title: Strain-Initialized Robust Bone Surface Detection in 3-D Ultrasound.
abstract: Three-dimensional ultrasound has been increasingly considered as a safe radiation-free alternative to radiation-based fluoroscopic imaging for surgical guidance during computer-assisted orthopedic interventions, but because ultrasound images contain significant artifacts, it is challenging to automatically extract bone surfaces from these images. We propose an effective way to extract 3-D bone surfaces using a surface growing approach that is seeded from 2-D bone contours. The initial 2-D bone contours are estimated from a combination of ultrasound strain images and envelope power images. Novel features of the proposed method include: (i) improvement of a previously reported 2-D strain imaging-based bone segmentation method by incorporation of a depth-dependent cumulative power of the envelope into the elastographic data; (ii) incorporation of an echo decorrelation measure-based weight to fuse the strain and envelope maps; (iii) use of local statistics of the bone surface candidate points to detect the presence of any bone discontinuity; and (iv) an extension of our 2-D bone contour into a 3-D bone surface by use of an effective surface growing approach. Our new method produced average improvements in the mean absolute error of 18% and 23%, respectively, on 2-D and 3-D experimental phantom data, compared with those of two state-of-the-art bone segmentation methods. Validation on 2-D and 3-D clinical in vivo data also reveals, respectively, an average improvement in the mean absolute fitting error of 55% and an 18-fold improvement in the computation time.
authors.affiliation: Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: arafat@ece.ubc.ca.
authors.forename: Mohammad Arafat
authors.initials: MA
authors.lastname: Hussain
authors.affiliation: Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Antony J
authors.initials: AJ
authors.lastname: Hodgson
authors.affiliation: Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Rafeef
authors.initials: R
authors.lastname: Abugharbieh
mesh_terms: D000328:Adult; D000465:Algorithms; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult
keywords: Bone; Gaussian mixture Regression; Segmentation; Strain imaging; Surface growing; Ultrasound