数字化摄影（DR）在X线诊断肋骨骨折方面的优势

目的：本文通过DR与普通平片的比较，探讨数字化摄影技术(DR)的应用在X线诊断，特别在肋骨骨折方面与普通X线平片相比较具有的不可比拟的优势。方法：通过选取我院DR及普通平片各200例肋骨骨折病人进行比较，探讨DR在肋骨骨折诊断方面的明显优势。结论：DR影像X线诊断比普通平片具有不可比拟的优势。     

计算机X线摄影在外伤性肋骨骨折诊断中的应用分析

目的 探讨计算机X线摄影（CR摄影）在肋骨骨折诊断中的应用价值.方法 随机选取本院2009年8月～2012年8月期间应用计算机X线摄影技术进行诊断的外伤性肋骨骨折患者临床资料235例,并将其结果与传统X线摄影结果进行对比分析.结果 计算机X线摄影与传统X线摄影相比,初诊肋骨骨折及复诊肋骨骨折的检出率分别为91％和83％,漏诊率分别为9％和17％,复诊的检出率分别为92.5％和85％,漏诊率分别为7.5％和15％,差异均具有统计学意义（P＜0.05）.结论 计算机X线摄影能够对肋骨骨折做出及时、快速的诊断,效果大大优于常规X线检查.     

计算机X摄影的原理及在肋骨骨折中的应用

目的：探讨计算机X摄影（CR）的基本原理及显示肋骨骨折的应用。总结：CR成像在诊断肋骨骨折诊断中的份值。方法对168例胸部闭合性创伤患者分别进行常规屏一片系统投照及计算机成像处理。结果：肋骨骨折168例，360处，2—3周后复查168例证明CR诊断正确率约达94％，而常规屏一片系统诊断正确率约74％。另外，CR对不明显骨折的诊断正确率约达88％，而屏一片系统对不明显骨折的诊断正确率仅约42％。结论：CR检查对肋骨骨折诊断准确率远高于常规屏一片系统。     

影响X线确诊肋骨骨折的原因分析

目的：探讨影响肋骨骨折X线确诊的因素。方法：回顾分析3294例肋骨骨折所涉及的临床资料、图像文字资料的每一环节。结果：摄影条件、体位、方式、图像质量以砭临床资料、X线诊断均对骨折确诊存在影响。结论：X线肋骨骨折摄影仍是其确诊的首选。摄影体位、方式、条件、X线诊断、对肋骨骨折确诊影响力由高到低逐渐减弱，值得临床工作关注。     

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。     

膈下肋骨骨折的X线诊断及X线摄影技术因素分析和改进

目的：探讨膈下肋骨X线摄影技术的改进，以提高膈下肋骨骨折的X线诊断准确性。方法：观察和分析膈下肋骨骨折52例，将膈下肋骨分为三等份，外1／3段病例用患侧小角度前后斜位摄影，中、内1／3段采用对侧反向大角度后前斜位摄影，并将摄影技术改进前后病例进行对比。结果：52例膈下肋骨骨折病例中，采用常规正斜位片有36例明确诊断，13例为疑似病例，未见骨折者3例。改进摄影技术后13例疑似病例中，11例明确诊断有骨折，3例未见异常病例中有2例明确显示骨折，其余3例经双层螺旋CT扫描图像重建后有明确骨折。结论：膈下肋骨骨折X线摄影技术的改进，进一步提高了其诊断准确性，降低了漏诊和误诊率，尤其在因条件所限的基层医院，具有一定的实用价值。     

屏胶乳腺X线摄影和数字化乳腺X线摄影的对比研究

数字乳腺X线摄影（DM）较屏胶乳腺X线摄影（SFM）具有更多的优势,其对于图像的获取、储存和显示都是相互分离的,每个系统都能优化产生最佳效果,而且数字图像能够由计算机处理并显示为多种形式。因此,DM系统正逐渐替代SFM系统并成为筛查及诊断乳腺癌的常规手段。就DM和SFM的成像原理、图像质量、图像处理以及临床应用进行比较。     

数字化X线摄影成像及评价

数字医学影像技术在近20年得到迅速的发展,因此被评价为20世纪医学发展的重要成就之一。电子计算机、信息技术的飞速发展,为医学影像技术的发展提供了充足的动力,数字化已成为医学影像技术发展的必然方向,计算机X线摄影(computed radiography,CR)、直接数字化X线摄影(digital radiography,DR)等数字化影像系统及应用已引起国内医学界广泛关注。全新的数字化影像技术应用于临床,丰富了形态医学诊断的信息、层次,逐步改变了传统放射技术并与快速发展的计算机、网络技术融合,     

双能量减影骨组织像与DR常规像在肋骨骨折诊断中的对比观察

目的:探讨双能量减影骨组织像与DR常规像在肋骨骨折诊断中的应用价值。方法:对48名共计192根临床疑诊肋骨骨折的患者,采用双能量减影法摄胸部正斜位片,获得DR常规像和骨组织像,两组医师分别作出诊断,比较DR常规像、骨组织像诊断的结果。结果:DR常规像、骨组织像对肋骨凹陷状骨折的检出率分别为26.92%、23.08%;对裂隙状骨折的检出率分别为11.11%、66.67%;对错位状骨折的检出率均为100%。DR常规像诊断肋骨骨折的敏感性76.72%,特异性100%,阳性预测值100%,阴性预测值73.79%,准确性85.94%;骨组织像则分别80.17%、97.37%、97.89%、76.29%和86.98%,两组的敏感性和准确性无显著差异(P>0.05)。结论:双能量减影骨组织像有利于细小裂隙状骨折的显示;DR常规像观察凹陷状骨折与骨组织像效果相同或更好,两者对肋骨骨折的诊断能力相当。     

临床疑诊骨折患者中应用计算机X线摄影分析

目的评价计算机X线摄影（CR）对探测可疑外伤性骨折的优势。方法 330例临床疑诊外伤性骨折患者均于外伤后20 min-3 h经X线摄影检查。83例经普通X线检查,247例经CR检查,66例先经普通X线检查,因高度怀疑骨折,后经CR检查。结果在接受了普通X线和CR两种方法检查的66例患者中,CR准确探测出未曾被普通X线发现的9例微细骨折患者。结论 CR系统具有丰富后处理功能,能够提高骨折的检出率,尤其对可疑细小骨折或复杂性骨折患者的诊断,应首选CR检查。     

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.     

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.     

数字X线摄影系统中低剂量应用的探讨

目的 通过数字X线摄影系统（DR）在胸部摄影检查中的应用评价DR的低剂量的优越性。方法 利用CDRAD 2.0低对比细节体模评价计算机X线摄影（CR）和DR的影像质量和表面空气吸收剂量（ESD）关系,分别利用两个系统（DR使用ESD约为CR的1/3）得到成人胸部30幅影像。由6位影像科医生来评价以上两者的影像系统对于肩胛骨内侧边缘等胸部结构的清晰程度。结果 CR影像和减少ESD的DR影像在影像诊断质量上差异没有统计学意义（P＞0.05）。结论 DR的较好的分辨率和低噪声特性,以及高DQE有助于减少患者接受的辐射剂量,而不影响诊断质量。     

Optimizing digital radiography of children

Pediatric projection imaging differs from imaging of the adult patient. Children are smaller, more radiosensitive, and less compliant than their adult counterparts. Their characteristics affect the way projection imaging is practiced and how dose is optimized.Computed radiography (CR) and digital radiography (DR) have been embraced by pediatric practitioners in order to reduce dose and improve image quality. Unfortunately, dose optimization with CR and DR has been hampered by a lack of definition of appropriate exposure levels, a lack of standardization in exposure factor feedback, and a lack of understanding of the fundamentals of CR and DR technology. The potential for over-exposure exists with both CR and DR. Both the Society for Pediatric Radiology and the American Association of Physicists in Medicine recognize the promise and shortcomings of CR and DR technology and have taken steps to join with manufacturers in improving the practice of CR and DR imaging. Although the risks inherent in pediatric projection imaging with CR and DR are low, efforts to reduce dose are worthwhile, so long as diagnostic quality is maintained. Long-standing recommendations for limiting radiation dose in pediatric projection imaging are still applicable to CR and DR.     

Optimisation of radiographic acquisition parameters for direct digital radiography: A systematic review

IntroductionThe objective of this systematic review was to uncover and synthesise all available literature regarding appropriate acquisition parameters for direct digital radiography. It sought to either confirm current practices as optimal, or to uncover practices that may produce more optimised results.MethodsA comprehensive search of published and unpublished literature was undertaken to find studies that evaluated how adjustment of different acquisition parameters affected subjective image quality and patient radiation dose. Eight hundred and fifty-eight studies were retrieved for title and abstract screening. Eighty-nine studies were retrieved for full-text screening, and 23 were included for review and methodological quality screening.ResultsNarrative synthesis of the 23 included studies revealed limited evidence to guide any potential change or acceptance of currently accepted best practice. Meta-analysis was unable to be performed for any of the included studies due to high levels of methodological heterogeneity. A key finding of this review was that the goals of optimisation research varied greatly across the included studies.ConclusionSignificant methodological heterogeneity in the included studies limited the number of clinically relevant findings that would give evidence to an acceptance of, or suggest changes to, currently accepted best practice. Improving consistency in approach across future works of technique optimisation will ensure future systematic reviews will be able to provide strong evidence and meta-analysis will be able to be performed.Implications for clinical practiceThis review highlights that in the literature, studies of optimisation of radiographic acquisition parameters have varying goals. This methodological heterogeneity limits the applicability of systematic reviews and precludes the use of meta-analysis. The authors recommend that a framework for optimisation research be produced as a priority to help improve homogeneity in future research.     

Pediatric digital chest radiography, comparison of grid versus non-grid techniques

Introduction

The usefulness of anti-scatter grid in digital pediatric chest radiography was investigated by a phantom study assessing image quality using subjective evaluations and dose measurements.

Method

A contrast detail study was undertaken. Images were taken with and without anti-scatter grids (grid ratio 15:1), for PMMA phantom thickness ranging from 1 to 15 cm. Fourteen radiographers, experienced in digital pediatric and/or skeletal radiography, read 96 images. At each thickness, the image with and without grid technique was read three times, and in random order. Correct Observation Ratio (COR) and Image Quality Figures (IQF) were calculated. Dose Area Products were measured with DAP-meter.

Results

The COR and IQF values indicated statistically significant (p < 0.05) enhanced image quality when using anti-scatter grid for all thicknesses 5 cm and more. The DAP values increased significantly by grid techniques (p = 0.01).

Conclusions

Grid techniques may be beneficial to image quality for PMMA objects over 5 cm, but this leads to a higher dose. Although the magnitude of dose may be low, the dose should be kept at a minimum. In conclusion, improving image quality should be based on optimizing post-processing settings and image evaluation conditions.     

Computed radiography versus indirect digital radiography for the detection of glass soft-tissue foreign bodies

AimThe principle aim of this study was to compare computed radiography (CR) and indirect, flat-panel, digital radiography (DR) for the visibility of radio-opaque glass foreign bodies.MethodsAn image-quality study was undertaken using a chicken thigh, as the soft-tissue model, implanted with varying sizes of glass particles (1 mm, 2 mm and 3 mm) which were imaged using CR and DR. Observers rated the acquired images based on the presence or absence and conspicuity of the foreign body. Ratings were then analysed in order to identify significance of any findings.ResultsCR (median = 4, interquartile range (IQR) = 1.0, n = 240) was found to be superior to DR (median = 3, IQR = 3.0, n = 240) in the detection of glass foreign bodies in soft-tissue (p = 0.001). Decreasing size of foreign bodies did not affect the performance of CR (p = 0.298), but did for DR with x² (2, n = 240) = 12.22, p = 0.002. The selected exposure factors were a limiting factor for DR but not for CR.ConclusionFor the systems used in the current study, CR should be considered ahead of DR for glass particles less than 3 mm while for the larger glass particles either CR or DR is appropriate. Finally, careful consideration should be taken when selecting exposure factors for imaging foreign bodies.     

骨盆数字化X射线摄影曝光剂量的优化研究

目的研究直接数字化X射线摄影照射剂量与成像质量的关系，确定骨盆X射线摄影的最佳摄影条件。方法以对比度一细节体模CDRAD2．0在不同照射剂量下所获取的影像的图像质量因子IQF，进行ANOVA及SNK统计学分析，确定最佳照射条件。应用X射线摄影模拟人拍摄骨盆X射线影像，按照欧共体（CEC）图像质量标准验证最佳摄影条件与常规摄影条件下照射剂量与成像质量的差别。结果不同照射剂量条件下，对比度一细节体模影像质量因子IQF有显著性差别（P=0．0001），照射剂量大于0．61mGy时，不同剂量组间IQF差异无统计学意义。对以最佳照射条件和常规照射条件所拍摄的X射线摄影模拟人影像按照CEC标准评判，两者影像质量的差异无统计学意义。结论直接数字化X射线摄影时通过增大照射剂量可以提高影像质量，但是当曝光剂量达到足够大时，再增大曝光剂量并不能显著改善图像质量，影像质量与曝光剂量间存在一个优化剂量。标准体模骨盆X射线摄影的优化剂量为0．61mGy。