North Wales Cardiac Centre, Rhyl, UK.
Bangor University, Bangor, UK.
Br J Radiol. 2022 Jan 1;95(1129):20210269. doi: 10.1259/bjr.20210269.
To audit whether using magnification of images by use of a large viewing screen using digital matrix magnification which enlarges the image by 33% without using the X-ray machine zoom magnification protocols on a Siemens Artis Zee X-ray machine in a cardiac catheter laboratory results in a reduction of kerma-area product (KAP) for both diagnostic and interventional procedures. This reduction was predicted in an study in our laboratory, which has previously shown a 20.4% reduction in KAP.
A retrospective analysis was conducted of the radiation exposure to compare the measured KAP recorded during the period when conventional magnification with automatic brightness and dose control was used on a Siemens Artis Zee X-ray machine with a flat panel detector and when magnification settings were avoided by using a large screen to enlarge and project a non-magnified image by digital magnification. The analysis was carried out for patients having a diagnostic coronary angiogram and those having an interventional coronary procedure.
For diagnostic coronary angiograms the median KAP per procedure in the period using conventional magnification was 2124.5 µGy.m compared to 1401 µGy.m when image matrix magnification was used, a 34% reduction ( < 0.0001). For interventional coronary procedures, the median KAP per procedure in the period using conventional magnification was 3791 µGy.m compared to 2568.5 µGy.m when image matrix magnification was used, a 32% reduction ( < 0.0001).
Avoiding using conventional magnification in the cardiac catheter laboratory and using a large screen to magnify images was associated with a statistically significant greater than 30% reduction in KAP.
This paper is the proof in clinical practice of a theoretical conclusion that radiation dose (KAP) is reduced by use of Image matrix magnification using a large viewing screen without the need to use X-ray tube magnification without significant loss of image resolution in interventional cardiology. The same approach will be useful in interventional radiology.
审计在心脏导管实验室中使用西门子 Artis Zee X 射线机的数字矩阵放大功能（通过使用大屏幕将图像放大 33%，而不使用 X 射线机变焦放大协议）放大图像，是否会降低诊断和介入程序的比释动能面积乘积（KAP）。我们实验室的一项研究预测会有这种减少，该研究先前表明 KAP 减少了 20.4%。
对辐射暴露进行回顾性分析，比较在西门子 Artis Zee X 射线机上使用常规放大和自动亮度及剂量控制与避免使用放大设置，通过大屏幕放大和投影非放大图像的数字放大时，记录的测量 KAP。该分析针对进行诊断性冠状动脉造影的患者和进行介入性冠状动脉程序的患者进行。
在使用常规放大的时期，诊断性冠状动脉造影的每个程序的中位数 KAP 为 2124.5 µGy.m，而使用图像矩阵放大时为 1401 µGy.m，减少了 34%（<0.0001）。在使用常规放大的时期，介入性冠状动脉程序的每个程序的中位数 KAP 为 3791 µGy.m，而使用图像矩阵放大时为 2568.5 µGy.m，减少了 32%（<0.0001）。
在心脏导管实验室中避免使用常规放大并使用大屏幕放大图像与使用大显示屏的数字矩阵放大功能相结合，与 KAP 显著降低 30%以上相关。
本文在临床实践中证明了一个理论结论，即在介入心脏病学中，无需使用 X 射线管放大而使用大的观察屏幕使用图像矩阵放大可降低辐射剂量（KAP），而不会显著损失图像分辨率。同样的方法在介入放射学中也将是有用的。
