DR与CR的区别与联系

在现代医学科学发展过程中,医学影像学一直起着很重要的作用。X线摄影的数字化,是所有医学影像学检查中,最后实现数字化的检查项目,但是由于其使用范围广泛,数字X线成像技术CR与DR近来年发展非常迅速。近年来,国内一些大中型医院的放射科已基本     

CR与DR摄影特点的对比分析

目的对计算机X线摄影(CR)和数字化X线摄影(DR)的图像质量进行评价对比,分析其摄影特点,旨在提高摄影质量并为其合理应用提供参考。方法随机抽取各类CR片和DR片各200张,依照X线照片评片标准进行质量评定。结果 DR甲级片率高于CR片(71.0%vs62.0%,P<0.05),丙级片CR与DR相当,两者废片率均低。结论 CR与DR具有共同数字化储存和传输,DR作为直接数字成像,在成像环节、图像分辨率、成像速度、宽容度、后处理功能及辐射剂量方面均优于CR,但CR在灵活性方面略显优势。因此,CR与DR可能会互补互存,共同发展。DR与CR到底哪个更适用,应根据医院目前的发展规模、经济状况及工作量的大小来决定,但DR将是数字化技术发展的终端目标。     

招飞体检中数字化X线摄影的应用

随着我军招飞信息管理系统的应用,数字化X线摄影成为提高招飞体检质量的发展方向和重要组成部分。作为计算机数字化图像处理技术,DR、CR系统的发展日趋成熟,并且逐步替代常规X线摄片技术,这种新的医学成像技术,为医学影像信息系统的建立提供了扎实的技术基础,为招飞学员的临床诊断记录了丰富、长久、可靠的影像资料,也在一定程度上提升了招飞质量的整体水平。1X线数字化摄片特点传统X线摄影系统的最大缺点是有限的动态范围。如     

MARK标记分次曝光法在下肢全长X线摄影技术中的应用价值

本文探讨MARK标记分次曝光法自负重位下肢全景X线摄影技术的应用价值. 1 资料与方法 对106例患者进行下肢测量,摄负重位双下肢全长片.68例采用Koda感绿屏片摄影,15例以Kodak CR 900系统进行计算机X线成像,20例以Kodak DR 3000系统行数字化X线成像,3例行屏片与DR对照.     

DR在肢体全长成像中的应用

目前,直接数字化摄影(DR)已成为比较成熟的临床检查技术.由于DR是直接数字化成像,因此其影像质量、成像速度、操作流程等都比CR有很大进步,已逐渐成为各大医院放射科的主要X线影像设备.本文探讨运用DR设备结合相关的影像处理软什制作肢体全长X线片的方法.     

CR成像系统应用的初步体会

X线从发现距今已有百年历史 ,传统的X线成像是经X线摄影 ,将影像信息记录在胶片上 ,在显定影处理后 ,影像才能于照片上显示。近 2 0年来随着电子技术及计算机的发展 ,出现了许多与X线相关的数字成像医疗设备 ,例如CT ,DSA等。而CR的出现 ,是传统的X线成像技术向数字化成像技术方向发展迈出的重要一步。我科引进的是美国柯达CR- 90 0成像系统 ,经过实际操作 ,对CR的使用情况有一定的体会 ,现介绍如下。1　X线机及投照技术要求CR成像系统对X线机没有特殊的要求 ,目前科室内的各种普通X线机均可与它配套使用。由于CR图像处理系统可调…     

CR系统在乳腺成像中的应用价值

目的：评价计算机X线成像技术（CR）系统在乳腺成像中的应用价值。方法：我们对42位女性患者双侧84例乳腺进行CR检查,并与传统X线检查结果对照。结果：CR检查检出乳腺正常者30例,乳腺增生者48例,良性占位者1例,检出率与传统X线平片无差异。但在5例乳腺癌中有3例在传统X线片未能确诊;CR在显示乳腺层次及微小病变及降低X线照射剂量方面优于传统X线片。结论：乳腺CR成像技术是一种值得进一步推广使用的X线检查新技术。     

乳腺摄影自动曝光模式控制下DR系统、PCM系统和CR系统的比较

目的 比较三种数字乳腺摄影系统(DR,PCM,CR)在自动曝光控制(AEC)模式下成像性能的差异.方法 使用不同厚度的PASMAM-1054模体和CDMAM3.4模体,以AEC模式分别在DR、PCM和CR系统进行摄影;测量腺体平均剂量(AGD);由三位观察者分析模体的X线影像,计算CDMAM 3.4模体的IQF值;采用SAS 9.1软件,广义线性模型统计分析方法,比较三套系统总体影像质量之间的差异.结果 PASMAM-1054模体分析结果,DR与PCM图像质量差异无统计学意义(P=0.3960),DR、PCM图像质量都优于CR(P=0.0024);CDMAM 3.4模体的影像质量DR优于PCM(P＜0.05),PCM优于CR(P=0.0003).结论 在本实验的三套数字乳腺成像系统中,DR与PCM系统的成像性能相对较好,不仅影像质量较高,而且具有较低的AGD;CR系统的AGD虽然较低,但是影像质量相对较低,综合成像能力不如DR和PCM系统.     

比较传统X线片与CR片的投照及影像

目的：传统X线片由增感屏、胶片系统获得，CR片由计算机X线成像获得。R系统是当前发展的总趋势，它使传统X线摄影步入了数字化医学影像学家族。本文比较传统X片与氓片的投照及影像的优势，了解各自的利弊，供大家参考。     

CR在慢性副鼻窦炎诊断中的应用价值

近来发展起来的计算机X线成像技术(computedra diography；CR)，是利用计算机实现副鼻窦成像信息数字化，已逐渐成为近年来采用的一种副鼻窦影像检查诊断的新方法。我们自2003年6月至2004年3月，对46例临床诊断副鼻窦炎患者进行了，CR检查，同时进行CR与传统X线片检查对比，以评价CR系统在副鼻窦成像中的应用价值。     

Diagnostic radiography students' experiences of a practical method demonstrating the effect of milliampere-second in digital X-ray imaging systems

BackgroundThe effect of exposure technique factors varies between analogue and digital X-ray imaging systems (DR). Understanding these variations is paramount to optimising radiation protection, yet radiographers are unclear about these effects. A practical method to demonstrate milliampere second (mAs) effect in DR was developed to assist diagnostic radiography students in understanding exposure technique factors in DR.ObjectivesTo explore second-year diagnostic radiography students' experiences of a practical method to demonstrate the effect of mAs in DR.MethodsA qualitative research approach employing an open-ended questionnaire explored second-year diagnostic radiography students' experiences of the practical method demonstrating the effect of mAs in DR. Twenty students participated in the study, and the data collected underwent thematic analysis.ResultsStudents appreciated working in small groups and provided suggestions to improve the practical method's instruction sheet. Most students' predicted outcome differed from the actual outcome of the demonstration. Seeing and documenting the effect of mAs in DR not only enhanced students' understanding of it but showed the implications of increasing mAs on image quality and radiation exposure.ConclusionStudents found that the practical method enhanced their understanding of mAs and exposure technique factors in DR. Additionally, the practical method highlighted exposure creep in DR and radiographers' role in protecting patients from overexposure to ionising radiation in the digital era.     

43例数字X线摄影误诊原因分析

目的 对500例患者DR诊断中出现的43例误诊进行原因分析并归类,针对性提出减少误诊的对策.方法 选择经DR检查有阳性发现的500例患者影像及临床资料,摄影部位为头、胸、脊椎等部位,诊断3个月后重新对上述患者阳性征象进行回顾性软阅片分析.结果 不同部位的误诊率不尽相同,大多数误诊可以归结为对技术的不正确应用、对图像后处理不当以及对图像的误阅读等三类主要原因.结论 针对三类误诊原因,笔者提出三点建议:①DR诊断结论还应充分结合临床资料;②了解DR特性和操作要点,充分发挥DR客观反映病变的优势;③仔细分析影像细节,对成像后呈现的信息进行正确理解.     

Dose Optimization in Lumbar Spine Radiographic Examination by Air Gap Method at CR and DR Systems: A Phantom Study

ObjectiveThis study aims at investigating the feasibility of replacing an antiscatter grid with an air gap to achieve dose reduction for lumbar spine radiography while retaining image quality at an acceptable diagnostic level.MethodsFrontal and lateral projections of lumbar spine radiographic examinations were performed on an anthropomorphic phantom. Nongrid images of both the computed radiography (CR) and digital radiography (DR) systems with air gap thickness ranging from 0 to 25 cm were produced and compared with their corresponding grid images. Dose measurements using thermoluminescent dosimeters at the ovary and testes regions of the phantom were conducted. The image quality of all the images was evaluated by five radiographers using image quality score and visual grading analysis tests. Data on dose measurements and image quality tests were input for statistical analysis. The dose area product (DAP) of all the examinations was recorded and input for the computation of effective doses using a PC-based Monte Carlo program (PCXMC 2.0; STUK, Helsinki, Finland).ResultsSignificant dose reduction effects on the ovaries of 60.2%–74.1% and 55.1%–73.3% were found, respectively, at the frontal and lateral projections of nongrid lumbar spine examinations compared with their corresponding grid ones in both the CR and DR systems. Results on the image quality score and visual grading analysis tests showed that nongrid images with 10-cm and 5-cm of air gap thicknesses respective to the frontal and lateral images of the lumbar spine were rated with the highest scores. In general, a dose reduction effect using the air gap method was found to be more pronounced in the CR system compared with the DR system. Nevertheless, the CR system delivered a 2.4–4.5 times higher ovary dose respective to the frontal and lateral projections of lumbar spine examinations compared with the DR system.ConclusionsTen and 5 centimeters were found to be the optimal air gap thicknesses respective to the frontal and lateral lumbar spine radiographic examinations of the tested Rando phantom (Alderson Laboratories, Stamford, CT) in both the CR and DR systems. Significant dose reduction effects on both the ovary and testes regions of the nongrid examinations were shown. The effective dose computed from PCMCX 2.0 reflected that the risk of cancer induction was halved when an antiscatter grid was replaced by the nongrid method with an optimal air gap thickness in the tested examinations. Further reduction on cancer risk could be achieved by using DR instead of the CR system.     

乳腺癌影像诊断技术应用进展

乳腺癌是女性最常见的恶性肿瘤,目前诊断方法 较多.本文就乳腺钼靶X射线照相、超声、计算机体层扫描、核磁共振和核医学核素示踪技术在乳腺癌中的应用作一介绍.     

DR-PACS-RIS系统在批量胸部X线体检中的应用

目的探讨DR-PACS-RIS系统在胸部X线体检中的应用价值。方法对150112例胸部体检者的X线胸片资料进行分析,计算日体检工作量、人均体检时间、医师平均每例阅片时间以及存储成本情况。结果日均检查223例,平均每例体检耗时仅1.1分钟,摄片工作时间约4小时,医师平均阅片及报告时间约1分钟/例。日均图像存储成本约1元。工作站具有统计工作量及多种查询功能。结论在体检中心配备DR-PACS-RIS胸片体检系统切实可行,能够收到明显的正面效益。合理优化检查流程可以进一步提高收益。     

PCM乳腺摄影系统与CR系统临床应用的初步比较

目的 探讨相位对比乳腺X线摄影系统(PCM)与CR系统在乳腺实体成像质量上的差异.方法 24例患者,患侧乳腺在PCM系统或CR系统(随机选择)进行轴位(CC)或侧斜位(MLO)投照,在另一系统进行另一体位投照.30名正常体检者,一侧乳腺在PCM系统或CR系统上(随机选择)进行CC及MLO投照,另一侧乳腺在另一系统进行两个体位的投照.对所得影像进行解剖及病变细节显示情况的评分,分析PCM与CR系统对于乳腺实体摄影成像质量的差异.结果 病变组:PCM系统在肿块边缘清晰度、内部结构显示及钙化边缘清晰度方面均明显优于CR系统(P=0.0003);正常体检组:正常乳腺双侧对照:PCM系统在锐利度、对比度和噪声方面均明显优于CR系统(P<0.05).结论 PCM系统与CR系统在乳腺实体成像质量上存在显著差异,PCM系统的图像基本质量及对病变细节的显示情况明显优于CR系统.     

联合压缩感知技术优化脑神经一站式三维可调制翻转角超长回波链回聚脉冲(3D-MATRIX)成像

目的 采用联合压缩感知（uCS）技术优化脑神经一站式三维可调制翻转角超长回波链回聚脉冲（3D-MATRIX）成像，并筛选最佳加速因子（AF）。方法 前瞻性对11例三叉神经痛患者及28名健康志愿者以敏感度编码（SENSE）并行采样技术（SENSE=3）及AF为3~6的3D-MATRIX序列行脑神经成像，比较不同序列间脑神经图像质量，以及嗅神经、视神经、三叉神经信噪比（SNR）和对比度噪声比（CNR）的差异；测量脑池内与听神经相近处小血管信号强度，计算其与脑脊液的对比度（CR），比较不同序列间差异。结果 各序列图像间，嗅神经、视神经及三叉神经SNR、CNR，以及血管与脑脊液CR差异均有统计学意义（P均<0.01）。随AF增加，扫描时间缩短，uCS5序列图像质量呈降低趋势；AF为5时，uCS5序列图像中各神经主观评分、SNR及CNR均与SENSE3序列无明显差异（P均>0.05），而血管与脑脊液CR大于SENSE3序列（P<0.05）；AF为6时，uCS6序列图像中副神经及舌下神经主观评分低于其他序列（P均<0.01）。结论 利用3D-MATRIX序列结合uCS技术可对脑神经进行一站式成像，以AF为5最佳。     

Multicenter,Head-to-Head,Real-World Validation Study of Seven Automated Artificial Intelligence Diabetic Retinopathy Screening Systems

OBJECTIVEWith rising global prevalence of diabetic retinopathy (DR), automated DR screening is needed for primary care settings. Two automated artificial intelligence (AI)–based DR screening algorithms have U.S. Food and Drug Administration (FDA) approval. Several others are under consideration while in clinical use in other countries, but their real-world performance has not been evaluated systematically. We compared the performance of seven automated AI-based DR screening algorithms (including one FDA-approved algorithm) against human graders when analyzing real-world retinal imaging data.RESEARCH DESIGN AND METHODSThis was a multicenter, noninterventional device validation study evaluating a total of 311,604 retinal images from 23,724 veterans who presented for teleretinal DR screening at the Veterans Affairs (VA) Puget Sound Health Care System (HCS) or Atlanta VA HCS from 2006 to 2018. Five companies provided seven algorithms, including one with FDA approval, that independently analyzed all scans, regardless of image quality. The sensitivity/specificity of each algorithm when classifying images as referable DR or not were compared with original VA teleretinal grades and a regraded arbitrated data set. Value per encounter was estimated.RESULTSAlthough high negative predictive values (82.72–93.69%) were observed, sensitivities varied widely (50.98–85.90%). Most algorithms performed no better than humans against the arbitrated data set, but two achieved higher sensitivities, and one yielded comparable sensitivity (80.47%, P = 0.441) and specificity (81.28%, P = 0.195). Notably, one had lower sensitivity (74.42%) for proliferative DR (P = 9.77 × 10⁻⁴) than the VA teleretinal graders. Value per encounter varied at $15.14–$18.06 for ophthalmologists and $7.74–$9.24 for optometrists.CONCLUSIONSThe DR screening algorithms showed significant performance differences. These results argue for rigorous testing of all such algorithms on real-world data before clinical implementation.     

CR图像自适应增强方法在头颈部的应用

数字CR检查在头颈部的应用克服了常规X线摄影一次曝光难以清晰显示骨与软组织位置关系的不足,使X线诊断更趋全面,并降低了X线辐射量.在成像过程中,由于各种不利因素的影响导致图像质量下降,要对其进行增强处理方能满足医生临床诊断的需要.一般的图像边缘细节增强算法未考虑人体不同部位的结构和密度特性.本文提出一种根据人体头颈部特点的自适应CR医学图像增强算法,利用该算法对头颈部图像进行边缘细节增强处理,并与线性反锐化掩模法处理后的图像进行比较,结果 表明该算法处理后的CR图像细节丰富,信噪比高,细节方差和背景方差之比(DV/BV)高,增强后的CR图像具有良好的视觉效果,是一种有效的适合头颈部CR医学放射图像的边缘细节增强方法.