Eigler N L, Eckstein M P, Mahrer K N, Whiting J S
Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048.
Circulation. 1994 Jun;89(6):2700-9. doi: 10.1161/01.cir.89.6.2700.
We have developed a digital display method that stabilizes the motion of a stenosis in sequential frames of a coronary angiogram, allowing it to be scrutinized at high display frame rates. The purpose of this study was to determine whether this technique improves visual detection of low-contrast luminal morphological features.
An observer detection study was conducted using computer-simulated arterial segments containing known target features, inserted into clinical digital coronary angiograms. Four observers performed a forced-choice detection of a simulated filling defect in each of 320 angiograms using the conventional and stenosis-stabilized dynamic displays (at 7.5, 15, and 32 frames per second) and a single-frame static display (total of 8960 detections). In a second simulated clinical task, three observers detected a bridging stenotic lumen in 600 angiograms using the two displays (3600 detections). In a third experiment, two angiographers rated the likelihood of intraluminal thrombus in 89 right coronary digital angiograms by consensus reading with both dynamic displays. Detectability of the simulated filling defect was similar for both dynamic display methods at 7.5 frames per second (averaging twice that for static images). As display rate was increased to 32 frames per second, detectability for the conventional display declined, whereas the stabilized display detectability increased for all observers (P < .05). On average, stabilization allowed detection of filling defects equivalent to a 71% increase in feature contrast. Response time for the conventional display averaged 12.9 +/- 4.7 seconds. For the stenosis-stabilized display, response time fell with increased frame rate (P < .05) to 4.9 +/- 1.2 seconds at 32 Hz, similar to the time for static images (4.6 +/- 0.8 seconds). The detectability of the bridging stenotic lumen was increased by 62% with the stabilization compared with conventional dynamic display (P < .00001). Consensus reading of coronary angiograms showed differences between the two dynamic display methods (kappa = 0.11) that may be explained by an improvement in observer uncertainty. A rating of definite for thrombus present or absent was more frequent with the stabilized display (39% versus 15%, P < .0001).
These data suggest that stabilized display of coronary angiograms significantly increases detectability, reduces the time required for detection, and improves observer uncertainty for the presence of small luminal morphological features. The method of angiographic display may thus have an impact on clinical coronary angiographic interpretation.
我们开发了一种数字显示方法，可稳定冠状动脉造影连续帧中狭窄部位的运动，使其能够以高显示帧率进行仔细检查。本研究的目的是确定该技术是否能改善低对比度管腔形态特征的视觉检测。
使用插入临床数字冠状动脉造影中的包含已知目标特征的计算机模拟动脉段进行观察者检测研究。四名观察者使用传统和狭窄稳定动态显示（每秒7.5、15和32帧）以及单帧静态显示，对320幅血管造影中的每一幅进行模拟充盈缺损的强制选择检测（共8960次检测）。在第二项模拟临床任务中，三名观察者使用两种显示方式对600幅血管造影中的桥接狭窄管腔进行检测（3600次检测）。在第三个实验中，两名血管造影师通过对两种动态显示进行一致解读，对89幅右冠状动脉数字血管造影中管腔内血栓的可能性进行评分。对于每秒7.5帧的两种动态显示方法，模拟充盈缺损的可检测性相似（平均是静态图像的两倍）。当显示速率增加到每秒32帧时，传统显示的可检测性下降，而稳定显示的可检测性对所有观察者均增加（P < 0.05）。平均而言，稳定显示使充盈缺损的检测能力相当于特征对比度提高了71%。传统显示的响应时间平均为12.9 +/- 4.7秒。对于狭窄稳定显示，响应时间随着帧率增加而下降（P < 0.05），在32 Hz时降至4.9 +/- 1.2秒，与静态图像的时间（4.6 +/- 0.8秒）相似。与传统动态显示相比，稳定显示使桥接狭窄管腔的可检测性提高了62%（P < 0.00001）。冠状动脉造影的一致解读显示两种动态显示方法之间存在差异（kappa = 0.11），这可能是由于观察者不确定性的改善所致。对于存在或不存在血栓的明确评级，稳定显示更为常见（39%对15%，P < 0.0001）。
这些数据表明，冠状动脉造影的稳定显示显著提高了可检测性，减少了检测所需时间，并改善了观察者对小管腔形态特征存在与否的不确定性。因此，血管造影显示方法可能会对临床冠状动脉造影解释产生影响。
