Suppression of IVUS Image Rotation. A Kinematic Approach Misael Rosales 1,2 , Petia Radeva 2 , Oriol Rodriguez 3 , and Debora Gil 2 1 Lab. de F´ ısica Aplicada, Fac. de Cs. Dpto. de F´ ısica (ULA), M´ erida/Venezuela misael@cvc.uab.es 2 CVC, Edifici O, Campus UAB, 08193 Bellaterra, Spain 3 Universitary Hospital ”Germans Tries i Pujol”, Badalona, Spain Abstract. IntraVascular Ultrasound (IVUS) is an exploratory technique used in interventional procedures that shows cross section images of ar- teries and provides qualitative information about the causes and severity of the arterial lumen narrowing. Cross section analysis as well as visu- alization of plaque extension in a vessel segment during the catheter imaging pullback are the technique main advantages. However, IVUS sequence exhibits a periodic rotation artifact that makes difficult the longitudinal lesion inspection and hinders any segmentation algorithm. In this paper we propose a new kinematic method to estimate and remove the image rotation of IVUS images sequences. Results on several IVUS sequences show good results and prompt some of the clinical applications to vessel dynamics study, and relation to vessel pathology. 1 Introduction The introduction of the IntraVascular UltraSound (IVUS) in the field of medical imaging [1, 2] as an exploratory technique has significantly changed the under- standing of the arterial diseases and individual patterns of diseases in coronary arteries. Each IVUS plane visualizes the cross-section (Fig. 1 (left)) of the artery allowing extraction of qualitative information about: the causes and severity of the narrowing of the arterial lumen, distinction of thrombus of the arterioscle- rotic plaque, recognition of calcium deposits in the arterial wall, determination and location of morpho-geometrics arteries parameters [3, 4, 5], among others. The main role of IVUS is to serve as a guide in the interventional procedures al- lowing to measure the morphological structures along the vessel. Artifacts caused by the periodic rotation of the image, introduce an error in the measurements precision in tangential direction [6, 8]. The vessel wall follows a periodic oscilla- tory motion in an image sequence corresponding to the heart cycles. This motion has a rotation center positioned on the vessel wall border in most cases. We can visually evidence this effect by using the mean of an IVUS sequence along its temporal direction, as shown in Fig. 1 (right). This image represent the average grey level of pixels along 25 frames corresponding to approximately one heart A.F. Frangi et al. (Eds.): FIMH 2005, LNCS 3504, pp. 359–368, 2005. c  Springer-Verlag Berlin Heidelberg 2005