgical procedure beforehand, reach deep-seated or centrally located brain tumors employing the safest and least invasive route possible. Figure 1 shows reformatted and three-dimensional images of a patient with a brain tumor.

The most common disadvantages of craniotomy for resection of brain tumor include, but are not limited to:

1. A large skin and bone opening is necessary.
2. A surgeon can get lost attempting to find the tumor. Normal brain tissue can be damaged unnecessarily. This can result in neurologic deficit and prolonged stay in the hospital.
3. In most cases it is difficult to tell where tumor ends and normal brain tissue begins. Thus, there is risk that the surgeon can resect normal brain tissue along with the tumor. In important brain areas, this will also result in neurologic deficit.
4. A surgeon performs a subtotal removal of the tumor. The consequence is only partial tumor resection that will result in a faster recurrence of the tumor and neurological symptoms.

Anybody who needs brain surgery and wants a precise and minimally invasive operation is a candidate, The conditions include brain tumors, vascular malformations, infections, surgery for Parkinson's disease, and other movement disorders.

Computer-assisted craniotomy provides the following major advantages to the surgeon in the management of intra-axial brain lesions:

1. It allows a small skin and bone opening.
2. It allows locating the lesion promptly.
3. It allows removal of the tumor respecting the normal brain and vascular anatomy.
4. The surgeon is guided by the computer and thus knows exactly where tumor ends and normal brain begins. This allows a more complete tumor removal with much less risk to surrounding brain tissue.
5. "Inoperable" tumors (inoperable by conventional surgical techniques) can be resected with computer-assisted procedures. Frequently, these are deep seated-relatively benign tumors in children and young adults or elderly patients. Many of these tumors can be cured with computer-assisted craniotomy.
6. Neurologic results are better; fewer patients require rehabilitation programs and return to work sooner.