Integrating digital systems: commitment and collaboration

One year ago, the radiology department at Ball Memorial Hospital, a 350-bed facility in Muncie, IN, was completely film-based. The need to support a new all-digital, 35-room emergency department (ED) hastened the facility's transition to a digital environment. Today, with the exception of mammography, the hospital's imaging services are now digital. To develop and implement the project, the hospital formed an internal implementation team. An independent consultant was also hired to evaluate the impact of these new technologies and to provide an estimated cost payback. After research, site visits, and vendor demonstrations, the hospital selected a single vendor for its picture archiving and communication system (PACS), digital radiography (DR), computed radiography (CR), and overall project management. The DR system was installed in the ED to provide digital image capture for a full range of trauma exams. The ED also initially began utilizing a Web-based PACS distribution originally implemented for after-hours teleradiology. The majority of the hospital's imaging studies are captured with 2 multi-cassette CR systems that serve 7 exam rooms in the radiology department. The hospital also installed remote operations panels to expedite entry of patient and exam information. Technologists readily embraced both CR and DR systems. The Web distribution system now transmits images to hospital-based computers and to 150 remote referring physicians. The PACS platform automatically e-mails key images and radiology reports to referring physicians. Authorized physicians can also request reports and images on an as-needed basis. The PACS vendor had previously performed multiple integrations with the radiology information system (RIS) vendor; the integration of PACS and RIS was extremely smooth. One of the critical components of a successful conversion is experienced, dedicated management. The hospital retained professional project management services to facilitate implementation and to ensure adequate training for all users.     

A tale of two CRs: hospital conducts side-by-side test

While we elected to install a digital radiography system in the busiest exam room in emergency room (ER) suite at our 535-bed hospital, we selected computed radiography as the primary platform for digital capture throughout the facility because of its flexibility, productivity and cost-effectiveness. We now use CR systems to handle six exam rooms and portable exams conducted by the radiology department, as well as imaging studies conducted in two ER exam rooms. Before committing to a CR vendor, we conducted an eight-week, side-by-side pilot study with two vendors' systems. One CR system was located in the emergency room and the other unit was located in the main radiology department. Our staff received education and training from both vendors. I led an evaluation team that included representatives from the radiology group, the information services (IS) department, biomedical engineering, staff physicians, ER physicians, pulmonologists and orthopedic specialists. Our team met to design the trial and develop a list of factors that technologists would use to evaluate the two systems. The team met after installation and again after the trial was complete to provide verbal input on each vendor for each category and to review feedback from the technologists' survey. Categories included image quality, interactions with each vendor's sales and service staff, workflow, time studies, durability of cassettes and plates, entry of John Doe patients for ER, and other factors. After the trial, we chose a system by unanimous vote. We learned a lot about CR technology throughout this process. Overall we are extremely satisfied with the platform we selected and with this method of evaluating the two systems prior to making this important decision.     

A new approach to RIS/DR interconnection.

The article focuses on a new, standards-based approach for linking modalities to a radiology information system (RIS) in the radiology department. Computers have been used in radiology for quite some time-for the complex processing of algorithms used by CT and MR, for example. The advent of computed radiography (CR) and direct radiography (DR) has helped bring x-ray film into the world of computers. DR uses a technology similar to that in digital cameras to convert the intensity and location of the diagnostic image into digital form. Many radiology departments now store images on disks and read from computer monitors in a reading room. With its high-volume radiology department, the Cleveland Clinic Foundation (CCF) has been a long-time user of one particular RIS system. As the department moved to DR implementation, it required a means to automatically include patient demographic information with the image at the time of study acquisition, so this information would be associated with the image throughout its history. Using an approach developed by several companies in connection with CCF, technologists now use only two interfaces on one computer screen. Further, a technologist can close the study from the DR unit, allowing more time for patient care. The collaborative effort between CCF and the companies involved has resulted in an exciting standards-based approach to linking its RIS and DR systems.     

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。     

Typetesting of physical characteristics of digital mammography systems for screening within the Flemish breast cancer screening programme

To investigate compliance with the acceptance criteria of the European guidelines for quality assurance in breast cancer screening, a typetesting programme of the physical characteristics of digital mammography systems based on direct readout (DR) technology or computed radiography (CR) was organised and executed within the Flemish breast cancer screening programme. While in general image quality/dose characteristics of flat panel DR systems passed the acceptance criteria more easily than CR systems, the slit-scanning direct photon counting system included in present study was outstanding in combining a very low dose with a good image quality. The data obtained up to now indicate the necessity of retuning the AEC for DR systems according to constant contrast to noise ratio (CNR) over the whole range of PMMA thicknesses (20–70 mm) to improve image quality in imaging breasts of large thickness at the cost of higher doses. For the two CR systems which passed the typetesting procedure dose levels do not allow a similar improvement of CNR for thick objects for these systems. The obtained results highlight the importance of the use of high Z target/filter combinations in X-ray generating systems for imaging thick objects to meet the image quality/dose criteria. With respect to image display aspects high-quality 3-megapixel LCD monitors succeeded also in the typetesting procedure in addition to 5-megapixel monitors. However, as zooming and scrolling are necessary for 3-megapixel monitors to get the full resolution capabilities of the image capture system, 5-megapixel monitors are preferred in a busy screening environment.     

New computed radiography technologies in digital radiography

Digital radiography (DR) has become integral to modern diagnostic radiology. One of the earliest forms of DR, computed radiography (CR) using storage phosphors, has established itself as the mainstay of DR-based diagnostic imaging over the past 20 years. More recently, flat-panel DR systems based on solid state X-ray detectors with integrated, large-area, active-matrix readout electronics are promising further improvements in clinical workflow and image quality. Despite CR's longevity, innovations continue to be made. New developments in CR screen technologies, like structured (needle) screens, and new scanner concepts based on line-at-a-time reading promise major improvements in image quality (comparable to that of flat-panel systems), system through-put and physical size, at a cost comparable to that of today's systems. Thus, despite the advent of flat-panel acquisition systems, there will still be an important role for CR in the foreseeable future. After a brief review of the current state of CR technology, this paper will explore several of these new CR developments and present some examples of their potential clinical impact.     

数字X线照片影像质量相关因素初步分析

目的：探讨影响数字X线照片影像质量的相关因素，提高数字X线照片影像质量。方法：通过分析计算机X线摄影(CR)与直接数字X线摄影(DR)所产生的数字X线照片影像质量相关因素：曝光量与自动曝光控制(AEC)的使用；DR、CR主机(扫描仪)及图像读取工作站；影像板(IP)因素；图像后处理工作站功能；激光打印机等。针对数字X线照片成像的各个环节加以控制。结果：获得优质数字X线照片影像必需做到：选择合适的曝光条件并合理使用AEC；掌握DR主机、CR扫描仪及图像读取工作站的性能特点；保证IP质量及定期清洗保养IP；充分了解并利用好图像后处理工作站的功能；正确设置配套激光打印机参数。结论：了解影响数字X线照片影像影像质量的相关因素，充分发挥数字X线照片影像图像的后处理优势，可以明显提高数字X线照片影像图像的质控水平。     

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.     

A comparison of low contrast performance for amorphous Silicon/caesium iodide direct radiography with a computed radiography: A contrast detail phantom study

A range of digital image acquisition devices exists in diagnostic radiology. This study compares contrast performance of two such systems: an amorphous Silicon/caesium iodide (a-Si:CsI) based flat panel (DR) digital chest radiography system and a computed radiography (CR) system. Images of a contrast detail resolution phantom were acquired at a range of radiation doses. Three observers assessed all hardcopy images using a four-alternative forced choice observer perception technique. Contrast detail performance was calculated and low contrast performance quantified.The DR system demonstrated significantly better low contrast performance and potential dose savings of up to 75% compared to the CR system. Threshold levels of contrast detail resolution were defined and levels of under- and over-exposure, compared to the threshold level, were highlighted. Both systems were noise limited at lower exposures and latitude limited at higher exposures. The results demonstrate that the DR system should perform better than the CR system under typical clinical conditions relevant to chest radiography particularly for the detection of low contrast details such as lung metastases or pneumothoraces.     

上海市数字化乳腺X射线摄影装置质量控制检测分析

目的 对上海市数字化乳腺X射线摄影装置使用情况与设备性能质量状况进行对比分析,为合理选择数字化乳腺X射线摄影装置提供参考。 方法 依据国家相关标准和规范,采用X射线检测仪和乳腺成像性能检测模体,对上海市53台数字化乳腺X射线摄影装置的9项技术指标进行质量控制检测,并将两类数字化乳腺X射线机——计算机X射线摄影装置（CR）与数字X射线摄影装置（DR）的性能检测结果进行统计学分析。在分析两类乳腺机各项性能指标合格率差异的基础上,对两类乳腺机的乳腺平均剂量与图像质量进行进一步的比较分析。 结果 两类乳腺X射线机的合格率及乳腺平均剂量差异无统计学意义;对于模体影像,两类设备的差异具有统计学意义,DR乳腺机的图像质量优于CR乳腺机。 结论 应加强对数字化乳腺X射线摄影装置的日常检测,从辐射防护最优化角度推荐选择DR乳腺机代替CR乳腺机开展数字化乳腺摄影工作。     

Increased productivity of a digital imaging system: one hospital's experience.

During peak hours of operation, it was not uncommon for the radiology department at St. Luke's Episcopal Hospital in Houston, Texas, to have a backlog of six to ten patients. While some of this was due to competing schedules from the emergency department (ED) and inpatients, the major problem was an inefficient workflow, especially for emergency department patients. Our staff in the radiology department worked with the hospital management to include plans for a new radiology room in an ED renovation project. In designing the new radiology room the most important issues under consideration were the physical location of the room and the type of radiography system to be installed. With plans to implement PACS, we evaluated computed radiography and digital radiography options. At St. Luke's, we had had our first experience with digital radiography after the purchase of a dedicated digital chest system. As a beta test site for the manufacturer, we had an opportunity to test--what was at the time--a new digital radiography system. The powerful impact of digital radiography became most evident by the decreased patient backlog. Even without PACS, workflow became dramatically more efficient. Images now are available for review within seconds after exposure, since there are no films to process. This has reduced our average exam time from ten minutes to one and a half minutes, not including patient transport time. The efficiency demonstrated with the digital chest system provided evidence that digital systems could handle significantly more patients than computed radiography or screen-film systems, without a compromise in image quality. Therefore, we decided to put a digital radiography system in the new ED radiology room. We estimate that the new unit will pay for itself in less than three years.     

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。     

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.     

Flat panel digital radiography compared with storage phosphor computed radiography: assessment of dose versus image quality in phantom studies

RATIONALE AND OBJECTIVE: To assess and quantify the dose reduction by use of a CsI-flat panel digital radiography (DR)-system compared with digital computed radiography (CR). MATERIALS AND METHODS: A TCDD-test using the CDRAD-phantom was performed at mAs-values of 5, 4, 2.5, 2, 1, and 0.5 mAs for both digital systems. Entrance surface doses were recorded for all images. Images were presented to four independent observers. For quantitative comparison the image quality figure (IQF) was calculated. Statistical analysis was performed using the Pearson correlation and the Wilcoxon test. A ROC analysis was performed using the TRG-phantom. Settings of 4, 2.5, 2 mAs for both systems were used. In addition, 1 and 0.5 mAs were used for the DR system only. Statistical significance was evaluated using Student test. RESULTS: The DR system provided equivalent results compared with CR with respect to high frequency information and superior results with respect to low contrast details. Compared with computed radiography, the flat panel detector demonstrated significantly lower IQFs, ensuring a better image quality with respect to contrast and detail detectability. IQFs for DR and CR were equal at a surface dose reduction of 87% for DR. ROC analysis revealed significantly higher values under the curve for DR up to a surface dose reduction of 70%. CONCLUSIONS: Image quality of DR proved to be far superior to CR in particular for low contrast details. The image quality of CR is similar to that of DR only at high dose levels.     

Digital skeletal radiography.

Skeletal radiography accounts for a large proportion of the plain film images generated in most radiology departments, yet it has been underemphasized in the investigation of digital imaging technologies. Unique features of skeletal radiography provide a challenge in the evaluation and investigation of digital skeletal imaging. This review summarizes the results of ongoing research in digital skeletal radiography. Elementary concepts of digital imaging are reviewed to provide a foundation for discussion of nominal contrast and resolution requirements for clinically useful digital skeletal radiography. Methods of acquiring digital skeletal images are reviewed, and digital image display, image compression, and basic image processing techniques are discussed with emphasis on specific skeletal applications.     

A comparison of film-screen, CR and DR: a community hospital time-motion study

The purpose of this study was to compare technologist efficiency for conventional radiography, computed radiography (CR) and direct radiography (DR) for two types of general x-ray examinations. The study was performed at St. Joseph's Health Centre, in Toronto, Canada. The study spanned eight calendar months. Two views of the chest and three views of the ankle were chosen as representative examinations for analysis. Patient examination times were recorded on the radiology information system for both types of studies for conventional radiography, CR and DR. There was a significant difference in average time of examination for all three types of imaging formats for chest studies and between conventional radiography and CR or DR for ankle radiographs. There was no significant difference between examination times for ankle studies when CR and DR were compared. The median time of examination of the chest was 18 minutes, eight minutes and six minutes for conventional radiography, CR and DR respectively. The median time of examination for ankle radiographs were 22 minutes, seven minutes and five minutes for conventional radiography, CR and DR respectively. Technologists efficiency is significantly improved with the implementation of a DR system and CR system when compared to conventional radiography. DR may not deliver significant improvements in efficiencies for certain types of examinations.     

两种数字化X射线摄影技术影像质量与成像剂量的比较

目的对比研究非晶硒平板探测器直接数字化X射线摄影(DR)及计算机x射线摄影(CR)两种数字化X射线摄影技术影像质量与吸收剂量的关系。方法应用DR和CR系统分别对对比度．细节体模(CDRAD2．0)进行不同吸收剂量的曝光成像。记录每次曝光的体模表面吸收剂量，并将所获取的影像在图像诊断工作站显示器上由4位观片者进行观察，计算影像质量表征因子(IQF)。应用ANOVA检验法统计、比较两种数字化摄影技术的图像质量与吸收剂量的差别。结果与CR相比，DR具有更低的IQF值，对人体组织对比度和结构细节有更好的信息检出特性。两种成像技术产生相同IQF值时，DR系统在体模表面产生的表面剂量比CR系统降低了77％。结论DR技术对于低对比度组织细节的检测好于CR技术。在获得相同影像信息的前提下，与CR相比应用DR大大降低了被检者吸收剂量。     

Digital radiography detectors – A technical overview: Part 1

During the last two decades screen-film (SF) systems have been replaced by digital X-ray systems. The advent of digital technologies brought a number of digital solutions based on different detector and readout technologies. Improvements in technology allowed the development of new digital technologies for projection radiography such as computed radiography (CR) and digital radiography (DR). The large number of scientific papers concerning digital X-ray systems that have been published over the last 25 years indicates the relevance of these technologies in healthcare.There are important differences among different detector technologies that may affect system performance and image quality for diagnostic purposes. Radiographers are expected to have an effective understanding of digital X-ray technologies and a high level of knowledge and awareness concerning the capabilities of these systems. Patient safety and reliable diagnostic information are intrinsically linked to these factors.In this review article – which is the first of two parts – a global overview of the digital radiography systems (both CR and DR) currently available for clinical practice is provided.     

Solid-state, flat-panel, digital radiography detectors and their physical imaging characteristics

Solid-state, digital radiography (DR) detectors, designed specifically for standard projection radiography, emerged just before the turn of the millennium. This new generation of digital image detector comprises a thin layer of x-ray absorptive material combined with an electronic active matrix array fabricated in a thin film of hydrogenated amorphous silicon (a-Si:H). DR detectors can offer both efficient (low-dose) x-ray image acquisition plus on-line readout of the latent image as electronic data. To date, solid-state, flat-panel, DR detectors have come in two principal designs, the indirect-conversion (x-ray scintillator-based) and the direct-conversion (x-ray photoconductor-based) types. This review describes the underlying principles and enabling technologies exploited by these designs of detector, and evaluates their physical imaging characteristics, comparing performance both against each other and computed radiography (CR). In standard projection radiography indirect conversion DR detectors currently offer superior physical image quality and dose efficiency compared with direct conversion DR and modern point-scan CR. These conclusions have been confirmed in the findings of clinical evaluations of DR detectors. Future trends in solid-state DR detector technologies are also briefly considered. Salient innovations include WiFi-enabled, portable DR detectors, improvements in x-ray absorber layers and developments in alternative electronic media to a-Si:H.     

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.