< Back to topics
> Cover Page, Authors, Institutions
> View tables/images/videos
In preparation of a proton radiosurgery program for functional brain disorders and epilepsy, we are performing studies to define and improve the accuracy of MRI-based stereotactic localization of intracranial targets. MRI localization is not without problems since it has a poor geometric fidelity .
In this report, we summarize the methods and results of MRI-based stereotactic localization studies in a phantom performed in comparison to precision dimensional inspection by a metrology laboratory.
The two aims of this work were
1. To quantify the typical errors involved in a stereotactic localization procedure based on MRI.
2. To find ways to minimize these errors.
Possible ways to minimize the distortion errors inherent in MRI include
- Use of a MRI-compatible stereotactic frame.
- Use of all available internal correction methods provided by the manufacturer of the MRI scanner.
- Use of a scanner sequence that is less prone to distortion.
- Use a specially developed correction procedure for distortions introduced by gradient nonlinearities based on the scan of an oil-filled cubic phantom.