Biomedical Engineering Reference
In-Depth Information
Figure 6.5-8 Examples of neurosurgical cases. The last example includes a fusion of fMRI data overlaid on top of the structure model.
Localizing key blood vessels.
Orienting the surgeon's frame of reference.
Selected examples are shown in
Fig. 6.5-8
.
To qualitatively validate the system's performance,
the surgeon placed the pointer on several known land-
marks: skull marks from previous surgeries, ventricle tip,
inner skull bones such as eye orbits, sagittal sinus, and
small cysts or necrotic tissues. He then estimated their
position in the MRI scan, and we compared the distance
between the expected position and the system's tracked
position. Typically, this error was less than two voxels
(MRI resolution was 0.9375 mm by 0.9375 mm by 1.5
mm), although this does depend in some cases on the
administration of drugs to control brain swelling.
high-grade and low-grade supratentorials; meningiomas;
metastases; posterior fossa; meningioangiomatosis; in-
tractable epilepsy; vascular; biopsies; and demyelinating
lesion.
In all cases the system effectively supported the sur-
gery as follows:
By providing guidance in planning bone cap
removaldthis was done through the augmented
reality visualization in which the surgeon could
visualize paths to the critical tissue and plan an
appropriate entry point.
Identifying margins of tumor
this was done by
tracing the boundaries of tissue with the trackable
probe.
d
