Division of Image Processing, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2300 RC Leiden, The Netherlands.
Int J Cardiovasc Imaging. 2011 Feb;27(2):197-207. doi: 10.1007/s10554-011-9809-2. Epub 2011 Jan 25.
The combination/fusion of quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS)/optical coherence tomography (OCT) depends to a great extend on the co-registration of X-ray angiography (XA) and IVUS/OCT. In this work a new and robust three-dimensional (3D) segmentation and registration approach is presented and validated. The approach starts with standard QCA of the vessel of interest in the two angiographic views (either biplane or two monoplane views). Next, the vessel of interest is reconstructed in 3D and registered with the corresponding IVUS/OCT pullback series by a distance mapping algorithm. The accuracy of the registration was retrospectively evaluated on 12 silicone phantoms with coronary stents implanted, and on 24 patients who underwent both coronary angiography and IVUS examinations of the left anterior descending artery. Stent borders or sidebranches were used as markers for the validation. While the most proximal marker was set as the baseline position for the distance mapping algorithm, the subsequent markers were used to evaluate the registration error. The correlation between the registration error and the distance from the evaluated marker to the baseline position was analyzed. The XA-IVUS registration error for the 12 phantoms was 0.03 ± 0.32 mm (P = 0.75). One OCT pullback series was excluded from the phantom study, since it did not cover the distal stent border. The XA-OCT registration error for the remaining 11 phantoms was 0.05 ± 0.25 mm (P = 0.49). For the in vivo validation, two patients were excluded due to insufficient image quality for the analysis. In total 78 sidebranches were identified from the remaining 22 patients and the registration error was evaluated on 56 markers. The registration error was 0.03 ± 0.45 mm (P = 0.67). The error was not correlated to the distance between the evaluated marker and the baseline position (P = 0.73). In conclusion, the new XA-IVUS/OCT co-registration approach is a straightforward and reliable solution to combine X-ray angiography and IVUS/OCT imaging for the assessment of the extent of coronary artery disease. It provides the interventional cardiologist with detailed information about vessel size and plaque size at every position along the vessel of interest, making this a suitable tool during the actual intervention.
定量冠状动脉造影（QCA）与血管内超声（IVUS）/光学相干断层扫描（OCT）的结合/融合在很大程度上取决于 X 射线血管造影（XA）与 IVUS/OCT 的配准。本研究提出并验证了一种新的、强大的三维（3D）分割和配准方法。该方法首先在 XA 的两个视图（双平面或两个单平面视图）中对感兴趣的血管进行标准 QCA。接下来，通过距离映射算法将感兴趣的血管在 3D 中重建，并与相应的 IVUS/OCT 回拉系列进行配准。在 12 个植入冠状动脉支架的硅树脂体模和 24 例同时接受冠状动脉造影和左前降支 IVUS 检查的患者中，对配准的准确性进行了回顾性评估。支架边缘或分支被用作验证的标记物。虽然最靠近近端的标记物被设定为距离映射算法的基线位置，但随后的标记物用于评估配准误差。分析了注册误差与评估标记物到基线位置的距离之间的相关性。12 个体模的 XA-IVUS 配准误差为 0.03±0.32mm（P=0.75）。由于一个 OCT 回拉系列未覆盖远端支架边缘，因此从体模研究中排除了一个 OCT 回拉系列。其余 11 个体模的 XA-OCT 配准误差为 0.05±0.25mm（P=0.49）。在体内验证中，由于分析时图像质量不足，排除了 2 例患者。从其余 22 例患者中总共识别出 78 个分支，并对 56 个标记物进行了配准误差评估。配准误差为 0.03±0.45mm（P=0.67）。误差与评估标记物与基线位置之间的距离无关（P=0.73）。总之，新的 XA-IVUS/OCT 配准方法是一种简单可靠的方法，可用于结合 X 射线血管造影和 IVUS/OCT 成像来评估冠状动脉疾病的严重程度。它为介入心脏病专家提供了有关感兴趣血管内每个位置的血管大小和斑块大小的详细信息，使其成为实际干预过程中的合适工具。
