title: A Method for Delineation of Bone Surfaces in Photoacoustic Computed Tomography of the Finger.
abstract: Photoacoustic (PA) imaging of interphalangeal peripheral joints is of interest in the context of using the synovial membrane as a surrogate marker of rheumatoid arthritis. Previous work has shown that ultrasound (US) produced by absorption of light at the epidermis reflects on the bone surfaces within the finger. When the reflected signals are backprojected in the region of interest, artifacts are produced, confounding interpretation of the images. In this work, we present an approach where the PA signals known to originate from the epidermis are treated as virtual US transmitters, and a separate reconstruction is performed as in US reflection imaging. This allows us to identify the bone surfaces. Furthermore, the identification of the joint space is important as this provides a landmark to localize a region-of-interest in seeking the inflamed synovial membrane. The ability to delineate bone surfaces allows us to identify not only the artifacts but also the interphalangeal joint space without recourse to new US hardware or a new measurement. We test the approach on phantoms and on a healthy human finger.
authors.affiliation: Biomedical Photonic Imaging, University of Twente, Enschede, The Netherlands Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Biswas
authors.affiliation: Biomedical Photonic Imaging, University of Twente, Enschede, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: van Es
authors.affiliation: Biomedical Photonic Imaging, University of Twente, Enschede, The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Steenbergen
authors.affiliation: Biomedical Photonic Imaging, University of Twente, Enschede, The Netherlands s.manohar@utwente.nl.
authors.forename: S
authors.initials: S
authors.lastname: Manohar
mesh_terms: D005240:Feasibility Studies; D005384:Finger Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005385:Fingers / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000600:supply & distribution*; D019047:Phantoms, Imaging; D061088:Photoacoustic Techniques / Q000379:methods*; D012016:Reference Values; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: bone delineation; finger; photoacoustic tomography; photoacoustically induced ultrasound