全脊柱DR与CR成像质量的对比分析

目的 探讨直接数字X线摄影(DR)在立位脊柱全长摄片中的应用.方法 177例患者按就诊时间先后分2组分别使用CR和DR技术拍摄全脊柱正侧位片,由放射科经验丰富的医师技师各2名对所有全脊柱影像进行评析.结果 (1)DR摄影成像的密度对比优于CR.(2)DR图像的拼接成功率低于CR.结论 使用DR进行全脊柱摄片,图像质量优于CR摄片.     

计算机X线摄影（CR）在新生儿胸部床旁片中的应用及注意事项

目的：探讨计算机X线摄影（CR）在新生儿胸部床旁摄影中的临床应用价值，通过注意事项提高拍片质量。方法：选取200份新生儿胸部床旁CR片，利用曝光条件的宽容度，设置最佳参数，综合运用计算机后处理和空间处理技术等，对影像细节进行调节，并与传统X线拍片进行比较。结果：CR片对比度佳，层次清晰度高，摄影失真度小，废片率为1％，普通片为90，4。结论：CR在新生儿胸部床旁摄影技术，以其高清晰度的图像质量，有效地实现了X线平片的数字化。但考虑到新生儿有其特殊性，在操作CR的过程中，要重视一些注意事项，从而提高质量。     

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.     

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。     

新生儿床旁胸片质量探讨(附78张床旁胸片报告)

新生儿床旁胸片在儿童医院放射科的日常工作中占一定的比例。现将我院开展的此项工作报告如下。使用设备:200ｍＡ沪产移动Ｘ线摄片机、日产柯尼卡感兰胶片、国产钨酸钙增感屏、自制新生儿摄片架。材料来源:本文随意抽出我科1999年1月1日～1999年10月30日66份78张新生儿床旁胸片(以下简称床旁片),其中加拍水平侧位12张,分别按出生天数、投照条件、投照位置、评级(合格片、次片、废片)进行统计分析。统计结果:78张床旁片中新生儿日龄:1天内32张,为41%;1～10天28张为35%;10～30天18张为23%。78张床旁片中照像位置好45张为56.4%,摄影条件好38张…     

直接数字X线摄影在尘肺病诊断中的应用价值

目的 探讨直接数字X线摄影(DR)在尘肺病诊断中的应用价值.方法 对随机抽取的298例接尘对象分批组织同期分别摄高仟伏和DR胸片,先由6名具有尘肺病诊断资质的医师随机均分甲、乙两组分别进行诊断,然后甲、乙两组合并阅片,使分组诊断不一致的结果得到统一.对DR和高仟伏两种胸片统一后诊断的胸片质量、小阴影的形态和大小、总体密集度、小阴影分布肺区数、尘肺分期等结果进行分析比较.结果 DR胸片质量等级集中在优片(97.99％),高仟伏胸片集中在良片(93.63％);DR胸片和高仟伏胸片小阴影的形态和大小、小阴影总体密集度、尘肺分期经一致性检验Kappa值分别为0.642、0.406、0.436,符合率分别为88.26％(263/298)、67.79％(202/298)、65.77％(196/298);小阴影分布肺区数在下肺区DR胸片明显多于高仟伏胸片.结论 DR胸片质量明显优于高仟伏胸片,可用于尘肺病的诊断.     

新生儿床旁X射线摄影辅助器的临床应用

目的探讨新生儿床旁摄影中应用床旁X射线摄影辅助器(专利号:202 023 219 898.1)的临床应用价值。方法选择2021年4月至2022年2月在华中科技大学同济医学院附属协和医院新生儿重症监护病房(NICU)拟行床旁胸片摄影的180例患儿为研究对象, 根据是否应用床旁X射线摄影辅助器, 分为两组:对照组90例(男48例, 女42例), 年龄(3.3±2.0)d(0～10 d),按常规工作流程对患儿胸部进行摄影;试验组90例(男50例, 女40例), 年龄(3.1±2.2)d(0～12 d), 采用床旁摄影防护和体位固定装置对患儿胸部进行摄影。比较两组患者检查所用时间、重拍率及图像质量。结果试验组诊断医师评分及患儿舒适度评分均高于对照组, 差异具有统计学意义(t=3.98、3.82, P<0.001)。试验组成功率高于对照组, 差异具有统计学意义(χ2 =7.84, P<0.05)。试验组检查平均耗时较对照组, 差异无统计学意义(P>0.05)。结论在新生儿床旁摄影中应用床旁X射线摄辅助器能够在不显著增加检查时间的情况下, 显著提高检查成功率和图像质量, 降低患儿...     

CR床旁摄影的临床应用与质量控制

计算机X线摄影（computed radiography，CR）是影像科数字化X线摄影的开端和过渡，其与常规X线摄影设备相兼容，具有良好的成像性能。强大的图像后处理功能以及网络化，使其在国内各级医院均有应用，并不断普及，尤其是在床旁摄影中的应用，显著提高了床旁摄影的成功率和图像质量。床旁摄影的对象主要是危重患者、严重外伤、术后患者及新生儿等。部分患者带有各种导管、心电监护、呼吸机等装置，由于受多种因素的制约影像质量难以保证。CR在床旁摄影中，激光读取器具有较高的灵敏度，能够检出极强与极弱的信号，IP宽容度大，加之计算机强大的图像后处理功能，因而提高了床旁摄影的成功率、病变显示率和诊断准确率。CR床旁摄影的影像质量控制（quality control，QC）是获得优质图像的关键。     

影响计算机X线摄影图像质量因素的临床分析

目的:探讨影响计算机X线摄影(CR)图像质量的因素及优化图像质量的方法.方法:分析2000例不同部位计算机X线摄影成像的技术参数、伪影、IP板使用方式及后处理方法,并与计算机X线摄影的图像质量标准作对照研究,分析影响图像质量的各相关因素.结果:2000例中甲级片1720张,乙级片182张,丙级片98张.乙级与丙级片共280张,其中因摄影技术不当所致141张,伪影引起65张,后处理不当74张.结论:计算机X线摄影图像质量受多种因素影响,合理设置参数及采取各种针对措施能有效提高图像质量.     

CR与DR系统胸部摄影参数对比的实验研究

目的：比较CR、DR在胸部摄影中的最优化摄影参数。方法：CR、DR系统分别对胸部等效衰减模体行不同参数曝光成像,记录每次曝光的模体表面剂量,并计算模体影像图像质量因子反数值IQFinv。应用统计学软件分析获取CR组、DR组最佳图像的IQFinv值,并换算成摄影参数。结果：CR组、DR组摄影剂量和图像质量IQFinv值之间的线性回归方程为DR：IQFinv=0.005D＋3.359,CR：IQFinv=0.005D＋1.651,D为辐射剂量。ROC曲线分析（曲线下面积AUC=0.893,P〈0.001）,最佳IQFinv值为3.55,获得DR、CR最佳图像摄影参数分别为125 kV、1.6 mAs,125 kV、16 mAs。结论：要得到满足诊断要求且一致的图像质量,CR的摄影剂量大致是DR的4倍。     

床旁DR与床旁CR胸部摄影质量对比分析

目的 通过对床旁数字化X线摄影系统(DR)与计算机X线摄影系统(CR)拍摄胸片图像的质量分析总结,探讨床旁DR摄影的优势.方法 应用床旁DR系统拍摄床旁胸片900张,与随机抽取的既往床旁CR胸片900张进行对比.结果 床旁DR的应用进一步减少了重拍率,降低了辐射剂量,可提供更加优良的影像信息.结论 床旁DR胸部摄影较CR胸部摄影有着明显的优势,在危重患者和手术患者的诊治中起到了积极作用.

Abstract：

Objective To explore the advantages of the bedside DR,taking the quality analysis of the chest image taken from the bedside digital radiography systems (DR) and computed radiography system (CR).Method All of the 900 pieces chest image taken by bedside DR,compared with the 900 pieces CR image randomly chosen.Results Bedside DR could further reduce the rate of the remake and the radiation dose,and provided more excellent image information.Conclusion The chest image taken by bedside DR has obviously advantage than CR.It can play a positive role in the diagnosis and treatment of the critical patient and surgical patient.     

Value of high-resolution ultrasound in detecting a pneumothorax

This study was designed to compare the detectability of high-resolution ultrasound (HRUS) and bedside chest radiography (CR) for a pneumothorax. During the last 14 months, 97 consecutive patients who were admitted to our institute to undergo a transthoracic needle aspiration and biopsy (TNAB) of the lung were included. Both HRUS and CR were performed immediately after the TNAB procedure. The HRUS images were saved in sequence using the cine-review mode and displayed as an animation on a workstation. Four radiologists independently analyzed both HRUS images and a soft copy of the CR on a diagnostic monitor and identified the pneumothorax. With CT as the reference standard, statistical parameters were calculated. From 97 patients, 35 pneumothorax cases were found on CT after the TNAB. The sensitivities in detecting the pneumothorax were 80 and 47% in HRUS and CR, respectively. The specificities were 94 and 94%. The diagnostic accuracies were 89 and 77%. The inter-observer agreement was excellent (=0.85) in the HRUS images and moderate (=0.49) in the CR. The results of this study suggest that HRUS is a more sensitive and confident method for diagnosing a pneumothorax when compared to bedside chest radiography.     

Digital radiography of the chest: state of the art

Digital image acquisition possesses a number of advantages over conventional systems in radiographic examination of the chest, the most important of which is its greater dynamic range. In addition, one digital images are acquired, they can be processed by computer in ways that cannot be rivalled by conventional analog techniques. Finally, digital images can be stored, retrieved and transmitted to local or remote sites. Here the status of the different digital systems employed in chest radiology and commonly used image processing techniques are reviewed. Also discussed are the current clinical applications of integrating digital chest radiography with a picture archiving and communication system (PACS) along with the difficulties typically encountered. Studies with a variety of digital techniques have been carried out on several fronts. Computer radiography based on photostimulabe phosphor (CR) has replaced screen-film imaging in certain applications (i.e. bedside imaging). However, CR has limitations, namely its poor X-ray utilisation efficiency at high X-ray tube voltages and sensitivity to scatter; therefore, it is not ideal for all applications. Recently, a dedicated digital chest unit with excellent X-ray utilisation efficiency at high X-ray tube potentials has been introduced. On the basis during the past decade, recommendations are made regarding the most desirable equipment specifications for dedicated and bedside digital chest radiography.     

Imaging characteristics of an amorphous silicon flat-panel detector for digital chest radiography

PURPOSE: To evaluate the imaging characteristics of an amorphous silicon flat-panel detector (FPD) for digital chest radiography. MATERIALS AND METHODS: The 41 x 41-cm digital FPD is constructed on a single monolithic glass substrate with a structured cesium iodide scintillator layer and an amorphous silicon thin-film transistor array for image readout. Basic imaging characteristics of the FPD and associated image processing system were assessed on acquired images, including linearity, repeatability, uniformity of response, modulation transfer function (MTF), noise power spectrum, detective quantum efficiency (DQE), contrast sensitivity, and scatter content. Results with the FPD system were compared to those with a storage phosphor computed radiography (CR) system. RESULTS: Images obtained with the FPD demonstrated excellent uniformity, repeatability, and linearity, as well as MTF and DQE that were superior to those with the storage phosphor CR system. The contrast and scatter content of images acquired with the FPD were equivalent to those acquired with the storage phosphor system. CONCLUSION: The FPD provides radiographic images with excellent inherent physical image quality.     

A comparison of conventional film,CR hard copy and PACS soft copy images of the chest: analyses of ROC curves and inter-observer agreement

STUDY OBJECTIVE: The aim of this study was to determine whether the accuracy of diagnosis of a spectrum of chest pathology was affected by the imaging technique used, and to compare conventional film/screen, hard copy computed (phosphor plate) radiography (CR) and soft copy CR (PACS) images. MATERIALS AND METHODS: For each of 44 patients who had a CT examination of the thorax, PA and lateral chest radiographs were produced using conventional film, hard copy CR and soft copy PACS images. Five radiologists independently scored all images for the presence of abnormalities. The data were analysed in two stages using the result of the CT scan as the reference standard diagnosis: firstly, to investigate differences in abnormality scores between image modalities and observers using ROC analysis; secondly, to investigate the agreement of the diagnoses with the reference standard by the analysis of kappa scores. RESULTS: The ROC analyses and comparison of kappa scores showed no differences between image modalities (P=0.72, P=0.87), but highly significant differences between observers (P<0.001, P=0.003). CONCLUSION: The detection of chest lesions did not vary between conventional film, CR hard copy and PACS soft copy images. For all three image types, there were statistically significant differences between observers.     

数字X线成像系统图像质量影响因素的实验研究

目的 比较非晶体硒平板探测器DR系统和CR系统的图像噪声、空间分辨率和入射体表剂量（ESD），研究数字X线图像质量影响因素的相关性。方法 采用相同管电压（125kVp）和不同mAs对仿真胸部体模用分辨率测试卡进行DR和CR曝光成像，测量ESD、空间分辨率，计算均方根（RMS）值，分析mA8、ESD、RMS及空间分辨率之间的变化关系。结果 两种系统的RMS随mAs的增加而降低，ESD随mAs的增加而增加。两种系统成像相同ESD时，DR的RMS略高于CR。ESD增加至一定量时，空间分辨率达到极限值（CR为3．1lp／mm，DR为3．4lp／mm）。结论 数字系统放射线剂量的改变会导致噪声、分辨率变化。适度的噪声水平对空间分辨率影响不明显。     

Coronal thick CT reconstruction: an alternative for initial chest radiography in trauma patients

It has been proposed that the imaging workup of trauma patients be accelerated by omitting the initial chest radiography (CR) and directly performing a computed tomography (CT); however, the baseline CR is then lacking. The purpose of this study was to assess if coronal thick reconstructions generated from chest CT could present an adequate alternative for CR. Sixty trauma patients underwent bedside CR and multidetector row chest CT in the emergency room. The image quality of thoracic anatomical structures, the diagnostic accuracy for chest pathology, and the depiction of indwelling devices were assessed on both modalities. Main pulmonary arteries and perihilar bronchi were equally visualized with both modalities. Central bronchi, retrocardial lung parenchyma, diaphragm, descending aorta, and vertebral pedicles were better visualized on thick CT reconstructions, whereas peripheral lung vessels were better depicted on CR (p<0.05). The accuracy to delineate various pathological findings did not differ between both modalities, except for a higher sensitivity to diagnose bronchial cuffing on CR (p<0.05). The location of indwelling devices was similarly and correctly depicted with both modalities. Coronal thick CT reconstructions provide a similar image quality and diagnostic accuracy compared with CR. These reconstructions may serve as an equivalent baseline image in trauma patients in whom emergency radiological evaluation has to be accelerated.     

Mobile chest imaging of neonates in incubators: Optimising DR and CR acquisitions

IntroductionNeonates are a particularly vulnerable patient group with complex medical needs requiring frequent radiographic examinations. This study aims to compare computed radiography (CR) and direct digital radiography (DDR) portable imaging systems used to acquire chest x-rays for neonates within incubators.MethodsAn anthropomorphic neonatal chest phantom was imaged under controlled conditions using one portable machine but captured using both CR and DDR technology. Other variables explored were: image receptor position (direct and incubator tray), tube current and kV. All other parameters were kept consistent. Contrast-to-noise ratio (CNR) was measured using ImageJ software and dose-area-product (DAP) was recorded. Optimisation score was calculated by dividing CNR with the DAP for each image acquisition.ResultsThe images with the highest CNR were those acquired using DDR direct exposures and the images with lowest CNR were those acquired using CR with the image receptor placed within the incubator tray. This is also supported by the optimisation scores which demonstrated DDR direct produced the optimal combination with regards to CNR and radiation dose. The CNR had a mean increase of 50.3% when comparing DDR direct with CR direct respectively. This was also evident when comparing DDR and CR for in-tray acquisitions, with CNR increasing by a mean of 43.5%. A mean increase of 20.4% was seen in CNR when comparing DDR tray exposures to CR direct.ConclusionDDR direct produced images of highest CNR, with incubator tray reducing CNR for both CR and DDR. However, DDR tray still had better image quality compared to CR direct.Implications for practiceWhere possible, DDR should be the imaging system of choice for portable examinations on neonates owing to its superior image quality at lower radiation dose.     

Image preprocessing for a picture archiving and communication system.

OBJECTIVES AND RATIONALE. In a picture archiving and communication system (PACS), images are acquired from multiple modalities and displayed on an electronic workstation. Each modality has different image characteristics. This variability must be addressed before the image is displayed. METHODS. The authors developed methods to automatically process magnetic resonance (MR), computed tomographic (CT), and computed radiography (CR) images before display and subjectively evaluated their effectiveness. RESULTS. Unwanted background successfully was automatically removed from 89.5% of 615 CR images. Of 803 chest, abdomen, and hand images 93% were automatically rotated to the correct orientation. CONCLUSIONS. Automated preprocessing of PACS images can be performed successfully, improving speed and convenience for the radiologist interpreting images at an electronic workstation.