Modeling the Human Peritony

M2R-Mosig internship, 2010

Resp: Olivier Palombi and François Faure

Context

The EVASION research team is involved in Passport for Liver Surgery, a project on patient-specific simulation of laparoscopic liver surgery. The purpose is to train surgeons on virtual models corresponding to the real anatomy and pathology of the patient. There are many challenges to tackle in order to achieve this goal. One of them is the geometrical modeling of a specific human anatomy, based on medical (volumetric) images of the patient. Though the big organs are visible and segmentable in such images, many anatomical entities are too small or too complex to be modeled. One of these entities is the peritony, a membrane which surrounds the liver and its incoming vessels. Cutting the peritony and removing the fat tissue in contains to access the liver and the surrounding organs is a difficult task for the surgeon, and we have to model it in order to provide a good training. We currently have patient-specific models of the liver and the surrounding organs, as illustrated in the next figure, and we need to model the peritony. These models are simulated in  SOFA, a simulation library developed at EVASION and INRIA.  Moreover, the modeling  needs to be as automatic as possible, based on anatomical knowledge. Such anatomical knowledge can be represented in MyCorporisFabrica, an anatomical database developed at EVASION by prof. Olivier Palombi.


patient-specific model
Figure: Simulation of a patient-specific model built using medical images.

Goal

The goal of this work is to create a model of the peritony surrounding a given liver and its surrounding organs. We will not consider the whole peritony, but focus on the region of the hepatic pedicle. This video of a real operation gives an idea of the geometry we target. Rendering will not have to reach a high degree of realism in this work, since we will focus on geometry. The geometry of the peritony in this area is similar with a folded sheet with fat tissues inside the folds. The geometric model will include, in addition to the big organs already modeled (arteries, bile ducts), the folded sheet as a 2D surface and the fat as 3D volume. The geometry will then be exported as a SOFA scene. As far as possible, the anatomical knowledge will be expressed in the MyCorporisFabrica anatomical database. Physical simulation will probably be needed to model the complex folds of the membrane.
The validation will be done by simulating the cutting of the peritony in SOFA.


Work

The practical work may be organized as follows:
SOFA, MyCorporisFabrica, C++ will be used.

Organization