Method of needle localization via partial computerized tomographic scanning and system thereof

A computer-based volume reconstruction unit configured to operate in conjunction with a CT scanner,

• the volume reconstruction unit comprising a processing and memory circuitry, the processing and memory circuitry being configured to perform a method of locating a tip of a metallic instrument inserted in a body, wherein the method utilizes a baseline sinogram derived from a prior computerized tomography (CT) scanning of the body, and wherein the baseline sinogram comprises projections in N exposure directions, the method comprising:
• a) performing, by a computer, three-dimensional Radon space registration of a sparse repeat sinogram to the baseline sinogram, thereby giving rise to registration parameters,
• wherein the sparse repeat sinogram is derived from a repeat CT scanning of the body and comprises projections in n exposure directions, n being substantially less than N, and wherein the repeat CT scanning is provided with the metallic instrument inserted into the body, the metallic instrument having an attached marker located at a known distance from the instrument tip;
• b) subtracting, by the computer, the baseline sinogram from the repeat sinogram in accordance with the registration parameters to obtain projection difference images, wherein each of the projection difference images is associated with an exposure direction of a respective projection in the repeat sinogram;
• and
• c) using, by the computer, the projection difference images and the known distance of the attached marker from the metallic instrument tip to determine a three-dimensional location of the metallic instrument tip.

A computer program product implemented on a non-transitory computer usable medium having computer readable program code embodied therein to cause the computer to perform a method of locating a tip of a metallic instrument inserted in a body, wherein the method utilizes a baseline sinogram derived from a prior computerized tomography (CT) scanning of the body, and wherein the baseline sinogram comprises projections in N exposure directions, the method comprising:

• a) performing, by a computer, three-dimensional Radon space registration of a sparse repeat sinogram to the baseline sinogram, thereby giving rise to registration parameters,
• wherein the sparse repeat sinogram is derived from a repeat CT scanning of the body and comprises projections in n exposure directions, n being substantially less than N, and wherein the repeat CT scanning is provided with the metallic instrument inserted into the body, the metallic instrument having an attached marker located at a known distance from the instrument tip;
• b) subtracting, by the computer, the baseline sinogram from the repeat sinogram in accordance with the registration parameters to obtain projection difference images, wherein each of the projection difference images is associated with an exposure direction of a respective projection in the repeat sinogram;
• and
• c) using, by the computer, the projection difference images and the known distance of the attached marker from the metallic instrument tip to determine a three-dimensional location of the metallic instrument tip.