Selective Internal Radiation Therapy is an emerging, minimally invasive therapy of liver cancer. Millions of microspheres are injected through a catheter into tumor vascular supply. Microspheres distribution in liver is strongly dependent on patient's arteries geometry and catheter tip positioning, which is currently chosen by the physician based on qualitative image interpretation. A patient-specific numerical simulation of blood flow would have a crucial importance in therapy optimization, allowing in-silico research of microspheres trajectories.

We developed a procedure to segment patient's hepatic arterial vasculature with a Hessian based approach on 3D angiography, and to perform blood flow numerical simulation in the extracted geometry with ANSYS Fluent. In vivo blood velocity measurements were performed using phase contrast MRI to constrain these simulations.

Flow results in the larger vessels are coherent with literature, but very little is known for smaller arteries: simulation results are compared to velocity measures on hepatic arteries down to 2.2 mm of diameter on phase contrast MRI, which gave encouraging results for validation.

A viable procedure for arteries segmentation and patient-specific blood flow simulation is proposed, phase contrast MRI allowing for tuning and validation of velocity values. The proposed personalized blood flow simulation is compulsory for the simulation of microspheres trajectories in the aim of tumor targeting.