How it Works

MODELING

To assign portions of a clinical scan to a specific anatomic structure, CardinalSim currently requires the use of external segmentation tools.  Such tools allow the identification of a variety of structures in a temporal bone scan as shown: inner ear (purple), nerves (orange), ossicles (green), and sigmoid sinus (blue).

We are currently investigating options to introduce more semi-automated methods of providing segmentation data for simulation purposes.

Segmented temporal bone model derived from a cone-beam CT of a patient scheduled for cochlear implantation.

The segmented internal structures are seen as the bone is made transparent.

CT and MRI provide complementary anatomic information for the rehearsal of of skull base procedures.

The images shown are clinical studies of a normal left temporal bone and skull base.  The CT (left) provides a high-resolution images of bone, which provides the basis for simulated dissection.  The co-registered MRI FIESTA sequence (right) provides additional information regarding soft tissues, such are the basilar artery (red arrow), cochleovestibulat nerves (yellow arrow), and sigmoid sinus (blue arrow).

These studies can be fused to provide additional data to be used during simulated surgery.

Video showing the fused CT and FIESTA studies of the left temporal bone and skull base.

Note the registration of soft tissue and bony anatomy that can achieved though the combined use of these studies.

Modeled left cranial base, derived from the fused CT and MRI datasets as seen in CardinalSim.

The bone was segmented using threshold segmentation based on the Hounsfield units from the CT.  The intracranial soft tissue structures were modeled as polygonal surfaces based on the data from the FIESTA sequences.

The sigmoid sinus (blue), carotid artery (light red), vertebrobasilar system (dark red) are shown.  The cranial nerves (VI through XII) are also added (yellow).