Method for estimating a scattered radiation, particularly to correct tomography or bone densitometry measurements
AssigneeCommissariat a l'Energie Atomique
InventorsJean-Marc Dinten, Michel Darboux
Life of this patent
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Abstract
The image of an object is improved by estimating the scattered radiation that it transmits to the detectors. To achieve this, one uses the scattered radiation effectively measured through an imitation of the object, having analogous attenuation properties, and which one modifies by the weighting coefficients obtained by a transformation of the values of the total radiation received through the object (3) and the selected imitation (8). One thus manages to improve the image without subjecting the object to a double irradiation in order to measure the scattered radiation separately. The principal applications are tomography, bone densitometry and non-destructive controls.
Claims11
An object imaging method by multiple acquisitions, the acquisitions consisting in passing a radiation through the object, measuring the radiation having passed through the object, the radiation being attenuated through the object from an initial radiation (Φo) to a total measurement radiation (Φt object), and subtracting an estimation of a scattered radiation (Φdobject) from the total measurement radiation, the measurement radiation and scattered radiation consisting of values associated to respective parts of the object, and wherein:
- for at least one of said acquisitions, values of scattered radiation (Φdimitation) are measured in passing the initial radiation through an imitation (8) of the object, transposition coefficients (K) relating the scattered radiation through the object to the scattered radiation through the imitation (8) are calculated based on the initial radiation (Φo), the total measurement radiation (Φt object) through the object and a total measurement radiation through the imitation (Φt imitation),
- the scattered radiation through the object in estimated with the transposition coefficients and the scattered radiation through the imitation,
- the values of total measurement radiation through the objects, the values of scattered radiation through the imitation and the transposition coefficients being spread in respective tables comprising corresponding elements so that each of the transposition coefficients is associated to a respective part of the object.
Dependencies are inferred from the claim text.