title: Automatic adaptive parameterization in local phase feature-based bone segmentation in ultrasound.
abstract: Intensity-invariant local phase features based on Log-Gabor filters have been recently shown to produce highly accurate localizations of bone surfaces from three-dimensional (3-D) ultrasound. A key challenge, however, remains in the proper selection of filter parameters, whose values have so far been chosen empirically and kept fixed for a given image. Since Log-Gabor filter responses widely change when varying the filter parameters, actual parameter selection can significantly affect the quality of extracted features. This article presents a novel method for contextual parameter selection that autonomously adapts to image content. Our technique automatically selects the scale, bandwidth and orientation parameters of Log-Gabor filters for optimizing local phase symmetry. The proposed approach incorporates principle curvature computed from the Hessian matrix and directional filter banks in a phase scale-space framework. Evaluations performed on carefully designed in vitro experiments demonstrate 35% improvement in accuracy of bone surface localization compared with empirically-set parameterization results. Results from a pilot in vivo study on human subjects, scanned in the operating room, show similar improvements.
authors.affiliation: Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Ilker
authors.initials: I
authors.lastname: Hacihaliloglu
authors.forename: Rafeef
authors.initials: R
authors.lastname: Abugharbieh
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Hodgson
authors.forename: Robert N
authors.initials: RN
authors.lastname: Rohling
mesh_terms: D000465:Algorithms; D000818:Animals; D016477:Artifacts; D002417:Cattle; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D010384:Pelvic Bones / Q000000981:diagnostic imaging*; D010388:Pelvis / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D011885:Radius Fractures / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000379:methods*