3 results about "Ct measurements" patented technology

A computer system, a non-transitory computer readable medium, and a method for computed tomography (CT) reconstruction. The computer system is configured to perform the method and the computer readable medium is configured to store instructions for performing the method. The method includes obtaining two or more spectral CT measurement data of different materials of a target from one or more 2D or 3D spectral CT images acquired by a CT imaging system using more than one CT imaging energy regimes; and producing a pair reconstructed spectral CT images that are representative of densities of the different materials of the target by performing one or more iterations on the two or more spectral CT measurement data using a trained machine learning network that is trained to performing a diffusion sampling operation and a forward-model-based likelihood on one or more intermediate data sets representing the two or more spectral CT measurement data.

A method for adapting depth structure model data to coherence tomography measurement data of a sample having a plurality of layers composed of layer materials in a layer construction in a depth direction. A plurality of layers having layer thicknesses and a plurality of layer transitions upstream of the respective layers in the depth direction are derived from the depth structure. Furthermore, model reflectivity coefficients are adapted to the respective layer-transition-specific, spectrally resolved reflectivity coefficients by way of a value that optimizes the adaptation being calculated in each case for the at least one parameter of one of the model layer transitions. On the basis of the value calculated for the at least one parameter, depth structure model data can be obtained, the resolution of which in the depth direction goes beyond the resolution predefined by a CT measurement on which the spectral complex field reflectivity is based.

The invention provides an oral cavity CBCT (cone beam computed tomography) multi-material beam hardening correction method, which is particularly suitable for a multi-material scene and can be used for removing dark bands and stripe artifacts around teeth, bones and metal implants to obtain a reconstructed high-precision image. The method comprises the following steps: firstly, removing scattering artifacts in CBCT imaging data to obtain projection data after scattering correction, then determining all materials included in the data, areas where the materials are located and segmentation volumes, and simulating to obtain multispectral simulation multicolor projection and monochromatic projection simulation data; and calculating a difference value between the fitting multicolor projection simulation data and the optimized reference projection data to obtain a non-linear correction item between a CT measurement value and a true value, and then superposing the non-linear correction item to the projection data after scatter correction to recover the FDK measurement value to the true value so as to complete beam hardening correction of the original CBCT imaging data.