Vascular data processing and image registration systems, methods, and apparatuses
In part, the invention relates to processing, tracking and registering angiography images and elements in such images relative to images from an intravascular imaging modality such as, for example, optical coherence tomography (OCT). Registration between such imaging modalities is facilitated by tracking of a marker of the intravascular imaging probe performed on the angiography images obtained during a pullback. Further, detecting and tracking vessel centerlines is used to perform a continuous registration between OCT and angiography images in one embodiment.
1. A method of detecting an intravascular probe marker comprising:
obtaining a first frame of angiography image data that is substantially free of contrast agent image data and includes the intravascular probe marker, the first frame stored in one or more electronic memory devices;
obtaining a second frame of angiography image data that comprises contrast agent image data in a vicinity of the intravascular probe marker, the second frame stored in the one or more electronic memory devices;
detecting, using an intravascular data collection system, the intravascular probe marker in the first frame and the second frame;
processing the plurality of pullback frames using a Hessian-based vessleness filter; and
tracking the intravascular probe marker from one of the first frame or the second frame through the plurality of pullback frames using template matching.
2. The method of claim 1 , further comprising:
applying an image processing transform, using an intravascular data collection system, to the second frame to remove or modify a feature in the second frame; and
increasing an intensity of a plurality of pixels in the second frame, the plurality of pixels comprising a guidewire image in the second frame.
3. The method of claim 1 further comprising:
generating an average intensity value for a plurality of images; and
subtracting the average intensity from the first or second frame.
4. The method of claim 1 further comprising:
applying a bottom hat operator, using an intravascular data collection system, to the second frame; and
applying, using an intravascular data collection system, a morphological close operation.
5. A method of detecting an intravascular probe marker comprising:
obtaining a first frame of angiography image data that is substantially free of contrast agent image data and includes the intravascular probe marker, the first frame stored in one or more electronic memory devices;
obtaining a second frame of angiography image data that comprises contrast agent image data in a vicinity of the intravascular probe marker, the second frame stored in the one or more electronic memory devices; and
detecting, using an intravascular data collection system, the intravascular probe marker in the first frame and the second frame,
wherein detecting the intravascular probe marker comprises:
filtering candidate markers comprising pixels in the first frame and the second frame by applying a multiscale Laplacian of Gaussian operator on the first frame and the second frame; and
performing a non-maxima suppression process to identify blobs having a relative maximum in a neighborhood of pixels.
6. A method of detecting an intravascular probe marker comprising:
obtaining a first frame of angiography image data that is substantially free of contrast agent image data and includes the intravascular probe marker, the first frame stored in one or more electronic memory devices;
obtaining a second frame of angiography image data that comprises contrast agent image data in a vicinity of the intravascular probe marker, the second frame stored in the one or more electronic memory devices;
detecting, using an intravascular data collection system, the intravascular probe marker in the first frame and the second frame;
generating a guidewire-based potential by applying a Euclidian distance transform on a binary image; and
applying an exponent to a negative fractional power times the distance transform.
7. The method of claim 6 further comprising determining a plurality of geodesic distances based on the guidewire-based potential using a fast marching method.
8. The method of claim 1 further comprising:
removing a shadow from the first frame and the second frame;
increasing a contrast level of a guidewire on one of the first frame or second frame; and performing a morphological image reconstruction for each marker candidate.
9. A method of detecting an intravascular probe marker comprising:
obtaining a first frame of angiography image data that is substantially free of contrast agent image data and includes the intravascular probe marker, the first frame stored in one or more electronic memory devices;
obtaining a second frame of angiography image data that comprises contrast agent image data in a vicinity of the intravascular probe marker, the second frame stored in the one or more electronic memory devices;
detecting, using an intravascular data collection system, the intravascular probe marker in the first frame and the second frame; and
tracking the intravascular probe marker through a plurality of frames obtained during a pullback using a Viterbi dynamic programming method.