Koning G, Hekking E, Kemppainen J S, Richardson G A, Rothman M T, Reiber J H
Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.
Catheter Cardiovasc Interv. 2001 Mar;52(3):334-41. doi: 10.1002/ccd.1077.
Catheters usually are used for calibration purposes in quantitative coronary angiography (QCA). The systematic and random errors in these calibration factors (CFs) are dependent on the size and quality of the catheters and limited by out-of-plane magnification (OPM). Theoretically, a guide wire with evenly spaced marker bands would solve many of these potential problems. For this reason, we tested the Cordis Stabilizer marker wire, featuring 10 radiopaque platinum marker bands 15 mm apart, in in vitro and in vivo studies. To assess the effect of foreshortening, wires were positioned in a tube phantom; a centimeter grid was used as the gold standard. Radiographic images were acquired at 5-inch and 7-inch image-intensifier sizes, 512(2) and 1,024(2) matrix sizes and angulations from 0 degrees to 70 degrees in steps of 10 degrees. It was concluded that the relative errors in CFs are less than 7% if the foreshortening angles remain less than 20 degrees. In DICOM images of 15 patients, 65 measurements were taken after calibration on an 8F catheter and on a guide wire positioned in the coronary lesion. In all but two cases, the wire CFs were larger than the catheter CFs (relative difference, 24.7 +/- 19.6%). The measurements were divided into four groups: (I) no apparent OPM or foreshortening (n = 7), (II) only OPM (n = 4), (III) only foreshortening (n = 10), and (IV) the combination of both (n = 44). In group I (no OPM or foreshortening) the QCA results were similar using the guide wire or catheter as the calibration device (relative CF difference, 2.9% only). In group III the diameters were overestimated using the guide wire (obstruction diameter difference, 0.22 +/- 0.11 mm; reference diameter difference, 0.35 +/- 0.06 mm). For only OPM (group II) and the combination of OPM and foreshortening (group IV), the lesion length was underestimated on average by 2.4 mm using the catheter instead of the guide wire. In conclusion, if accurate assessment of the lesion length is important, the marker wire should be used for calibration purposes. For vessel diameter measurements, the conventional catheter calibration approach is the method of choice.
在定量冠状动脉造影（QCA）中，导管通常用于校准目的。这些校准因子（CFs）中的系统误差和随机误差取决于导管的尺寸和质量，并受平面外放大率（OPM）的限制。理论上，带有均匀间隔标记带的导丝可以解决许多此类潜在问题。因此，我们在体外和体内研究中测试了Cordis Stabilizer标记导丝，其具有10个不透射线的铂标记带，间隔为15毫米。为了评估缩短的影响，将导丝放置在管模体中；使用厘米网格作为金标准。在5英寸和7英寸图像增强器尺寸、512(2)和1024(2)矩阵尺寸以及从0度到70度以10度步长的角度下采集射线图像。得出的结论是，如果缩短角度保持小于20度，CFs中的相对误差小于7%。在15名患者的DICOM图像中，在对位于冠状动脉病变处的8F导管和导丝进行校准后进行了65次测量。除两例情况外，在所有情况下，导丝CFs均大于导管CFs（相对差异，24.7±19.6%）。测量结果分为四组：（I）无明显OPM或缩短（n = 7），（II）仅OPM（n = 4），（III）仅缩短（n = 10），以及（IV）两者皆有（n = 44）。在第一组（无OPM或缩短）中，使用导丝或导管作为校准设备时，QCA结果相似（仅相对CF差异为2.9%）。在第三组中，使用导丝时直径被高估（阻塞直径差异，0.22±0.11毫米；参考直径差异，0.35±0.06毫米）。对于仅OPM（第二组）以及OPM和缩短两者皆有的情况（第四组），使用导管而非导丝时，病变长度平均低估2.4毫米。总之，如果对病变长度的准确评估很重要，应使用标记导丝进行校准。对于血管直径测量，传统的导管校准方法是首选方法。
