Session P95.4

Assessment of Global Cardiac Function in MSCT Imaging Using Fuzzy Connectedness Segmentation

J Fleureau, M Garreau*, A Simon, R Hachemani, D Boulmier

Université de Rennes
Rennes, France

The goal of this work is to assess global cardiac function, in terms of ventricular volume, from MSCT (Multi-Slice Computed Tomography) dynamic dataset. MSCT dynamic acquisitions provide a volume sequence representing the whole cardiac cycle. In clinical routine, radiologists measure the ventricular volume only at the end-diastolic and end-systolic phases in order to obtain ejection fraction. However, the computation of the ventricular volume along the whole cardiac cycle could provide a more precise description of the cardiac function. We propose an approach for the segmentation of the left ventricle, its dynamic visualization and the ventricular volume measurement from MSCT dataset. It is based on four steps. The first step is the segmentation of the left cavities, along the whole cardiac cycle, using a fuzzy connectedness algorithm: from a seed point (chosen interactively at the first time-instant and used for the whole cardiac cycle), it generates a connectedness map, associating each voxel to the seed. The connectedness is based on affinity (measuring the similarity, in terms of intensity and spatial distance, between voxels and the seed) and path (linking voxels to the seed). The second step is the surface reconstruction of the segmented volumes using Marching Cubes algorithm resulting to surface meshes representing the left cavities (left ventricle and auricle, beginning of the aorta). The third step is to cut through the reconstructed surface in order to extract the left ventricle. This is based on the interactive placement of a 3D plane at the valvular plane at the first time-instant of the sequence. The selected plane is used to cut through the surface and to initialize the same process at the following time (only few corrections are therefore needed). The fourth step is the left ventricle volume computation according to the acquisition resolution. This method therefore gives access, with few interactions, to the evolution of the cardiac volume along the whole cardiac cycle. Results have been compared to measures made during clinical routine with MSCT and MRI (only at end-diastolic and end-systolic phases) and have provided satisfying results (volume difference less than 10%).

(Abstract Control Number: 278)