Joshi Anuja, Gislason-Lee Amber J, Keeble Claire, Sivananthan Uduvil M, Davies Andrew G
1 Division of Biomedical Imaging, University of Leeds, Leeds, UK.
2 Division of Epidemiology and Biostatistics, University of Leeds, Leeds, UK.
Br J Radiol. 2017 Mar;90(1071):20160660. doi: 10.1259/bjr.20160660. Epub 2017 Jan 26.
The aim of this research was to quantify the reduction in radiation dose facilitated by image processing alone for percutaneous coronary intervention (PCI) patient angiograms, without reducing the perceived image quality required to confidently make a diagnosis.
Incremental amounts of image noise were added to five PCI angiograms, simulating the angiogram as having been acquired at corresponding lower dose levels (10-89% dose reduction). 16 observers with relevant experience scored the image quality of these angiograms in 3 states-with no image processing and with 2 different modern image processing algorithms applied. These algorithms are used on state-of-the-art and previous generation cardiac interventional X-ray systems. Ordinal regression allowing for random effects and the delta method were used to quantify the dose reduction possible by the processing algorithms, for equivalent image quality scores.
Observers rated the quality of the images processed with the state-of-the-art and previous generation image processing with a 24.9% and 15.6% dose reduction, respectively, as equivalent in quality to the unenhanced images. The dose reduction facilitated by the state-of-the-art image processing relative to previous generation processing was 10.3%.
Results demonstrate that statistically significant dose reduction can be facilitated with no loss in perceived image quality using modern image enhancement; the most recent processing algorithm was more effective in preserving image quality at lower doses. Advances in knowledge: Image enhancement was shown to maintain perceived image quality in coronary angiography at a reduced level of radiation dose using computer software to produce synthetic images from real angiograms simulating a reduction in dose.
本研究的目的是量化仅通过图像处理对经皮冠状动脉介入治疗（PCI）患者血管造影实现的辐射剂量降低，同时不降低做出可靠诊断所需的感知图像质量。
向五张PCI血管造影图像中添加递增的图像噪声，模拟在相应较低剂量水平（剂量降低10 - 89%）下采集的血管造影图像。16名有相关经验的观察者对这些血管造影图像在三种状态下的图像质量进行评分，即未进行图像处理以及应用两种不同的现代图像处理算法。这些算法用于最先进的和上一代心脏介入X射线系统。使用考虑随机效应的有序回归和德尔塔方法来量化处理算法在等效图像质量评分下可能实现的剂量降低。
观察者认为，使用最先进的图像处理算法和上一代图像处理算法处理后的图像，在剂量分别降低24.9%和15.6%时，质量与未增强的图像相当。与上一代处理相比，最先进的图像处理实现的剂量降低为10.3%。
结果表明，使用现代图像增强技术可在不损失感知图像质量的情况下实现具有统计学意义的剂量降低；最新的处理算法在较低剂量下更有效地保持图像质量。知识进展：通过计算机软件利用真实血管造影图像生成模拟剂量降低的合成图像，图像增强技术在冠状动脉造影中以降低的辐射剂量水平保持了感知图像质量。
