Résumé
In 2019, ImageCLEF proposed a task using CT (Computed
Tomography) scans of patients with tuberculosis (TB). The task was
divided into two subtasks: TB severity assessment (SVR subtask) and
automatic CT report generation (CTR subtask). In this work we present
our participation in the task. We participated with a graph model of the
lungs with a morphology{based structure that was previously validated
for the detection of TB types. The graph is based on a parcellation of
the lung elds into supervoxels, where each region is identied as a node
of the graph. A weighted edge is dened between nodes representing
adjacent regions. The associated weight is computed as the distance between
3D texture descriptors extracted from the two connected regions.
This model encodes the texture distribution along the lungs, making it
suitable for detecting the tissue abnormalities present in TB patients.
In this work we explore two techniques to classify these graphs: (i) a
lung descriptor vector based on the aggregation of graph centrality measures
and (ii) a set of 2D histograms encoding the binary distribution of
node features. The nal classication is performed with support vector
machines for the lung descriptor vector and with convolutional neural
networks for the 2D histograms. The results show the strength of the
technique, leading to 6th and 3rd place in the SVR and CTR subtasks,
respectively.