Registration Methods for IVUS: Transversal and Longitudinal Transducer Motion Compensation.

G. D. MASO TALOU; P. J. BLANCO; I. LARRABIDE; C. GUEDES BEZERRA; P. A. LEMOS; R. A FEIJOO

IEEE TRANSACTIONS ON BIO-MEDICAL ENGINEERING

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Lugar: New York; Año: 2016 vol. 64 p. 890 - 903

0018-9294

Abstract? Objective: Intravascular ultrasound is a fundamen-tal imaging technique for atherosclerotic plaque assessment, in-terventionist guidance and, ultimately, as a tissue characterizationtool. The studies acquired by this technique present the spatialdescription of the vessel during the cardiac cycle. However, thestudy frames are not properly sorted. As gating methods dealwith the cardiac phase classification of the frames, the gatedstudies lack motion compensation between vessel and catheter.In this work, we develop registration strategies to arrange thevessel data into its rightful spatial sequence. Methods: Registra-tion is performed by compensating longitudinal and transversalrelative motion between vessel and catheter. Transversal motion isidentified through MLE optimization, while longitudinal motionis estimated by a neighborhood similarity estimator among thestudy frames. A strongly coupled implementation is proposed tocompensate for both motion components at once. Loosely cou-pled implementations (DLT and DTL) decouple the registrationprocess, resulting in more computationally efficient algorithmsin detriment of the size of the set of candidate solutions.Results and Conclusions: The DTL outperforms DLT and coupledimplementations in terms of accuracy by a factor of 1.9 and 1.4,respectively. Sensitivity analysis shows that perivascular tissuemust be considered to obtain the best registration outcome.Evidences suggest that the method is able to measure axial strainalong the vessel wall. Significance: The proposed registrationsorts the IVUS frames for spatial location, which is crucial fora correct interpretation of the vessel wall kinematics along thecardiac phases.