Visualizing a vascular structure
A system ( 500 ) for visualizing a vascular structure represented by a three-dimensional angiography dataset is disclosed. Respective voxel values are associated with respective voxels. The dataset represents a vascular structure. The system comprises means ( 502 ) for establishing respective filling values; means ( 504 ) for identifying respective minimum filling values; means ( 506 ) for computing respective deficiency values; and an output ( 514 ) for providing a visualization in dependence on the deficiency values. A respective filling value is indicative of an amount of blood flow at the respective position in the vascular structure. A respective minimum filling value is a minimum of the filling values associated with the positions upstream of the respective position. A respective deficiency value is indicative of a difference between the filling value associated with the respective position and the minimum filling value associated with the respective position.
1. A system ( 500 ) for visualizing a vascular structure ( 306 ) represented by a three-dimensional dataset in which respective voxel values are associated with respective voxels, the system comprising:
means ( 502 ) for establishing respective filling values ( 314 ), based on the voxel values, associated with respective positions in the vascular structure, a respective filling value being indicative of an amount of blood in a neighborhood of the respective position in the vascular structure;
means ( 504 ) for determining respective minimum filling values ( 316 ) associated with the respective positions in the vascular structure, a respective minimum filling value being a minimum of the filling values ( 314 ) associated with positions upstream of a respective position;
means ( 506 ) for computing respective deficiency values ( 318 ) associated with the respective positions in the vascular structure, a respective deficiency value being computed in dependence on the filling value ( 314 ) associated with the respective position and the minimum filling value ( 316 ) associated with the respective position; and
an output ( 514 ) for providing a visualization ( 408 ) in dependence on the deficiency values.
2. The system according to claim 1 , wherein the means for establishing the respective filling values comprises:
means ( 516 ) for computing a generalized distance map in which respective generalized distance values based on the voxel values are associated with respective voxels; and
means ( 518 ) for establishing a vessel centerline in dependence on the generalized distance map or in dependence on the voxel values;
means ( 520 ) for establishing the respective filling values in dependence on the respective generalized distance values associated with the respective voxels at the vessel centerline.
3. The system according to claim 2 , wherein the means for establishing the vessel centerline comprises:
means for identifying a plurality of voxels on a crest line of the generalized distance map or of the voxel values; and
is arranged for using the plurality of voxels as the vessel centerline.
4. The system according to claim 1 , wherein the voxel values are indicative of a local concentration of contrast agent, and the means for establishing the respective filling values is arranged for computing the respective filling value as an estimate of a degree of local contrast agent filling in a cross section of the vessel at the respective position in the vascular structure.
5. The system according to claim 1 , wherein the means for identifying respective minimum filling values comprises means for establishing the positions upstream of the respective position by identifying positions along the vascular structure between the respective position and a predefined inflow point of the vascular structure.
6. The system according to claim 1 , wherein the means for computing the respective deficiency values is arranged for computing the respective deficiency value in dependence on a difference between the filling value associated with the respective position and the minimum filling value associated with the respective position.
7. The system according to claim 1 , further comprising a rendering means ( 508 ) for rendering the three-dimensional dataset on a display in dependence on the computed deficiency values, the rendering means comprising:
a storage for storing a mapping ( 522 ) associating respective deficiency values with respective rendering parameters;
means ( 524 ) for applying the parameters according to the mapping and the deficiency values.
8. A method of visualizing a vascular structure ( 306 ) represented by a three-dimensional dataset in which respective voxel values are associated with respective voxels, the method comprising:
establishing respective filling values ( 314 ), based on the voxel values, associated with respective positions in the vascular structure, a respective filling value being indicative of an amount of blood in a neighborhood of the respective position in the vascular structure;
determining respective minimum filling values ( 316 ) associated with the respective positions in the vascular structure, a respective minimum filling value being a minimum of the filling values ( 314 ) associated with positions upstream of a respective position;
computing respective deficiency values ( 318 ) associated with the respective positions in the vascular structure, a respective deficiency value being computed in dependence on the filling value ( 314 ) associated with the respective position and the minimum filling value ( 316 ) associated with the respective position; and
providing a visualization ( 408 ) in dependence on the deficiency values.