Abstract: A method for measuring geometric quantities intrinsic to an anatomical system of a patient, based on two stereoscopic images. Registration data are received on each of the two stereoscopic images. By using geometric calibration information, a three-dimensional geometric primitive is determined defined by at least a portion of the received registration data. Based on the three-dimensional geometric primitive, a value of geometric quantity intrinsic to the anatomical system is computed.

Abstract: A method for measuring geometric quantities intrinsic to an anatomical system of a patient, based on two stereoscopic images. Registration data are received on each of the two stereoscopic images. By using geometric calibration information, a three-dimensional geometric primitive is determined defined by at least a portion of the received registration data. Based on the three-dimensional geometric primitive, a value of geometric quantity intrinsic to the anatomical system is computed.

Abstract: In voludensitometry and in cases in which it is necessary to acquire only a small number of views, the artifact ratio resulting from reconstructions is reduced. There is acquired at least one view of the object to be reconstructed, the principal direction of irradiation of which is oriented substantially at right angles to a plane formed by or containing the other directions of irradiation corresponding to the other views.

Abstract: In order to reconstruct the structure of a body by way of iterative algorithms, the first iterations are carried out with lower resolution in order to limit the number of calculations. The image can then be reconstructed when the calculation time is reduced to one-third or even one-quarter. The image thus reconstructed is of better quality than images reconstructed using only a single resolution.

Abstract: In order to represent the bone structure of a patient's body, acquisitions are made with different irradiation energies. The irradiations are compared with these two energies in order to deduce a two-dimensional projected image which is representative of the bone structure alone. To this end, there is assigned to each pixel in the projected images a value corresponding to the thickness of bone traversed by an x-ray which has terminated at said pixel. This value is obtained by calibrating the measuring system, detector cell by detector cell, so as to correct the spatial non-uniformities of the acquisition system.

Abstract: The fact that a vascular tree occupies a very small portion of the surrounding space is profitably employed for reducing the number of reconstruction calculations and improving the quality of this reconstruction without thereby making restrictive geometrical hypotheses. A support region of the object is determined. An estimation of the object to be reconstructed is then carried out on the support region by means of an algebraic method. Determination of the object support involves a statistical evaluation of the detected observations and a comparison of this evaluation with a measurement of the intrinsic noise of the measurement chain. Noise problems are overcome by means of the statistical study. By utilizing a second estimation stage, and taking the support into account, one avoids a restrictive implicit assumption on a convex shape of the objects to be studied.