Methods and systems for identifying anatomical landmarks in image data
Systems, devices, and methods are described for locating and identifying anatomical landmarks, such as ligament attachment points, in image data. These systems, devices, and methods may provide an oblique plane that contains an anatomical landmark such as a ligament attachment point to the tibia. For example, the position at which the anterior cruciate ligament (ACL), medial collateral ligament (MCL) posterior cruciate ligament (PCL), or patellar tendon attaches to the tibia may be identified. The systems, devices, and methods allow for tracing of an anatomical landmark to generate a 3-D marking on a 3-D surface model of a patient's bone. The attachment points may be useful landmarks for patient-matched instrumentation.
1. A system for locating anatomical landmarks in image data, comprising:
a device configured to receive image data representative of a patient's joint;
one or more graphical user interface units configured to:
receive user inputs identifying a first point and a second point along a portion of soft tissue of the patient represented in the image data representative of the patient's joint;
receive user inputs tracing a feature of the portion of soft tissue of the patient having a longitudinal axis;
one or more processors coupled to the device configured to receive image data representative of a patient's joint and the one or more graphical user interface units configured to:
identify one of a line or a curve that connects the first point and the second point along a portion of soft tissue of the patient;
identify a set of planes comprising (i) an oblique plane intersecting a normal to the line or the curve and (ii) at least one other plane parallel to the oblique plane;
generate, using the image data representative of the patient's joint, a set of reformatted images;
generate a 3-D model representative of the patient's joint using the set of reformatted images;
generate a 3-D marking representing the traced feature of the portion of soft tissue of the patient on the 3-D model representative of the patient's joint; and
one or more screens coupled to the one or more graphical user interface units and the one or more processors configured to display one or more of the image data representative of the patient's joint, the first point and the second point along the portion of soft tissue of the patient represented in the image data representative of the patient's joint, the traced feature of the portion of soft tissue of the patient, the oblique plane, the 3-D model representative of the patient's joint, one or more reformatted images from the set of reformatted images, and the 3-D marking representing the traced feature of the portion of soft tissue of the patient.
2. The system of claim 1 , wherein the image data representative of the patient's joint comprises image slices taken in parallel image planes selected from one of sagittal planes, coronal planes, or axial planes of the patient.
3. The system of claim 2 , wherein the oblique plane is parallel to the parallel image planes.
4. The system of claim 1 , wherein receiving user inputs tracing the feature of the portion of soft tissue of the patient comprises receiving user inputs tracing the feature in two or more reformatted images from the set of reformatted images.
5. The system of claim 1 , wherein receiving user inputs tracing the feature of the portion of soft tissue of the patient comprises:
displaying on the one or more graphical user interface units a first reformatted image from the set of reformatted images; and
displaying on the one or more graphical user interface units a second reformatted image from the set of reformatted images, wherein the second reformatted image is parallel to and offset from the first reformatted image.
6. The system of claim 1 , wherein the 3-D model of the patient's joint is generated using the image data of the patient's joint prior to tracing the feature of the portion of soft tissue of the patient.
7. The system of claim 1 , wherein receiving user inputs tracing the feature of the soft tissue of the patient comprises storing data representing the tracing in a matrix.
8. The system of claim 1 , wherein receiving user inputs tracing the feature of the soft tissue of the patient comprises outlining a cross-section of the feature of the soft tissue of the patient one or more reformatted images from the set of reformatted images.
9. The system of claim 1 , wherein generating the set of reformatted images comprises sampling the image data representative of the patient's joint along the oblique plane.
10. The system of claim 1 , wherein the one or more graphical user interface units further comprise one or more pointing devices, including a mouse.
11. The system of claim 1 , wherein the first point along the portion of soft tissue of the patient is an attachment point of the soft tissue of the patient to the patient's bone and the second point along the portion of soft tissue of the patient is a midpoint of the soft tissue of the patient.
12. The system of claim 1 , wherein the soft tissue of the patient is a patellar tendon of a patient.
13. A system for locating anatomical landmarks in image data, comprising:
a device configured to generate image data representative of a patient's joint;
one or more graphical user interface units configured to:
receive user inputs identifying a first point and a second point along a portion of soft tissue of the patient represented in the image data representative of the patient's joint;
receive user inputs tracing a feature of the portion of soft tissue of the patient having a longitudinal axis that is curved;
one or more processors coupled to the device configured to receive image data representative of a patient's joint and the one or more graphical user interface units configured to:
identify one of a line or a curve that connects the first point and the second point along a portion of soft tissue of the patient;
identify a set of planes comprising (i) an oblique plane intersecting a normal to the line or the curve and (ii) at least one other plane parallel to the oblique plane;
generate, using the image data representative of the patient's joint, a set of reformatted images;
generate a 3-D model representative of the patient's joint using the set of reformatted images;
generate a 3-D marking representing the traced feature of the portion of soft tissue of the patient on the 3-D model representative of the patient's joint; and
one or more screens coupled to the one or more graphical user interface units and the one or more processors configured to display one or more of the image data representative of the patient's joint, the first point and the second point along the portion of soft tissue of the patient represented in the image data representative of the patient's joint, the traced feature of the portion of soft tissue of the patient, the oblique plane, the 3-D model representative of the patient's joint, one or more reformatted images from the set of reformatted images, and the 3-D marking representing the traced feature of the portion of soft tissue of the patient.
14. The system of claim 13 , wherein identifying the oblique plane comprises:
receiving, at the one or more graphical user interfaces, a user input identifying a curve substantially parallel to the longitudinal axis of the portion of soft tissue of the patient; and
evaluating, using the one or more processors, an oblique plane normal to the curve at the point where the oblique plane intersects the curve.
15. The system of claim 13 , wherein the set of reformatted images is normal to the curve at the point where each reformatted image intersects the curve.
16. A system for locating anatomical landmarks in image data, comprising:
a device configured to receive image data representative of a patient's joint;
one or more graphical user interface units configured to:
receive user inputs identifying a first point and a second point along a portion of soft tissue of the patient represented in the image data representative of the patient's joint;
receive user inputs tracing a feature of the portion of soft tissue of the patient having a longitudinal axis;
one or more processors coupled to the device configured to receive image data representative of a patient's joint and the one or more graphical user interface units configured to:
identify one of a line or a curve that connects the first point and the second point along a portion of soft tissue of the patient;
identify a set of planes comprising (i) an oblique plane intersecting a normal to the line or the curve and (ii) at least one other plane parallel to the oblique plane;
generate, using the image data representative of the patient's joint, a set of reformatted images by:
receiving the location and orientation of the oblique plane;
generating a set of oblique planes parallel or orthogonal to the oblique plane;
sampling the image data representative of the patient's joint along the set of oblique planes;
computing the corners of the set of oblique planes by determining the intersection of each of the oblique planes in the set of oblique planes with the image data representative of the patient's joint;
generating texture coordinates using the corners of the set of the oblique planes;
assigning pixel intensity values to the texture coordinates; and
interpolating pixel intensity values for texture coordinates that do not coincide with points in the image data representative of the patient's joint;
generate a 3-D model representative of the patient's joint using the set of reformatted images;
generate a 3-D marking representing the traced feature of the portion of soft tissue of the patient on the 3-D model representative of the patient's joint; and
one or more screens coupled to the one or more graphical user interface units and the one or more processors configured to display one or more of the image data representative of the patient's joint, the first point and the second point along the portion of soft tissue of the patient represented in the image data representative of the patient's joint, the traced feature of the portion of soft tissue of the patient, the oblique plane, the 3-D model representative of the patient's joint, one or more reformatted images from the set of reformatted images, and the 3-D marking representing the traced feature of the portion of soft tissue of the patient.
17. The system of claim 16 , wherein the set of oblique planes span the entire volume of the image data representative of the patient's joint.
18. The system of claim 16 , wherein the set of oblique planes are equally spaced.
19. The system of claim 16 , wherein the pixel intensity values represent radiodensity measurements, attenuation coefficients, tissue relaxation time, or proton density.
20. The system of claim 16 , wherein the interpolation is achieved using nearest-neighbor interpolation, bilinear interpolation, trilinear interpolation, cubic interpolation, or any combination thereof.