Automatic improvement of tracking data for intraoperative c-arm images in image guided surgery

A method of adjusting a registration mapping combining data indicative of spatial positions in a three-dimensional operating space and imaging data acquired with an imaging device located in a position and orientation in operating space referred to as an imaging pose, the method comprising:

• a) bringing a phantom into a first pose, wherein the phantom is at least in partial view of the imaging device located in a second pose, the phantom comprising an assembly of markers that can be detected by the imaging device;
• b) acquiring image data of the marker assembly of the phantom with the imaging device in the second pose;
• c) locating imaged markers in the acquired image data of the marker assembly;
• d) obtaining mapped markers by submitting spatial positions of the markers in the marker assembly of the phantom in the first pose to the registration mapping using the second pose as imaging pose;
• e) determining a distance measure of the imaged markers and the mapped markers as a measure of accuracy of the registration mapping;
• f) jointly performing step g) and repeating steps d) and e) a predetermined number of times or until two consecutive measures of accuracy obtained in step e) approach one another up to a predetermined threshold or until a predetermined convergence criterion is met;
• and
• g) transforming the imaging pose used in the registration mapping to a different pose.

A system for determining a measure of accuracy of a registration mapping combining data indicative of spatial positions in a three-dimensional operating space and imaging data, the system comprising:

• an imaging device located in a position and orientation in operating space and referred to as an imaging pose, said imaging device operable to acquire said imaging data;
• a phantom comprising an assembly of markers that can be imaged by the imaging device, wherein the phantom is placed in a first pose and in at least partial view of the imaging device located in a second pose, said imaging device operable to acquire image data of the marker assembly of the phantom with the imaging device in the second pose;
• and
• a computer system configured to
• locate imaged markers in the acquired image data of the marker assembly,
• obtain mapped markers by submitting spatial positions of the markers in the marker assembly of the phantom in the first pose to the registration mapping using the second pose as the imaging pose, and
• determine a distance measure of the imaged markers and the mapped markers as the measure of accuracy of the registration mapping.

A system for adjusting a registration mapping combining data indicative of spatial positions in a three-dimensional operating space and imaging data, the system comprising:

• an imaging device located in a position and orientation in operating space and referred to as an imaging pose, said imaging device operable to acquire said imaging data;
• a phantom comprising an assembly of markers that can be imaged by the imaging device, wherein the phantom is placed in a first pose and in at least partial view of the imaging device located in a second pose, said imaging device operable to acquire image data of the marker assembly of the phantom with the imaging device in the second pose;
• and
• a computer system configured to
• locate imaged markers in the acquired image data of the marker assembly,
• obtain mapped markers by submitting spatial positions of the markers in the marker assembly of the phantom in the first pose to the registration mapping using the second pose as the imaging pose,
• determine a distance measure of the imaged markers and the mapped markers as the measure of accuracy of the registration mapping,
• transform the imaging pose used in the registration mapping to a different pose, and
• determine whether two consecutive measures of accuracy of different camera poses approach one another up to a predetermined threshold or until a predetermined convergence criterion is met.

A computer program embodied on a machine readable medium for determining a measure of accuracy of a registration mapping combining data indicative of spatial positions in a three-dimensional operating space and imaging data acquired with an imaging device located in a position and orientation in operating space referred to as an imaging pose, wherein a phantom is placed in a first pose and is at least in partial view of the imaging device located in a second pose, the phantom comprising a marker assembly that can be imaged by the imaging device, the program comprising:

• code that directs the imaging device to acquire image data of the marker assembly of the phantom with the imaging device in the second pose;
• code that locates imaged markers in the acquired image data of the marker assembly;
• code that obtains mapped markers by submitting spatial positions of the markers in the marker assembly of the phantom in the first pose to the registration mapping using the second pose as the imaging pose;
• and
• code that determines a distance measure of the imaged markers and the mapped markers as the measure of accuracy of the registration mapping.