Continuous roadmapping in liver TACE procedures using 2D–3D catheter-based registration

PURPOSE: Fusion of pre/perioperative images and intra-operative images may add relevant information during image-guided procedures. In abdominal procedures, respiratory motion changes the position of organs, and thus accurate image guidance requires a continuous update of the spatial alignment of the (pre/perioperative) information with the organ position during the intervention. METHODS: In this paper, we propose a method to register in real time perioperative 3D rotational angiography images (3DRA) to intra-operative single-plane 2D fluoroscopic images for improved guidance in TACE interventions. The method uses the shape of 3D vessels extracted from the 3DRA and the 2D catheter shape extracted from fluoroscopy. First, the appropriate 3D vessel is selected from the complete vascular tree using a shape similarity metric. Subsequently, the catheter is registered to this vessel, and the 3DRA is visualized based on the registration results. The method is evaluated on simulated data and clinical data. RESULTS: The first selected vessel, ranked with the shape similarity metric, is used more than 39 % in the final registration and the second more than 21 %. The median of the closest corresponding points distance between 2D angiography vessels and projected 3D vessels is 4.7–5.4 mm when using the brute force optimizer and 5.2–6.6 mm when using the Powell optimizer. CONCLUSION: We present a catheter-based registration method to continuously fuse a 3DRA roadmap arterial tree onto 2D fluoroscopic images with an efficient shape similarity

Vesselness-based 2D-3D registration of the coronary arteries

Purpose Robust and accurate automated co-registration of the coronary arteries in 3D CTA and 2D X-ray angiography during percutaneous coronary interventions (PCI), in order to present a fused visualization. Methods A novel vesselness-based similarity measure was developed, that avoids an explicit segmentation of the X-ray image. A stochastic optimizer searches the optimal registration using the similarity measure. Results Both simulated data and clinical data were used to investigate the accuracy and capture range of the proposed method. The experiments show that the proposed method outperforms the iterative closest point method in terms of accuracy (average residual error of 0.42 mm vs. 1.44 mm) and capture range (average 71.1 mm/20.3¿ vs. 14.1 mm/5.2¿). Conclusion The proposed method has proven to be accurate and the capture range is ample for usage in PCI. Especially the absence of an explicit segmentation of the interventionally acquired X-ray images considerably aids the robustness of the method.Keywords: Percutaneous coronary interventions - Chronic total occlusions - X-ray fluoroscopy-CT image fusion - Registratio

Real-time integration of 3-D multimodality data in interventional neuroangiography

We describe a novel approach to using soft-tissue data sets, such as computer tomography on magnetic resonance, in the minimally invasive image guidance of intra-arterial and intravenous endovascular devices in neuroangiography interventions. Minimally invasive x-ray angiography procedures rely on the navigation of endovascular devices, such as guide wires and catheters, through human vessels, using C-arm fluoroscopy. Although the bone structure may be visible and the injection of iodine contrast medium allows one to guide endovascular devices through the vasculature, the soft-tissue structures remain invisible in the fluoroscopic images. We intend to present a method for the combined visualization of soft-tissue data, a 3-D rotational angiography (3-DRA) reconstruction, and the live fluoroscopy data stream in a single fused image. Combining the fluoroscopic image with the 3-DRA vessel tree offers the advantage that endovascular devices can be located within the vasculature without additional contrast injection, while the position of the C-arm geometry can be altered freely. The additional visualization of the soft-tissue data adds contextual information to the position of endovascular devices. We address the clinical applications, the real-time aspects of the registration algorithms, and fast-fused visualization of the proposed method

On-line multi-slice computed tomography interactive overlay with conventional X-ray : a new and advanced imaging fusion concept

Abstract Background Computed tomography (CT) has revolutionized noninvasive cardiovascular evaluations. Complicated percutaneous procedures require precise imaging guidance that conventional X-ray is often unable to provide. By combining X-ray imaging with real-time, interactive, CT-based landmarks, interventional procedures could be facilitated. We describe two cases using the first CT/Live X-ray overlay in which this technology shows its potential. Case reports A 31-year-old male with an anatomically complicated atrial septal defect (ASD) was referred for percutaneous closure. Transesophageal echocardiography (TEE) revealed an inferior location of the ASD complicated by it's proximity to a prominent Eustachian ridge. The CT was used to create a patient-specific physical model in preparation for the procedure and an in-lab real-time CT overlay allowing successful closure. A second case of a 41-year-old male with coronary artery disease status-post coronary artery bypass, aortic valve replacement (AVR), and aortic root replacement with an abnormal coronary computed tomography angiogram (CTA). In a prior procedure years ago the saphenous vein graft (SVG) to the left anterior descending artery (LAD) could not be cannulated during invasive angiography, given the patient's complicated and unusual anatomy. Using CT overlay, the superiorly and anteriorly located SVG was cannulated successfully. Discussion CT/Live X-ray overlay provided an adequate anatomical intra-procedural ASD evaluation, defect sizing, and guidance in one case and localization of an anatomically challenging graft ostium in the other case. Adding the CT landmarks as an overlay to traditional X-ray techniques provides a revolutionary and advanced imaging fusion concept that should improve procedural success. Keywords: Computed tomography; Angiography; Structural heart disease; Image fusion; OverlayGarcia J.A., Bhakta S., Kay J., Chan K.-C., Wink O., Ruijters D., Carroll J.D., ''On-line multi-slice computed tomography interactive overlay with conventional X-ray : a new and advanced imaging fusion concept'', International journal of cardiology, vol. 133, no. 3, pp. e101-e105, 2009.status: publishe