Four dimensional spiral volume imaging using fast retrace

A method of computed tomographic imaging comprising:

• (a) moving a radiation source and a subject relative to each other so as to irradiate a subject along a generally spiral path;
• (b) progressively collecting a spiral data set that includes a plurality of progressively temporally displaced views of image data over a data collection duration, each view being indicated by an angular position around the subject and by an angular position along a spiral;
• (c) repeating steps (a) and (b) over time to generate a plurality of temporally displaced spiral data sets, each data set having progressively temporally displaced views;
• (d) spatially interpolating corresponding views within each spiral data set and reconstructing the spatially interpolated views into a plurality of temporally displaced three-dimensional image representations, each of the three-dimensional image representations being temporally distorted by being reconstructed from the temporally displaced views of image data collected over the collection duration;
• (e) temporally interpolating such that at least selected data in each of the temporally distorted three-dimensional image representations is corrected to correspond to a common time.

A method of contrast agent enhanced CT imaging comprising:

• (a) generating a three-dimensional reference image representation of a subject;
• (b) injecting the subject with a contrast agent;
• (c) after injecting the contrast agent, moving a radiation source and the subject relative to each other so as to irradiate the subject along a generally spiral path;
• (d) collecting a spiral data set that includes a plurality of views of image data, each view being indicated by an angular position around the subject and by an angular position along a spiral;
• (e) repeating steps (c) and (d) over time to generate a plurality of temporally displaced spiral data sets;
• (f) spatially interpolating corresponding views within each spiral data set and reconstructing the spatially interpolated views into a plurality of temporally displaced three-dimensional image representations illustrative of a time evolution of the contrast agent, whereby the plurality of three-dimensional image representations represent a common volume of the subject at time displaced intervals.

A method of diagnostic imaging comprising:

• (a) moving a subject and a radiation source such that a volume of interest of the subject is irradiated along a generally spiral path of a preselected axial length over a preselected duration;
• (b) collecting a plurality of views of data each identifiable by a corresponding position along the spiral path and being temporally displaced over the preselected duration;
• (c) spatially interpolating corresponding axially displaced views with a spatially interpolation function;
• (d) reconstructing the spatially interpolated views into a three-dimensional image representation;
• (e) repeating steps (a)-(d) a plurality of times to generate a plurality of the three-dimensional image representations which are linear in three spatial dimensions;
• (f) temporally interpolating at least selected regions of the plurality of three-dimensional image representations to create a four-dimensional image representation in the three spatial dimensions and a time dimension, which four-dimensional image representation is linear in all four dimensions.

A method of computed tomographic imaging comprising:

• (a) moving a radiation source and a subject relative to each other so as to irradiate a subject along a generally spiral path;
• (b) progressively collecting a spiral data set that includes a plurality of progressively temporally displaced views of image data over a data collection duration, each view being indicated by an angular position around the subject and by an angular position along a spiral;
• (c) repeating steps (a) and (b) over time to generate a plurality of temporally displaced spiral data sets, each spiral data set having progressively temporally displaced views;
• (d) spatially interpolating and reconstructing the views into a temporally displaced series of temporally distorted image representations, each of the temporally distorted image representations being temporally distorted by being reconstructed from the temporally displaced views of image data collected over the collection duration;
• (e) processing the temporally distorted image representations to generate a temporally displaced series of temporally distorted diagnostic information representations;
• (f) temporally interpolating the temporally distorted diagnostic information representations such that each is corrected to correspond to one of a series of common times.

In a computed tomographic imaging apparatus which includes a means for repeatedly moving a radiation source and a subject relative to each other such that the fan of radiation irradiates the subject along a generally spiral path over a data collection duration;

• radiation detectors for detecting the radiation fan and generating a plurality of temporally displaced views of electronic data, each view being identified by an angular position around the subject and by an angular position along a spiral;
• a spatial interpolating means for spatially interpolating corresponding views of each spiral;
• and a reconstructing means for reconstructing the temporally displaced, spatially interpolated views into a plurality of temporally distorted three-dimensional image representations, THE IMPROVEMENT COMPRISING:
• a temporal interpolating means for temporally interpolating the plurality of temporally distorted three-dimensional image representations such that the data in each of the three-dimensional image representations corresponds to a common time, whereby the three-dimensional image representations are corrected for temporal distortion caused by generating views over the data collection duration.

A diagnostic imaging apparatus comprising:

• a means for repeatedly moving a subject and a radiation source such that the subject is irradiated along a generally spiral path over a preselected axial length over a preselected duration;
• a detector means for detecting radiation that has traversed the subject and producing a plurality of views of electronic data each identifiable by a corresponding position along the spiral path;
• a means for interpolating axially corresponding views with an interpolation function;
• a means for reconstructing the views into a plurality of temporally displaced, temporally distorted three-dimensional image representations;
• and,
• a temporal interpolation means for temporally interpolating the plurality of temporally distorted image representations to create a four-dimensional image representation in three physical dimensions and a time dimension, which four-dimensional image representation is linear in all four dimensions.

A diagnostic imaging apparatus comprising:

• a means for repeatedly moving a radiation source and a subject relative to each other such that radiation from the source repeatedly traverses a common region of the subject along a plurality of spiral paths;
• a detector means for detecting the radiation that has traversed the subject and producing a plurality of spiral data sets, each spiral data set including a plurality of progressively temporally displaced views of image data collected over one of the spiral paths during a spiral paths during a duration, each view being identified by a position along the spiral path;
• a spatial interpolating means for spatially interpolating corresponding views within each spiral data set;
• a reconstruction means for reconstructing the spatially interpolated views into a temporally displaced series of temporally distorted image representations, each of the temporally distorted image representations being temporally distorted by being reconstructed from the temporally displaced views of image data collected over the spiral path traversal duration;
• a processing means for processing the temporally distorted image representations to generate a temporally displaced series of temporally distorted diagnostic information representations;
• a temporal interpolating means for temporally interpolating the temporally distorted diagnostic information representations such that each is corrected to correspond to a one of a series of common times;
• a display means for converting the temporally interpolated diagnostic information representations into a series of human-readable displays.