Feature-based composing for 3D MR angiography images
First Claim
1. A method of aligning by a processor of a plurality of volumes from a patient, comprising:
- reading by the processor of the plurality of volumes being Magnetic Resonance Angiography (MRA) volumes in DICOM format and correcting at least one of the plurality of volumes for shearing based on a tilt angle obtained from a DICOM header;
equalizing the plurality of volumes with the highest resolution of the plurality of volumes;
detecting edges in a plurality of 2D slices of a first volume of the plurality of volumes within a search range and a plurality of 2D slices of a second volume of the plurality of volumes within the search range to form a first and a second plurality of edge maps, respectively, the first and second edge maps having an overlap region wherein the overlap region depends upon the search range;
designating the first plurality of edge maps as a fixed image If with a location p=(px, py, pz);
designating the second plurality of edge maps as a moving image It with a translation t=(tx, ty, tz) with respect to the fixed image;
determining the search range based on a shift in a horizontal, vertical and depth direction of a parameter, the parameter determined from at least a relative table position and an image position; and
determining a correlation of the first plurality of edge maps to the second plurality of edge maps at a plurality of overlapping positions in the overlap region O containing the location p for all 2D slices in the overlap region of the first and the second volume to determine a best alignment of the first volume and the second volume.
2 Assignments
0 Petitions
Accused Products
Abstract
Multiple volumes that are to be aligned to form a single volume are processed. The system and method use an equalization step, a edge detection step and a correlation step to determine the overlapping positions between the first volume and the second volume of a volume pair having a maximum correlation value, and the best alignment of the first volume and the second volume of the volume pair is determined by the correlation value. A coarse correlation step using lower resolution volumes can be performed first followed by a fine correlation step using higher resolution images to save processing time. Initial preprocessing steps such as volume shearing can be performed. Equalization involves equalizing voxel size and edge detection can be performed using a Canny edge detector.
-
Citations
20 Claims
-
1. A method of aligning by a processor of a plurality of volumes from a patient, comprising:
-
reading by the processor of the plurality of volumes being Magnetic Resonance Angiography (MRA) volumes in DICOM format and correcting at least one of the plurality of volumes for shearing based on a tilt angle obtained from a DICOM header; equalizing the plurality of volumes with the highest resolution of the plurality of volumes; detecting edges in a plurality of 2D slices of a first volume of the plurality of volumes within a search range and a plurality of 2D slices of a second volume of the plurality of volumes within the search range to form a first and a second plurality of edge maps, respectively, the first and second edge maps having an overlap region wherein the overlap region depends upon the search range; designating the first plurality of edge maps as a fixed image If with a location p=(px, py, pz); designating the second plurality of edge maps as a moving image It with a translation t=(tx, ty, tz) with respect to the fixed image; determining the search range based on a shift in a horizontal, vertical and depth direction of a parameter, the parameter determined from at least a relative table position and an image position; and determining a correlation of the first plurality of edge maps to the second plurality of edge maps at a plurality of overlapping positions in the overlap region O containing the location p for all 2D slices in the overlap region of the first and the second volume to determine a best alignment of the first volume and the second volume. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A system for aligning a plurality of volumes from a patient, comprising:
-
means for reading the plurality of volumes being Magnetic Resonance Angiography (MRA) volumes in DICOM format and correcting at least one of the plurality of volumes for shearing based on a tilt angle obtained from a DICOM header; means for equalizing the plurality of volumes with the highest resolution of the plurality of volumes; means for detecting edges in a plurality of 2D slices of a first volume of the plurality of volumes within a search range and in a plurality of 2D slices of a second volume of the plurality of volumes within a search range to form a first and a second plurality of edge maps, respectively, the first and second edge maps having an overlap region, wherein the-overlap region of the first and the second volume depends upon the search range; means for determining the search range based on a shift in a horizontal, vertical and depth direction of a parameter, the parameter determined from at least a relative table position and an image position; and means for determining a correlation of the first plurality of edge maps to the second plurality of edge maps for all 2D slices in the overlap region of the first and the second volume to determine a best alignment of the first volume and the second volume. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A system for aligning a first volume of image data and a second volume of image data from a single patient, comprising:
-
a device for imaging a body part to form the first volume and the second volume; a processor that reads the plurality of volumes being Magnetic Resonance Angiography (MRA) volumes in DICOM format and corrects at least one of the plurality of volumes for shearing based on a tilt angle obtained from a DICOM header, that equalizes data from the first volume and data from the second volume, that detects edges within a search range in the first volume to form a first plurality of edge maps of a plurality of 2D slices of the first volume, that detects edges within a search range in the second volume to form a second plurality of edge maps of a plurality of 2D slices of the second volume, the first and second edge maps having an overlap region, the overlap region being determined by a search range, based on shifts in a horizontal, vertical and depth direction of a parameter, the parameter determined from at least a relative table position and an image position, that performs determining a correlation between the first plurality of edge maps and the second plurality of edge maps at a plurality of overlapping positions in the search range between the first plurality of edge maps and the second plurality of edge maps, and that determines the best alignment of the first volume and the second volume based on the correlation; and means for displaying a single image derived from the first and second volumes. - View Dependent Claims (20)
-
Specification