Method and apparatus for motion correction and image enhancement for optical coherence tomography

摘要

Images of an object, such as OCT scans of a human eye, can include distortions and data gaps due to relative motion of the object and the image acquisition device. Methods and systems for correction of such distortions and data gaps are described herein. Motion-corrected data is arrived at by applying three-dimensional transforms to input three-dimensional data sets that represent at least partially overlapping regions of the imaged object. The three dimensional transforms are computed based on an objective function that accounts for similarity between the transformed three-dimensional data sets and the estimated motion of the object relative to an imaging instrument. Methods and systems described herein advantageously eliminate the need for postulated assumptions and reliance on landmarks and are capable of filling data gaps, thereby producing high quality, undistorted images of objects subject to movement during imaging. Multiple motion-corrected data sets can be merged or combined to produce a data set with improved image quality.

主权项

1. A computer-implemented method of correcting a data set representing an object for the object's motion relative to an optical coherence tomography (OCT) imaging instrument, comprising:
acquiring at least a first three-dimensional data set and a second three-dimensional data set representing overlapping regions of an object with the OCT imaging instrument, wherein the first three-dimensional data set and the second three-dimensional data set are obtained in an instrument coordinate system; optionally, computing at least one of a first derivative three-dimensional data set corresponding to the first three-dimensional data set, a second derivative three-dimensional data set corresponding to the second three-dimensional data set, a first preprocessed three-dimensional data set corresponding to the first three-dimensional dataset, or a second preprocessed three-dimensional data set corresponding to the second three-dimensional dataset; determining sample positions in an object coordinate system; for at least the first and the second three-dimensional data sets, computing a first three-dimensional transform and a second three-dimensional transform respectively, wherein every transform associates a three-dimensional displacement vector with each sample position in the object coordinate system, and wherein computing the first and the second three-dimensional transforms includes: a. for each of the first and the second three-dimensional transform, computing a first three-dimensional displacement vector for each sample position in the object coordinate system; b. for each of the first and the second three-dimensional transform, computing, based on the first three-dimensional displacement vectors, positions in the instrument coordinate system; c. for each of the first and the second three-dimensional transform, interpolating data of the respective three-dimensional data set or preprocessed three-dimensional data set at the positions in the instrument coordinate system, thereby producing a first set of interpolated values and a second set of interpolated values; d. evaluating an objective function by calculating similarity between the first and the second sets of interpolated values and estimating motion of the object relative to the OCT imaging instrument; and e. based on the value of the objective function, for each of the first and the second three-dimensional transform, computing a second three-dimensional displacement vector for each sample position in the object coordinate system; and applying at least one three-dimensional transform to at least one of the first or the second three-dimensional data sets, or the first or the second derivative three-dimensional data sets to obtain at least one motion-corrected data set representing the object.