Abstract: The present invention relates to optimizing values for scan parameters for a scan of an object. An object specific exposure time is determined based on a maximal required value of a z-dependent tube current by exposure time product along a z-axis of the object and a maximal available tube current value of a tube used for the scan of the object (140). The maximal available tube current value depends on a tube voltage and maximal electric power of the tube at given focal spot area (110) and the z-dependent tube current by exposure time product profile is based on a dose index value or a pixel noise index value for the scan of the object, the tube voltage, and a z-dependent object size along the z-axis (120). The object specific exposure time is used for determining values of the scan parameters for the scan of the object (150).

Abstract: The present invention relates to optimizing values for scan parameters for a scan of an object. An object specific exposure time is determined based on a maximal required value of a z-dependent tube current by exposure time product along a z-axis of the object and a maximal available tube current value of a tube used for the scan of the object (140). The maximal available tube current value depends on a tube voltage and maximal electric power of the tube at given focal spot area (110) and the z-dependent tube current by exposure time product profile is based on a dose index value or a pixel noise index value for the scan of the object, the tube voltage, and a z-dependent object size along the z-axis (120). The object specific exposure time is used for determining values of the scan parameters for the scan of the object (150).

Abstract: A method includes enhancing a contrast to noise ratio (CNR) of image data, generating CNR enhanced image data, wherein the CNR enhanced image data has a substantially same image quality as the image data. A computing system (118) includes a computer readable storage medium (122) encoded with computer readable instructions for enhancing a contrast to noise ratio (CNR) of image data and one or more processors (120), which, when executing the computer readable instructions, causes the computing system to enhance the CNR of the image data. A method includes generating CNR enhanced image data, wherein CNR enhanced image data has a substantially same noise level, noise power spectrum, and spatial resolution of the image data.

Abstract: A method includes enhancing a contrast to noise ratio (CNR) of image data, generating CNR enhanced image data, wherein the CNR enhanced image data has a substantially same image quality as the image data. A computing system (118) includes a computer readable storage medium (122) encoded with computer readable instructions for enhancing a contrast to noise ratio (CNR) of image data and one or more processors (120), which, when executing the computer readable instructions, causes the computing system to enhance the CNR of the image data. A method includes generating CNR enhanced image data, wherein CNR enhanced image data has a substantially same noise level, noise power spectrum, and spatial resolution of the image data.

Abstract: A method for producing an artifact-corrected image of negative jaw impression in a recipient jaw comprising, forming a negative impression of said recipient jaw, producing a first digital image of said negative jaw impression, producing a second digital image, including said artifacts of said negative jaw impression in said recipient jaw and using said first digital image to produce an artifact-corrected computer representation of said negative impression in said recipient jaw.

Abstract: A method for producing an artifact-corrected image of negative jaw impression in a recipient jaw comprising, forming a negative impression of said recipient jaw, producing a first digital image of said negative jaw impression, producing a second digital image, including said artifacts of said negative jaw impression in said recipient jaw and using said first digital image to produce an artifact-corrected computer representation of said negative impression in said recipient jaw.

Abstract: A method for producing an artifact-corrected image of a negative jaw impression in a recipient jaw comprising, forming a negative impression of said recipient jaw, producing a first digital image of said negative jaw impression, producing a second digital image, including said artifacts of said negative jaw impression in said recipient jaw and using said first digital image to produce an artifact-corrected computer representation of said negative impression in said recipient jaw.

Abstract: A method for producing an artifact-corrected image of a negative jaw impression in a recipient jaw comprising, forming a negative impression of said recipient jaw, producing a first digital image of said negative jaw impression, producing a second digital image, including said artifacts of said negative jaw impression in said recipient jaw and using said first digital image to produce an artifact-corrected computer representation of said negative impression in said recipient jaw.

Abstract: A method and a system for calibrating an x-ray scanner, in which the lengths d.sub.ij of x-ray paths are first computed by means of the image of the calibration standard. There are then computed both the theoretical attenuations Ac.sub.ij and the attenuations Am.sub.ij measured on the image. There are then deduced the coefficient of proportionality K between the values Ac.sub.ij and Am.sub.ij in order to obtain values of K.times.Ac.sub.i. The values KAc.sub.i and Am.sub.i are employed for calculating the corrections to be made per channel as a function of the attenuation.

Abstract: The disclosure concerns X-ray scanners and, more particularly, a method to measure the bone density of a patient that takes his or her build into account. The disclosed method consists in performing a calibration of the bone density measurement by means of a phantom that simulates the patient's body and the vertebra an calibration phantom comprising a water insert and an insert with a high concentration of K.sub.2 HPO.sub.4. A measurement is made of the densities of several inserts of different concentrations and of the concentration of the water insert and of the K.sub.2 HPO.sub.4 high concentration insert, in the presence and without the presence of the bag of water, enabling the computation of corrections of the measured density of the patient's vertebra depending on his or her build.

Abstract: A method for elimination of parasitic noise in an x-ray scanner consists of computing the mean value of the signals of the ten first views in a circuit (26). This mean value is subtracted from the signals of the first view V.sub.1 in a circuit (27) so as to obtain the high-frequency components H.sub.1 which are considered as parasitic noise. The signals H.sub.1 are filtered in a high-pass filter before being subtracted from the signals of the view V.sub.1 to obtain signals V'.sub.1 which are free of parasitic components. The signals V'.sub.1 are processed in a sequential circuit (31) in order to obtain signals V'.sub.2 which are free of parasitic component. The same process is repeated for the signals of the other views V.sub.3 to V.sub.m.

Abstract: A method and system to calibrate an X-ray scanner uses a single circular phantom. The circular phantom is off-centered with respect to the axis of rotation of the scanner so as to introduce different paths in the phantom for each channel, depending on the angular positions of the scanner. This results in different attenuation measurements which are compared with values obtained by the computation of the path lengths which depend on the off-centered coordinates r and .PHI. and on the position of the scanner, thus enabling computation of the polynomial approximation coefficients to be applied to the measurements.

Abstract: The invention relates to x-ray scanners and more particularly to a method for calibrating scanners by means of a single standard of elliptical shape, for example. Attenuation measurements are performed with respect to a number of principal angular positions of the scanner about the standard. In addition, a number of meaurements or views are taken on each side of this principal position in order to compute a mean attenuation with respect to each channel. The attenuation curve is then smoothed by filtering and polynomial approximation.

Abstract: Disclosed is a method for the correction, in a scanner, of the defects due to the movements of the scanner. The method consists in having a rod which introduces a major attenuation and causing the scanner to make a full turn around a center of rotation O and obtaining m distinct views of the rod, each corresponding to an angular position .alpha..sub.j. The analysis of the signals of each view enables determining the angle .beta..sub.j of the rod. The knowledge of this angle .beta..sub.j leads to the computation of the coordinates b and c of the rod and the theoretical value .beta..sub.th of the angle .beta. for each view. The difference between the theoretical value .beta..sub.th and the measured value .beta..sub.j is used in the device for processing the scanner image.