This software is a surgical planning environment which was designed in a modular way. The basic module provides visualization of DICOM files in two and three dimensions. The surgical planning module provides the necessary tools to plan a surgery using a single imaging modality (CAT or MRI for example). The registration module allows the specialist to see the patient using simultaneously two modalities of images (CAT and MRI for example). It is also possible to get a module for virtual surgery simulation using electromagnetic positioning. Only available for training purposes of students of neurosurgery.

The following figure shows the environment of the program, with the DICOM tree on the left, and a 3D view of the patient obtained from MRI. Also you can see the following three widgets:

An interactive cannula which emulates the cannula used during surgery.
A cube to cut the patient model.
A custom color palette which includes four types of fuzzy classification,

The following figure shows the program environment with the DICOM tree on the left, and the original axial DICOM data base. To the right of the image, the software provides a box with five options for image manipulation.

The following figure shows the simulation and planning of surgery using MRI images. The user interacts with the following two types of graphic elements.

• The cannula in 3D, which was designed under the concept of a billiard cue.

• The representation of the cannula in 2D, which consists of the dotted lines and red dots (distal end and the entry point to the skin).

The graphical elements are fully interconnected in their movement, which means that the movement of one of them is used to update the position of the others. The bidimensional images correspond to three orthogonal cutting planes, two of these three planes containing the cannula, the third plane (upper-left image) is perpendicular to the cannula at its distal end. These three views are updated in real time when the user interacts with the graphical elements. The entry point to the skin is automatically detected.

The following figure shows the simulation and planning of the same surgery using MRI and CT images. Surgery is simulated on a model of the patient obtained from a study of MRI, which was previously registered with the CT study. The specialist interacts mixing images from CT and MRI on the planning environment. The two upper images show the target positioned on one anatomical reference for verifying the quality of the registration.

The following figure shows the first surgery which was planned with our system. The patient is a woman aged 55, with a disease called Arachnoidoceles. The surgery was performed at Metropolitan Hospital of the city of Valencia, Venezuela. The figure shows the path of access on two oblique views containing the path of the instrumental. Also the figure shows the 3D model of the patient containing the stereotactic frame and the cannula. The stereotactic frame support is not available.

The upper slider shows seven images that demonstrate the interaction capability of our software in three dimensions. We are using a skull to which we have placed fiduciaries to simulate tumors inside the brain, it can be clearly observed in the first figure of the slider.