Radiation Exposure Estimation of full surgical procedures using CamC^?

Thesis by:
Advisor: Nassir Navab
Supervision by: Séverine Habert and Ulrich Eck

Abstract

CamC^? (Camera Augmented Mobile C-arm) is a C-arm augmented with a RGBD camera (color + depth images). Thanks to a mirror construction, the X-ray image can be overlaid on the video image, which gives to the surgeon a context to the X-ray image and reduce to the minimum the amount of X-ray radiation for steps like entry-point search during surgery. However, to have a valid image of the patient with the video camera, this one has to be placed on top of the patient table, as well as the X-ray source due to the mirror construction. This configuration “over the patient table” is going against the recommendations and usages of surgeons that usually place the X-ray source under the patient table. Indeed, in this configuration, the back-scattering (the radiation bouncing on the table) is going to the lower part of the surgeon (supposedly, less vital than the upper part). Previous works realized with CamC^? have shown an important reduction of the amount of X-ray images required for certain surgery steps. Diotte et al. and Londei et al. have shown that only 2 Xray images are required for the full interlocking procedure of intramedullary nails, instead of an average of 13 images in the standard clinical practice. A full study needs to be done to know if CamC^? technology is enough to compensate its required “over the table” configuration. Physical study during operation using dosimeters is a heavy setup and dosimeters are not very reliable. Therefore, for this work, we would like to use a radiation simulation framework in order to estimate the full radiation exposure during a given surgical procedure. This framework relying on Geant4, a radiation estimation library by CERN, has already been set up for CamC^? and would need to be adapted to this project, by creating a full scenario of surgical procedure and calculating radiation along this procedure.

Tasks

• getting used to Geant 4 framework and CamC^? framework
• adapting the existing code to the simulation of a full surgery
• establishing and realizing (data acquisition) of several full surgical scenario using real procedure observations
• computation of the radiation exposure during those scenario

Requirements

The student must have a good C++ knowledge.

Contact & Working place

If you are interested by this project, you can contact Séverine Habert. You will be working in Narvis lab in Sendlinger Tor, where you will have access to CamC^? for your experiments.

Literature

• CamC^? description in details: link
• A surgical workflow analysis using CamC^? for interlocking procedure of intramedullary nails: link
• Geant 4 library: link