3D Modelling and Virtual Reality

Three-dimensional modelling is a method that brings together the anatomical information contained in the patient’s MRI, CT and angiography images so that it can be examined in a digital environment. In complex cranial surgery in particular, these models help in assessing, before the operation, the relationship of the lesion to the surrounding vessels, bony structures and other anatomical features.

As part of research directed at surgical planning and neurosurgical training, work is carried out on three-dimensional anatomical modelling, virtual reality and digital visualisation technologies. These methods are also used in the preoperative planning of selected surgical cases.

On this page

How are three-dimensional models built?

According to the patient’s clinical needs, the relevant anatomical structures are separated out in the digital environment (segmentation) from imaging data such as MRI, CT or CT angiography.

Bony structures, vessels, lesions and, where required, the white-matter tracts defined by tractography can be represented in three dimensions. The resulting model can be examined from different angles to assess the anatomical features of the surgical approach.

Suitable models can be transferred to a virtual reality environment and examined in three dimensions. The imaging methods used and the level of detail of the model vary with the features of the case.

Uses in surgical planning

Brain aneurysms and vascular surgery

The relationship of the aneurysm neck to the parent vessel and its branches, the surrounding bony structures and the direction of the surgical approach can be assessed on three-dimensional models. In selected cases these models are used to examine the position of the craniotomy and the clip placement options before the operation.

Skull base surgery

In skull base lesions, the relationship of the tumour to the bony structures, the vessels and the surrounding anatomical features can be examined. This assessment supports the comparison of different surgical corridors and the planning of the approach.

Deep-seated brain lesions

In lesions around the thalamus, the ventricles, the pineal region and the brainstem, the relationship of the surgical target to the surrounding structures can be assessed in three dimensions. The models are an auxiliary planning tool for examining the anatomical corridors.

Virtual reality in neurosurgical training

Three-dimensional anatomical atlases, digital modelling of cadaveric dissections and virtual operating room applications are among the areas of research directed at neurosurgical training.

Anatomical data obtained by photogrammetry and three-dimensional modelling can allow surgical structures to be examined from different angles and teaching material to be prepared.

This work is carried out together with the surgical neuroanatomy research.

Limits of the method

Three-dimensional models are tools that support preoperative anatomical assessment; they do not replace surgical experience, direct observation or the other methods used during the operation.

The accuracy of a model depends on the quality of the imaging data used and on the segmentation of the anatomical structures. Very small vessels and nerves cannot always be shown. In addition, the displacement of tissue during surgery may create a difference between the preoperative model and the actual anatomical position.

The findings of three-dimensional planning are therefore considered together with direct anatomical observation during surgery and, in cases where they are needed, with neuronavigation, ultrasonography and other auxiliary methods.