Interventional radiology is a new medical field which allows percutaneous punctures on patients for tumoral
destruction or tissue analysis. The patient lies on a CT or MRI table and the practitioner guides the needle
insertion iteratively using repetitive acquisitions (2D slices). We aim at designing a guidance system to reduce the
number of CT/MRI acquisitions, and therefore decrease the irradiation and shorten the duration of intervention.
We propose a system composed of two calibrated cameras and a structured light videoprojector. The cameras
track at 15Hz the needle manipulated by the practitioner and a software displays the needle position with respect
to a preoperative segmented image of the patient. To register the preoperative image in the camera frame, we firstly reconstruct the patient skin in 3D using the structured light. Then, the surfacic registration between the
reconstructed skin and the segmented skin from the preoperative image is performed using the Iterative Closest
Point (ICP) algorithm. Ensuring the quality of this registration is the most challenging task of the system.
Indeed, a surfacic registration cannot correctly converge if the surfaces to be registered are too smooth.
The main contribution of our work is the evaluation on patients of the conditions that can ensure a correct
registration of the preoperative skin surface with the reconstructed one. Furthermore, in case of unfavourable
conditions, we propose a method to create enough singularities on the patient abdomen so that the convergence
is guaranteed. In the coming months, we plan to evaluate the full system during standard needle insertion on