双能量减影数字化胸部X线摄片

双能量减影胸部摄片是指应用密度不同的骨与软组织对能量不同的X线光子的吸收衰减方式不同的特点，将普通胸片中骨或软组织的影像成分选择性减去后，生成仅有软组织或骨成分的图像的技术。早在1925年就有人提出利用不同能量X线曝光的方法来鉴别原子量不同的物质，但由于操作复杂，也不能解决两次曝光问运动所造成的2幅图像不     

数字化双能量减影胸部摄片在医学体检中的应用价值

目的:评价双能量减影胸部摄片在医学体检中的应用价值.材料和方法:选择参加2005年度体格检查者1000例.其中男567例,女433例,年龄45～92岁,平均73岁,对其进行普通DR胸片和DES检查.结果:1000例胸片中有阳性征象者,普通DR胸片136例(肺内结节性病变63例、炎性病变19例、钙化病变49例和骨病5例),双能量减影摄片227例(肺内结节性病变98例、炎性病变21例、钙化病变87例和骨病21例).两者总检出率分别为13.6%和22.7%,两者对肺内结节性病变、钙化病变、骨病的检出率分别为6.3%和9.8%、4.9%和8.7%、0.5%和2.1%,有显著差异(P<0.01),两者对炎性病变的检出率分别为1.9%和2.1%,无显著差异(P>0.05).结论:双能量减影摄片对胸部病变的早期诊断筛查是对普通DR平片的-个很好补充,大大提高了肺内结节性病变、钙化病变及骨病等的检出率,在医学体检中有重要意义,值得推广应用.     

数字化双能量减影在胸部病变中的应用探讨

数字化X线摄影(DR)是探测器接收X线信息,再转换成数字信息,并立即显示在监视器中的一摄影模式[1]。由于数字X线成像便于计算机后处理,也便于图像的储存、管理和传输,已成为X线摄影技术发展的新方向[2]。我院于2004年购进的数字摄影设备具有双能量减影功能,即摄片一次实现两次自动曝光(包括高能量与低能量,时间间隔200ms)获得三副图像。现将我们的应用体会报告如下。1材料与方法本组88例患者,男48例,女40例,年龄20~72岁,平均年龄46岁。其中一部分是2004年4月~7月期间,在胸部查体的3000余例患者中,筛查出可疑肺部结节病变者为48例,另40例是…     

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。     

数字化双能量减影技术在胸部结节性病变诊断中的应用价值

目的探讨数字化双能量减影(dual-energy subtraction,DES)摄片技术在胸部结节性病变临床诊断中的优势。资料与方法搜集在本院行DES胸部摄影和CT检查,发现胸部结节的36例患者及证实无胸部结节的16例患者的资料,由两名高年资放射科医师对其普通数字化摄影(DR)图像与DES图像采用双盲法进行分析,评价两者对胸部结节的显示情况。结果DES软组织图像比普通DR图像检出更多的结节,同时对结节边缘的显示更清晰,有利于定位定性诊断。结论DES能将骨与软组织单独分开显示,分别得出标准影像、软组织影像和骨组织影像,有效地去除胸廓骨组织影的遮挡影响,提高肺结节性病变的可视性,是对DR图像诊断胸部结节的有效补充。     

胸部双能量减影摄影对气胸的诊断价值

目的 探讨双能量减影摄片技术对气胸的诊断价值.方法 收集在本院行双能量胸部摄影,经CT检查证实为气胸的42例患者,由1位高年资放射科医师及1位高年资胸外科医生共同阅片,对其标准数字化摄影(DR)图像与双能量数字减影(DES)软组织图像进行分析,评价两者对气胸的显示情况.结果 对于大、中量气胸(13例,肺压缩≥20%),标准DR图像及DES软组织图像均能清楚显示(100%),但对于少量气胸(肺压缩＜20%),尤其肺压缩边缘与肋骨、锁骨、肩胛骨重叠者,DES软组织图像比标准DR图像检出率更高,对肺压缩边缘的显示更清晰,差异有统计学意义.结论 双能量减影摄片技术能提高气胸的诊断率,降低漏诊率,是对DR图像诊断气胸的有效补充.     

数字化双能量减影技术在胸部肺结节及结节内钙化诊断中的应用价值

目的评价数字化双能量减影技术在肺结节及结节内钙化诊断中的临床价值。方法使用美国GE公司Revolution DR-XR/d数字化摄影系统,为80例患者行胸部双能量摄片,将所获得的3幅图像(肺组织像、肋骨像、原像)进行对比分析。结果经CT证实的186个结节中,减影像共检出肺内结节126个(其中含钙化结节32个,无钙化结节94个);原像共检出肺内结节109个(其中钙化结节26个,无钙化结节83个);两者相比较,减影像对病灶显示更敏感。结论减影像在检出肺内结节及结节内钙化等方面有明显优势,可作为原像的重要补充。     

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。     

DR双能量减影技术在胸部摄影中的应用进展

数字X线摄影（digital radiography,DR）图像处理的功能强大,除一般的窗口技术外,某些DR还配备了各种高级应用软件,如时间减影、能量减影和CAD等,使胸部疾病的诊断提升了一个台阶[1]。双能量减影（dual energy subtraction,DES）是DR高级后处理技术,主要应用于胸部摄影,     

DR双能量减影骨组组像对肋骨骨折的诊断价值

目的：探讨数字化X线摄影（digital radiography。DR）中的双能量减影（dual—energy subtraction，DES）所成的骨组织像对诊断肋骨骨折的价值．材料与方法：26例胸部外伤可疑肋骨骨折病例。分别常规DR与双能量减影两种摄影技术拍片检查，统计两种方法对肋骨骨折的检出率；结果：DR双能量减影对于隐匿部位和细小骨折的诊出率高于常规DR。结论：运用双能量减影技术摄影对隐匿部位（重叠和切线位）骨折显示更好，能提高诊断准确率。     

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.     

Bone images from dual-energy subtraction chest radiography in the detection of rib fractures

Objective

To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures.

Materials and methods

In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference.

Results

The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p = 0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p = 0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, p < 0.001).

Conclusions

Despite a better image quality, adding ES bone images to standard radiographs of the chest does not provide better sensitivity or improved diagnostic confidence in the detection of rib fractures.     

胸部双能减影与常规数字X线摄影对信号检出效能的比较

目的比较双能减影(DES)与常规数字X线摄影(CDR)对信号的检出效能。方法将200个直径为4mm塑料小球作为信号分别置于塑料板和健康志愿者右胸上部摄取CDR和DES片。由3位放射科医师用5等级判别法各自独立阅片,用ROCkit软件对观察结果进行ROC曲线分析。结果当信号置于塑料板上时,CDR和DES的Az值分别为0.9931和0.9879,P值为0.4851(双尾)>0.05,差异无统计学意义。当信号置于右胸上部时,CDR和DES的Az值分别为0.7276和0.8561,P值为0.0002(双尾)<0.01,差异有统计学意义。结论DES可以去除肋骨对胸部信号的遮挡,使DES对胸部信号的检出能力明显高于CDR,提示DES在胸部的应用具有良好的前景。     

Detection of lung cancer using single-exposure dual-energy subtraction chest radiography

PURPOSE: The aim of this study was to evaluate the detectability of lung cancer by chest radiography with a single-exposure dual-energy subtraction (ES) method. MATERIALS AND METHODS: Five radiologists read two sets of chest radiographs from 77 patients (66.5 +/- 9.6 years old) with histologically proven lung cancer measuring or=50 but <100%; (3) solid: TDR was <50%. RESULTS: Overall, detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7673 to 0.8265, P < 0.05). In the subgroup analysis of the nonsolid group and the solid group detectability did not change using the ES method, whereas in the partly solid group detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7162 to 0.8209, P < 0.005). CONCLUSION: The ES method improves the detectability of lung cancer by chest radiography, especially of the partly solid group.     

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.     

胸部双能减影的运动伪影分析与对策探讨

目的 分析胸部双能减影的运动伪影（MA）。方法 对连续抽取的211例胸部双能减影，评价运动伪影的影像特征及图像满意度。运动伪影可分为：没有、轻、中、重4级，整体图像满意度分为：优、良、中、差4级。结果 运动伪影表现为在运动方向上被观察结构边界处出现的黑色或白色条纹影。双侧中、下肺野内带、双侧下肺野中带以及左中肺野中带、心缘旁、横膈、骨性胸廓是最容易出现运动伪影的部位。左下心缘是重度伪影最常见的部位。心脏搏动在所有病例中参与了运动伪影形成，呼吸运动和胸部移动分别在91．0％和6．2％的病例中参与了运动伪影形成。图像满意度为中等及以上者共占所有病例的80．1％。结论 运动伪影是影响胸部双能减影图像质量的重要因素，呼吸运动和心脏搏动是运动伪影的主要来源，从抑制运动伪影入手，可进一步提高胸部双能减影图像质量。     

DR双能减影的肋骨成像与胸部成像的对比研究

目的 探讨双能减影对肋骨病变的诊断价值。方法 收集200例病人行胸部数字化X线摄影（DR）双能减影,对双能减影后胸廓的肋骨像与胸部的肋骨像进行对比分析,采用5阶法行ROC曲线解析。结果 200例中肋骨钙化50例,肋骨破坏7例,肋骨骨折22例。双能减影的胸廓肋骨像的ROC曲线解析参数（Az=0.9367）,大于胸部肋骨像的解析参数（Az=0.6830）。结论 胸部DR双能减影对肋骨病变及膈下肋显示明显优于胸部的肋骨像。     

Dual energy subtraction: Principles and clinical applications

Two technical solutions using single or dual shot offer different advantages and disadvantages for dual energy subtraction. The principles of these are explained and the main clinical applications with results are demonstrated. Elimination of overlaying bone and proof or exclusion of calcification are the primary aims of energy subtraction chest radiography, offering unique information in different clinical situations.