METHOD AND APPARATUS FOR CLASSIFICATION OF CORONARY ARTERY IMAGE DATA
First Claim
1. A method of automatically classifying anatomical features shown in a medical image volume data set, the method comprising:
- obtaining a polyline tree comprising a plurality of connected points in the data set corresponding to the centrelines of vessels in an arterial tree imaged in the data set, each vessel in the arterial tree being represented by a segment in the polyline tree;
forming a topological representation of the polyline tree which indicates the relative generational positions of the segments within the polyline tree;
comparing the topological representation with a set of topological rules specifying anatomically permissible relative generational positions of vessels in an arterial tree to identify feasible anatomical classifications for the vessels represented by each segment in the polyline tree;
generating a set of candidate labeled polyline trees by associating labels representing the identified anatomical classifications with the corresponding segments in the polyline tree, each candidate labeled polyline tree being one combination of the identified feasible anatomical classifications;
comparing each candidate labeled polyline tree with a set of geometric rules specifying anatomically permissible spatial attributes of vessels in an arterial tree which can be determined from a polyline representation and rejecting any candidate having one or more labels representing vessels which do not comply with the geometric rules;
calculating a figure of merit for each remaining candidate labeled polyline tree by comparing features of the vessels represented in the polyline tree with known features of vessels in the anatomical classes indicated by the labels associated with the segments representing the vessels to determine a probability of the correctness of the labels in each candidate, the figure of merit reflecting the probability; and
identifying the candidate labeled polyline tree having the best figure of merit.
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Accused Products
Abstract
A polyline tree representation of a coronary artery tree imaged in a volume data set is obtained, and its topology is extracted to give a topological representation indicating the relative positions of vessels in the tree. The topological representation is compared with a set of topological rules to find possible anatomical classifications for each vessel, and a set of candidate labeled polyline trees is generated by labeling the polyline tree with labels showing each combination of possible anatomical classifications. Each candidate labeled tree is filtered according to a set of geometric rules pertaining to spatial characteristics of vessels in arterial trees, and any labeled tree not satisfying the geometric rules is rejected A figure of merit is calculated for each remaining candidate by comparing features of the vessels measured from the polyline tree and from the volume data set with features of correctly classified vessels in other data sets to determine the probable correctness of the labeling of each candidate, and the candidate with the best figure of merit is selected as showing the proper classification of the vessels.
27 Citations
24 Claims
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1. A method of automatically classifying anatomical features shown in a medical image volume data set, the method comprising:
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obtaining a polyline tree comprising a plurality of connected points in the data set corresponding to the centrelines of vessels in an arterial tree imaged in the data set, each vessel in the arterial tree being represented by a segment in the polyline tree; forming a topological representation of the polyline tree which indicates the relative generational positions of the segments within the polyline tree; comparing the topological representation with a set of topological rules specifying anatomically permissible relative generational positions of vessels in an arterial tree to identify feasible anatomical classifications for the vessels represented by each segment in the polyline tree; generating a set of candidate labeled polyline trees by associating labels representing the identified anatomical classifications with the corresponding segments in the polyline tree, each candidate labeled polyline tree being one combination of the identified feasible anatomical classifications; comparing each candidate labeled polyline tree with a set of geometric rules specifying anatomically permissible spatial attributes of vessels in an arterial tree which can be determined from a polyline representation and rejecting any candidate having one or more labels representing vessels which do not comply with the geometric rules; calculating a figure of merit for each remaining candidate labeled polyline tree by comparing features of the vessels represented in the polyline tree with known features of vessels in the anatomical classes indicated by the labels associated with the segments representing the vessels to determine a probability of the correctness of the labels in each candidate, the figure of merit reflecting the probability; and identifying the candidate labeled polyline tree having the best figure of merit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 24)
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12. A system for automatically classifying anatomical features shown in a medical image volume data set, the system comprising:
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a topology extractor module operable to receive a polyline tree comprising a plurality of connected points in the data set corresponding to the centrelines of vessels in an arterial tree imaged in the data set, each vessel in the arterial tree being represented by a segment in the polyline tree, and to form a topological representation of the polyline tree which indicates the relative generational positions of the segments within the polyline tree; a set of topological rules specifying anatomically permissible relative generational positions of vessels in an arterial tree; a set of labels representing anatomical classifications of arterial vessels; a topology checker module operable to compare the topological representation with the set of topological rules to identify feasible anatomical classifications for the vessels represented by each segment in the polyline tree and to generate a set of candidate labeled polyline trees by associating labels from the label set which represent the identified anatomical classifications with the corresponding segments in the polyline tree, each candidate labeled polyline tree being one combination of the identified feasible anatomical classifications; a set of geometric rules specifying anatomically permissible spatial attributes of vessels in an arterial tree which can be determined from a polyline representation; a geometry checker module operable to compare each candidate labeled polyline tree with the set of geometric rules and reject any candidate having one or more labels representing vessels which do not comply with the geometric rules; and a merit figure module operable to calculate a figure of merit for each remaining candidate labeled polyline tree by comparing features of the vessels represented in the polyline tree with known features of vessels in the anatomical classes indicated by the labels associated with the segments representing the vessels to determine a probability of the correctness of the labels in each candidate, the figure of merit reflecting the probability, and to identify the candidate labeled polyline tree having the best figure of merit. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification