| 钟朝辉,卢东生.移动数字X线摄影条件对胸部影像质量的影响[J].中国医学影像技术,2011,27(3):618~621 |
| 移动数字X线摄影条件对胸部影像质量的影响 |
| Impact of exposure parameters on chest image quality of mobile digital radiography |
| 投稿时间：2010-09-08 修订日期：2010-12-01 |
| DOI： |
| 中文关键词: 放射摄影术,胸部 噪声 对比度噪声比 辐射剂量 |
| 英文关键词:Radiography, thoracic Noise Contrast to noise ratio Radiation dosage |
| 基金项目: |
|
| 摘要点击次数: 4363 |
| 全文下载次数: 1417 |
| 中文摘要: |
| 目的 探讨不同的摄影管电压和毫安秒对图像感兴趣区内像素值均值、噪声及对比度噪声比的影响,以寻找最适合的摄影条件,在获得较好的图像质量的前提下,减少患者的辐射剂量。方法 根据摄影参数的不同,分为两个实验组:第一组保持毫安秒不变(普通床边胸片的毫安秒条件),将管电压从55 kVp升至120 kVp,每5 kVp为1档。从第一组中选择出图像质量较好的四种管电压,改变毫安秒,从1.00 mAs至5.00 mAs共7档,作为第二实验组。测量并记录2个密度区内感兴趣区像素值均值和噪声值,计算对比度噪声比。结果 感兴趣区像素值均值基本不随管电压和毫安秒的变化而改变。管电压对各个区域的噪声值均有影响:<80 kVp时,噪声值随管电压的升高显著减小,对比度噪声比明显升高;≥80 kVp时,管电压的升高对各个区域噪声值的影响较小,对比度噪声比变化也较小。四种管电压固定的情况下,毫安秒对各个区域的噪声值均有影响:<2.00 mAs时,噪声值随毫安秒的升高显著减小,对比度噪声比明显升高;≥2.00 mAs时,毫安秒的升高对各区域噪声值的影响越来越小,对比度噪声比变化也较小。结论 胸部数字X线摄影的推荐管电压为75~85 kVp,根据患者的体型进行选择;推荐的毫安秒为2.00~3.00 mAs,既可获得比较好的图像质量,又可使患者接受较少的X线辐射剂量。 |
| 英文摘要: |
| Objective To assess the impact of different exposure tube voltage and mAs on pixel mean value, noise and contrast to noise ratio (CNR) of image in regions of interest, in order to recommend the best exposure parameters to reduce radiation dose on the condition of good image quality. Methods One group kept the mAs constantly (the mAs was used in conventional bedside X-ray photography) and raised the tube voltage from 55 kVp to 120 kVp by step of 5 kVp. Four suitable kVp values were selected out from first experiment and the mAs was raised from 1.00 to 5 by 7.00 steps as the second experiment. The pixel mean value and noise of the image in region of interest were measured and recorded in 2 density areas, and the CNR was calculated. Results The pixel mean value of the image in region of interest was not influenced by the exposure tube voltage or mAs. The exposure condition affected the noise and CNR: When tube voltage was <80 kVp, the noise decreased and CNR remarkably as tube voltage raised. When tube voltage was ≥80 kVp, increase of tube voltage affected the noise and CNR indistinctly. Keeping the tube valtage in 4 different values, the mAs influenced the noise and CNR: When mAs was <2.00, the noise decreased remarkably as the mAs raised. When mAs was ≥2.00, raising mAs affected less and less on the noise and CNR. Conclusion The suggested tube voltage of the chest radiography by DR is from 75 kVp to 85 kVp, depending on patients' form, and the suggested mAs is from 2.00 to 3.0 0 for obtaining better image quality and less patients' X-ray dose. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
