True 3-Dimensional Reconstruction of Coronary Arteries in Patients by Fusion of Angiography and IVUS (ANGUS) and Its Quantitative Validation

Abstract

Background-True 3D reconstruction of coronary arteries in patients based on intravascular ultrasound (IVUS) may be achieved by fusing angiographic and IVUS information (ANGUS). The clinical applicability of ANGUS was tested, and its accuracy was evaluated quantitatively. Methods and Results-In 16 patients who were investigated 6 months after stent implantation, a sheath-based catheter was used to acquire IVUS images during an R-wave-triggered, motorized stepped pullback. First, a single set of end-diastolic biplane angiographic images documented the 3D location of the catheter at the beginning of pullback. From this set, the 3D pullback trajectory was predicted. Second, contours of the lumen or stent obtained from IVUS were fused with the 3D trajectory. Third, the angular rotation of the reconstruction was optimized by quantitative matching of the silhouettes of the 3D reconstruction with the actual biplane images. Reconstructions were obtained in 12 patients. The number of pullback steps, which determines the pullback length, closely agreed with the reconstructed path length (rϭ0.99). Geometric measurements in silhouette images of the 3D reconstructions showed high correlation (0.84 to 0.97) with corresponding measurements in the actual biplane angiographic images. Conclusions-With

Effect of Endothelial Shear Stress on the Progression of Coronary Artery Disease, Vascular Remodeling, and In-Stent Restenosis in Humans

“…The 3D position of each ECG-gated IVUS frame was determined from the reconstructed trajectory of catheter pullback and pullback speed. 13 The rotation of the frame was determined by using computational geometry. 11 Each frame was aligned perpendicular to the catheter core.…”

Extension of Increased Atherosclerotic Wall Thickness Into High Shear Stress Regions Is Associated With Loss of Compensatory Remodeling

“…9 Briefly, a sheath-based IVUS catheter (CVIS 2.9F) was positioned in the studied vessel. The catheter in most distal position was filmed (25 frames/s) by a biplane angiographic system (Bicor, Siemens), and IVUS images were collected at successive end diastoles (EDs) using an ECG-triggered, motorized stepped pullback (0.5-mm steps, TomTec).…”

“…9 The IVUS frames were analyzed with a semiautomatic contour detection program 11 to provide lumen contours, signifying the blood vessel interface and media contours at the lamina elastica externa.…”

“…The angular rotation of the contours was determined from the best quantitative correspondence between the actual angiograms and simulated silhouette images derived from the 3D lumen reconstructions. 9 Finally, adding the media contours completed the 3D lumen reconstruction with the vessel wall.…”

Intravascular Palpography for High-Risk Vulnerable Plaque Assessment

“…Strain measurements give an indication of the mechanical properties of the plaque, without taking the shear forces into account, which may be responsible for activation of biological processes inducing instabilities. Assessment of shear stress is feasible by obtaining high-resolution reconstruction of 3-D coronary lumen and wall morphology using the combination of angiography and IVUS [32].…”