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.     

The relationship of patient waiting time to capacity and utilization in emergency room radiology.

The relationship between patient waiting time and capacity and utilization is quantified. By deciding upon the average acceptable and maximum allowable waiting times, the required capacity and resulting utilization rate are fixed. The data needed for analysis include waiting time, patient volume, time required for specific types of examinations, and technologist and equipment capacity. Cost reduction is achieved without adversely affecting waiting time if volume variability can be reduced. Steps to increase productivity should also be considered as a means of reducing cost per examination, given the cost structure in emergency room radiology and the personnel costs.     

Resource cost analysis of cervical spine trauma radiography

PURPOSE: To determine the resource costs of the technical component of cervical spine radiography in patients with trauma and the factors that drive resource costs, to provide a model for resource cost estimation, and to compare resource costs with other methods of cost estimation. MATERIALS AND METHODS: Direct measurement was made of technologist labor and supply costs of a cohort of 409 consecutive patients with trauma who underwent cervical spine radiography. Probability of cervical spine injury was determined by reviewing emergency department medical records. An animated simulation model was used to combine cost and injury probability estimates to determine resource costs. Sensitivity analysis explored factors that determined costs and estimated uncertainty in model estimations. Comparison was made with other cost estimates. RESULTS: The average technical resource cost for cervical spine radiography was $49.60. Both direct labor ($19.60 vs $13.33; P <.005) and film ($8.39 vs $6.76; P <.005) costs were greater in patients with high probability of injury than in those with low probability of injury. Overall costs in patients with high probability of injury exceeded those in patients with low probability of injury by 33%. Resource costs exceeded Medicare resource-based relative value unit reimbursements for all patients with trauma. CONCLUSION: Resource costs of the technical components of cervical spine radiography varied with patient probability of injury and were higher than Medicare reimbursements.     

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.     

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。     

Technical cost of radiologic examinations: analysis across imaging modalities

PURPOSE: To determine the individual technical costs of general diagnostic radiographic, ultrasonographic (US), computed tomographic (CT), magnetic resonance (MR) imaging, and scintigraphic examinations and interventional radiology. MATERIALS AND METHODS: The Radiology Cost and Productivity Benchmarking Study method of the University HealthSystem Consortium, a cooperative group of academic medical centers, was modified and extended to the six imaging modalities in a tertiary care academic setting. Hospital billing and cost records were analyzed for fiscal year 1996. Costs were divided into labor and nonlabor categories and were allocated to individual imaging modalities on the basis of resources consumed. Physician cost and hospital overhead were not included. Unit costs were analyzed per technical relative value unit (RVU) and per examination. RESULTS: The costs per technical RVU for diagnostic radiography, US, CT, MR imaging, scintigraphy, and interventional radiology were $65. 06, $28.74, $20.95, $17.69, $42.19, and $89.03, respectively. The technical costs per examination for diagnostic radiography, US, CT, MR imaging, scintigraphy, and interventional radiology were $41.92, $50.28, $112.32, $266.96, $196.88, and $692.60, respectively. CONCLUSION: The method of unit cost analysis for individual imaging modalities was successfully tested in a tertiary care setting. The method should be adopted to allow cost comparison across many institutions, which will permit the promotion of best practices.     

CR/DR systems: what each technology offers today; what is expected for the future

Computed radiography (CR) is considered by some to be the work-horse for digital image capture of general radiography exams because it is affordable, offers excellent image quality and exposure latitude and utilizes existing x-ray systems. CR systems deliver digital imaging to general radiology departments and lower-volume areas that can include hospital floors and outpatient imaging centers. Digital radiography (DR) technology is more expensive, but some believe it earns its keep with significant productivity gains and the capacity for higher image quality or lower dose. DR systems are especially appropriate for emergency room settings and high-volume areas in general radiology departments, orthopedic clinics, imaging centers and other facilities. Facilities with growing patient volumes and limited space often choose to install DR systems in one or 2 exam rooms to double the productivity of those rooms, while one or more CR systems serve the remaining rooms or remote areas. Patients benefit from both faster image capture (it takes less time for each imaging exam) and hospitals achieve a digital distribution process that speeds delivery of radiology reports to referring physicians and a more efficient imaging workflow that can lead to increased revenues.     

Acute multiple trauma: Analysis of the spectrum of radiologic workup and time requirement

As part of a prospective study of 140 patients who had sustained multiple trauma and were treated in the emergency department, we recorded the times needed for conventional radiography, sonography, and/or computed tomography (CT) for each patient, including the diagnostic-free intervals comprising the times for transporting and moving the patient and for waiting. Conventional radiography (on average, 8.5 radiographic films per patient) was performed in 98.6% of the patients, sonography in 78.6%, and CT in 67.8%. The average duration was 20.3 minutes (range, 1–80 minutes) for conventional radiography, 6.5 minutes (range, 2–15 minutes) for sonography, and 16.9 minutes (range, 12–135 minutes) for CT. The average cumulative total time consumed for diagnostic imaging in the emergency department was 78.4 minutes for all modalities (including CT) and 49.1 minutes for conventional radiography and sonography (excluding CT). The cumulative diagnostic-free time (i.e., time passing without actual performance of the imaging procedure) for all imaging modalities (including CT) was 31.9 minutes and for conventional radiography and sonography (without CT) 19.2 minutes of the total time. The average time for transporting the patient to and from the CT scanner and for positioning the patient for the CT examination was 14.5 minutes. When CT is added to the workup in the emergency department, transportation and waiting considerably prolong the time needed for diagnostic imaging.     

Trends in the use of CT and radiography in the evaluation of facial trauma, 1992-2002: implications for current costs

OBJECTIVE: CT has replaced conventional radiography of the face in many trauma centers. Concern exists that increased costs are associated with increased use of CT. Our goal was to compare the amount of CT and radiography performed for facial trauma at a level 1 trauma center in 1992 and in 2002 and to determine hospital costs for the imaging of these patients. MATERIALS AND METHODS: The changes in volume and types of facial imaging examinations were determined comparing 1992 and 2002. Hospital costs of different imaging examinations were determined for 2002. Current costs of imaging facial trauma were compared with what 2002 costs would have been if the practice pattern in 1992 had continued. RESULTS: In 1992, 890 patients were evaluated for facial trauma. Six hundred seventy-one had only radiography, 153 only CT of the face, and 66 both CT and radiography. In 2002, 828 patients were evaluated. Five hundred eighty-four patients had only CT of the face; 228, only radiography; and 16, both CT and radiography. The number of facial imaging examinations per patient in 1992 and 2002 was 1.23 and 1.03, respectively. The 2002 hospital cost of a facial CT examination was $121 and of a facial radiography series was $154. Using CT instead of radiography for evaluating facial injury resulted in an overall cost savings of 22% per patient in 2002. CONCLUSION: The availability of CT has not resulted in increased use of facial imaging. The increased use of CT from 1992 to 2002 results in decreased current costs for the hospital.     

Direct and indirect cost of general aviation crashes

BACKGROUND: There have been few well-designed studies which estimate the costs inflicted on society from injuries, fatalities, and property damage caused by aviation crashes. Furthermore, indirect cost estimates from the human capital (HC) approach tend to be substantially smaller than those obtained from the willingness-to-pay (WTP) approach. OBJECTIVES: To estimate the direct and indirect costs of general aviation crashes in New Zealand, and to contrast the HC and WTP approaches used to estimate indirect costs. METHODS: The incidence, morbidity, and mortality from aviation crashes between 1988 and 1997 were estimated from national health and aviation records. Direct costs included medical treatment, damage to aircraft and property, and the cost of crash investigation. For the HC approach, we valued losses to society as the value of lost production from both employed work and household activity. For the WTP approach, we used the Land Transport Safety Authority's estimated values of society's willingness to pay to avoid a fatality or injury. RESULTS: The annual average direct cost of aviation crashes was $9.1 m (range: $8.0 m to $11.4 m). The annual average indirect cost using the HC approach was $13.6 m ($5.6 m to $32.2 m). Using the WTP approach the annual average indirect costs was $49.3 m ($20.6 m to $106.5 m). Indirect costs from premature deaths were the key cost drivers. A sensitivity analysis showed that these values were relatively robust to changes in parameters. CONCLUSION: The annual average cost of general aviation crashes in New Zealand was between $22.6 m and $58.4 m. Indirect costs using the WTP approach were 3.5 times greater than those estimated using the HC approach.     

Conventional radiography,rapid MR imaging,and conventional MR imaging for low back pain: activity-based costs and reimbursement

PURPOSE: To incorporate personnel and equipment use time in an activity-based cost comparison of conventional radiography and conventional and rapid magnetic resonance (MR) imaging for low back pain (LBP). MATERIALS AND METHODS: At each of four Seattle Lumbar Imaging Project (SLIP) sites, patients were randomized to undergo conventional radiography or rapid MR imaging of the lumbar spine. For sample SLIP patients and for similar non-SLIP patients undergoing conventional lumbar spine MR imaging as usual care in calendar year 2000, measured imaging room use and technologist and radiologist times were multiplied by costs per minute of standard equipment acquisition, personnel compensation, and related expenses. Resulting provider-perspective costs and Seattle area Medicare reimbursements for conventional MR imaging and radiography for calendar year 2001 were used to estimate future "normative" reimbursement for rapid MR imaging. RESULTS: For 23 conventional radiography, 27 rapid MR imaging, and 38 conventional MR imaging examinations timed in calendar year 2000, all rapid MR imaging times exceeded those of conventional radiography but were less than those of conventional MR imaging. All 0.3- and 0.35-T MR imaging room and technologist times exceeded those for 1.5-T MR imaging. Average costs (in 2001 dollars) were $44 for conventional radiography, 126 US dollars for 1.5-T rapid MR imaging, 128 US dollars for 0.3-0.35-T rapid MR imaging, 267 US dollars for 1.5-T conventional MR imaging, and 264 US dollars for 0.3-0.35-T conventional MR imaging. Conclusions regarding cost differences between conventional radiography and rapid MR imaging were robust to plausible parameter value changes evaluated in sensitivity analyses. Conventional radiography reimbursement was 44 US dollars. Applying the ratio of reimbursement (620 US dollars) to costs (264-267 US dollars) for conventional MR imaging to rapid MR imaging costs predicted reimbursement of 292-300 US dollars for the new modality. CONCLUSION: Times and costs for rapid MR imaging are roughly three times those for conventional radiography but about half those for conventional MR imaging for LBP. While current conventional radiography costs exceed reimbursement, current conventional MR and projected rapid MR imaging reimbursements exceed costs.     

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。     

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.     

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。     

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.     

Time-Driven Activity-Based Cost Comparison of Three Imaging Pathways for Suspected Midgut Volvulus in Children

ObjectiveTo use time-driven activity-based costing to compare the costs of pathways for evaluating suspected pediatric midgut volvulus using either fluoroscopic upper gastrointestinal examination (UGI) or focused abdominal ultrasound (US).MethodsProcess maps were created through patient shadowing, medical record review, and frontline staff interviews. Using time-driven activity-based costing methodology, practical capacity cost rates were calculated for personnel, equipment, and facility costs. Supply costs were included at institutional purchase prices. The cost of each process substep was determined by multiplying step-specific capacity costs by the median time required for each step, and substep costs were summed to generate total pathway cost. Multivariate sensitivity analyses were performed applying minimum and maximum labor costs. Assuming UGI would be used to troubleshoot nondiagnostic US, a break-even analysis was performed to determine the cost impact of varying frequencies of UGI on the total cost of the US-based pathway.ResultsProcess maps were created from 105 (48 girls, 57 boys) patient encounters. Base case pathway times were 90 min (UGI) and 55 min (US). Base case cost for UGI was $282.74 (range: $170.86-$800.82) when performed by a radiology practitioner assistant and $545.66 (range: $260.97-$1,974.06) when performed by a radiologist. Base case cost for US was $155.67 (range: $122.94-$432.29) when performed by a sonographer and $242.64 (range: $147.46-$1,330.05) when performed by a radiologist. For a US-based pathway, the total cost break-even pathway mix (percent UGI required for troubleshooting) was 57%.ConclusionUS can be a faster and less costly alternative to UGI in pediatric patients with suspected midgut volvulus.     

Economic and utilization analysis of magnetic resonance imaging units in the United States in 1985

Of the 72 clinical magnetic resonance imaging (MRI) installations operating in the United States in 1985, operations data were obtained from 47. The average annual technical operating cost of each unit is estimated at $841,500 when performing 2000 clinical procedures. Most costs are fixed and the annual cost varies slightly, between $800,000 and $882,000, with procedure volumes of 1000-3000 annually. The "typical" clinical MRI unit currently is examining 1500 patients and billing 1260 patients annually with a mean technical charge of $500. Of the procedures, 77% are neuroradiologic (head and spine). Radiologists are responsible for 93% of MRI procedures. The partial-pay/bad-debt revenue deduction is high (40%). With annual technical costs of about $820,000 and net technical revenues of $378,000, the typical unit is operating at an annual economic loss of about $440,000. An economic break-even point would be met with a charge of $1100 at the current procedure volume or a volume of 2700 procedures/year at the current charge. MRI units in outpatient locations study more patients, perform considerably more spinal examinations, and have higher charges. Compared with computed tomography at a comparable stage of development, MRI has less clinical demand, more outpatient locations, three to five times higher costs, and two-and-one-half times higher charges. To achieve economic viability with a technical charge of $500 or less, increased patient volume and third-party payer acceptance to reduce the partial-pay/bad-debt revenue factor will be required.     

Direct detector radiography versus dual reading computed radiography: feasibility of dose reduction in chest radiography

The image quality of dual-reading computed radiography and dose-reduced direct radiography of the chest was compared in a clinical setting. The study group consisted of 50 patients that underwent three posteroanterior chest radiographs within minutes, one image obtained with a dual read-out computed radiography system (CR; Fuji 5501) at regular dose and two images with a flat panel direct detector unit (DR; Diagnost, Philips). The DR images were obtained with the same and with 50% of the dose used for the CR images. Images were evaluated in a blinded side-by-side comparison. Eight radiologists ranked the visually perceivable difference in image quality using a three-point scale. Then, three radiologists scored the visibility of anatomic landmarks in low and high attenuation areas and image noise. Statistical analysis was based on Friedman tests and Wilcoxon rank sum tests at a significance level of P<0.05. DR was judged superior to CR for the delineation of structures in high attenuation areas of the mediastinum even when obtained with 50% less dose (P<0.001). The visibility of most pulmonary structures was judged equivalent with both techniques, regardless of acquisition dose and speed level. Scores for image noise were lower for DR compared with CR, with the exception of DR obtained at a reduced dose. Thus, in this clinical preference study, DR was equivalent or even superior to the most modern dual read-out CR, even when obtained with 50% dose. A further dose reduction does not appear to be feasible for DR without significant loss of image quality.     

Radiation dose in digital chest radiography: comparison among three technologies

PURPOSE: To compare the Entrance Surface Dose (ESD) for a normal patient, measured on three types of dedicated digital equipment for chest radiography: an amorphous selenium system, a CR (Computed Radiography) system, and a system for direct radiography (DR) based on an amorphous silicon active matrix (a-Si) connected to a CsI(T1) detector. MATERIALS AND METHODS: The ESD values were measured with different dosimeters placed in the air parallel to the detector plane, and at a distance equal to the thickness of a normal-build patient. The measurements were taken with the radiological parameters (Posterior-Anterior projection (PA) and Lateral projection (L)) used in diagnostic practice to obtain high-quality diagnostic radiographic images. The measurements taken with the DR equipment were repeated after the manufacturer added a 0.2 mm-thick Cu filter. The ESD values obtained by this series of measurements were reported as mean and standard deviation values (M+/-SD). RESULTS: With the PA projection, the doses measured for the different devices were the following: amorphous selenium system 0.12+/-0.06 mGy, CR system 0.3+/-0.05 mGy, DR system 0.05+/-0.02 mGy. With the L projection: amorphous selenium system 0.40+/-0.13 mGy, CR system 0.9+/-0.17 mGy, and DR system 0.21+/-0.15 mGy. CONCLUSIONS: The use of digital systems allows a significant reduction of the patient dose. In particularly the Direct Radiography system, based on a CsI/a-Si detector, administers the lowest patient dose.