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.

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.

Conventional versus digital radiographs for intraoperative cervical spine-level localization: a prospective time and cost analysis

BACKGROUND

In today's health-care environment, operational efficiency is intrinsic to balancing the need for increased productivity driven by rising costs and potentially decreasing reimbursement. Other operational factors kept constant, decreasing the time for a procedure can be viewed as one marker for increased efficiency.

PURPOSE

To prospectively evaluate the time and operating room efficiency differences between the two methods for intraoperative level localization. STYDY DESIGN: Prospective nonrandomized study.

PATIENT SAMPLE

Prospective consecutive patients undergoing a single-level anterior cervical discectomy and fusion (ACDF) with plate and allograft.

OUTCOMES MEASURES

Time for performance and interpretation of intraoperative localization radiograph.

METHODS

This is a prospective nonrandomized study of patients treated consecutively with a single-level ACDF with allograft and plating. All the patients underwent a conventional approach to the cervical spine. After exposure, a spinal needle was placed in the exposed intervertebral disc and a radiography was performed. Either a conventional or a digital radiography was used in each case.

RESULTS

Eighteen patients were enrolled in this study. Ten patients underwent localization with conventional radiography, whereas eight patients underwent localization with digital imaging. The mean time for conventional radiography was 823 seconds (standard deviation [SD], 159), and for digital, it was 100 seconds (SD, 34; p<.001).

CONCLUSIONS

Current technology provides options for level localization. Digital imaging provides equally accurate information as conventional radiography in a significantly reduced amount of time. Image quality, ease or archival, and manipulation provided by digital radiography are superior to those by provided fluoroscopy. Keeping operational factors constant, decreasing the time for a procedure, and increasing the efficiency of the environment may be viewed as a surrogate for improving the cost basis for a procedure.

Évaluation 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.

Cost-effectiveness of screening with contrast enhanced magnetic resonance imaging vs X-ray mammography of women at a high familial risk of breast cancer

Contrast enhanced magnetic resonance imaging (CE MRI) is the most sensitive tool for screening women who are at high familial risk of breast cancer. Our aim in this study was to assess the cost-effectiveness of X-ray mammography (XRM), CE MRI or both strategies combined. In total, 649 women were enrolled in the MARIBS study and screened with both CE MRI and mammography resulting in 1881 screens and 1–7 individual annual screening events. Women aged 35–49 years at high risk of breast cancer, either because they have a strong family history of breast cancer or are tested carriers of a BRCA1, BRCA2 or TP53 mutation or are at a 50% risk of having inherited such a mutation, were recruited from 22 centres and offered annual MRI and XRM for between 2 and 7 years. Information on the number and type of further investigations was collected and specifically calculated unit costs were used to calculate the incremental cost per cancer detected. The numbers of cancer detected was 13 for mammography, 27 for CE MRI and 33 for mammography and CE MRI combined. In the subgroup of BRCA1 (BRCA2) mutation carriers or of women having a first degree relative with a mutation in BRCA1 (BRCA2) corresponding numbers were 3 (6), 12 (7) and 12 (11), respectively. For all women, the incremental cost per cancer detected with CE MRI and mammography combined was £28 284 compared to mammography. When only BRCA1 or the BRCA2 groups were considered, this cost would be reduced to £11 731 (CE MRI vs mammography) and £15 302 (CE MRI and mammography vs mammography). Results were most sensitive to the unit cost estimate for a CE MRI screening test. Contrast-enhanced MRI might be a cost-effective screening modality for women at high risk, particularly for the BRCA1 and BRCA2 subgroups. Further work is needed to assess the impact of screening on mortality and health-related quality of life.

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.

Cassette based digital X-ray systems: evaluating the Konica Minolta Xpress CR

Cassette-based digital x-ray systems--also called computed radiography (CR) systems--are flexible and affordable, qualities that have secured their continued use in clinical settings. In this follow-up to our August 2001 Evaluation of CR systems, we examine the Konica Minolta Xpress CR. Our testing examines the ability of the Xpress CR to provide at least the same amount of diagnostic information as screen-film systems, while significantly increasing the overall efficiency of a radiology department. This article also includes updated information on the new products now offered by the suppliers whose CR systems we examined in August 2001. In addition, it describes the general developments that have occurred in CR technology. These developments include the use of new phosphor types to increase image quality and the wider implementation of wall-mounted touchscreens to improve workflow.

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.

Soft copy using image processing in place of hard copy for detection of subtle pulmonary lesions: is it actually cost-effective?

PURPOSE

To comparatively assess the interpretation performance of hard-copy versus soft-copy presentations for detecting subtle pulmonary lesions and to estimate soft-copy cost-effectiveness.

METHODS

Computed radiography was used to obtain images with a 1,600x 1,200 matrix having 8 bits of gray-scale definition. The two separate image formats (hard and soft copy), which consisted of 60 chest radiograph combinations, were shown to five board-certified radiologists. The costs of hard copies, chemicals, waste disposal, and labor were calculated.

RESULTS

The mean accuracies and Az values were 0.63 (hard) vs. 0.64 (soft) and 0.657 (hard) vs. 0.729 (soft), respectively. Reading one set of hard copies took on average 8.0 sec less than reading soft copies (30.3 vs. 38.3 sec). Estimated savings resulting from replacement of hard copy with soft were US$128,004 per year or US$6.20 per patient at our hospital.

CONCLUSION

Conversion from hard copy to soft copy, using image processing, is feasible and cost-effective.

Comparison of Seven Digital Cameras for Digitizing Radiographs

The purpose of this study was to evaluate seven digital cameras for their ability to adequately capture quality radiographic images and their relative cost effectiveness. Radiographs of line pair (LP) phantoms (ranging from 0.6 to 16.6 LP/mm) and a 20-step contrast phantom were photographed at a near distance of 30.0 cm and a far distance (determined for each camera) at which a full 14 x 17 in film filled the viewfinder. Of the seven cameras tested, the Canon EOS-D30 consistently performed the best in LP/mm resolved (7.7 at close distance, 1.4 at far distance) and in contrast latitude (all 20 steps at both close and far distances). The Canon EOS-D30, determined to be the best camera used in this study for photographing radiographic images, is also the most expensive camera that was used. Two cameras, the Nikon Coolpix 995 and the Sony DSC-F707, were very close to the Canon in performance at considerably less cost. Certain inexpensive cameras may not be acceptable choices for teleradiology.

Taking digital imaging to the next level: challenges and opportunities

New medical imaging technology, such as multi-detector computed tomography (CT) scanners and positron emission tomography (PET) scanners, are creating new possibilities for non-invasive diagnosis that are leading providers to invest heavily in these new technologies. The volume of data produced by such technology is so large that it cannot be "read" using traditional film-based methods, and once in digital form, it creates a massive data integration and archiving challenge. Despite the benefits of digital imaging and archiving, there are several key challenges that healthcare organizations should consider in planning, selecting, and implementing the information technology (IT) infrastructure to support digital imaging. Decisions about storage and image distribution are essentially questions of "where" and "how fast." When planning the digital archiving infrastructure, organizations should think about where they want to store and distribute their images. This is similar to decisions that organizations have to make in regard to physical film storage and distribution, except the portability of images is even greater in a digital environment. The principle of "network effects" seems like a simple concept, yet the effect is not always considered when implementing a technology plan. To fully realize the benefits of digital imaging, the radiology department must integrate the archiving solutions throughout the department and, ultimately, with applications across other departments and enterprises. Medical institutions can derive a number of benefits from implementing digital imaging and archiving solutions like PACS. Hospitals and imaging centers can use the transition from film-based imaging as a foundational opportunity to reduce costs, increase competitive advantage, attract talent, and improve service to patients. The key factors in achieving these goals include attention to the means of data storage, distribution and protection.

The value of digital imaging in diabetic retinopathy

OBJECTIVES

To assess the performance of digital imaging, compared with other modalities, in screening for and monitoring the development of diabetic retinopathy.

DESIGN

All imaging was acquired at a hospital assessment clinic. Subsequently, study optometrists examined the patients in their own premises. A subset of patients also had fluorescein angiography performed every 6 months.

SETTING

Research clinic at the hospital eye clinic and optometrists' own premises.

PARTICIPANTS

Study comprised 103 patients who had type 1 diabetes mellitus, 481 had type 2 diabetes mellitus and two had secondary diabetes mellitus; 157 (26.8%) had some form of retinopathy ('any') and 58 (9.9%) had referable retinopathy.

INTERVENTIONS

A repeat assessment was carried out of all patients 1 year after their initial assessment. Patients who had more severe forms of retinopathy were monitored more frequently for evidence of progression.

MAIN OUTCOME MEASURES

Detection of retinopathy, progression of retinopathy and determination of when treatment is required.

RESULTS

Manual grading of 35-mm colour slides produced the highest sensitivity and specificity figures, with optometrist examination recording most false negatives. Manual and automated analysis of digital images had intermediate sensitivity. Both manual grading of 35-mm colour slides and digital images gave sensitivities of over 90% with few false positives. Digital imaging produced 50% fewer ungradable images than colour slides. This part of the study was limited as patients with the more severe levels of retinopathy opted for treatment. There was an increase in the number of microaneurysms in those patients who developed from mild to moderate. There was no difference between the turnover rate of either new or regressed microaneurysms for patients with mild or with sight-threatening retinopathy. It was not possible in this study to ascertain whether digital imaging systems determine when treatment is warranted.

CONCLUSIONS

In the context of a national screening programme for referable retinopathy, digital imaging is an effective method. In addition, technical failure rates are lower with digital imaging than conventional photography. Digital imaging is also a more sensitive technique than slit-lamp examination by optometrists. Automated grading can improve efficiency by correctly identifying just under half the population as having no retinopathy. Recommendations for future research include: investigating whether the nasal field is required for grading; a large screening programme is required to ascertain if automated grading can safely perform as a first-level grader; if colour improves the performance of grading digital images; investigating methods to ensure effective uptake in a diabetic retinopathy screening programme.

The path of least resistance: is there a better route?

In May 2000, the radiology department at Stanford University Medical Center embarked on a five-year journey toward complete digitization. While the end goal was known, there was much less certainty about the steps involved along the way. Stanford worked with a team from GE Medical Systems to implement Six Sigma process improvement methodologies and related change management techniques. The methodical and evidence-based framework of Six Sigma significantly organized the process of "going digital" by breaking it into manageable projects with clear objectives. Stanford identified five key areas where improvement could be made: MR outpatient throughput, CT inpatient throughput, CT outpatient throughput, report turnaround time, and Lucile Packard Children's Hospital CR/Ortho throughput and digitization. The CT project is presented in this article. Although labor intensive, collecting radiology data manually is often the best way to obtain the level of detail required, unless there is a robust RIS in place with solid data integrity. To gather the necessary information without unduly impacting staff and workflow at Stanford, the consultants working onsite handled the actual observation and recording of data. Some of the changes introduced through Six Sigma may appear, at least on the surface, to be common sense. It is only by presenting clear evidence in terms of data, however, that the improvements can actually be implemented and accepted. By converting all appointments to 30 minutes and expanding hours of operation, Stanford was able to boost diagnostic imaging productivity, volume and revenue. With the ability to scan over lunch breaks and rest periods, potential appointment capacity increased by 140 CT scans per month. Overall, the CT project increased potential for outpatient appointment capacity by nearly 75% and projected over $1.5 million in additional annual gross revenue. The complex process of moving toward a digital radiology department at Stanford demonstrates that healthcare cannot be healed by technology alone. The ability to optimize patient services revolves around a combination of leading edge technology, dedicated and well-trained staff, and careful examination of processes and productivity.

Using a saline chaser to decrease contrast media in abdominal CT

OBJECTIVE

The purpose of this study was to compare hepatic tumor conspicuity on CT after injection of either 150 mL of contrast material or 100 mL of contrast material plus a 50-mL saline chaser.

SUBJECTS AND METHODS

We evaluated 86 hypoattenuating liver metastases in 26 patients. Patients underwent CT in two sessions separated by a mean of 85 days: one time with 150 mL of contrast material and the other time with 100 mL of contrast material followed by a 50-mL saline chaser. The order of the sessions was randomized. Contrast material was administered via power injector and matched for injection rate and delay time. Attenuation values were obtained from normal liver tissue and metastases and from the spleen, kidney, aorta, and inferior vena cava.

RESULTS

The 150 mL dose of contrast material caused slightly greater liver and tumor attenuation than 100 mL of contrast material with a chaser (mean hepatic attenuation, 95.6 vs 89.8 H, respectively; p < 0.03, paired t test; mean tumor attenuation, 53.2 vs 49.1 H, respectively; r = 0.71, p = 0.09). The difference in conspicuity of liver lesions was slightly greater with 150 mL than with 100 mL with a chaser (46.8 H vs 44.2 H; r = 0.46, p = 0.08, paired t test), but was of doubtful clinical significance (2.6 H). Kidney, spleen, and vascular structures enhanced more with 150 mL than with 100 mL and a chaser.

CONCLUSION

Using 100 mL of contrast material and a saline chaser did not result in a meaningful difference in liver parenchyma attenuation or lesion conspicuity compared with using 150 mL of contrast medium alone. Routine use of a chaser for abdominal CT may yield cost savings and a decreased risk of contrast nephropathy.

[Simultaneous digital ICG and fluorescein videoangiography with the personal computer]

BACKGROUND

Since the invention of the simultaneous ICG and fluorescein (SIF) videoangiography in 1995 none of the available SLOs were significantly improved. Digital video recording with a PC can simplify and improve the quality of the angiography.

METHOD

SIF angiography images of a two-wavelength scanning laser ophthalmoscope were digitized with a personal computer and written to disk with at rate of 25 images/s as a non-compressed digital video file. The digitized image sequence could be replayed with any standard video player and converted to different image and video file formats with a file conversion utility, developed specifically for the needs of SIF angiography.

RESULTS

Recording of digital SIF videoangiograms with a personal computer is not more complicated than the conventional video method. Since most of the parameters of the recording software are customizable, processing methods can be tailored to individual needs. Off-line processing and/or storage of the images in a digital database are possible immediately after recording. To facilitate localization of the pathological landmarks on the fundus the two channels of the SIF angiograms can be observed as combined red-green images.

CONCLUSIONS

Compared to conventional videoangiography, digital SIF videoangiography has only advantages: the image quality is better, it is less complicated and not more expensive than the conventional one. Digital recording should replace the conventional one.

Cost of managing digital diagnostic images for a 614-bed hospital

The cost of recording and archiving digital diagnostic imaging data is presented for a Radiology Department serving a 614 bed University-Hospital with a large outpatient population. Digital diagnostic imaging modalities include computed tomography, nuclear medicine, ultrasound, and digital radiography. The archiving media include multiformat video film recordings, magnetic tapes, and disc storage. The estimated cost per patient for the archiving of digital diagnostic imaging data is presented.

A novel vacuum device for extremity immobilisation during digital angiography: preliminary clinical experiences

Our objective was to develop and evaluate a non-invasive device for rigid immobilisation during extremity angiography. The patented BodyFix immobilisation device (Medical Intelligence, Schwabmünchen, Germany) consists of a vacuum pump connected to special cushions and a plastic foil that covers the body part to be immobilised. First, the patient's extremity is covered by a thin plastic bag and then wrapped in one of the cushions, placed on the top of the therapy couch, and covered with the plastic foil. The air is evacuated from the cushion under the covering foil by the vacuum pump, resulting a hardening of the cushion and thus immobilisation of the patient's extremity. The rigid immobilisation resulted in a complete absence of motion artefacts in the majority of patients. No pixeling of the images was required in any of the 100 patients vs 32% in the control group. Repetition of series could be avoided in all cases and a substantial increase in the quality of the images was obtained. Setup of the device takes an additional 1-2 min. Vacuum immobilisation allows for comfortable, effective immobilisation during digital subtraction angiography, eliminating motion artefacts. This device has become an indispensable tool in daily clinical routine at our department.

[Financial impact of introducing filmless CRT diagnosis]

There has been a great deal of discussion as to the cost and benefit of introducing filmless CRT diagnosis for radiological exams. Although the various advantages of the filmless system tend to be highlighted, very few studies have attempted to provide a quantitative estimate of the degree of impact. We analyzed the potential financial impact on the cost of film management (film development, maintenance, and transportation) if CRT diagnosis were to be introduced in Seirei Hamamatsu Hospital. In conducting this analysis, we assumed that CRT diagnosis initially would be limited to CT and MR. The analysis demonstrated that the actual yearly cost of managing films amounts to about 240 million yen. As individual items, the cost of film materials, labor, and depreciation of assets were the three largest cost sectors, with the cost of film accounting for more than 30% of the total. The expense attributable to CT and MR exams was roughly half of the total cost. Against this level of expense, the expected savings in the first year after shifting to the filmless system would be 100 million yen, or a 36% reduction in current expenses. This savings reflects various effects of system change, including lack of need for related materials, reduction in staff workload, elimination of unnecessary equipment, etc. Under the simulation we conducted, 70% of savings occurred in the area of variable costs and 30% in the area of fixed costs.

Productivity and cost assessment of computed radiography, digital radiography, and screen-film for outpatient chest examinations

An objective assessment and comparison of computed radiography (CR) versus digital radiography (DR) and screen-film for performing upright chest examinations on outpatients is presented in terms of workflow, productivity, speed of service, and potential cost justification. Perceived ease of use and workflow of each device is collected via a technologist opinion survey. Productivity is measured as the rate of patient throughput from normalized timing studies. The overall speed of service is calculated from the time of examination ordering as stamped in the radiology information system (RIS), to the time of image availability on the picture archiving and communication system (PACS), to the time of interpretation rendered (from the RIS). A cost comparison is discussed in terms of potential productivity gains and device expenditures. Comparative results of a screen-film (analog) dedicated chest unit versus a CR reader and a DR dedicated chest unit show a higher patient throughput for the digital systems. A mean of 8.2 patients were moved through the analog chest room per hour, versus 9.2 patients per hour using the CR system and 10.7 patients per hour with the DR system. This represents a 12% increase in patient throughput for CR over screen-film; a 30% increase in patient throughput for DR over screen-film, which is statistically significant; and a 16% increase in patient throughput for DR over CR, which is not statistically significant. Measured time to image availability for interpretation is much faster for both CR and DR versus screen-film, with the mean minutes to image availability calculated as 29.2 +/- 14.3 min for screen-film, 6.7 +/- 1.5 min for CR, and 5.7 +/- 2.5 min for DR. This represents an improved time to image availability of 77% for CR over screen-film, 80% for DR over screen-film, and 15% for DR over CR. These results are statistically significant (P <.0001) for both CR over screen-film and DR over screen-film but not statistically significant for DR over CR. A comparison of the digital technology costs illustrates that the high cost of DR may not be justifiable unless a facility has a steady high patient volume to run the device at or near 100% productivity. Both CR and DR can improve workflow and productivity over analog screen-film in a PACS for delivery of projection radiography services in an outpatient environment. Cost justification for DR over CR appears to be tied predominantly to high patient volume and continuous rather than sporadic use patterns.

The solitary pulmonary nodule: aggressive excisional strategy

Treatment of cancer at an early stage leads to enhanced survival. Low-dose spiral computed tomography (CT) scanning is readily available and allows early detection of solitary pulmonary nodules. Thoracic surgeons should embrace a calculated yet aggressive approach to early definitive diagnosis of solitary pulmonary nodules. Sputum cytology, bronchoscopy and biopsy, image-guided fine-needle aspiration cytology, and positron emission tomography with (18)fluorodeoxyglucose (FDG-PET) scanning are useful diagnostic tools, but problems unique to each and the possibility of false-negative examination have relegated their use to selected nodules. Serial radiographic examination remains the main noninvasive test for diagnosis of solitary pulmonary nodules. Video-thoracic surgery allows resection of pulmonary nodules with minimal morbidity and mortality. Today, diagnosis by excisional biopsy is an acceptable management strategy as more and smaller nodules are being detected but not diagnosed. In 2002, when in doubt, we should take out the solitary pulmonary nodule.

Digitizing pediatric chest radiographs: comparison of low-cost, commercial off-the-shelf technologies

OBJECTIVE

To compare low-cost, off-the-shelf technology for digitizing pediatric chest radiographs.

MATERIALS AND METHODS

Forty pediatric chest radiographs (hard copy), each with a single abnormality, were digitized using a commercial film digitizer and two low-cost

METHODS

a digital camera and a flatbed scanner. A stratified, randomized, block design was used where 20 readers evaluated 40 different images to determine the ability to accurately detect the abnormality. Readers then rated all 160 images (40 images x 4 methods) for conspicuity of the abnormality and overall image quality.

RESULTS

Abnormalities were correctly identified on 82.3 % of hard copy images, 82.9 % of flatbed scanner images, 74.3 % of film digitizer images, and 69.7 % of digital camera images (p < 0.05) when compared to hard copy or flatbed scanner images. Lesion conspicuity was rated higher on hard copy (p < 0.05) than all digitized images. Conspicuity ratings were similar for flatbed scanner and film digitizer images, but lower in digital camera images (p < 0.05). For overall image quality, all were rated significantly different from each other (p < 0.05), with hard copy > flatbed scanner > film digitizer > digital camera images.

CONCLUSION

A low-cost flatbed scanner yielded digital pediatric chest images which were significantly superior to digital camera images While flatbed scanner images were interpreted with the equivalent diagnostic accuracy of hard copy images, they were rated lower for image quality and lesion conspicuity.

Digital x-ray systems. Part 2. An overview of digital radiography concepts and an evaluation of cassetteless DX systems

In this article, we conclude our two-part series on digital x-ray (DX) systems, which we began in our August 2001 issue. Part 2 includes an overview of some important digital radiography concepts, as well as the results of our testing of three cassetteless DX systems. The Technology Overview discusses new radiographic concepts pertaining specifically to DX systems, as well as how established measures of image quality apply to DX technology. These concepts will help buyers objectively compare systems and will help healthcare facilities realize the greatest benefits from digital radiography. Our product testing covers three cassetteless DX systems from three suppliers. We looked at whether these systems provide at least the same amount of diagnostic information as conventional screen-film systems while significantly increasing the efficiency of the radiology department and the entire healthcare facility. We rate all the evaluated systems Acceptable but consider two to be superior, based on the overall versatility of one and the user interface of the other.

Digital x-ray systems. Part 1. An introduction to DX technologies and an evaluation of cassette DX systems

Film is an effective means for capturing diagnostic information. However, film images cannot be easily integrated into a digital communication system. Thus, as the number of healthcare facilities moving toward a digital work-flow increases, so too does the interest in digital x-ray (DX) systems, which produce images as collections of digital data, rather than as static films. In this first part of our two-part series on DX systems, we present an overview of DX technology, we review the cost factors to consider when deciding whether to invest in DX technology, we offer guidance to help facilities determine which type of system--cassette or cassetteless--will best meet their needs, and we evaluate cassette DX systems from four suppliers. Part 2 of our series, which features an evaluation of cassetteless DX systems, will be published later this year. Our testing of DX systems identifies whether a system can provide at least the same amount of diagnostic information as a screen-film system while significantly increasing the efficiency of operations. We found all the evaluated systems to be effective, but we rank the systems from two suppliers above the others because their user interfaces allow easier and more efficient operation.

The length of time necessary to break even after converting to digital mammography

The cost differences between film-based mammography (FBM) and digital mammography (DM) were estimated after discussions with hospital personnel and industry representatives. Human resource costs were not included. The fixed cost of FBM per machine was estimated to be $50,000 and the variable cost $4.60 per examination. The fixed cost of DM per machine was estimated to be $102,000 and the variable cost $0.10 per examination. The total number of examinations required to break even was therefore 11,556. At a rate of 15 examinations per machine per day and with 251 working days per year, it would take 3.1 years to break even. In the first year after the break-even point had been attained, $16,943 would be saved for every 3765 examinations performed. Extrapolating to the USA as a whole, in which 23 million mammographic examinations are performed each year, suggests that the annual savings from going filmless would be more than $103 million.

[Digital imaging system are rapidly introduced in Swedish departments of radiography. This calls for new strategic planning]

Diagnostic radiology in Sweden is changing rapidly to digital (filmless) technique. The advantages are more rapid delivery of radiologic service, better working conditions and less negative effects on the environment. Teleradiology is also facilitated. The Swedish Board of Health and Welfare has investigated the speed with which this change is taking place. In 1998, 26 of the 118 departments of diagnostic radiology had already turned digital; it is estimated that in the near future at least five departments will become fully digital each year. For planning purposes, less emphasis should be put on the supply of radiographic film, and more on telecommunications, computer hardware and digital storage.

Digital detectors in mammography. A technological overview

At a first glance the future of digital mammography seems very bright considering the wealth of offerings for new detectors, made by companies on the market or in journals. However technically spoken, digital mammography is one of the most demanding applications in the spectrum of radiology along with a high degree of cost consciousness in the mammography screening programs. The functional requirements are so high for digital mammography that only the best and most expensive components are good enough to compete with the current screen-film systems. Next difficulties are the lack of quality standards for digital detectors, not at all existing in the past and still under discussion, and the non-existence or changing of approval procedures. This is discouraging the industries to enter the field and is slowing down the phase-in time. After these obstacles are removed, there will come the discussions on acceptance of digital mammography within the professional community, due to the 'look' of the images and also the need to gain confidence with these images.

Digital vs conventional radiography: cost and revenue analysis

The objective of this study was to analyse and compare the operating and investment costs of two radiographic systems, a conventional and a digital one, and to evaluate the cost/revenue ratio of the two systems. The radiological activity over 1 year for chest and skeletal exams was evaluated: 13,401 chest and 7,124 skeletal exams were considered. The following parameters of variable costs were evaluated: the difference between variable proportional costs of the two technologies, the effective variable cost of any size film, including the chemicals, and for different sizes of digital film, variable costs of chest plus skeletal exams performed with the two techniques. Afterwards the economical effect was considered taking into account depreciation during a time of utilization ranging between 8 and 4 years. In the second part of the analysis the total cost and the revenues of the two technologies were determined. The comparison between the digital and conventional systems has shown the following aspects: 1. Digital radiography system has a much higher investment cost in comparison with the conventional one. 2. Operating costs of digital equipment are higher or lower depending on the film size used. Evaluating chest X-ray we reach a breakeven point after 1 year and 10,000 exams only if displayed over 8 x 10-in. film and after 30,000 if displayed over a 11 x 14-in. film. 3. The total cost (variable cost, technology cost, labour cost) of digital technology is lower than that of the conventional system by 20 % on average using 8 x 10-in. film size. 4. Digital technology also allows lesser film waste and lesser film per exam

[The economic expediency of digital fluorography]

The paper shows the advantages of digital versus routine film fluorography, which allows a user to make a choice of the type of an apparatus for fluorographic examination. The expenses of a fluorographic room on developing equipment and expendable materials for different types of the room's equipment. It gives the cost and specific features of the use of current film and digital fluorographs and the data on the cost of an examination using film and digital fluorography in case of the most cost-effective fluorographic systems.

Gastrointestinal imaging: a systems analysis comparing digital and conventional techniques

OBJECTIVE

The purpose of this study was to compare digital and conventional methods of gastrointestinal imaging based on the cost of image storage and estimated overall costs, radiation exposure to the patient, and duration of the examination.

MATERIALS AND METHODS

Our study sample consisted of 128 patients who underwent conventional gastrointestinal studies (64 double-contrast upper gastrointestinal examinations and 64 double-contrast barium enemas) and 139 patients who underwent digital gastrointestinal studies (66 double-contrast upper gastrointestinal examinations and 73 double-contrast barium enemas). The number of images and films for each study was recorded, and the mean cost of image storage and the estimated overall costs for digital versus conventional studies were calculated. Both the duration of fluoroscopy and the time from start to completion of the study were obtained from our radiology information system. From these data, we calculated mean radiation exposure to the patient and the duration of the examination. Finally, referring physicians completed a questionnaire about their level of satisfaction with paper prints generated from digital gastrointestinal studies.

RESULTS

When digital studies were compared with conventional studies, the mean cost of image storage decreased by 45% and the estimated overall 10-year costs decreased by 8%. The mean number of spot images increased by 8% for upper gastrointestinal examinations and by 25% for barium enema examinations, whereas the mean duration of fluoroscopy decreased by 4% and by 10%, respectively. As a result, radiation exposure to patients increased by only 2%, a difference that did not approach statistical significance. Finally, the mean duration of examinations decreased by 24% for upper gastrointestinal examinations and by 33% for barium enemas. Approximately 85% of the physicians who completed the questionnaires indicated that they reviewed the paper prints generated from digital studies and that they would like to continue receiving them.

CONCLUSION

Digital gastrointestinal imaging systems are associated with higher initial costs than conventional systems, but the long-term costs of these digital imaging systems are slightly less because of the lower cost of image storage, and radiation exposure to patients is comparable. The shorter duration of digital examinations is a potential benefit of this technology, allowing improved patient throughput. Finally, referring physicians have a high level of satisfaction with paper prints generated from digital imaging.

A time-motion study of digital radiography at implementation

With increasing budgetary restraints on the health system, it is apparent that the main contribution that radiology departments can make to significant cost reduction in hospitals is to decrease the length of time between requesting an X-ray examination and receiving the report (and images). Digital radiography (DR) was introduced into the Radiology Department at the Royal Adelaide Hospital as a pilot project to research the cost-benefits and efficiency of the system, and to determine future directions for planning a digital department. The business plan developed prior to implementation of this pilot project predicted a saving of one bed-day per inpatient when a fully digital department with a picture archiving and communication system (PACS) is installed. This initial study comparing DR and conventional radiography (convR) provides baseline data and shows encouraging results for more rapid transmission of reports to clinicians.

Filmless cardiac imaging: motion or commotion?

At present times the medical cardiology imaging is still arguing about the usefulness of X-Ray Cine film in comparison with digital and filmless imaging. It is clear that both techniques have their advantages. X-Ray Cine film is a well established technique of which the possibilities are well known. At a first glance filmless imaging offers nothing but advantages. However the whole picture becomes clear when trying to implement these systems in a clinical environment, because at that time aspects of investments, technological continuity and risks, needed skills and effects on the workflow appear. This article has the purpose to clarify some of these aspects and give guidance in the difficult process of making the right decision.