Image-based Co-Registration of Angiography and Intravascular Ultrasound Images

Abstract

In image-guided cardiac interventions, X-ray imaging and intravascular ultrasound (IVUS) imaging are two often used modalities. Interventional X-ray images, including angiography and fluoroscopy, are used to assess the lumen of the coronary arteries and to monitor devices in real time. IVUS provides rich intravascular information, such as vessel wall composition, plaque, and stent expansions, but lacks spatial orientations. Since the two imaging modalities are complementary to each other, it is highly desirable to co-register the two modalities to provide a comprehensive picture of the coronaries for interventional cardiologists. In this paper, we present a solution for co-registering 2-D angiography and IVUS through image-based device tracking. The presented framework includes learning-based vessel detection and device detections, model-based tracking, and geodesic distance-based registration. The system first interactively detects the coronary branch under investigation in a reference angiography image. During the pullback of the IVUS transducers, the system acquires both ECG-triggered fluoroscopy and IVUS images, and automatically tracks the position of the medical devices in fluoroscopy. The localization of tracked IVUS transducers and guiding catheter tips is used to associate an IVUS imaging plane to a corresponding location on the vessel branch under investigation. The presented image-based solution can be conveniently integrated into existing cardiology workflow. The system is validated with a set of clinical cases, and achieves good accuracy and robustness.

Pre-Angioplasty Instantaneous Wave-Free Ratio Pullback Provides Virtual Intervention and Predicts Hemodynamic Outcome for Serial Lesions and Diffuse Coronary Artery Disease

“…Such systems are already used for integrating intravascular ultrasound images directly with angiography (24). By using coregistration systems in a similar manner to track the position of a pressure wire along the course of the vessel rather than an intravascular ultrasound catheter, it will be possible to perform a manual pressure wire pullback while simultaneously attaining a distance coordinate from coregistration.…”

Novel Method for Real Time Co‐Registration of IVUS and Coronary Angiography

“…The length dimension is obtained by dividing the pullback velocity by its time. However, as specified above, while using the automated pull back method, we cannot always be certain regarding the precise length despite the constant and motorized pull back applied outside the patient body . On the other hand using the manual pull back in our method, as described above, we obtain accurate length measurements and precise location of the individual IVUS cross section image over the angiogram roadmap.…”

“…Wang et al described another method which uses co‐registration based on guiding catheter (GC) tip tracking that at times could be hard to observe. Our method is based on a mapping technique obtained on multiple objects distances (i.e., GC tip, radiopaque part of the guide wire, visible markers on the Eagle Eye® Platinum and the IVUS transducer) versus only one distance (GC‐tip to IVUS transducer) in Wang's method.…”

Multimodal Medical Image Fusion in Cardiovascular Applications

“…Angiography is another X-ray application with a radio-opaque material, which acts as contrast agent, injected into the circulation before taking multiple X-rays that give two-dimensional images of the heart [28]. It creates diagnostic motion picture Xray that is usually used to examine the circulatory system.…”

“…Unlike US, the conventional IVUS is most commonly used for CAD diagnosis as it is working in range of 20-45 MHz [5]. It obtains information on vessel wall composition, plaque morphology and stent expansion [28,[31][32][33]. IVUS is able to detect changes in plaque burden over time.…”