Christenson P C, Ovitt T W, Fisher H D, Frost M M, Nudelman S, Roehrig H
AJR Am J Roentgenol. 1980 Dec;135(6):1145-52. doi: 10.2214/ajr.135.6.1145.
The clinical application of intravenous angiography to study the cervicocerebrovascular system using the digital video subtraction system described in a companion article is reported. About 0.75 ml/kg of a standard 76% iodine contrast solution is injected into an antecubital vein using a power injector. Then 15-20 exposures of the head and neck region at a 1/sec rate are made on the image intensifier. The images are recorded by a high performance video system and the output signal is digitized for subsequent computer manipulation. The subtraction images of these vessels produced by the computer show the vessels clearly, even though they contain very low concentrations of contrast media. Standard exposure factors of 75-80 kVp, 9-10 msec at 800-1,000 mA are used. Clinically pertinent features of the data alteration and flow through the system and the step-by-step computer procedures used to achieve and analyze the various forms of subtracted images are described. Five experimental and clinical cases demonstrate appropriate applications to cervicocerebrovascular disease: (1) evaluating the effects of surgical and medical therapy on atherosclerosis; (2) providing a screening angiographic test for patients with asymptomatic bruits and/or positive noninvasive studies; (3) evaluating patients who have significant generalized vascular disease either precluding or presenting hazardous contraindications to transarterial catheterization; (4) evaluating significantly aged patients in whom standard angiography has higher risk; and (5) evaluating currently asymptomatic patients who are medically at higher risk for developing atherosclerotic lesions. Numerous examples of the various types of image manipulations are presented: (1) linear subtraction; (2) logarithmic subtraction; (3) alterations of electronic contrast enhancement (map slope); (4) the usefulness of a series of angiographic images; and (5) the importance of multiple projections with this technique.
本文报道了使用配套文章中描述的数字视频减法系统，将静脉血管造影术应用于颈脑血管系统研究的临床情况。使用动力注射器，将约0.75毫升/千克的标准76%碘造影剂注入肘前静脉。然后，在影像增强器上以每秒1次的速率对头颈部区域进行15 - 20次曝光。图像由高性能视频系统记录，输出信号数字化以便后续计算机处理。计算机生成的这些血管的减法图像能清晰显示血管，即使它们所含造影剂浓度很低。使用的标准曝光参数为75 - 80千伏峰值、800 - 1000毫安下9 - 10毫秒。文中描述了数据变化及通过该系统的血流的临床相关特征，以及用于生成和分析各种减法图像形式的逐步计算机程序。五个实验和临床病例展示了该技术在颈脑血管疾病中的恰当应用：（1）评估手术和药物治疗对动脉粥样硬化的效果；（2）为无症状杂音和/或无创检查阳性的患者提供筛选血管造影检查；（3）评估患有严重全身性血管疾病、排除经动脉导管插入术或存在危险禁忌证的患者；（4）评估标准血管造影风险较高的老年患者；（5）评估目前无症状但患动脉粥样硬化病变医学风险较高的患者。文中给出了各种图像操作的大量示例：（1）线性减法；（2）对数减法；（3）电子对比度增强（映射斜率）的改变；（4）一系列血管造影图像的作用；（5）该技术多投影的重要性。
