title: Automatic detection of luminal borders in IVUS images by magnitude-phase histograms of complex brushlet coefficients.
abstract: We present a new technique to delineate lumen borders in intravascular ultrasound (IVUS) volumes of images acquired with a high-frequency Volcano (Rancho Cordova, CA) 45MHz transducer. Our technique relies on projection of IVUS sub-volumes onto orthogonal directional brushlet functions. Through selective projection of IVUS sub-volumes images and their Fourier transforms, tissue-specific backscattered magnitudes and phases identified within brushlet coefficients. We take advantage of such characteristics and construct 2.5-dimensional (2.5-D) magnitudes-phase histograms of coefficients in the transformed complex brushlet domain that contain distinct peaks corresponding to blood and non-blood regions. We exploit these peaks to mask out coefficients that represent blood regions and ultimately detect the luminal border after spatial regularization employing a parametric deformable model. We quantify our results by comparing them to manually traced borders by an expert on 2 datasets, containing 108 frames. We show that our approach is well suited for isolating coherent (i.e. plaque) structures from incoherent (i.e. blood) ones in IVUS pullbacks and detecting the lumen border, a challenging problem particularly in images acquired with high frequency transducers.
authors.affiliation: Heffner Biomedical Imaging Lab in the Department of Biomedical Engineering of Columbia University, New York, NY, USA. ak2432@columbia.edu
authors.forename: Amin
authors.initials: A
authors.lastname: Katouzian
authors.forename: Elsa D
authors.initials: ED
authors.lastname: Angelini
authors.forename: Bernhard
authors.initials: B
authors.lastname: Sturm
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Laine
mesh_terms: D000465:Algorithms; D001331:Automation; D002309:Cardiology / Q000379:methods; D003331:Coronary Vessels / Q000473:pathology*; D003952:Diagnostic Imaging / Q000379:methods; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008490:Medical Informatics / Q000379:methods; D015233:Models, Statistical; D019047:Phantoms, Imaging; D012542:Scattering, Radiation; D018084:Ultrasonography, Interventional / Q000379:methods*