Kidney function testing prior to contrast-enhanced CT: a comparative cost analysis of a personalised risk-stratified pathway versus a test all approach.

AIM: To map current contrast-enhanced computed tomography (CT) pathways, develop a risk-stratified pathway, and model associated costs and resource use. MATERIALS AND METHODS: Phase 1 comprised multicentre mapping of current practice and development of an alternative pathway, replacing pre-assessment of estimated glomerular filtration rate (eGFR) with a scan-day screening questionnaire for risk stratification and point of care (PoC) creatinine. Phase 2 measured resource use and analysis of routinely collected data, used to populate a model comparing the costs of current and risk-stratified pathways in Phase 3. RESULTS: Site variation across a range of processes within the clinical care pathway was identified. Data from a single centre suggested that 78% (n=347/447) could have avoided their pre-scan laboratory test as they did not have post-contrast acute kidney injury (AKI) risk factors. Only 24% of outpatients who underwent computed tomography (CT) would have identified risk factors, which would have prompted a scan-day PoC test. There was a 94% probability that the risk-stratified pathway was cost-saving, with an estimated 5-year potential cost saving of £69,620 (95% CI: -£13,295-£154,603). Although the cost of a laboratory serum creatinine test is cheaper than the PoC equivalent (£5.29 versus £5.96), the screening questionnaire ruled out the need for a large majority of the eGFR measurements specifically for the CT examination. CONCLUSION: The present study proposes an alternative pathway, which has the potential to improve the efficiency of the current CT pathway. A multicentre appraisal is required to demonstrate the impact of embedding this new pathway on a wider NHS level, particularly in light of new diagnostic guidance (DG37) published by NICE.

Lodox®: the invaluable radiographic solution in the forensic setting.

The benefits of a comparatively inexpensive radiographic system such as the Lodox® scanner in forensic facilities where CT-imaging and radiologist support is not financially viable will be explored. Prodigious caseloads in many under-resourced mortuaries preclude the use of advanced radiological modalities. The aim of this research is to examine the utilization of the Lodox® scanner in one of the busiest mortuaries in South Africa in relation to the nature of the cases scanned and, furthermore, to provide case studies where this imaging modality proved vital in the examination of the deceased and in the approach to the autopsy. The research is a retrospective epidemiological review on the use of the Lodox® scanner at the Salt River Medico-legal Laboratory, Cape Town, South Africa, from 1 January 2017 to 31 December 2017. A total of 3885 cases was admitted to the mortuary; the majority was scanned. A large proportion of cases were male. Ages ranged from foetuses to the elderly. The manner of death in more than a third of the cases was homicide which mainly involved firearm fatalities. This was followed by natural deaths. Pertinent case studies are presented to demonstrate that the use of the Lodox® scanner as an adjunct (or even obviating autopsy) proves to save time and labour and is financially beneficial. In conclusion, the Lodox® scanner is an indispensable tool in mortuaries with heavy caseloads because its use improves quality assurance, saves time, and is cost effective in the examination of both natural and unnatural deaths.

Cost-Effectiveness of Tomosynthesis in Annual Screening Mammography.

OBJECTIVE: The purpose of this study was to evaluate the cost-effectiveness of the addition of annual screening tomosynthesis to 2D digital mammography alone for women beginning at 40 years old and to determine differences for age decade subgroups. MATERIALS AND METHODS: Decision-tree analysis comparing annual tomosynthesis versus 2D mammography alone from a federal payer perspective and lifetime horizon was created from published multiinstitutional data, published institutional data, literature values, and Medicare reimbursement rates. Cost-effectiveness was calculated through incremental cost-effectiveness ratios and net monetary benefit calculations. Sensitivity analyses were performed to determine the implication of different variables including changes in recall rate and disutility for false-positives. RESULTS: Base-case analysis showed an incremental cost per quality-adjusted life year gained for tomosynthesis over 2D alone for all ages (≥ 40 years old) of $20,230, 40- to 49-year-old subgroup of $20,976, 50- to 59-year-old subgroup of $49,725, 60- to 69-year-old subgroup of $44,641, and ≥ 70-year-old subgroup of $82,500. Net monetary benefit per decade in the 40- to 49-year-old subgroup was $1,598, 50- to 59-year-old subgroup of $546, 60- to 69-year-old subgroup of $535, and ≥ 70-year-old subgroup of $501. Tomosynthesis was the better strategy in 63.2% of the iterations according to probabilistic sensitivity analysis. CONCLUSION: Addition of annual screening tomosynthesis to 2D mammography beginning at the age of 40 years was cost-effective compared with 2D mammography alone in our analysis. Three times greater net monetary benefits were found in women 40-49 years old compared with those 50-59 years old.

Comparative effectiveness of combined digital mammography and tomosynthesis screening for women with dense breasts.

PURPOSE: To evaluate the effectiveness of combined biennial digital mammography and tomosynthesis screening, compared with biennial digital mammography screening alone, among women with dense breasts. MATERIALS AND METHODS: An established, discrete-event breast cancer simulation model was used to estimate the comparative clinical effectiveness and cost-effectiveness of biennial screening with both digital mammography and tomosynthesis versus digital mammography alone among U.S. women aged 50-74 years with dense breasts from a federal payer perspective and a lifetime horizon. Input values were estimated for test performance, costs, and health state utilities from the National Cancer Institute Breast Cancer Surveillance Consortium, Medicare reimbursement rates, and medical literature. Sensitivity analyses were performed to determine the implications of varying key model parameters, including combined screening sensitivity and specificity, transient utility decrement of diagnostic work-up, and additional cost of tomosynthesis. RESULTS: For the base-case analysis, the incremental cost per quality-adjusted life year gained by adding tomosynthesis to digital mammography screening was $53 893. An additional 0.5 deaths were averted and 405 false-positive findings avoided per 1000 women after 12 rounds of screening. Combined screening remained cost-effective (less than $100 000 per quality-adjusted life year gained) over a wide range of incremental improvements in test performance. Overall, cost-effectiveness was most sensitive to the additional cost of tomosynthesis. CONCLUSION: Biennial combined digital mammography and tomosynthesis screening for U.S. women aged 50-74 years with dense breasts is likely to be cost-effective if priced appropriately (up to $226 for combined examinations vs $139 for digital mammography alone) and if reported interpretive performance metrics of improved specificity with tomosynthesis are met in routine practice.

Diagnostic accuracy of digitized chest X-rays using consumer-grade color displays for low-cost teleradiology services: a multireader-multicase comparison.

INTRODUCTION: In teleradiology services and in hospitals, the extensive use of visualization displays requires affordable devices. The purpose of this study was to compare three differently priced displays (a medical-grade grayscale display and two consumer-grade color displays) for image visualization of digitized chest X-rays. MATERIALS AND METHODS: The evaluated conditions were interstitial opacities, pneumothorax, and nodules using computed tomography as the gold standard. The comparison was accomplished in terms of receiver operating characteristic (ROC) curves, the diagnostic power measured as the area under ROC curves, accuracy in conditions classification, and main factors affecting accuracy, in a factorial study with 76 cases and six radiologists. RESULTS: The ROC curves for all of the displays and pathologies had similar shapes and no differences in diagnostic power. The proportion of cases correctly classified for each display was greater than 71.9%. The correctness proportions of the three displays were different (p<0.05) only for interstitial opacities. The evaluation of the main factors affecting these proportions revealed that the display factor was not significant for either nodule size or pneumothorax size (p>0.05). CONCLUSIONS: Although the image quality variables showed differences in the radiologists' perceptions of the image quality of the three displays, significant differences in the accuracy did not occur. The main effect on the variability of the proportions of correctly classified cases did not come from the display factor. This study confirms previous findings that medical-grade displays could be replaced by consumer-grade color displays with the same image quality.

Digital tomosynthesis: a new future for breast imaging?

The aim of this article is to review the major limitations in current mammography and to describe how these may be addressed by digital breast tomosynthesis (DBT). DBT is a novel imaging technology in which an x-ray fan beam sweeps in an arc across the breast, producing tomographic images and enabling the production of volumetric, three-dimensional (3D) data. It can reduce tissue overlap encountered in conventional two-dimensional (2D) mammography, and thus has the potential to improve detection of breast cancer, reduce the suspicious presentations of normal tissues, and facilitate accurate differentiation of lesion types. This paper reviews the latest studies of this new technology. Issues including diagnostic efficacy, reading time, radiation dose, and level of compression; cost and new innovations are considered.

Comparison of radiation dose, workflow, patient comfort and financial break-even of standard digital radiography and a novel biplanar low-dose X-ray system for upright full-length lower limb and whole spine radiography.

OBJECTIVE: To compare the radiation dose, workflow, patient comfort, and financial break-even of a standard digital radiography and a biplanar low-dose X-ray system. MATERIALS AND METHODS: A standard digital radiography system (Ysio, Siemens Healthcare, Erlangen, Germany) was compared with a biplanar X-ray unit (EOS, EOS imaging, Paris, France) consisting of two X-ray tubes and slot-scanning detectors, arranged at an angle of 90° allowing simultaneous vertical biplanar linear scanning in the upright patient position. We compared data of standing full-length lower limb radiographs and whole spine radiographs of both X-ray systems. RESULTS: Dose-area product was significantly lower for radiographs of the biplanar X-ray system than for the standard digital radiography system (e.g. whole spine radiographs; standard digital radiography system: 392.2 ± 231.7 cGy*cm(2) versus biplanar X-ray system: 158.4 ± 103.8 cGy*cm(2)). The mean examination time was significantly shorter for biplanar radiographs compared with standard digital radiographs (e.g. whole spine radiographs: 449 s vs 248 s). Patients' comfort regarding noise was significantly higher for the standard digital radiography system. The financial break-even point was 2,602 radiographs/year for the standard digital radiography system compared with 4,077 radiographs/year for the biplanar X-ray unit. CONCLUSION: The biplanar X-ray unit reduces radiation exposure and increases subjective noise exposure to patients. The biplanar X-ray unit demands a higher number of examinations per year for the financial break-even point, despite the lower labour cost per examination due to the shorter examination time.

Comparison between different cost devices for digital capture of X-ray films: an image characteristics detection approach.

A common teleradiology practice is digitizing films. The costs of specialized digitizers are very high, that is why there is a trend to use conventional scanners and digital cameras. Statistical clinical studies are required to determine the accuracy of these devices, which are very difficult to carry out. The purpose of this study was to compare three capture devices in terms of their capacity to detect several image characteristics. Spatial resolution, contrast, gray levels, and geometric deformation were compared for a specialized digitizer ICR (US$ 15,000), a conventional scanner UMAX (US$ 1,800), and a digital camera LUMIX (US$ 450, but require an additional support system and a light box for about US$ 400). Test patterns printed in films were used. The results detected gray levels lower than real values for all three devices; acceptable contrast and low geometric deformation with three devices. All three devices are appropriate solutions, but a digital camera requires more operator training and more settings.

Comparison between differently priced devices for digital capture of X-ray films using computed tomography as a gold standard: a multireader-multicase receiver operating characteristic curve study.

OBJECTIVE: Film digitizers are a specialized technology that is available for scanning X-ray radiographs; however, their cost makes them unaffordable for developing countries. Thus, less expensive alternatives are used. The purpose of this study was to compare three devices for digital capture of X-ray films: a film digitizer (US $15,000), a flatbed scanner (US $1800), and a 10-megapixel digital camera (US $450), in terms of diagnostic accuracy, defined as the area under the receiver operating characteristic curves and computed tomography as the gold standard. MATERIALS AND METHODS: The sample included 136 chest X-ray cases with computed tomography confirmation of the presence or absence of pneumothorax, interstitial opacities, or nodules. The readers were six radiologists who made observations of eight variables for each digital capture of the X-ray films: three main variables to determine the accuracy in the detection of the above-mentioned pathologies, four secondary variables to categorize other pathological classifications, and one variable regarding digital image quality. RESULTS: The receiver operating characteristic curves for each device and pathology were very similar. For the main variables, there was no significant statistical difference in diagnostic accuracy between the devices. For the secondary variables, >84% of cases were correctly classified, even those that were classified with the lowest image quality. High accuracy was determined for the three main variables (0.75 to 0.96), indicating good performance for all tested devices, despite their very different prices. CONCLUSIONS: Choosing a device for a teleradiology service should involve additional factors, such as capture time, maintenance concerns, and training requirements.

Cassette-size digital radiography detectors. A better way to make the switch to DR.

Cassette-size wireless digital radiography detectors combine the image-quality and workflow advantages of DR with the patient-positioning advantages of computed radiography--and they can be used with just about any X-ray system. Find out how three models stack up.

Diagnostic accuracy, biohazard safety, and cost effectiveness-the Lodox/Statscan provides a beneficial alternative for the primary evaluation of patients with multiple injuries.

BACKGROUND: Lodox/Statscan is a new digital X-ray machine with a low dose of radiation exposure that provides rapid, whole-body scans. In the setting of acute trauma management, the importance of image study is well recognized. Here, we report the accuracy of diagnoses made using Lodox/Statscan in patients with multiple injuries. We analyze the cost effectiveness, biohazard safety, and detection rate for treatment using the Lodox/Statscan and evaluate whether it is a viable alternative to the conventional trauma X-ray. METHODS: We retrospectively reviewed patients who received a Lodox/Statscan between November 2007 and January 2009. All patients who had received both a Lodox/Statscan and a computed tomographic (CT) scan were enrolled. The CT scan was used to make the final diagnosis. The detection rate for treatment, sensitivity, and specificity of the Lodox/Statscan in diagnosis was analyzed. RESULTS: One hundred eighty-four patients were eligible for the study during the 15-month study period. The detection rates for treatment using the Lodox/Statscan for pneumothorax, pelvic fracture, cervical spine injury, and thoracic-lumbar spine injury were 95%, 96.0%, and 57.1%, and 100%, respectively. CONCLUSION: In our series, the Lodox/Statscan provided similar quality images and conventional series to the CT scans. Although the Lodox/Statscan missed some injuries, most of the subsequent treatments were not changed. Overall, there were several advantages to using this system, including the short interval of study, low-radiation exposure, and low cost. The Lodox/Statscan could therefore be used as an alternative to the traditional trauma X-ray for evaluation of acute trauma patients.

The x-ray light valve: a potentially low-cost, digital radiographic imaging system-concept and implementation considerations.

New x-ray radiographic systems based on large-area flat-panel technology have revolutionized our capability to produce digital x-ray images. However, these imagers are extraordinarily expensive compared to the systems they are replacing. Hence, there is a need for a low-cost digital imaging system for general applications in radiology. A novel potentially low-cost radiographic imaging system based on established technologies is proposed-the X-Ray Light Valve (XLV). This is a potentially high-quality digital x-ray detector made of a photoconducting layer and a liquid-crystal cell, physically coupled in a sandwich structure. Upon exposure to x rays, charge is collected on the surface of the photoconductor. This causes a change in the optical properties of the liquid-crystal cell and a visible image is generated. Subsequently, it is digitized by a scanned optical imager. The image formation is based on controlled modulation of light from an external source. The operation and practical implementation of the XLV system are described. The potential performance of the complete system and issues related to sensitivity, spatial resolution, noise, and speed are discussed. The feasibility of clinical use of an XLV device based on amorphous selenium (a-Se) as the photoconductor and a reflective electrically controlled birefringence cell is analyzed. The results of our analysis indicate that the XLV can potentially be adapted to a wide variety of radiographic tasks.

The x-ray light valve: a potentially low-cost, digital radiographic imaging system--a liquid crystal cell design for chest radiography.

Digital x-ray radiographic systems are desirable as they offer high quality images which can be processed, transferred, and stored without secondary steps. However, current clinical systems are extraordinarily expensive in comparison to film-based systems. Thus, there is a need for an economical digital imaging system for general radiology. The x-ray light valve (XLV) is a novel digital x-ray detector concept with the potential for high image quality and low cost. The XLV is comprised of a photoconductive detector layer and liquid crystal (LC) cell physically coupled in a sandwich structure. Upon exposure to x rays, charge is collected at the surface of the photoconductor, causing a change in the reflective properties of the LC cell. The visible image so formed can subsequently be digitized with an optical scanner. By choosing the properties of the LC cell in combination with the appropriate photoconductor thickness and bias potentials, the XLV can be optimized for various diagnostic imaging tasks. Specifically for chest radiography, we identified three potentially practical reflective cell designs by selecting from those commonly used in LC display technology. The relationship between reflectance and x-ray exposure (i.e., the characteristic curve) was determined for all three cells using a theoretical model. The results indicate that the reflective electrically controlled birefringence (r-ECB) cell is the preferred choice for chest radiography, provided that the characteristic curve can be shifted towards lower exposures. The feasibility of the shift of the characteristic curve is shown experimentally. The experimental results thus demonstrate that an XLV based on the r-ECB cell design exhibits a characteristic curve suitable for chest radiography.

Digital radiographic imaging: is the dental practice ready?

BACKGROUND: Digital radiographic imaging is slowly, but surely, replacing film-based imaging. It has many advantages over traditional imaging, but the technology also has some drawbacks. The author presents an overview of the types of digital image receptors available, image enhancement software and the range of costs for the new technology. PRACTICE IMPLICATIONS. The expenses associated with converting to digital radiographic imaging are considerable. The purpose of this article is to provide the clinician with an overview of digital radiographic imaging technology so that he or she can be an informed consumer when evaluating the numerous digital systems in the marketplace.

Cost-effective handling of digital medical images in the telemedicine environment.

BACKGROUND: This paper concentrates on strategies for less costly handling of medical images. Aspects of digitization using conventional digital cameras, lossy compression with good diagnostic quality, and visualization through less costly monitors are discussed. METHOD: For digitization of film-based media, subjective evaluation of the suitability of digital cameras as an alternative to the digitizer was undertaken. To save on storage, bandwidth and transmission time, the acceptable degree of compression with diagnostically no loss of important data was studied through randomized double-blind tests of the subjective image quality when compression noise was kept lower than the inherent noise. A diagnostic experiment was undertaken to evaluate normal low cost computer monitors as viable viewing displays for clinicians. RESULTS: The results show that conventional digital camera images of X-ray images were diagnostically similar to the expensive digitizer. Lossy compression, when used moderately with the imaging noise to compression noise ratio (ICR) greater than four, can bring about image improvement with better diagnostic quality than the original image. Statistical analysis shows that there is no diagnostic difference between expensive high quality monitors and conventional computer monitors. CONCLUSION: The results presented show good potential in implementing the proposed strategies to promote widespread cost-effective telemedicine and digital medical environments.

[Cost-effectiveness evaluation of a digital radiography system]. / Evaluation médico-économique d'un système capteur-plan grand champ en radiopédiatrie.

PURPOSE: To evaluate the impact of a completely automated digital radiography (DR) unit in a pediatric radiology department on productivity. Materials and methods. Comparative evaluation of DR and computerized radiography (CR) units on 193 patients imaged in a pediatric radiology department. The time to complete each step of all examinations was recorded. Half of the exams were performed using CR and the other half was performed using DR. RESULTS: There was a 52% time gain for simple projection exams using DR and a 51% time gain for dual projection exams using DR (p<0.001). A workflow study performed a 9 month period showed that DR could absorb 84% of work previously performed on two conventional radiography units. CONCLUSION: DR is necessary for digital imaging departments to increase productivity, while providing added ergonomic comfort and flexibility. It is particularly well suited for pediatric imaging departments.

A methodology to evaluate differential costs of full field digital as compared to conventional screen film mammography in a clinical setting.

PURPOSE: The use of full field digital mammography (FFDM) in alternative to conventional screen film mammography (SFM) in the current practice is delayed by the high costs of FFDM. The present study, performed at the Centro per lo Studio e la Prevenzione Oncologica of Florence, using both FFDM and SFM, was aimed at estimating the impact of introducing the new FFDM technique on overall mammography costs. MATERIAL AND METHODS: We estimated the differential costs of both methods, based on real expenditures, as provided by the administrative department, and on radiologists, radiographers and other staff's working time. Two different workload scenarios (5000 and 10,000 tests/year per mammography equipment) were considered. Common costs of both techniques were censored for study purpose. RESULTS: Beside a higher cost due to purchase and hire/leasing costs of equipment, FFDM implies a greater workload for radiologists (reading time almost doubled). SFM implies a greater workload for the administrative staff to run the archive and for loading/unloading films of the roller viewer, whereas no different workload has been observed for radiographers. Overall FFDM costs 24.22-26.46 for examination more than SFM for the 5000 tests scenario and 9.91-12.15 more for the 10,000 tests scenario. DISCUSSION: Although present study estimates cannot easily be generalised to any local setting, the model for cost calculation is easy to be exported to another scenario by applying different local parameters. The advantages made available by FFDM (computerised data recording, tele-transmission, tele-reporting, tele-consulting, automatic display on monitor of previous exams and use of CAD) may justify the higher cost, but a limited reduction in purchase and assistance costs could easily allow a turnover, with FFDM being more convenient than SFM even on the cost side.