计算机X线摄影与屏片系统摄影对比分析

目的:评价计算机X线摄影(CR)的应用价值。方法:抽取我院CR照片和常规X线摄影照片各1200 例,由2位主管技师和1位副主任技师对照片进行分析,统计出甲、乙、丙及废片率。并对乙、丙级片及废片产生的 原因进行了分析。结果:①照片影像质量:CR照片甲级片率51.6%,乙级片率35.5%,丙级片率12.2%,废片率 0.7%。常规X线摄影照片甲级片率40.6%,乙级片率42.5%,丙级片率15.2%,废片率1.7%。②摄影条件:数字 比模拟摄影电压高1～5kV,曝光量高20%左右。结论:CR摄影影像质量好于模拟摄影(即甲级片率高,废片率 小),可为临床提供可靠诊断。但曝光条件比屏 片系统高,增加了病人的X线接受剂量。     

CR系统在乳腺摄影中的应用分析

目的:评价CR系统在乳腺摄影中的应用价值。方法:抽取我院CR乳腺照片和传统钼靶X线照片各800张进行分析,统计出甲、乙、丙级片及废片率;统计CR片及传统屏-片乳腺癌的诊断正确率。结果:①照片影像质量:CR照片甲级片率67%,乙级片率26%,丙级片率7%,废片率0.25%。传统屏-片甲级片率36%,乙级片率50%,丙级片率11%,废片率2.5%。②照片诊断正确率:CR照片90%,传统屏-片73%。③摄影条件:CR系统比屏-片系统摄影管电压低4 kV,曝光量低4 mAs。结论:CR摄影影像质量好于传统屏-片摄影,可为临床提供可靠的诊断依据,且减少了病人的X线接受剂量。     

床边CR摄影与传统床边摄影的对比研究

目的：评价计算机X线摄影术(CR)在床边照片的应用。方法：抽取我院CR床边按照影像和传统床过照片备1000例，由2位放射学医师及1位主管技师对影像进行分析，分别统计甲、乙、丙及废片率，同时也对条件进行分析评价。结果：(1)CR影像：甲级片率32．1％，乙级片率44.5％，丙级片率23．4％，废片率0％。(2)传统床造影像：甲级片率20．3％，乙级片率53．5％，丙片率16．8％，废片率9．4％。结论：CR床边照片质量明显比传统床边投照优秀，CR床边照片有利于放射诊断。     

CR与屏-胶系统摄影在乳腺疾病诊断中的价值

目的评价X线计算机成像技术在乳腺摄影中的应用价值。方法抽取乳腺CR片和屏-胶乳腺片各500例,由1位副教授和2位主管技师,对摄影条件、照片影像质量及照片影像显示进行对比。结果①CR系统照片影像质量明显高于屏-胶系统;②摄影条件CR数字摄影比屏-胶系统摄影电压高2~3kV,曝光量高35%左右;③照片的X线征象显示率明显高于屏-胶系统。结论CR摄影提高了照片影像质量,为临床提供可靠诊断依据。缺点是曝光条件比屏-胶系统高,相对增加了患者的X线辐射剂量。     

移动DR和CR床旁胸部摄影临床应用对比研究

目的:探讨移动DR床旁胸部摄影临床应用的价值.材料和方法:随机抽取CR和DR床旁胸部摄影各200例患者的胸片进行比较.结果:(1) 照片质量:DR胸片的甲级片率77.5%、乙级片率20.5%、丙级片率2%、无废片.CR胸片的甲级片率53%、乙级片率31.5%、丙级片率12.5%、废片率3%.(2) 胸内各结构的显示:DR明显优于CR.结论:移动DR床旁胸部摄影操作方便,成像快捷,更有利于放射诊断.     

CR系统在X线摄影中的应用原理与临床价值

目的：探讨CR系统在X线摄影中的应用原理与临床价值。方法：对12000张胶片进行影像质量综合评估，分甲级片、乙级片、和废片三类。结果：甲级片占96％、乙级片占3．7％、废片占0．3％。结论：CR系统在X线摄影中其卓越的性能与数字化影像的特征有广泛的临床使用价值。     

CR系统在床边摄片中的临床应用

目的：探讨CR系统在床边摄片中的临床应用。方法：对2018张床边摄影X线胶片进行影像质量综合评估，分甲级片、乙级片和废片三类.结果：甲级片1874张，占92．9％，乙级片138张．占6．8％，废片6张．占0．3％，结论：CR系统床边摄片有明显优势，有着广泛推广价值。     

计算机X线摄影与传统摄片影像质量对比分析

目的：探讨计算机X线摄影(computed radiography,CR)的影像质量及其主要影响因素。材料和方法：参照卫生部“三甲”医院检查采用的标准,评定甲、乙、丙级和废片。对1000份不同部位CR影像片和1000份与前者部位相同的传统片影像的质量进行评定,分析造成非甲级片的成因,对两组影像质量及影响因素进行统计学分析。结果：CR片的甲片率为53．6％,明显高于传统片42．5％的甲片率,造成CR非甲级片主要成因是体位及铅字号码放置缺陷、摄影体部有异物和摄影前患者准备不佳(98．92％),传统片为76．7％;摄影条件不佳、影像处理技术不良(暗室技术)对CR影像质量影响不大(1．08％),而对传统片影像质量的影响为23．3％。CR片的废片率为0．0％(不包括机器故障造成的废片),低于传统片的2．0％废片率。结论：CR片影像质量明显优于传统片的影像质量,可广泛应用于除动态影像检查外的临床影像学检查。     

CR系统在乳腺钼靶摄影中的临床应用

目的：探讨计算机X线成像系统（CR系统）在乳腺钼靶X线摄影中的应用价值。方法：随机抽查屏／片乳腺片、CR钼靶乳腺图像各100份，比较两组照片的满意率、废片率、检出率和投照剂量。结果：普通钼靶摄影组的满意率、废片率、检出率分别为78％、2．8％和76％；数字化乳腺摄影组的满意率、废片率、检出率分别为99．7％、0和85％。CR系统仅用常规摄影剂量的1／5—1／10。结论：利用CR成像系统与钼靶摄影机的结合可以实现乳腺数字化摄影，效果优于普通屏／片摄影，在提高乳腺疾病的检出率方面更具优势，为临床早发现早治疗乳腺疾病提供了可靠依据。     

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.     

Clinical evaluation of digital radiography based on a large-area cesium iodide-amorphous silicon flat-panel detector compared with screen-film radiography for skeletal system and abdomen

The aim of this clinical study was to compare the image quality of digital radiography using the new digital Bucky system based on a flat-panel detector with that of a conventional screen-film system for the skeletal structure and the abdomen. Fifty patients were examined using digital radiography with a flat-panel detector and screen-film systems, 25 for the skeletal structures and 25 for the abdomen. Six radiologists judged each paired image acquired under the same exposure parameters concerning three observation items for the bone and six items for the abdomen. Digital radiographic images for the bone were evaluated to be similar to screen-film images at the mean of 42.2%, to be superior at 50.2%, and to be inferior at 7.6%. Digital radiographic images for the abdomen were judged to be similar to screen-film images at the mean of 43.4%, superior at 52.4%, and inferior at 4.2%; thus, digital radiographic images were estimated to be either similar as or superior to screen-film images at over 92% for the bone and abdomen. On the statistical analysis, digital radiographic images were also judged to be preferred significantly in the most items for the bone and abdomen. In conclusion, the image quality of digital radiography with a flat-panel detector was superior to that of a screen-film system under the same exposure parameters, suggesting that dose reduction is possible with digital radiography.     

直接数字X线摄影与传统高千伏胸部摄影对比分析

目的　评价直接数字X线摄影术 (DR)在胸部的应用。方法　抽取我院DR胸部影像和传统高kV胸片各 10 0 0例 ,由 3位放射学医师对影像进行分析 ,分别统计甲、乙、丙及废片率 ,同时对胸部的细微结构显示率进行评价。结果　 (1)DR影像 :甲片率 5 0 6% ,乙片率 3 8 5 % ,丙片率 10 9% ,废片率 0 %。 (2 )传统高kV胸片 :甲片率 41 1% ,乙片率 44 1% ,丙片率 13 3 % ,废片率 1 5 %。 (3 )肺内的细微结构显示率 :DR影像为 10 0 0 % ,传统高kV胸片为 78 6%。经统计学处理 ,差异有非常显著性意义 (χ2 =968 6,P <0 0 0 1)。结论　DR胸部影像的诊断图像质量好于传统高kV胸片。DR系统操作简单 ,成像快捷 ,有利于放射诊断     

Lumbar spine radiography: digital flat-panel detector versus screen-film and storage-phosphor systems in monkeys as a pediatric model

PURPOSE: To assess image quality and exposure dose requirements of a flat-panel detector system versus screen-film and storage-phosphor systems for radiographic depiction of the lumbar spine in Cynomolgus monkeys as a pediatric model. MATERIALS AND METHODS: Twenty Cynomolgus monkeys underwent anteroposterior radiography of the lumbar spine. The size and weight of these monkeys are comparable to those of infants 3-4 months of age. Images were acquired with speed class 400 screen-film, flat-panel, and storage-phosphor systems with identical exposure dose. All other conditions were matched exactly. Additional images were acquired with the flat-panel and storage-phosphor systems at exposure doses equivalent to speed classes 800 and 1600. All images were obtained at 66 kVp without antiscatter grid. Images were assessed independently by three radiologists for visibility of 60 anatomic structures by using a five-point confidence scale. Scores were calculated for the seven combinations of imaging mode and exposure dose and were compared by using the Friedman test. RESULTS: Scores were 1.70 (speed class 400), 1.97 (speed class 800), and 2.27 (speed class 1600) for the flat-panel system; 2.50 (speed class 400) for the screen-film system; and 2.58 (speed class 400), 2.77 (speed class 800), and 3.13 (speed class 1600) for the storage-phosphor system. Scores for the flat-panel system at speed classes 400 and 800 were significantly lower (indicating better visibility) than those of the screen-film and storage-phosphor systems (P <.05). CONCLUSION: The flat-panel system is superior to screen-film and storage-phosphor systems in lumbar spine radiography in monkeys. With the flat-panel system, exposure dose can be reduced by 75% without loss in image quality.     

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.     

Comparison of radiation doses to patients undergoing standard radiographic examinations with conventional screen-film radiography, computed radiography and direct digital radiography

New flat-panel direct digital radiography equipment has recently been installed in our Accident and Emergency Department; its characteristics and versatility are well suited to the work undertaken in this environment. The aim of this study was to compare radiation doses to patients undergoing standard radiographic examinations using conventional screen-film radiography, computed radiography and direct digital radiography; entrance surface dose and effective dose were calculated for six standard examinations (a total of 10 projections) using standard patient exposure parameters for the three imaging modalities. It was found that doses for computed radiography (all examinations) were higher than the doses for the other two modalities; effective doses for direct digital radiography were approximately 29% and approximately 43% lower than those for screen-film radiography and computed radiography, respectively. The image quality met the criteria in the European guidelines for all modalities.     

Digital radiography of scoliosis with a scanning method: initial evaluation

PURPOSE: To evaluate the radiation dose, image quality, and Cobb angle measurements obtained with a digital scanning method of scoliosis radiography. MATERIALS AND METHODS: Multiple images were reconstructed into one image at a workstation. A low-dose alternative was to use digital pulsed fluoroscopy. Dose measurements were performed with thermoluminescent dosimeters in an Alderson phantom. At the same time, kerma area-product values were recorded. A Monte Carlo dose calculation also was performed. Image quality was evaluated with a contrast-detail phantom and visual grading system. Angle measurements were evaluated with an angle phantom and measurements obtained on patient images. RESULTS: The effective radiation dose was 0.087 mSv for screen-film imaging, 0.16 mSv for digital exposure imaging, and 0.017 mSv for digital fluoroscopy; the corresponding kerma area-product values were 0.43, 0.87, and 0.097 Gy. cm(2), respectively. The image quality of the digital exposure and screen-film images was about equal at visual grading, whereas fluoroscopy had lower image quality. The angle phantom had lower angle values with digital fluoroscopy, although the difference in measured angles was less than 0.5 degrees. The patient images showed no difference in angles. CONCLUSION: The described digital scanning method has acceptable image quality and adequate accuracy in angle measurements. The radiation dose required for digital exposure imaging is higher than that required for screen-film imaging, but that required for digital fluoroscopy is much lower.     

旋转DSA技术在肺栓塞诊疗中应用的研究

目的研究旋转DSA技术在肺栓塞(pulmonary embolism，PE)诊疗中的应用。方法建立小型猪肺栓塞模型13头，进行常规肺动脉造影并应用旋转DSA技术，对造影结果进行分析、评价和研究。结果将每头猪的肺分为相应的15条血管，共有195条血管。以病理阳性结果为标准，评价肺动脉造影及旋转。DSA技术诊断PE的价值。肺动脉造影及旋转。DSA共有47个血管阳性(24．1％)，敏感性为98％，特异性为99％，诊断准确性98％；有2个血管数字减影肺动脉造影阳性，病理阴性，假阳性率为1％；有1个血管数字减影肺动脉造影阴性，病理阳性，假阴性率为2％。结论旋转DSA技术有助于肺栓塞诊断，尤其对疑似病变有一定临床意义。     

我国X射线摄影程序受检者入射体表剂量调查结果与分析

目的 通过调查全国15个省市不同级别医疗机构使用数字和屏片设备开展X射线摄影时受检者的入射体表剂量（ESD）,为制定适合我国国民体质特征的X射线摄影诊断参考水平提供数据。方法 按照《医用辐射危害评价与控制技术研究》实施方案的要求,选择年龄在20~70岁的受检者,男性体重在55~80 kg,女性体重在50~70 kg;采用热释光探测器（TLD）测量不同X射线摄影程序中成人受检者ESD,每台设备同一体位患者应不少于10名受检者;测量部位包含头颅、胸部的后前位（PA）和侧位（LAT）,腹部、骨盆、腰椎、胸椎的前后位（AP）和腰椎、胸椎的LAT等。结果 共在全国15个省的342家医院调查了19 975例X射线摄影受检者,1 813台不同类型X射线摄影设备,包括屏片X射线摄影、计算机X射线摄影（CR）和直接数字化X射线摄影（DR）设备,对于这3种类型的设备,不同摄影体位时受检者ESD的平均值分别为头颅PA：1.75、1.90、1.15 mGy;头颅LAT：1.69、1.46、1.03 mGy;胸部PA：0.75、0.65、0.36 mGy;胸部LAT：1.81、1.26、0.88 mGy;腹部AP：4.37、3.77、2.15 mGy;骨盆AP：3.73、3.56、2.75 mGy;腰椎AP：5.49、5.84、4.17 mGy;腰椎LAT：12.01、9.37、6.82 mGy;胸椎AP：4.53、3.65、2.49 mGy;胸椎LAT：6.91、6.43、4.15 mGy。结论 不同照射部位X射线摄影致受检者ESD有较大的差异。DR设备致受检者的ESD均低于屏片设备;除胸椎AP外,DR设备致受检者ESD均低于CR设备。在所有检查部位中,CR和屏片设备所致受检者ESD的差异均无统计学意义。     

Computed radiography utilizing laser-stimulated luminescence: detectability of simulated low-contrast radiographic objects

Threshold contrasts of low-contrast objects with computed radiography (CR) images were compared with those of blue and green emitting screen-film systems by employing the 18-alternative forced choice (18-AFC) procedure. The dependence of the threshold contrast on the incident X-ray exposure and also the object size was studied. The results indicated that the threshold contrasts of CR system were comparable to those of blue and green screen-film systems and decreased with increasing object size, and increased with decreasing incident X-ray exposure. The increase in threshold contrasts was small when the relative incident exposure decreased from 1 to 1/4, and was large when incident exposure was decreased further.