Method for reconstructing a fluorescence-enhanced optic tomography image of an object with any outline
The method enables a heterogeneous object containing fluorophores to be examined. A first face of the object is illuminated with an excitation light exciting the fluorophores. The light emitted by a second face of the object, opposite the first face, is detected by means of a matrix of detectors. The fluorophore distribution is determined by means of relevant Green's functions each associated with a selected source and/or detector, able to be assimilated to a point of the surface of the object. Thus, a first spatial coordinate of each of the relevant Green's functions corresponds to a point of the first face of the object and/or a second spatial coordinate of each of the relevant Green's functions corresponds to a point of the second face of the object.
1. A method for reconstructing a fluorescence-enhanced optic tomography image to examine a heterogeneous object of any shape comprising fluorophores and disposed in air, said method comprising:
defining a dummy volume containing the object,
selecting relevant sources and detectors, assimilated to points of the surface of the object,
defining relevant Green's functions, in said dummy volume, each associated with a selected relevant source and/or a selected relevant detector, each relevant Green's function comprising a first spatial coordinate associated with a selected relevant source and corresponding to a point of a first face of the object, and/or a second spatial coordinate associated with a selected relevant detector and corresponding to a point of a second face of the object, opposite the first face,
adapting the relevant Green's functions to the heterogeneity of the dummy volume,
illuminating the first face of the object with a fluorophore excitation light from sources including the selected relevant sources,
detecting a light emitted by the second face of the object by a matrix of detectors, the detectors including the selected relevant detectors, and
determining the fluorophore distribution using a processor by said relevant Green's functions according to signals detected by the detectors.
2. The method according to claim 1 , further comprising compression of the object between locations of the selected relevant sources and detectors, and zero resetting of the signals from the sources and/or the detectors corresponding to locations which are not in contact with the object.
3. The method according to claim 2 , wherein, the object being compressed between two transparent plates, the outline of the points of the surface of the object which are in contact with the object is previously determined by lateral illumination of the object.
4. The method according to claim 1 , wherein, the object being compressed, selection of the relevant sources and detectors comprises elimination of the measurements corresponding to a source and/or a detector associated with a location which is not in contact with the object.
5. The method according to claim 4 , wherein, the object being compressed between two transparent plates, the outline of the points of the surface of the object which are in contact with the object is previously determined by lateral illumination of the object.
6. The method according to claim 1 , further comprising experimental determination of the shape of at least a part of the surface of the object, the selected relevant sources and detectors being the sources and detectors optically associated with a point of a known part of the surface of the object.
7. The method according to claim 6 , wherein selection of the relevant sources and detectors comprises elimination of the measurements associated with the sources and/or the detectors which are not optically associated with a known part of the surface of the object.
8. The method according to claim 6 , wherein selection of the relevant sources and detectors comprises zero resetting of the signals from the sources and/or the detectors which are not associated with a known part of the surface of the object.
9. The method according to claim 6 , wherein a point of the known surface is eliminated if the perpendicular to the surface at this point forms an angle with the vertical that is larger than a predetermined threshold.
10. The method according to claim 1 , wherein adaptation of the relevant Green's functions to the inhomogeneities of the dummy volume comprises reconstruction of the three-dimensional spatial mapping of an attenuation variable representative of the diffusion and absorption inhomogeneities.