Balter Stephen, Simon Dan, Itkin Max, Granada Juan F, Melman Haim, Dangas George
Departments of Radiology and Medicine, Columbia University, New York, New York 10032.
Vascular Access Center West Orange, West Orange, New Jersey 07052.
Med Phys. 2016 Mar;43(3):1531-8. doi: 10.1118/1.4941955.
This paper reports the first results obtained using a novel technology called eye controlled region of interest (ECR) that substantially reduces both staff and patient irradiation during an interventional fluoroscopy procedure without interfering with workflow. Its collimator includes a partially x-ray attenuating plate with a nonattenuating aperture. An eye tracker follows the operator's gaze to automatically position the aperture to the clinical region of interest (CROI) anywhere in the image in real-time.
Experiments were performed in a swine model using a mobile fluoroscope with a 30 cm image intensifier and manual control of fluoroscopic factors. The factory collimator and image display monitor were replaced with different components for this study. The full 30 cm field-of-view (FOV) of the image intensifier was irradiated at normal levels, and served as a baseline, when ECR was disengaged. With ECR engaged, most of the 30 cm FOV was irradiated to less than 20% of normal levels while the CROI was normally irradiated. Animal irradiation was determined by physical KAP (kerma area product) measurements. Operator irradiation was characterized by air kerma and air kerma rate measurements near the operator. Data were collected from three pairs of interventions in each of five swine models.
When ECR was engaged, KAP was reduced to 0.22 (p < 0.001) of baseline and operator irradiation to 0.27 (p < 0.001) of baseline. Overall procedure time had a borderline increase (p = 0.07) but fluoroscopy time was unchanged (p = 0.36) (Wilcoxon signed rank). Measured staff and patient radiation reductions are consistent with this collimator's design. Subjective impressions of imaging improvements are consistent with less scatter reaching the CROI. Engaging ECR reduced irradiation without subjectively or objectively increasing operator workload.
The first in vivo evaluation of ECR demonstrated that this technology has objectively reduced KAP and operator irradiation by approximately 75% without interfering with the performance of fluoroscopically guided interventional procedures. In addition, reduced scatter production subjectively improved device visualization. These findings indicate the practicability of achieving better radiation optimization.
本文报告了使用一种名为眼控感兴趣区域（ECR）的新技术所取得的首批成果。该技术在不干扰工作流程的情况下，在介入性荧光透视检查过程中大幅减少了工作人员和患者所受的辐射。其准直器包括一块带有非衰减孔径的部分X射线衰减板。一个眼动追踪器跟踪操作员的视线，以自动将孔径实时定位到图像中任何位置的临床感兴趣区域（CROI）。
在猪模型中使用配备30厘米影像增强器的移动荧光镜进行实验，并手动控制荧光透视参数。本研究用不同组件替换了原厂准直器和图像显示监视器。当ECR未启用时，影像增强器的整个30厘米视场（FOV）以正常水平照射，作为基线。启用ECR后，30厘米视场的大部分区域照射剂量降至正常水平的20%以下，而CROI则以正常剂量照射。通过物理KAP（比释动能面积乘积）测量来确定动物所受辐射。通过在操作员附近测量空气比释动能和空气比释动能率来表征操作员所受辐射。从五个猪模型中的每一个模型的三对干预措施中收集数据。
启用ECR后，KAP降至基线的0.22（p < 0.001），操作员所受辐射降至基线的0.27（p < 0.001）。总体手术时间有边缘性增加（p = 0.07），但荧光透视时间未变（p = 0.36）（Wilcoxon符号秩检验）。测量到的工作人员和患者辐射减少与该准直器的设计一致。对成像改善的主观印象与到达CROI的散射减少一致。启用ECR减少了辐射，而在主观或客观上均未增加操作员的工作量。
ECR的首次体内评估表明，该技术在不干扰荧光透视引导介入手术性能的情况下，客观上使KAP和操作员所受辐射减少了约75%。此外，散射产生的减少在主观上改善了设备的可视化效果。这些发现表明实现更好的辐射优化是可行的。
