Ge Healthcare Finland Oy

Instrumentarium Corporation

Palodex Group Oy

Samuli Siltanen

Martti Kalke

Matti Lassas

Jari Kaipio

Ville Kolehmainen

Esa Suuronen

Maaria Rantala

Henri Setälä

Erkki Somersalo

Petri Jouhikainen

Simopekka Vänskä

Ville Petteri Kolehmainen

The invention relates to a method and system for determining a sharp panoramic image constructed from a group of projection images, especially the invention relates to defining a structure of the panoramic X-ray image of an area of a dentition and of jaws. The structure of a panoramic image to be generated from a group of projection images is determined by at least two crucial parameters, namely parameters of the central surface S of the sharp layer and thickness t(s) of the sharp layer, using penalty function F(S,t), which is at least a penalty function F(S,t) of low-frequency changes in the computed panoramic image corresponding to the choices S and t(S). After computing F(S,t) the best center surface and thickness function (in other words the sharpest layer of the panoramic image) is obtained by minimizing said penalty function F(S,t) over parameter space.

Method and system for determining a sharp panoramic image constructed from a group of projection images

The present invention relates to a method for producing a three-dimensional digital x-ray image by using digital x-ray images taken of the object from at least two different directions as input for a reconstruction algorithm. In the method, at least one of the images used as input is taken as a tomosynthetic slice image of a region of interest () in the object () of imaging.

Method for producing a three-dimensional digital x-ray image

This invention relates to a medical X-ray device arrangement for producing three-dimensional information of an object in a medical X-ray imaging, the medical X-ray device arrangement comprising an X-ray source for X-radiating the object from at least two different directions and a detector for detecting the X-radiation to form projection data of the object. The medical X-ray device () arrangement comprises means () for utilizing said projection data in a regularized reconstruction method based on solving the non-linear evolution equation&#x2202;&#x3c6;()=&#x2212;()*(((&#x3c6;()))&#x2212;)+&#x3b1;&#x3c6;()to produce three-dimensional information of the object, x representing the coordinates inside the object under imaging, t representing time, &#x3c6; representing a level set function indicating the boundary of the object, h representing a positive-valued function, m representing projection data, the operator A representing the X-radiation attenuation model, A* representing the backprojection operator of A, &#x3b1; representing a positive number, P representing high pass filtering, and f representing a cut-off function returning zero for non-positive arguments and positive values for positive arguments.

Method and arrangement for three-dimensional medical X-ray imaging

The invention relates to a medical X-ray devicearrangement for producing three-dimensional information of an objectin a medical X-ray imaging medical X-ray device arrangement comprising an X-ray sourcefor X-radiating the object from different directions and a detectorfor detecting the X-radiation to form projection data of the object. The medical X-ray devicearrangement comprises: to produce three-dimensional information of the object, the prior distribution p(x) representing mathematical modelling of the object, the object image vector x, which comprise values of the X-ray attenuation coefficient inside the object, m representing projection data, the likelihood distribution p(m|x) representing the X-radiation attenuation model between the object image vector x and projection data m, p(m) being a normalization constant and the posteriori distribution p(x|m) representing the three-dimensional information of the object

Method and arrangement for medical X-ray imaging and reconstruction from sparse data

A medical X-ray device arrangement for producing three-dimensional information of an object in a medical X-ray imaging, the medical X-ray device arrangement comprising an X-ray source for X-radiating the object from at least two different directions and a detector for detecting the X-radiation to form projection data of the object. The medical X-ray device arrangement comprises means for modelling X-ray attenuation coefficient of said object using a multiresolution representation, eliminating part of the coefficients in said multiresolution representation to form reduced multiresolution representation, and utilizing said projection data in a regularized reconstruction method based on minimizing the penalty()=&#x2225;&#x2225;2/2+&#x3b1;&#x2225;()over the coefficients in the said reduced multiresolution representation to produce three-dimensional information of the object.

Method and arrangement for multiresolutive reconstruction for medical X-ray imaging

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Helsinki, Finland

Samuli Siltanen