Co-registration Of Optical Coherence Tomography Research Articles

BOOM: A novel bifurcation stent technique using optical coherence tomography co-registration

Background/purposeBifurcation lesions comprise 20 % of percutaneous coronary interventions (PCI) and are associated with worse long-term outcomes. With an increasing percentage of patients presenting with complex anatomy, including bifurcation disease, there is a need for treatment strategies to optimize PCI outcomes. Methods/materialsWe retrospectively analyzed 48 patients undergoing OCT guided bifurcation PCI using the ‘Bifurcation and Ostial OCT Mapping’ (BOOM) technique. The primary efficacy variable studied was stent precision following deployment, defined as the distance of the most proximal stent strut from the true ostium of the target vessel. Additionally, targeted follow-up occurred by phone at 6- and 12-months post procedure, where the frequency of myocardial infarction, target lesion revascularization, target vessel and non-target vessel revascularization, and mortality were collected. ResultsA total of 40 (83.3 %) had an ostial lesion that required treatment while the remaining patients had true bifurcation disease. Most target lesions were in either the LAD or its branches (29 lesions (60.3 %)). With respect to stent positioning, the median absolute geographic miss, (i.e., stent protrusion into the main branch or lack of complete ostial stent coverage), was 0.75 mm. At 6 months, one patient required target lesion revascularization with no additional patients at 12 months. ConclusionsBOOM is a safe and simple strategy that can be a useful technique to optimize precise stent placement for ostial and bifurcation lesions.

Automatic Coregistration Between Coronary Angiography and Intravascular Optical Coherence Tomography: Feasibility and Accuracy.

This study sought to evaluate a novel approach for automatic coregistration of optical coherence tomography (OCT) and coronary angiography. Lumen diameters and side branches from both coronary angiography and OCT were used to create 2 feature sets. Subsequently, a 2-step coregistration approach was performed on the feature sets for matching of each OCT cross section on the angiographic centerline. For validation, all side branches with≥1.0mm diameter were identified and used as paired fiduciary landmarks. Geographical error was defined as the distance between the automatically coregistered and the true-paired landmarks. Altogether 212 vessels from 181 patients were analyzed. Mismatch of coronary angiography and OCT occurred in 64 of 1,530 reference landmarks. Median geographical error was 0.32 (interquartile range: 0.00-0.56) mm. The mean time for coregistration was 20.69 ± 1.07 seconds. In conclusion, fast and automatic coregistration of OCT and angiography using a single standard angiographic loop is feasible and accurate.

107Diagnostic accuracy of optical coherence tomography for the identification of in-stent fibroatheroma following stent implantation: an ex-vivo histological validation study

Abstract Background Previous histopathological studies have demonstrated that new atherosclerotic formation within the neointima, called neoatherosclerosis, is one of the most important mechanisms leading to both very late in-stent restenosis and stent thrombosis after stent implantation. Therefore, to distinguish lipid-containing atherosclerotic neointima from other tissues using intracoronary imaging modalities is clinically important to prevent late stent failures. Purpose This study evaluated the diagnostic performance of optical coherence tomography (OCT) for the detection of “in-stent fibroatheroma” following stent implantation by comparing cross-sections of the model with the corresponding histological images. Methods Fifty stented coronary arteries from the 31 autopsy hearts were imaged by OCT. Coronary arterial histopathological specimens, all of which included more than 30% of %neointimal hyperplasia, were compared with the corresponding OCT cross-sections. Histological in-stent fibroatheroma was defined as neointima containing large necrotic core and inflammatory cells. OCT-derived in-stent fibroatheroma comprised a low-intensity tissue containing a poorly delineated region with invisible stent strut behind low signal intensity. Results A total of 122 OCT cross-sections were compared with histological images. OCT examination revealed that 24 images (20%) contained low-intensity tissue inside the neointima. Of those, 5 images, in which stent strut behind low signal intensity was invisible, were diagnosed as OCT-derived in-stent fibroatheroma (4%) (Figure A). By histological analysis, only 4 images were classified as in-stent fibroatheroma (3%) (Figure B). With histology as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy for OCT-derived in-stent fibroatheroma were 100%, 99%, 80%, 100%, and 99%, respectively. The only histological finding underlying the false-positive-diagnosis of OCT-derived in-stent fibroatheroma was foam cells accumulation without necrotic core on the neointimal surface (Figure C and D). Most tissue that showed low-intensity tissue with visible stent strut by OCT contained proteoglycan matrix and organized thrombus in the absence of an underlying necrotic core. Coregistration of OCT with histology Conclusion This study showed the potential capability of OCT based on the visualization of stent struts behind low-intensity regions for discriminating in-stent fibroatheroma from other neointimal tissues following stent implantation.

Impact of Plaque Erosion on Stress/Strain and Flow Shear Stress Calculation: An OCT-Based FSI Modeling Study

Plaque erosion, one of the primary causes for coronary thrombosis, is responsible for about one third of the patients with acute coronary syndrome (ACS) [1]. Histological studies characterized the eroded plaque as a plaque with following morphological features: 1) plaque intima having direct contact with intraluminal thrombus due to the absence of endothelium or endothelial injury; 2) without rupture in the fibrous cap; 3) abundance of proteoglycans and smooth muscle cells on the luminal surface under the thrombus [2]. These characteristics has been applied in in vivo diagnosis of plaque erosion using optical coherence tomography (OCT) image technology and specific treatment strategy has also been developed for plaque erosion related ACS [3]. However, The pathogenesis mechanisms that cause plaque erosion are not fully understood [2]. It is postulated that plaque erosion has close association with biomechanical conditions in the coronary vessel [2]. In this work, a patient-specific OCT-based modeling approach was develop 3D fluid-structure interaction (FSI) models to investigate the biomechanical conditions in eroded plaque and investigate the impact of erosion-induced inflammation on plaque stress/strain conditions. Patient-specific OCT data of eroded coronary plaque were acquired from one male patient (age: 64) with frequency-domain OCT C7XR system and the Dragon Fly catheter (Lightlab Imaging/St. Jude Medical). Erosion sites were identified as the luminal surface having direct contact with intraluminal thrombus on the OCT images. Biplane X-ray angiographic data (Allura Xper FD10 System, Philips, Bothel, WA) were also acquired with the information of the location of the coronary artery stenosis and vessel curvature. OCT images were segmented manually with external elastic membrane (EEM) contour assumed to have positive remodeling ratio 1.1 for this plaque. The trailing edge of the lipid-rich necrotic core (lipid) was also assumed since it cannot be seen on the OCT images. Co-registration of OCT and angiographic data were performed to reconstruct the 3D coronary geometry. Our FSI modeling procedures with pre-shrink–stretch process and anisotropic material properties were previously developed. Blood flow was assumed to be laminar, Newtonian and incompressible, with arbitrary Lagrangian–Eulerian formulation of the Navier–Stokes equations used as the governing equations. The governing equations of the structure models included equations of motion, the nonlinear Cauchy–Green strain–displacement relation and Mooney–Rivlin material properties. To reflect tissue weakening caused by erosion-induced inflammation, the material stiffness of plaque intima at the erosion site was adjust to one tenth of un-eroded fibrous plaque tissue [2]. Three FSI models were constructed to investigate the impacts of erosion-induced inflammation and lipid component on plaque stress/strain conditions: M1, without erosion (this means plaque intima at the erosion sites were not softened) and without inclusion of lipid component; M2, with erosion but no lipid component; M3, with erosion and inclusion of lipid component. Pulsating pressure conditions were prescribed at the inlet and outlet of the vessel segment. Fluid–structure interaction boundary conditions including force balance and no-slip conditions were imposed to the fluid–structure interface between blood flow and vessel lumen surface. Results for plaque wall stress/strain (PWS/PWSn) and flow wall shear stress (WSS) from the FSI models corresponding to peak blood pressure were extracted for analysis. Table 1 summarizes the average values of the biomechanical factors both at erosion sites and fibrous cap overlaying lipid component for 3 models. By comparing M1 and M2 at the erosion sites, Mean PWS value decreases from 49.98 kPa to 18.83 kPa (62.32% decrease) while Mean PWSn value increases from 0.1231 to 0.1384 (12% increase) as the material stiffness becomes 10 times soft. At the fibrous cap, M3 (with inclusion of lipid) will elevates mean PWS and PWSn values by 48.59% and 16.09%, respectively. The impacts of erosion and lipid on flow shear stress were limited (<2%). Table 1: Average values of three biomechanical factors over erosion sites and fibrous cap overlaying lipid core. Average values of biomechanical factors over Erosion sites for 3 Models M1 M2 M3 Mean PWS (kPa) 49.9759 18.8318 18.8298 Mean PWSn 0.1231 0.1384 0.1384 Mean WSS (dyn/cm2) 101.0637 99.9383 99.4303 Average values of biomechanical factors over fibrous cap overlaying lipid for 3 Models M1 M2 M3 Mean PWS (kPa) 68.3209 68.3199 101.5173 Mean PWSn 0.0870 0.0870 0.1010 Mean WSS (dyn/cm2) 18.5260 18.4634 18.1910 To conclude, erosion-induced inflammation on blood vessel would lead to lower stress distribution but larger strain distribution, while lipid component would elevate both stress and strain conditions. This shows the influence of erosion and lipid component has impacts on stress/strain calculations which are closely related to plaque assessment.

A prospective, single-center, randomized study to assess whether automated coregistration of optical coherence tomography with angiography can reduce geographic miss.

We sought to evaluate whether automated coregistration of optical coherence tomography (OCT) with angiography reduces geographic miss (GM) during coronary stenting. Previous intravascular ultrasound or OCT studies have showed that residual disease at the stent edge or stent edge dissection was associated with stent thrombosis or edge restenosis. This has been termed GM. Two hundred de novo coronary lesions were randomized in a 1:1 ratio to OCT-guided percutaneous coronary intervention (PCI) with versus without automated coregistration of OCT with angiography. GM, the primary endpoint, was defined as angiographic ≥type B dissection or diameter stenosis >50% or OCT minimum lumen area <4.0 mm2 with significant residual disease or dissection (dissection flap >60°) within 5 mm from the stent edge. The prevalence of GM was not different comparing OCT-guided PCI with versus without automated coregistration (27.6% vs 34.0%, P = 0.33). However, there was a trend toward a reduced prevalence of significant distal stent edge dissection in lesions with automated coregistration (11.1% vs 20.8%, P = 0.07). The discrepancy in the distance between planned versus actual implanted stent location with automated coregistration was significantly shorter than without coregistration (1.9 ± 1.6 mm vs 2.6 ± 2.7 mm, P = 0.03), especially the prevalence of ≥5 mm discrepancy that was less frequent with automated coregistration. Automated coregistration of OCT with angiography did not reduce the primary endpoint of GM after stent implantation.

P5498Real-time optical coherence tomography coregistration with angiography in patients underground percutaneous coronary intervention

P5498Real-time optical coherence tomography coregistration with angiography in patients underground percutaneous coronary intervention

Real-time optical coherence tomography coregistration with angiography in percutaneous coronary intervention-impact on physician decision-making: The OPTICO-integration study.

Intracoronary optical coherence tomography (OCT) imaging allows for high-resolution characterization of coronary lesions. Difficulties in matching cross-sectional OCT-images with angiographic lesion localization may limit optimal clinical utilization. We sought to prospectively assess the impact of a novel system of real-time OCT coregistration with angiography (ACR) on physician decision-making during percutaneous coronary interventions (PCI). Strategy for PCI (stent - length, - diameter, - strategy, landing zone) and PCI-optimization (stent-malappostion, -underexpansion, edge-dissections, geographical mismatch) was prospectively assessed in 50 patients with 58 coronary lesions after (I) angiography, (II) OCT imaging, and (III) ACR. Preprocedural OCT imaging altered stent-length (58.9%), diameter (33.9%), and PCI-strategy (12.5%) in 40 (71.4%) lesions. The use of ACR resulted in additional changes in PCI strategy in 40.7% of mostly complex lesions in comparison to OCT imaging alone and involved mainly device landing zone (24.1%) and stent length (22.2%). Postprocedural OCT imaging revealed the need for PCI optimization in 52.2% of the lesions, whereas post-procedural ACR had no further impact. Real-time OCT ACR had significant impact on PCI strategy, favoring mainly complete lesion coverage especially in complex lesions.

P2350Real-time optical coherence tomography co-registration with angiography to optimize percutaneous coronary intervention: results of the OPTICO-Integration study

P2350Real-time optical coherence tomography co-registration with angiography to optimize percutaneous coronary intervention: results of the OPTICO-Integration study

Optical Coherence Tomography for Online Guidance of Complex Coronary Interventions.

Decision making on lesion preparation and stent/scaffold optimization are cornerstones of patient outcome. Intravascular imaging recently emerged as a critical modality to achieve better results of stent/scaffold implantation and superior clinical outcomes compared with coronary angiography alone. Optical coherence tomography (OCT), a light-based intravascular imaging modality with high frame rate in acquisition and very high speed pullback, can interrogate the target vessel in a couple of seconds, and immediately display a pristine longitudinal lumen contour with automatic detection of lesion severity, site and lumen/stent areas. Further, OCT provides pivotal information on sites of calcium, with accurate measurements of the minimum distance from the lumen, a major determinant of stent/scaffold underexpansion, malapposition and eccentricity. Finally, to guide the PCI procedure using OCT without operator misjudgment, a real-time point-to-point correspondence between angiographic and OCT images has been recently created. Co-registration of OCT with angiography with direct tableside control of acquisition and analysis enables the operator to plan and map optimal stent/scaffold implantation. To prove the clinical relevance of OCT-guided PCI, simple, standardized interventional planning, including pre- and postprocedural automatic lumen detection metrics, has to be translated into effective treatment flow algorithms. A similar OCT algorithm is being tested in the ongoing prospective, randomized, multicenter ILUMIEN III study, to demonstrate that OCT-guided stent placement is superior to angiography-guided and non-inferior to IVUS-guided stent implantation. (Circ J 2016; 80: 2063-2072).

A case of on-line software-based co-registration of optical coherence tomography and angiography guided percutaneous coronary intervention for a patient with angina pectoris

Recently developed imaging modalities provide precise and accurate evaluation of lesions within the coronary arteries. Among them, optical coherence tomography (OCT) provides higher resolution cross-sectional imaging than intravascular ultrasound [ [1] Prati F. Regar E. Mintz G.S. et al. Expert review document on methodology, terminology, and applications of optical coherence tomography: physical principles, methodology of image acquisition, and clinical application for assessment of coronary arteries and atherosclerosis. Eur. Heart J. 2010; 31: 401-415 Crossref PubMed Scopus (665) Google Scholar ]. Recently, software-based on-line co-registration of OCT and angiography has become available as a new tool in percutaneous coronary intervention. Here, we describe a case where this new modality was critical for successful percutaneous coronary intervention.

Co-registration of optical coherence tomography and X-ray angiography in percutaneous coronary intervention. The Does Optical Coherence Tomography Optimize Revascularization (DOCTOR) fusion study

BackgroundIntracoronary imaging provides accurate lesion delineation and precise measurements for sizing and positioning of coronary stents. During percutaneous coronary intervention (PCI), it may be challenging to identify corresponding segments between intracoronary imaging and angiography. Computer based online co-registration may aid the target segment identification. MethodsThe DOCTOR fusion study was a prospective, single arm, observational study including patients admitted for elective PCI. Optical coherence tomography (OCT) was acquired pre-stent implantation for sizing of stents. The operator subsequently indicated on the angiogram the target area as identified by OCT. Computer based co-registration was performed on-line immediately after pre-stent acquisition to assess feasibility. The cumulated numerical difference between operator based, and computer based co-registration was assessed as the “Operator Registration Error”. The operator implanted the stent blind to the co-registrated angiogram. The difference between the co-registered stent border positions and the actual stent deployment border positions was the “Geographic Miss Distance”. ResultsTwenty-two patients were included in the study. Two patients were excluded due to missing pre or post-OCT acquisitions. Online co-registration pre-stenting was successful in all analyzed cases. The mean “Operator Registration Error” was 5.4±3.5mm. The mean “Geographic Miss Distance” was 5.4±2.6mm. Without access to the computer-based co-registration, segments of the target lesion indicated on OCT were left uncovered by stent in 14 patients (70%). ConclusionComputer based online co-registration of OCT and angiography is feasible. Frequent inaccuracies in operator based registration indicate that computer aided co-registration may reduce errors in corresponding OCT findings to the angiogram.

TCT-665 Co-registration of Optical Coherence Tomography and X-ray Angiography in Percutaneous Coronary Intervention. The Does Optical Coherence Tomography Optimize Revascularization (DOCTOR) Fusion Study

TCT-665 Co-registration of Optical Coherence Tomography and X-ray Angiography in Percutaneous Coronary Intervention. The Does Optical Coherence Tomography Optimize Revascularization (DOCTOR) Fusion Study

Optimization of Tryton Dedicated Coronary Bifurcation System With Coregistration of Optical Coherence Tomography and Fractional Flow Reserve

The Tryton-Side Branch Stent (Tryton Medical, Newton, Massachusetts) is 1 dedicated bifurcation system, designed to be implanted in the side branch (SB) along with placement of a standard drug-eluting stent (DES) in the main vessel [(1)][1]. The procedure is completed by a final kissing balloon

In-situ imaging of articular cartilage of the first carpometacarpal joint using co-registered optical coherence tomography and computed tomography

Conventional imaging modalities are unable to depict the early degeneration of articular cartilage in osteoarthritis, especially in small joints. Optical coherence tomography has previously been used successfully in high-resolution imaging of cartilage tissue. This pilot cadaver study demonstrates the use of intra-articular optical coherence tomography in imaging of articular cartilage of the first carpometacarpal joint, producing high resolution images of the articular surface in which cartilage thickness and surface characteristics were assessed. Findings on optical coherence tomography were confirmed with histology. Furthermore, co-registration of optical coherence tomography and computed tomography was used to accurately determine the scanned trajectory and reconstruct a true-scale image overlay.