Section: New Results

Interventional neuroradiology

Participants : Marie-Odile Berger, Charlotte Delmas, Erwan Kerrien, Raffaella Trivisonne.

Tools reconstruction for interventional neuro-radiology

Minimally invasive techniques impact surgery in such ways that, in particular, an imaging modality is required to maintain a visual feedback. Live X-ray imaging, called fluoroscopy, is used in interventional neuroradiology. Such images are very noisy, and cannot show any brain tissue except the vasculature. Moreover only two projective fluoroscopic views are available at most, with absolutely no depth hint. As a consequence, the 3D shape of the micro-tool (guidewire, micro-catheter or micro-coil) can be very difficult, if not impossible to infer, which may have an impact on the clinical outcome of the procedure.

In collaboration with GE Healthcare, our project aims at devising ways to reconstruct the micro-tools in 3D from fluoroscopy images. Charlotte Delmas has been working as a PhD CIFRE student on this subject since April 2013. She presented her research and results about fluoroscopic image segmentation, live stereo reconstruction of the guidewire, and fast 3D coil reconstruction, together with in-depth validation, in her PhD manuscript [11].

Image driven simulation

We consider image-driven simulation, applied to interventional neuroradiology as a coupled system of interactive computer-based simulation (interventional devices in blood vessels) and on-line medical image acquisitions (X-ray fluoroscopy). The main idea is to use the live X-ray images as references to continuously refine the parameters used to simulate the blood vessels and the interventional devices (micro-guide, micro-catheter, coil).

Raffaella Trivisonne started her PhD thesis in November 2015 (co-supervised by Stéphane Cotin, from MIMESIS team in Strasbourg) to address this research topic. We investigated various image and mechanical constraints, and proposed an efficient constrained shape from template approach where a set of radio-opaque markers on the catheter are tracked in the fluoroscopic images, and the surface of the vessel defines a set of unilateral constraints to prevent the catheter from crossing the vessel wall [22]. In particular, a constraint on the insertion point of the catheter at the groin was necessary to retrieve an accurate 3D shape of the micro-device.