Müller R D, Von Koschitzki T, Hirche H, John V, Hering K, Gocke C, Turowski B
Central Radiological Diagnostic Institute, University Hospital, Essen, Germany.
Clin Radiol. 1996 Aug;51(8):577-86. doi: 10.1016/s0009-9260(96)80140-1.
The aim of the study was to optimize unsharp masking image post-processing of digital luminescence radiographs (DLR) for the representation of pulmonary nodules, and to compare DLR to screen-film radiography at two dose levels.
A total of 284 CT-validated pulmonary nodules were evaluated. One hundred and forty-nine nodules were exposed with a 200-speed screen-film combination (SFC) and 135 nodules with a 400-speed SFC, with correspondingly exposed storage phosphor images. The kernal size in digital post-processing using 'unsharp masking' was varied between S 10 (2.83 mm) and S 70 (19.80 mm). A total of 11928 individual assessments were obtained from six independent observers and evaluated in multifactorial variance analyses.
The large filter kernels of S 40 and S 70 were on a par with the 200-speed SFC (P > 0.05). As the exposure dose was reduced, the quality of the digital image vis-à-vis the 400-speed SFC improved significantly (P < 0.05). Smaller filter kernels (S 10; S 20) producing edge-enhancement processing were significantly inferior to the analog image technique in both dose ranges (P < 0.05).
At speed class 200, low-frequency emphasizing digital image post-processing with large filter kernels are significantly superior to high-frequency emphasizing filtrations for the recognition of pulmonary nodules. In the lower dose range DLR with large filter kernel unsharp masking processing showed significantly improved image quality compared to 400 speed SFC for the detection of pulmonary nodules.
本研究旨在优化数字发光X线片（DLR）的锐化掩膜图像后处理以呈现肺结节，并在两种剂量水平下将DLR与屏-片X线摄影进行比较。
共评估了284个经CT验证的肺结节。149个结节采用200速屏-片组合（SFC）进行曝光，135个结节采用400速SFC进行曝光，并相应地获取存储磷光体图像。在使用“锐化掩膜”进行数字后处理时，内核大小在S 10（2.83毫米）和S 70（19.80毫米）之间变化。六位独立观察者共进行了11928次个体评估，并在多因素方差分析中进行评估。
S 40和S 70的大滤波内核与200速SFC相当（P>0.05）。随着曝光剂量降低，相对于400速SFC，数字图像的质量显著提高（P<0.05）。在两个剂量范围内，产生边缘增强处理的较小滤波内核（S 10；S 20）明显不如模拟图像技术（P<0.05）。
在200速等级下，使用大滤波内核进行低频增强的数字图像后处理在识别肺结节方面明显优于高频增强滤波。在较低剂量范围内，与400速SFC相比，采用大滤波内核锐化掩膜处理的DLR在检测肺结节时图像质量有显著改善。
