To Compare The Quality Of Different Printers In Medical Image

Objective:1. To compare the physical parameters of film and paper media in order to analyze the difference image quality between the two media.2. To compare the number of the focus of common disease displayed in film and paper media, and explore the clinical value of paper media system in medical imaging.Material and method:1. A comparative study of image quality of dry laser printer and film printer using Medical Diagnostic Imaging Test Pattern SMPTE RP-133. Use Adobe Photoshop software to obtain the picture derived from the SMPTE RP-133 test scan results. To use JMicro Vision Image Analysis Toolkit to do x-axis image statistical computation, the density of points would derive from calculus. The space - density curves would be got through computation, and the results of display would be analyzed through the image curve.2. Imaging results were reviewed from 2007-10 to 2008-5 . Three hundred cases were recruited and divided into 3 groups including Group 1: 100 cases of normal thoracic X-ray film, Group 2: 100 cases of CT film which were diagnosed as injury of brain, Group 3: 100 cases of MR film which were diagnosed as lacunar infarction. All the images were printed in film and paper media in use of laserjet and digital medical imaging paper media printer system. Three radiologists with 5 years of professional experience evaluated the image quality of the two media and compared the demonstration of the common disease between film and paper media.Results:1. Analysis of the space - density curve generated by SMPTE RP-133 test showed that: the part of the high-contrast images showed that the curve of the paper media images compared with that of film images was closer to its ideal form images generated curve (similar to square wave, uniform amplitude); low-contrast image part display that, the image generated by the paper media image was burr-shaped curve (for the noise waveform). The curve generated by film images was a relatively smooth curve, but the uniformity of the amplitude was poor. The curve generated by ideal images was uniform in amplitude and square wave shape. The curves generated by two types of media images were not as good as the ideal results.2. No significant difference of image demonstration was found between the film and paper media in the main structure among the thoracic X-ray, the head trauma CT and lacunar infarction MR. However, there was significant difference in some aspects of details of the performance(P<0.05). When combined with the soft image workstation reading, the paper media image can meet the needs of the clinical diagnosis.Conclusion: 1. Analyzing the output results of SMPTE RP-133 test pattern of both printers. In high-contrast patterns, the output of dry laser printer resembled the original image better, the curve is more square-shaped and the amplitude is more consistent, means that more high-frequency signal is preserved and more accurate density of high-contrast patterns in the output of dry laser printer. In low-contrast patterns, the output of dry laser printer shows major amount of high-frequency noise, albeit the amplitude is consistent. The output of film printer shows less consistent amplitude but the curve is much smoother, means that the dry laser printer has higher noise and lower signal to noise ratio in low-contrast patterns, resulting in inferior image quality in subtle low-contrast fine details.2. There is no significant difference of the two types of images for this common disease in the main structure and signs in the clinical use of chest X-ray films, head trauma CT, lacunar infarction MR. However, the paper media image is poor in some details of the performance. When combined with the soft image workstation reading, the paper media image is qualified for the needs of the clinical diagnosis.3. As a result of the comprehensive comparison of these two categories of equipment, the paper media printing system as a new type of displaying method of medical imaging is simple, economic, good to environmental protection, easy to store. So it can be used in a certain range of medical imaging to display images.