Off-Line Fusion of Intravascular Ultrasound and Optical Coherence Tomography Images

Intravascular ultrasound (IVUS) and optical coherence tomography (IV-OCT) are widely used interventional imaging modalities to visualize vascular morphologies and identify atherosclerotic plaques. IVUS has high detection depth and low spatial resolution while IV-OCT has high resolution and poor tissue penetration. This work presents a registration and fusion method for IV-OCT and IVUS images acquired on a same vessel segment by separate imaging catheters. First, an IVUS image matched with an IV-OCT image is retrieved from the image sequence based on the Fourier descriptor of the detected lumen contour. Then, the IVUS image elastically deforms according to the geometrical transformation parameters to align with the IV-OCT image. Finally, the matched images are fused with Bandelet transform. The validity has been demonstrated with clinically acquired data. The advantages of the strong tissue penetration of IVUS and high resolution of IV-OCT are combined to obtain comprehensive assessment and description of the vessel wall tissues and atherosclerotic plaques.