直接数字化X线摄影在胸部的应用

目的 :探讨直接数字化胸部X线摄影 (DR)技术的应用价值。材料和方法 :对 10 0例胸部常规X线检查同时行数字化X线摄影图像进行对比分析。结果 :胸部DR能清楚显示病变 ,显示小病灶 ,其图像质量明显优于常规X线摄片。结论 :DR胸部数字化摄影弥补了常规X线片的不足 ,具有很大的临床应用价值和广泛前景。     

直接数字化X线摄影在胸部的应用价值

目的：探讨直接数字化X线摄影（DR）在胸部摄影中的应用价值。材料和方法：回顾性分析我院DR胸片和常规胸片各100例，分别统计一、二、三级片，同时对胸部结构进行评价对比分析。结果：胸部DR能清楚显示病变，尤其是微小病变，其图像质量明显优于常规X线摄片。结论：DR胸部数字化X线摄影弥补了常规X线摄影的不足，具有很大的临床应用价值和广泛的前景。     

DR在胸部X线摄影技术中的应用

我院在使用DR及其配套设备以来，主要承担所有门诊和住院患者的胸部X线检查任务。经过一年使用我们放射科为临床科室提供了高质量的医学影像，许多常规X线胸部检查无法检测到的影像信息，在DR胸部检查得到了再现。     

胸部X线摄影

本文描述当前放射摄影技术方面的研究状况,如：胸部Ｘ线摄影的技术问题,传统胸部Ｘ线摄影,新的屏一片系统,光束均衡的Ｘ线摄影,数字Ｘ线摄影,荧光储存系统,硒探测器系统等,并讨论有关选择和应用市场上已有的产品的实际问题。     

直接数字X线摄影技术在小儿胸部摄影中的应用

目的: 探讨直接数字X线摄影技术在小儿胸部摄影中的应用.材料和方法: 回顾性分析我院小儿DR胸片和常规胸片各500张,分别统计甲、乙、丙级片及废片,同时对显示胸部结构进行评价,并进行统计学处理.结果: (1)DR胸片: 甲级片51%、乙级片38%、丙级片10%、废片1%;(2)常规胸片: 甲级片42.4%、乙级片45%、丙级片11%、废片1.6%;(3)DR胸片可根据临床要求经不同后处理技术显示胸部各种结构.结论: 小儿DR胸片质量优于小儿常规胸片.     

婴幼儿胸部X线摄影的体会

婴幼儿胸部X线摄影是放射科检查婴幼儿胸部的常用检查方法,高质量的照片可为胸部疾病的诊断提供重要的依据。但因婴幼儿和部分儿童在检查时欠合作,有时甚至不能配合投照技师进行X线检查工作,致使婴幼儿的胸部X线照片达不到诊断要求,将重新进行投照或影响疾病的诊断,甚至造成漏、误诊。本文回顾分析200例婴幼儿X线胸部照片,就其投照技术的体会总结报告如下,供参考。1一般资料1.1本组200例,其中男性139例,女性61例。年龄1天～6岁,平均年龄3.67岁。1.2胸部X线摄影采用日本岛津公司生产的UD150L-30E500mAX线机及配套立式胸片架(固定式滤线…     

平板探测器数字胸部X线摄影

由于胸部组织结构的密度和厚度存在着较大的差异 ,传统X线平片往往难以同时显示不同部位组织结构的病变 ;与传统X线摄影相比 ,近年来出现的数字化X线摄影的最大优点就在于它只需一次曝光 ,通过调谐和空间频率的处理 ,可以获得多幅图像 ,分别显示不同的组织结构。数字化X线摄影现已成为未来X线诊断技术发展的必然方向。数字化X线摄影可分为荧光存储成像系统 (computerradiography ,CR)和数字X线成像系统 (digitalradiography ,DR )两大类。随着计算机技术和电子制造工业的飞速发展 ,新一代以平板探测器为核心的数字X线摄影 (digitalradi…     

小儿胸部X线片的评价及摄影注意事项

小儿胸部X线片是检查小儿胸部病变特别是小儿支气管肺部病变的重要方法之一．同时它具有X线辐射量小，较其它X线检查相对安全的特点。小儿胸部X线片质量的优劣，直接影响医师的诊断，因此要求我们应当利用科学的方法对照片质量进行评价，并注意改进摄影方法以获得优质的小儿胸部X线片。过去我们常套用成人胸片的评价方法     

DR双能量减影技术在胸部外伤摄影中的临床应用

目的：探讨直接数字化X线摄影（digital radiography,DR）双能量减影技术在胸部外伤摄影的检查方法、成像质量和临床应用价值。方法：分析在DR双能量减影技术下行胸部摄影的56例外伤的病例资料。结果：单纯肋骨骨折37例（其中单处骨折26例、多发骨折11例）,肋骨骨折合并肺挫伤8例,正常11例。结论：DR双能量减影技术可得出3幅图像——标准DR像、软组织像及骨骼像,其成像质量和图像所含信息量是普通单一X线成像所无法比拟的。     

Contrast-detail evaluation and dose assessment of eight digital chest radiography systems in clinical practice

The purpose of this study was to assess contrast-detail performance and effective dose of eight different digital chest radiography systems. Digital chest radiography systems from different manufacturers were included: one storage phosphor system, one selenium-coated drum system, and six direct readout systems including four thin-film transistor (TFT) systems and two charge-coupled device (CCD) systems. For measuring image quality, a contrast-detail test object was used in combination with a phantom that simulates the primary and scatter transmission through lung fields (LucAl). Six observers judged phantom images of each modality by soft-copy reading in a four-alternative-forced-choice experiment. The entrance dose was also measured, and the effective dose was calculated for an average patient. Contrast-detail curves were constructed from the observer data. The blocked two-way ANOVA test was used for statistical analysis. Significant difference in contrast-detail performance was found between the systems. Best contrast-detail performance was shown by a CCD system with slot-scan technology, and the selenium-coated drum system was compared to the other six systems (p values 0.003). Calculated effective dose varied between 0.010 mSv and 0.032 mSv. Significant differences in contrast-detail performance and effective dose levels were found between different digital chest radiography systems in clinical practice.     

Image quality of supine chest radiographs: intra-individual comparison of computed radiography and low-dose linear-slit digital radiography

The purpose of this retrospective study was to intra-individually compare the image quality of computed radiography (CR) and low-dose linear-slit digital radiography (LSDR) for supine chest radiographs. A total of 90 patients (28 female, 62 male; mean age, 55.1 years) imaged with CR and LSDR within a mean time interval of 2.8 days ± 3.0 were included in this study. Two independent readers evaluated the image quality of CR and LSDR based on modified European Guidelines for Quality Criteria for chest X-ray. The Wilcoxon test was used to analyse differences between the techniques. The overall image quality of LSDR was significantly better than the quality of CR (9.75 vs 8.16 of a maximum score of 10; p < 0.001). LSDR performed significantly better than CR for delineation of anatomical structures in the mediastinum and the retrocardiac lung (p < 0.001). CR was superior to LSDR for visually sharp delineation of the lung vessels and the thin linear structures in the lungs. We conclude that LSDR yields better image quality and may be more suitable for excluding significant pathological features of the chest in areas with high attenuation compared with CR.     

Clinical results of CsI-detector-based dual-exposure dual energy in chest radiography

The aim of this study was to compare the sensitivity and specificity of digital chest radiography alone with digital chest radiography combined with dual-energy chest radiography in the detection of small non-calcified pulmonary nodules. Standard and dual-energy radiographs were obtained with a flat-panel digital chest system. Four radiologists reviewed digital posteroanterior chest radiographs in random order either alone or in conjunction with dual-energy soft tissue and bone images. Twenty patients with a total of 59 pulmonary nodules (median 0.5 cm, range 0.3 – 2.5 cm) confirmed by computed tomography (HU 100) were included. A level of confidence for each diagnosis was documented using a rating scale of 1–5. Brunner and Langer's test was performed for statistical analysis. Subgroup analysis was performed for nodules greater than 1 cm, 1–0.5 cm, and <0.5 cm. For posteroanterior chest radiography, sensitivity was 33%, positive predictive value 83%, specificity 81%, and negative predictive value 30%. Review in conjunction with dual-energy images resulted in a sensitivity of 42%, positive predictive value 88%, specificity 85%, and negative predictive value 34%. The increase of nodule detection overall as well as for different size categories was significant (p<0.05). The increase of the confidence level rating was also significant (p<0.001). Dual energy added to standard posteroanterior chest radiography significantly improves the sensitivity, specificity, and confidence in detection of small non-calcified pulmonary nodules.     

双能量减影数字X线摄影技术的应用

目的:用双能量减影数字X线摄影提高肺部小结节病变的检出率。方法:双能量减影摄影可以用两次曝光法和一次曝光法来完成。结果:双能量减影数字化胸部摄影技术作为胸部X线检查的一种辅助手段,它能有效的提高肺部小结节病变的检出率,并能增加鉴别诊断的依据。结论:直接数字化X线摄影(DR)的使用,使两次曝光法得以实行。由于两次曝光法能量差大,它产生的双能量减影图像上组织对比良好,图像信噪比高,比一次曝光法具有更明显的优势。     

Temporal subtraction chest radiography

Radiologist are commonly required to compare a sequence of two or more chest radiographs of a given patient obtained over a period of time, which may range from a few hours to many years. In such cases, the task is one of detecting interval change. In the case of patients who have had a previous chest radiograph, an opportunity exists to enhance selectively areas of interval change, including regions with new or altered pathology, by using the previous radiographs as a subtraction mask. With temporal subtraction, the previous image is superimposed and registered with the current image, using automated two-dimensional warping to compensate for any differences in positioning. A “difference image” is then created, by subtracting the previous from the current radiograph. In this temporal subtraction image, areas that are unchanged appear as uniform gray, while regions of new opacity, such as due to pneumonia or cancer, appear as prominent dark foci on a lighter background. By cancelling out the complex anatomical background, temporal subtraction can provide dramatically enhanced visibility of new areas of disease.     

Direct detector radiography versus dual reading computed radiography: feasibility of dose reduction in chest radiography

The image quality of dual-reading computed radiography and dose-reduced direct radiography of the chest was compared in a clinical setting. The study group consisted of 50 patients that underwent three posteroanterior chest radiographs within minutes, one image obtained with a dual read-out computed radiography system (CR; Fuji 5501) at regular dose and two images with a flat panel direct detector unit (DR; Diagnost, Philips). The DR images were obtained with the same and with 50% of the dose used for the CR images. Images were evaluated in a blinded side-by-side comparison. Eight radiologists ranked the visually perceivable difference in image quality using a three-point scale. Then, three radiologists scored the visibility of anatomic landmarks in low and high attenuation areas and image noise. Statistical analysis was based on Friedman tests and Wilcoxon rank sum tests at a significance level of P<0.05. DR was judged superior to CR for the delineation of structures in high attenuation areas of the mediastinum even when obtained with 50% less dose (P<0.001). The visibility of most pulmonary structures was judged equivalent with both techniques, regardless of acquisition dose and speed level. Scores for image noise were lower for DR compared with CR, with the exception of DR obtained at a reduced dose. Thus, in this clinical preference study, DR was equivalent or even superior to the most modern dual read-out CR, even when obtained with 50% dose. A further dose reduction does not appear to be feasible for DR without significant loss of image quality.     

胸部数字摄影参数的最优化探索

目的探索胸部X线数字化摄影优化条件。方法应用柯尼卡Regins350(直接数字转换器350型)CR、柯达DirectviewCR-900、柯达DirectviewDR5000;西门子-MultixX光机;胸部X线摄影质量控制体模;EBM-上海岱嘉公司PACS系统-医学图像诊断工作站软件:Unisight;Barco1K显示器,采用不同摄影条件对专用测试体模进行摄影,同时,还对12名正常成人志愿者进行胸部X线摄影试验,分别对所获60幅体模图像和人体胸部图像的质量进行分析。结果通过对采集的60幅体模图像的肺野、心脏后缘及膈下的3个点测试表明获得最佳空间分辨率的摄影参数,对于柯尼卡Regins350为10mAs、109kV和20mAs、99kV,柯达CR-900和柯达DR5000均为10mAs、109kV和20mAs、109kV。结论DR图像显示胸部结构的清晰度和信息量均明显优于CR图像,胸部数字化摄影的最优化摄影条件为90kV～110kV,10mAs～(20±5)mAs。     

口腔X线数字牙片摄像技术及临床应用

目的探讨口腔X线数字牙片摄像技术及临床应用的实际意义。方法采用Planmeca数字化牙片机设备,对300例患者的400颗牙齿进行根尖摄片。结果与传统根尖摄片比较,口腔X线数字牙片摄影技术可使投照角度有不同程度的增大,曝光时间大量缩短,投照剂量明显减小,照片清晰度显著提高。结论数字化牙片X线摄影技术比传统根尖片摄像技术优越,在口腔医学及科研工作方面有着良好的应用前景。     

Radiation dose reduction in direct digital panoramic radiography

Objectives

(a) To measure the absorbed radiation doses at 16 anatomical sites of a Rando phantom and (b) to calculate the effective doses including and excluding the salivary gland doses in panoramic radiography using a conventional and a digital panoramic device.

Study design

Thermoluminescent dosimeters (TLD-100) were placed at 16 sites in a Rando phantom, using a conventional, Planmeca Promax and a digital, Planmeca PM2002CC Proline 2000 (Planmeca Oy, 00880 Helsinki, Finland) panoramic device for panoramic radiography. During conventional radiography the selected exposure settings were 66 kVp, 6 mA and 16 s, while during digital radiography two combinations were selected 60 kVp, 4 mA, 18 s and 66 kVp, 8 mA, 18 s with and without image processing function. The dosimeters were annealed in a PTW-TLDO Harshaw oven. TLD energy response was studied using RQN beam narrow series at GAEC's Secondary Standard Calibration Laboratory. The reader used was a Harshaw, 4500. Effective dose was estimated according to ICRP₆₀ report (E_ICRP60). An additional estimation of the effective dose was accomplished including the doses of the salivary glands (E_SAL). A Wilcoxon signed ranks test was used for statistical analysis.

Results

The effective dose, according to ICRP report (E_ICRP60) in conventional panoramic radiography was 17 μSv and E_SAL was 26 μSv. The respective values in digital panoramic radiography were E_ICRP60 = 23 μSv and E_SAL = 38 μSv; while using the lowest possible radiographic settings E_ICRP60 was 8 μSv and E_SAL was 12 μSv.

Conclusions

The effective dose reduction in digital panoramic radiography can be achieved, if the lowest possible radiographic settings are used.     

床旁DR与CR胸部摄影质量的对比研究

目的通过床旁数字化X线摄影(digitalradiography,DR)系统与计算机X线摄影(computedradiography,CR)系统胸部摄影图像质量的对比分析,探讨床旁DR摄影的优势。方法随机抽取2010年拍摄的DR床旁X线胸片1000份和既往CR床旁X线胸片1000份进行对比分析。结果床旁DR摄影的应用提供了更加优良的图像质量,明显减少了放射技师的工作量,同时还降低了患者接受的辐射剂量。结论床旁DR胸部摄影比CR胸部摄影有着明显的优势,对手术患者和危重患者的诊治起到了积极作用。