Determining needle position
In an embodiment, a method ( 100 ) is described. The method comprises receiving ( 102 ) data corresponding to a plurality of radiographic imaging slices of a body. The method further comprises determining ( 104 ) a position of a needle inserted in the body. The determination is based on combining information from at least one of the radiographic imaging slices comprising an indication of a first portion of the needle outside the body and at least one other of the radiographic imaging slices comprising an indication of a second portion of the needle inside the body. A combined needle region is generated by merging data corresponding to a position of the first portion of the needle outside the body with data corresponding to a position of the second portion of the needle inside the body. The method further comprises generating ( 106 ) display data for providing a visual representation of the needle in an image of the body in combination with a visual representation of at least the first and second portions of the needle superimposed on the image. The image is in a plane that is digitally tilted with respect to a plane parallel to the plurality of radiographic imaging slices.
1. A computer-implemented method for visualizing a needle inserted in a body, comprising:
receiving data corresponding to a plurality of radiographic imaging slices of the body;
determining a position of the needle inserted in the body based on combining information from at least one of the radiographic imaging slices comprising an indication of a first portion of the needle outside the body and at least one other of the radiographic imaging slices comprising an indication of a second portion of the needle inside the body, wherein determining the position of the needle comprises generating a combined needle region by merging data corresponding to a position of the first portion of the needle outside the body with data corresponding to a position of the second portion of the needle inside the body; and
generating display data for providing a visual representation of the needle in an image of the body in combination with a visual representation of at least the first and second portions of the needle superimposed on the image, wherein the image is in a plane that is digitally tilted with respect to a plane parallel to the plurality of radiographic imaging slices.
2. The method of claim 1 , further comprising causing a user interface to display the image.
3. The method of claim 2 , further comprising:
identifying the second portion of the needle inside the body by performing threshold truncation on the received data corresponding to the second portion of the needle; and
determining a three-dimensional region corresponding to the second portion of the needle based on a planned path for the needle, wherein the three-dimensional region comprises a plurality of candidate needle regions from which the real needle region can be determined.
4. The method of claim 3 , comprising extending the three-dimensional region corresponding to the second portion of the needle by searching for at least one neighboring candidate needle region removed by the threshold truncation and including data corresponding to a neighboring candidate needle region as part of the extended three-dimensional region.
5. The method of claim 1 , wherein determining the position of the needle comprises fitting a line to a plurality of regions in the received data indicative of the position of the first and second portions of the needle.
6. The method of claim 1 , wherein determining the position of the needle comprises determining a real needle region from a plurality of candidate needle regions by minimizing an energy function derived from the received data.
7. The method of claim 6 , wherein the energy function is based on at least one of: a discrete degree of the candidate needle region; an area of the candidate needle region; an average pixel value of an edge of the candidate needle region; an average pixel value of an inner part of the candidate needle region; a mean of all cross-sectional values of the candidate needle region; a circularity parameter; and a deviation parameter.
8. The method of claim 1 , further comprising:
identifying the first portion of the needle outside the body by performing morphological opening on the received data corresponding to the first portion of the needle; and
determining a three-dimensional region corresponding to the first portion of the needle based on a planned path for the needle, wherein the three-dimensional region comprises a plurality of candidate needle regions from which the real needle region can be determined.
9. The method of claim 1 , comprising detecting a tip of the needle based on a comparison of a measurement within a candidate needle tip region within the data with a threshold indicative of a lack of presence of needle structure within the candidate needle tip region.
10. The method of claim 9 , wherein:
if the comparison with the threshold is indicative of needle structure being present in the candidate needle tip region, another candidate needle tip region is identified from the data to determine whether or not the other candidate needle tip region comprises data indicative of the presence of needle structure; and
if the comparison with the threshold is indicative of lack of presence of needle structure within the data corresponding to the candidate needle tip region, a previously-identified candidate needle tip region comprising data indicative of the presence of needle structure within the previously-identified candidate needle tip region is determined to contain the tip of the needle.
11. The method of claim 1 , comprising detecting an insertion point on the body for the needle based on a first line fitted to a predicted trajectory of the needle determined based on the determined position of the needle and a second line fitted along a surface of the body.
12. The method of claim 1 , comprising causing a user interface to provide an indication of a difference between a predicted trajectory and a planned trajectory of the needle responsive to a determination that there is a deviation between the predicted trajectory and the planned trajectory.
13. An apparatus for visualizing a needle inserted in a body, the apparatus comprising:
a memory that stores a plurality of instructions;
a processor that couples to the memory and is configured to execute the plurality of instructions to:
receive data corresponding to a plurality of radiographic imaging slices of the body;
determine a position of the needle inserted in the body based on combining information from at least one of the radiographic imaging slices comprising an indication of a first portion of the needle outside the body and at least one other of the radiographic imaging slices comprising an indication of a second portion of the needle inside the body, wherein determining the position of the needle comprises generating a combined needle region by merging data corresponding to a position of the first portion of the needle outside the body with data corresponding to a position of the second portion of the needle inside the body; and
generate display data for providing a visual representation of the needle in an image of the body in combination with a visual representation of at least the first and second portions of the needle superimposed on the image, wherein the image is in a plane that is digitally tilted with respect to a plane parallel to the plurality of radiographic imaging slices; and
a display configured to display the image of the body superimposed with the position of the needle.
14. A non-transitory computer-readable medium for storing executable instructions, which cause a computer-implemented method to be performed to visualize a needle inserted in a body, the method comprising:
receiving data corresponding to a plurality of radiographic imaging slices of the body;
determining a position of the needle inserted in the body based on combining information from at least one of the radiographic imaging slices comprising an indication of a first portion of the needle outside the body and at least one other of the radiographic imaging slices comprising an indication of a second portion of the needle inside the body, wherein determining the position of the needle comprises generating a combined needle region by merging data corresponding to a position of the first portion of the needle outside the body with data corresponding to a position of the second portion of the needle inside the body; and
generating display data for providing a visual representation of the needle in an image of the body in combination with a visual representation of at least the first and second portions of the needle superimposed on the image, wherein the image is in a plane that is digitally tilted with respect to a plane parallel to the plurality of radiographic imaging slices.