Thierfelder Kolja M, Havla Lukas, Beyer Sebastian E, Ertl-Wagner Birgit, Meinel Felix G, von Baumgarten Louisa, Janssen Hendrik, Ditt Hendrik, Reiser Maximilian F, Sommer Wieland H
From the *Institute for Clinical Radiology, †Josef Lissner Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Departments of ‡Neurology, and §Neuroradiology, Ludwig Maximilians University Hospital Munich; and ∥Siemens AG, Healthcare Sector, Erlangen, Germany.
Invest Radiol. 2015 May;50(5):361-5. doi: 10.1097/RLI.0000000000000134.
The objective of this study was to develop a new method of displaying dynamic cerebral computed tomographic (CT) angiography (CTA) data sets in which the time delay to maximum enhancement (Tdelay) is displayed in a range of colors (color-coded CT angiography [cCTA]).
This institutional review board-approved study included multiparametric CT data sets from 16 patients with different types of supra-aortic large vessel occlusions. Color-coded CT angiography was reconstructed from CT perfusion raw data sets. All voxel enhancement curves were fitted to f(t) = α · AIFmtt(t - Δt), with AIFmtt(t), indicating enhancement of AIF dilated by convolution with boxcar function (with mean transit time [mtt]); α, scaling factor; and [INCREMENT]t, transition along the time. The time delay to maximum enhancement was defined as Tdelay = Δt +0.5 · mtt. Values of Tdelay were color-coded and superimposed on temporal maximum intensity projections CTA resulting in colored angiographic composite images. For a pilot clinical evaluation, diagnostic confidence in determining the pathology, quality of the visualization of leptomeningeal collaterals, and additional diagnostic information were assessed.
The reconstruction of cCTA was technically feasible in all 16 patients. Both diagnostic confidence (P < 0.01) and the quality of the visualization of collaterals (P < 0.0001) were significantly higher when using the combination of single-phase CTA and cCTA compared with single-phase CTA alone. Additional diagnostic information was obtained with cCTA regarding occlusion type (reader 1: 5 cases and reader 2: 4 cases), differentiation between arteries and veins (11/13), differentiation between antegrade and retrograde filling (12/13), as well as leptomeningeal collateralization (13/14).
Color-coded CT angiography is a technically feasible technique that provides additional information on cerebral hemodynamics in ischemic stroke patients.
本研究的目的是开发一种新的方法来显示动态脑计算机断层扫描（CT）血管造影（CTA）数据集，其中最大强化时间延迟（Tdelay）以一系列颜色显示（彩色编码CT血管造影[cCTA]）。
本研究经机构审查委员会批准，纳入了16例不同类型主动脉弓上大血管闭塞患者的多参数CT数据集。彩色编码CT血管造影由CT灌注原始数据集重建而成。所有体素强化曲线均拟合为f(t)=α·AIFmtt(t - Δt)，其中AIFmtt(t)表示通过与矩形函数卷积（平均通过时间[mtt]）扩张后的AIF强化；α为比例因子；Δt为沿时间的过渡。最大强化时间延迟定义为Tdelay = Δt + 0.5·mtt。Tdelay值进行彩色编码并叠加在时间最大强度投影CTA上，从而生成彩色血管造影合成图像。为进行初步临床评估，评估了在确定病变、软脑膜侧支循环可视化质量以及额外诊断信息方面的诊断信心。
16例患者中，cCTA重建在技术上均可行。与单独使用单相CTA相比，联合使用单相CTA和cCTA时，诊断信心（P < 0.01）和侧支循环可视化质量（P < 0.0001）均显著更高。通过cCTA获得了关于闭塞类型（读者1：5例，读者2：4例）、动静脉区分（11/13）、顺行和逆行充盈区分（12/13）以及软脑膜侧支循环（13/14）的额外诊断信息。
彩色编码CT血管造影是一种技术上可行的技术，可为缺血性脑卒中患者提供有关脑血流动力学的额外信息。
