Yang X M, Manninen H, Ji H X, Vainio P, Soimakallio S
Department of Clinical Radiology, Kuopio University Hospital, Finland.
Acta Radiol. 1994 Jul;35(4):378-82.
To evaluate the accuracy of digital videodensitometric technique in directly quantitating concentration of contrast medium, iohexol 300 mg I/ml was injected into a 2-mm-diameter plastic tube, in which clean water was circulated at a 190 ml/min flow, for digital subtraction angiography. Altogether 27 injections were performed with 3, 4 and 5 ml volumes at 3-, 4- and 5-ml/s flows of the contrast medium. A time-density curve was achieved by selecting a "vessel" region of interest (ROI) and a background ROI. Then, a frame corresponding to the maximum opacification of the contrast medium could be calculated. Finally, the average density and the time to peak density of the contrast medium were obtained. The average density was statistically higher (p < 0.01) with 5 ml/s flow than with 4- and 3-ml/s flows. Times to peak density reduced as injection flows or volumes increased. The results support the conclusion that digital videodensitometric technique is an accurate method for quantitation of contrast medium concentration during angiography. The angiographic opacification may be improved by injecting the iodine contrast medium with higher flows or larger volumes.
为评估数字视频密度测定技术在直接定量造影剂浓度方面的准确性，将300mg I/ml的碘海醇注入一根直径为2mm的塑料管中，管内清水以190ml/min的流速循环，用于数字减影血管造影。共进行了27次注射，造影剂的流速分别为3、4和5ml/s，注射量分别为3、4和5ml。通过选择一个“血管”感兴趣区（ROI）和一个背景ROI获得时间-密度曲线。然后，可以计算出对应于造影剂最大显影的帧。最后，获得造影剂的平均密度和达到峰值密度的时间。5ml/s流速下的平均密度在统计学上高于4ml/s和3ml/s流速（p<0.01）。达到峰值密度的时间随着注射流速或注射量的增加而缩短。结果支持以下结论：数字视频密度测定技术是血管造影术中定量造影剂浓度的一种准确方法。通过以更高的流速或更大的体积注射碘造影剂，血管造影显影可能会得到改善。
