Method and apparatus for 3-D computer tomography
AssigneeSiemens Medical Systems, Inc.
InventorsGioietta Kuo-Petravic, Rolf Hupke
Life of this patent
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Abstract
A computer tomographic system provides 3-D (three-dimensional) images of interior portions of a body, by scanning in a plurality of substantially orthogonal planes to obtain projection data on a 2-D (two-dimensional) detector surface, for each rotational position within a scanning plane and for each scanning plane. Reconstruction of the image data is obtained by backprojecting the projection data from each plane, and adding together the backprojected values from each plane for providing a 3-D mesh of the image data.
Claims16
In a computer tomography system, including at least one assembly having an x-ray source and opposing x-ray detector, said system being operable for relative rotation between said assembly and an object within said assembly under study, a method for obtaining a 3-D (three-dimensional) data set from which 2-D (two-dimensional) or 3-D images can be obtained of a portion of said object comprising the steps of:
- providing relative rotation between said assembly and said object in a first plane, for scanning to obtain related two-dimensional projection data;
- providing relative rotation between said assembly and said object in a second plane substantially perpendicular to said first plane, for obtaining related projection data;
- providing relative rotation between said assembly and said object in a third plane substantially orthogonal with said first and second planes, for obtaining related projection data;
- and
- processing said data from each one of said first through third substantially orthogonal planes for obtaining a 3-D mesh of data representative of a portion of said object.
In a 3-D computer tomography system, the method comprising the steps of:
- scanning mesh points in a plurality of substantially orthogonal planes associated with an object under investigation to obtain two-dimensional image data related thereto for each plane, respectively;
- processing the image data obtained from each plane via sequential steps including:
- computing the fast fourier transform (FFT);
- multiplying by ramp and window functions for filtering the FFT;
- computing the inverse FFT;
- interpolating and backprojecting the inverse FFT;
- rotating to the next scanning plane;
- and
- adding together the processed backprojected values from each plane for providing a 3-D mesh of said image data.
A 3-D computer tomography system, comprising:
- first through third two dimensional x-ray detectors;
- first through third x-ray scanning assembly means each operable for rotating about an object in first through third substantially orthogonal planes, respectively, for obtaining image data on said first through third two dimensional x-ray detectors, respectively;
- and
- processing means for processing said data from each one of said first through third substantially orthogonal planes, for obtaining a 3-D mesh of data representative of a portion of said object.
In a computer tomography system, including at least one assembly having an x-ray source and opposing x-ray detector, said system being operable for relative rotation between said assembly and an object under study, a method for obtaining a 3-D image of a portion of said object comprising the steps of:
- providing relative rotation between a source and detector assembly about said object in a first plane, for rotationally scanning said object to obtain related two-dimensional projection data;
- providing relative rotation between a source and detector assembly and said object in a second plane substantially perpendicular to aid first plane, for rotationally scanning said object to obtain related projection data;
- individually computing the fast Fourier transform (FFT) for the projection data for each singular position within the rotational scan, respectively;
- multiplying the FFT by a ramp function;
- filtering the data in Fourier space from the said projections at each angular position;
- individually computing the inverse FFT's for the filtered FFT's of the data from the said filtered data;
- individually interpolating and backprojecting the Fourier processed data for convolved data;
- individually rotating the source detector assembly to the next angular position;
- repeating the prior six steps for scanning said second plane;
- and
- adding together the rotated data to obtain a 3-D mesh of said data representative of a portion of said object.
Dependencies are inferred from the claim text.