title: Joint spatio-temporal registration and microvasculature segmentation of retinal angiogram sequences.
abstract: We discuss the problem of 2D+t intra- and inter-sequential registration of retinal angiograms. A joint spatio-temporal registration algorithm is presented based on a RANSAC (RANdom SAmple Consensus) approach incorporating a quadratic model to describe "pairwise" image homography. This is incorporated into a local-to-global hierarchical joint registration framework. After registration, vessel centrelines are segmented to subpixel accuracy by applying multi-scale steerable complex wavelet filters. Frame-by-frame microvascular centrelines in Regions-of-Interest (ROIs) are evaluated against segmented centrelines of the temporal average of the registered sequences. The microvascular centrelines in registered sequences can be compared intra-sequentially and inter-sequentially, allowing non-invasive clinical monitoring of micro-circulation. This has the potential to detect the presence of microemboli and pathological structural alterations.
authors.affiliation: Bioengineering Department, Imperial College London, South Beddington Campus, London SW7 2AZ. shuoying.cao@imperial.ac.uk
authors.forename: Shuoying
authors.initials: S
authors.lastname: Cao
authors.forename: Anil
authors.initials: A
authors.lastname: Bharath
authors.forename: Kim
authors.initials: K
authors.lastname: Parker
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Ng
authors.forename: John
authors.initials: J
authors.lastname: Arnold
authors.forename: Alison
authors.initials: A
authors.lastname: McGregor
authors.forename: Adam
authors.initials: A
authors.lastname: Hill
mesh_terms: D000465:Algorithms; D005451:Fluorescein Angiography; D006801:Humans; D012171:Retinal Vessels / Q000033:anatomy & histology*