Projection methods for producing two-dimensional images from three-dimensional data

Claim 1

A method of displaying a two-dimensional (2D) projection image of desired structures of a subject from collected three-dimensional (3D) image data of a volume of a subject comprising the steps of: a) acquiring a 3D data set having a plurality of entries, each entry being a value corresponding to at least one physical parameter representative of a voxel within said volume; b) selecting a statistical order k; c) choosing a viewing angle from which to view said volume; d) determining a set of intersected voxels which are intersected by a selected imaginary projection ray passing through said volume at the viewing angle and determining N intersected data set entries V i corresponding to the intersected voxels; e) calculating an average V and a standard deviation σ from the N intersected data set entries V i ; f) calculating a projection value P k from the N intersected data set entries V i according to the equation: ##EQU2## g) repeating steps "d"-"f" for a plurality of parallel imaginary projection rays at the viewing angle covering said volume; h) transferring the projection values P k to a two-dimensional display device; i) displaying a two-dimensional image created from the projection values P k on the two dimensional display device for analysis and interpretation; j) increase the value of the statistical order k and repeat steps "d"-"i" if a greater contrast of said structures in the projection image is desired; and k) decrease the value of the statistical order k and repeat steps "d"-"i" if a greater signal-to-noise ratio of said structures in the projection image is desired.

Claim 2

A method of displaying a two-dimensional (2D) projection image of desired structures of a subject from collected three-dimensional (3D) image data of a volume of a subject comprising the steps of: a) acquiring a 3D data set having a plurality of entries, each entry being a value corresponding to at least one physical parameter representative of a voxel within said volume; b) selecting a statistical order k; c) choosing a viewing angle from which to view said volume; d) determining a set of intersected voxels which are intersected by a selected imaginary projection ray passing through said volume at the viewing angle and determining N intersected data set entries V i corresponding to the intersected voxels; e) calculating an average V and a standard deviation σ from the N intersected data set entries V i ; f) calculating a projection value P k from the N intersected data set entries V i according to the equation: ##EQU2## g) repeating steps "d"-"f" for a plurality of parallel imaginary projection rays at the viewing angle covering said volume; h) transferring the projection values P k to a two-dimensional display device; i) displaying a two-dimensional image created from the projection values P k on the two dimensional display device for analysis and interpretation; j) increase the value of the statistical order k and repeat steps "d"-"i" if a greater contrast of said structures in the projection image is desired; and k) decrease the value of the statistical order k and repeat steps "d"-"i" if a greater signal-to-noise ratio of said structures in the projection image is desired.