Evaluation of a digital camera for acquiring radiographic images for telemedicine applications

Teleconsultation in orthopaedic surgery: A systematic review and meta-analysis of patient and physician experiences

INTRODUCTION

The primary purpose of this review was to evaluate patient and physician preference and satisfaction for teleconsultation in orthopaedic surgery compared to traditional face-to-face consultation. In addition, we evaluated the effects of teleconsultation on patient length of visit, healthcare costs, range of motion (ROM), pain, quality of life (QOL), and ongoing management plans.

METHODS

A systematic review of MEDLINE, Embase, Web of Science, and Cochrane Library was conducted according to PRISMA guidelines. Randomised control trials and case control studies comparing teleconsultation with traditional, face-to-face consultation in the management of orthopaedic conditions were included. The primary outcome measures were patient and physician preference and satisfaction. Secondary outcomes included patient length of visit, healthcare costs, ROM, pain, QOL, and ongoing management plans.

RESULTS

A total of 13 articles meeting the eligibility criteria were included for systematic review and 8 for meta-analysis. There was no significant difference in patient satisfaction, length of visit, or time spent with the physician between the telemedicine and in-office control group. The mean difference of patient preference for telemedicine was significantly higher in the telemedicine group compared to the in-office visit group (OR 1.44, 95% CI 1.12-1.87, p = 0.005).

DISCUSSION

Telemedicine was not inferior to face-to-face office visits in regard to patient and physician preference and satisfaction. Therefore, it would be an effective adjunct to face-to-face office visits, serving as a mechanism of triage and long-term continuity of care.

3D PED BURN app: A precise and easy‐to‐use pediatric 3D burn surface area calculation tool

Background and aims

Method

Result

Conclusion

Your mileage may vary: impact of data input method for a deep learning bone age app's predictions

OBJECTIVE

The purpose of this study was to evaluate agreement in predictions made by a bone age prediction application ("app") among three data input methods.

METHODS

The 16Bit Bone Age app is a browser-based deep learning application for predicting bone age on pediatric hand radiographs; recommended data input methods are direct image file upload or smartphone-capture of image. We collected 50 hand radiographs, split equally among 5 bone age groups. Three observers used the 16Bit Bone Age app to assess these images using 3 different data input methods: (1) direct image upload, (2) smartphone photo of image in radiology reading room, and (3) smartphone photo of image in a clinic.

RESULTS

Interobserver agreement was excellent for direct upload (ICC = 1.00) and for photos in reading room (ICC = 0.96) and good for photos in clinic (ICC = 0.82), respectively. Intraobserver agreement for the entire test set across the 3 data input methods was variable with ICCs of 0.95, 0.96, and 0.57 for the 3 observers, respectively.

DISCUSSION

Our findings indicate that different data input methods can result in discordant bone age predictions from the 16Bit Bone Age app. Further study is needed to determine the impact of data input methods, such as smartphone image capture, on deep learning app performance and accuracy.

Feasibility of Rapid Development and Deployment of a Telemedicine Program in a Foot and Ankle Orthopedic Practice

BACKGROUND

A lack of access to care is predictably associated with negative outcomes in foot and ankle surgery. Despite recent advances in telecommunication technologies, the field of orthopedics has been slow to adopt these resources in offsetting barriers to care. The COVID-19 pandemic has forced departments to change their clinical approach, lending unprecedented opportunity to better understand how telehealth may bridge this care gap in foot and ankle practices. The purpose of this study was to assess patient-reported outcomes of telemedicine encounters, including comfort and patient satisfaction. Our hypothesis was that patients would be significantly less satisfied with telemedicine when compared with in-office appointments for all nonemergency visit types.

METHODS

Telemedicine satisfaction was assessed via phone survey with a modified 1 to 5 Likert scale. Patients who had completed a telemedicine visit between April 13, 2020, and June 19, 2020, were eligible to participate. Patient demographics were recorded, and data were analyzed using paired and independent t tests for parametric continuous data and Fisher's exact and chi-square tests for noncontinuous data. A total of 216 patients completed the telemedicine questionnaire.

RESULTS

The overall mean satisfaction for telemedicine visits (4.7) was significantly lower than that for in-office visits (4.9) (P < .001). However, the majority (90.3%) of patients reported they would use telemedicine again in the future. When compared, patients seeking fracture care had significantly higher telemedicine satisfaction (4.9, n = 38) than those receiving nonfracture care (4.6, n = 178) (P = .001), and those greater than 50 miles from the clinic had higher satisfaction (5.0, n = 14) than patients living within 50 miles of the clinic (4.7, n = 202) (P < .001).

CONCLUSION

Patients were more satisfied with their in-office clinic visit than telemedicine, although the vast majority of patients endorsed a willingness to utilize telemedicine in the future. Patients with trauma and greater barriers to foot and ankle care were more satisfied with their telemedicine visits.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

"Evaluation of a very low-cost and simple teleradiology technique"

This paper describes and analyzes a proposed solution of fundamental limitative factor of teleradiology to overcome the teleradiology usages problems in underdeveloped and developing countries. The goal is to achieve a very simple and cost-efficient way to take advantage of teleradiology in anywhere even in remote and rural areas. To meet the goal of this study, the following methodology which is consists of two main procedures was done: (1) Using a digital camera in order to provide a digital image from radiographs. (2) Using an image compression tool in order to compress digital images. The results showed that there is no significant difference between digital images (non-compress and compress images) and radiographic films. Also, there was a logic relationship between the diagnostic quality and diagnostic accuracy. Since the maximum percent of diagnostic accuracy can be seen among "Good" quality images and the minimum to was related "Poor". The results of our study indicate that a digital camera could be utilized to capture digital images from radiographic films of chest x-ray. To reduce the size of digital images, a lossy compression technique could be applied at compression percent of 50 or less without any significant differences. The compressed images can be sent easily by email to other places for consultation and also they can be stored with a smaller size.

Image-based medical expert teleconsultation in acute care of injuries. A systematic review of effects on information accuracy, diagnostic validity, clinical outcome, and user satisfaction

Objective

To systematically review the literature on image-based telemedicine for medical expert consultation in acute care of injuries, considering system, user, and clinical aspects.

Design

Systematic review of peer-reviewed journal articles.

Data sources

Searches of five databases and in eligible articles, relevant reviews, and specialized peer-reviewed journals.

Eligibility criteria

Studies were included that covered teleconsultation systems based on image capture and transfer with the objective of seeking medical expertise for the diagnostic and treatment of acute injury care and that presented the evaluation of one or several aspects of the system based on empirical data. Studies of systems not under routine practice or including real-time interactive video conferencing were excluded.

Method

The procedures used in this review followed the PRISMA Statement. Predefined criteria were used for the assessment of the risk of bias. The DeLone and McLean Information System Success Model was used as a framework to synthesise the results according to system quality, user satisfaction, information quality and net benefits. All data extractions were done by at least two reviewers independently.

Results

Out of 331 articles, 24 were found eligible. Diagnostic validity and management outcomes were often studied; fewer studies focused on system quality and user satisfaction. Most systems were evaluated at a feasibility stage or during small-scale pilot testing. Although the results of the evaluations were generally positive, biases in the methodology of evaluation were concerning selection, performance and exclusion. Gold standards and statistical tests were not always used when assessing diagnostic validity and patient management.

Conclusions

Image-based telemedicine systems for injury emergency care tend to support valid diagnosis and influence patient management. The evidence relates to a few clinical fields, and has substantial methodological shortcomings. As in the case of telemedicine in general, user and system quality aspects are poorly documented, both of which affect scale up of such programs.

University-Based Teleradiology in the United States

This article reviews the University of Arizona's more than 15 years of experience with teleradiology and provides an overview of university-based teleradiology practice in the United States (U.S.). In the U.S., teleradiology is a major economic enterprise with many private for-profit companies offering national teleradiology services (i.e., professional interpretation of radiologic studies of all types by American Board of Radiology certified radiologists). The initial thrust for teleradiology was for after-hours coverage of radiologic studies, but teleradiology has expanded its venue to include routine full-time or partial coverage for small hospitals, clinics, specialty medical practices, and urgent care centers. It also provides subspecialty radiologic coverage not available at smaller medical centers and clinics. Many U.S. university-based academic departments of radiology provide teleradiology services usually as an additional for-profit business to supplement departmental income. Since academic-based teleradiology providers have to compete in a very demanding marketplace, their success is not guaranteed. They must provide timely, high-quality professional services for a competitive price. Academic practices have the advantage of house officers and fellows who can help with the coverage, and they have excellent subspecialty expertise. The marketplace is constantly shifting, and university-based teleradiology practices have to be nimble and adjust to ever-changing situations.

The 60 most highly cited articles published in the Journal of Telemedicine and Telecare and Telemedicine Journal and E-health

Summary

We analysed the most highly cited articles in two specialist telemedicine journals, the Journal of Telemedicine and Telecare (JTT) and Telemedicine Journal and E-health (TJEH). Articles were extracted from the Science Citation Index Expanded in September 2012. A total of 1810 articles were listed for the JTT and 1550 for TJEH. In the JTT, the mean number of citations was 43 (SD 13); in TJEH the mean number of citations was 30 (SD 11). The average number of citations for the JTT was significantly higher than for TJEH ( P < 0.001). In each journal, the 60 articles which had the most citations were identified as highly cited publications (HCPs). The 60 HCPs in the JTT originated from 16 countries; the 60 HCPs in TJEH originated from 10 countries. Considering both journals together, the majority of HCPs came from the US, UK, Australia and Canada. In the JTT, the mean number of authors for each HCP was 4.6 (SD = 3.1); in TJEH, the mean number of authors for each HCP was 4.5 (SD = 2.3). There was no difference between the two journals ( P = 0.84) and the characteristics of the HCPs published in the JTT and TJEH were broadly similar. Although HCPs are not a direct method of measuring quality, they are an indicator of the scientific impact of the articles.

A Low Cost Method of Digitizing Radiographs Using a Photo Light Box

We evaluated a low cost device for digitizing X-ray films. It consisted of a locally-made wooden box and a readily-available digital camera. Two experienced paediatric radiologists interpreted the original X-ray films (the reference standard) and the corresponding images obtained in the photo light box. Ninety paediatric chest X-ray films were used (30 were normal chest radiographs, 30 showed pneumonic-consolidation and 30 had interstitial infiltrates). The presence or absence of the three signs most frequently found in acute respiratory pathologies were evaluated: normal pulmonary transparency, pneumonic consolidation and interstitial infiltration. There was very good agreement between the X-ray films and the digitized images, with kappa values from 0.86 to 0.98. There was good agreement between the two observers, with kappa values from 0.67 to 0.90. The low-cost photo light box represents an accessible and low-cost approach to transmitting X-ray images, allowing findings or a second opinion from a specialist radiologist to be obtained from a distance.

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.

Validity of Cobb angle measurements using digitally photographed radiographs

BACKGROUND CONTEXT

Advances in technology are influencing the way that medical information is archived and shared. Considering that an estimated two-thirds of the world has little or no orthopedic care, high demand exists for adequate consultation regarding diagnostic images in orthopedic specialties.

PURPOSE

To validate the use of photographed scoliosis films for the accurate interpretation of Cobb angles.

STUDY DESIGN

Retrospective review.

PATIENT SAMPLE

Thirty scoliosis radiographs.

OUTCOME MEASURE

Cobb angle.

METHODS

Thirty scoliosis radiographs were photographed using a digital camera from a straight and a 45° angle position. Cobb angles were then measured on the digital images using standard measurement software. Comparison was made between two types of curves: convex and concave, relative to the left side (side for the angled position).

RESULTS

There was excellent reproducibility between the measurements of the conventional radiographs and the photographs taken from a straight on position, p value of .97 for convex curves and p value of .98 for concave curves. Photographs taken from a 45° angle significantly increased the magnitude of the curve convex to the angle (p=.001).

CONCLUSION

Sharing photographs of scoliosis radiographs can be done with reliability if the image is taken directly in front of the viewbox rather than at an oblique angle; pictures taken at oblique angles are prone to misinterpretation of curve magnitude.

Expert interpretation compensates for reduced image quality of camera-digitized images referred to radiologists

We compared the accuracy of five veterinary radiologists when reading 20 radiographic cases on both analog film and in camera-digitized format. In addition, we compared the ability of five veterinary radiologists vs. 10 private practice veterinarians to interpret the analog images. Interpretation accuracy was compared using receiver operating characteristic curve analysis. Veterinary radiologists' accuracy did not significantly differ between analog vs. camera-digitized images (P = 0.13) although sensitivity was higher for analog images. Radiologists' interpretation of both digital and analog images was significantly better compared with the private veterinarians (P < 0.05).

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.

Selecting the right digital camera for telemedicine-choice for 2009

Digital cameras are fundamental tools for store-and-forward telemedicine (electronic consultation). The choice of a camera may significantly impact this consultative process based on the quality of the images, the ability of users to leverage the cameras' features, and other facets of the camera design. The goal of this research was to provide a substantive framework and clearly defined process for reviewing digital cameras and to demonstrate the results obtained when employing this process to review point-and-shoot digital cameras introduced in 2009. The process included a market review, in-house evaluation of features, image reviews, functional testing, and feature prioritization. Seventy-two cameras were identified new on the market in 2009, and 10 were chosen for in-house evaluation. Four cameras scored very high for mechanical functionality and ease-of-use. The final analysis revealed three cameras that had excellent scores for both color accuracy and photographic detail and these represent excellent options for telemedicine: Canon Powershot SD970 IS, Fujifilm FinePix F200EXR, and Panasonic Lumix DMC-ZS3. Additional features of the Canon Powershot SD970 IS make it the camera of choice for our Alaska program.

Avaliação de métodos indiretos de digitalização de radiografias cefalométricas em comparação ao método digital direto

OBJETIVO: avaliar métodos de digitalização indireta de radiografias cefalométricas em comparação ao método digital direto. MÉTODOS: a amostra foi composta de dez radiografias cefalométricas adquiridas pelo Orthopantomograph OP100/Orthocef OC100 (GE - Instrumentarium), digital direto. As imagens foram inseridas no programa Adobe Photoshop® e cinco pontos cefalométricos foram marcados. Procedeu-se a impressão em transparência e foi feita a digitalização indireta das imagens impressas, por meio das câmeras fotográficas digitais Sony® DSC-W5 e Canon® Rebel XT/EOS 350D, fixas em estativa, nas distâncias de 25cm e 60cm e com o scanner Scan Jet 4C Hewlett Packard®. As imagens diretas e indiretas foram inseridas e calibradas no software Radiocef Studio (Radiomemory®, Brasil), marcando-se o centro dos pontos previamente assinalados. A análise cefalométrica computadorizada gerou três grandezas angulares e quatro lineares, as quais foram submetidas a tratamento estatístico. RESULTADOS: as imagens do scanner Scan Jet 4C HP® demonstraram pequenas alterações significativas, porém, sem relevância clínica. Quando da digitalização a 60cm da radiografia, as duas câmeras causaram distorções que foram significativas mas clinicamente aceitáveis; e, a 25cm, causaram as maiores distorções, com importância clínica, na Canon® Rebel XT. CONCLUSÃO: o scanner Scan Jet 4C HP® com leitor de transparências foi o melhor método e as câmeras operando a 60cm mostraram-se adequadas para digitalização de radiografias. As câmeras na distância de 25cm causaram distorções na imagem que alteraram as medidas lineares, podendo a Canon® Rebel XT comprometer o diagnóstico ortodôntico.

Telemedicine and telepresence for trauma and emergency care management

The use of telemedicine is long-standing, but only in recent years has it been applied to the specialities of trauma, emergency care, and surgery. Despite being relatively new, the concept of teletrauma, telepresence, and telesurgery is evolving and is being integrated into modern care of trauma and surgical patients. This paper will address the current applications of telemedicine and telepresence to trauma and emergency care as the new frontiers of telemedicine application. The University Medical Center and the Arizona Telemedicine Program (ATP) in Tucson, Arizona have two functional teletrauma and emergency telemedicine programs and one ad-hoc program, the mobile telemedicine program. The Southern Arizona Telemedicine and Telepresence (SATT) program is an inter-hospital telemedicine program, while the Tucson ER-link is a link between prehospital and emergency room system, and both are built upon a successful existing award winning ATP and the technical infrastructure of the city of Tucson. These two programs represent examples of integrated and collaborative community approaches to solving the lack of trauma and emergency care issue in the region. These networks will not only be used by trauma, but also by all other medical disciplines, and as such have become an example of innovation and dedication to trauma care. The first case of trauma managed over the telemedicine trauma program or "teletrauma" was that of an 18-month-old girl who was the only survival of a car crash with three fatalities. The success of this case and the pilot project of SATT that ensued led to the development of a regional teletrauma program serving close to 1.5 million people. The telepresence of the trauma surgeon, through teletrauma, has infused confidence among local doctors and communities and is being used to identify knowledge gaps of rural health care providers and the needs for instituting new outreach educational programs.

A comparative study of conventional mammography film interpretations with soft copy readings of the same examinations

An acceptable mammography film digitizer must provide high-quality images at a level of diagnostic accuracy comparable to reading conventional film examinations. The purpose of this study was to determine if there are significant differences between the interpretations of conventional film-screen mammography examinations and soft copy readings of the images produced by a mammography film digitizer. Eight radiologists interpreted 120 mammography examinations, half as original films and the other half as digital images on a soft copy work station. No radiologist read the same examination twice. The interpretations were recorded in accordance with the Breast Imaging Reporting and Data System and included other variables such as perceived image quality and diagnostic difficulty and confidence. The results provide support for the hypothesis that there are no significant differences between the interpretations of conventional film-screen mammography examinations and soft copy examinations produced by a mammography film digitizer.

Accident and emergency teleconsultation for primary care--a systematic review of technical feasibility, clinical effectiveness, cost effectiveness and level of local management

A systematic review of accident and emergency teleconsultation services was carried out. Studies (English language only) conducted worldwide and published between 1996 and 2003 were included. Evidence relating to technical feasibility, clinical effectiveness, cost effectiveness and level of local management was used as the main outcome measure. Thirty-one studies met the selection criteria. Only two studies were randomized controlled studies. All studies provided evidence that that the service was technically feasible. Of the studies, 97% suggested that the service was clinically effective; 48% (15) of the studies gave figures for the level of local management achieved. The range for local management was 35-100% with a mean of 76%. Only 23% of the studies provided evidence to suggest that the service was cost effective. The case for cost-effectiveness is far from proven and this area of research requires immediate attention if potential users are to be convinced of the value of telemedicine.

Comparison of digitized and conventional radiographic images for assessment of hip joint conformation in dogs

OBJECTIVE

To determine agreement between assessments of canine hip joint conformation provided by board-certified radiologists after evaluation of digitized and conventional radiographic images.

SAMPLE POPULATION

200 pelvic radiographs previously evaluated by radiologists using the Orthopedic Foundation for Animals standard grading system for canine hip joint conformation.

PROCEDURES

Each of 20 board-certified radiologists evaluated conventional and digitized pelvic radiographs from each of 200 dogs for hip joint conformation. A weighted kappa coefficient and intraclass correlation were used to determine agreement between assessments derived from digitized radiographic images and conventional radiographs and between the original Orthopedic Foundation for Animals conformation ratings and assessments derived from each image format.

RESULTS

Overall, agreement between assessments derived from the digitized images and conventional radiographs was good, with all but 1 radiologist attaining a weighted kappa coefficient > 0.61. Intraclass correlation for each radiologist ranged from 0.75 to 0.98 (95% confidence interval, 0.67 to 0.984). On comparison of conformation assessments, 95.7% of those derived from conventional radiographs and digitized images were within 1 grade. On comparison of digitized radiographic conformation assessments and conformation ratings, 94.2% were within 1 grade. On comparison of conventional radiographic conformation assessments and conformation ratings, 92.3% were within 1 grade.

CONCLUSIONS AND CLINICAL RELEVANCE

The use of digitized radiographic images does not appear to impact the radiographic assessments of canine hip joint conformation made by consultant radiologists. Compared with conventional radiographs, the use of digitized radiographic images decreases storage space requirements and enables more rapid reporting of assessment results for individual dogs.

Digital camera resolution and proximal caries detection

OBJECTIVES

To evaluate the diagnostic accuracy of proximal caries detection from digitized film images captured by a digital camera at different resolution settings.

METHODS

Twenty-five periapical radiographs of 50 premolar and 25 molar teeth were photographed using a digital camera, Sony Cyber-shot, DSC-S75 at three different resolution settings: 640 x 480, 1280 x 960 and 1600 x 1200. Seventy-five digital images were transferred to a computer, saved and opened using ACDSee software. In addition, a PowerPoint slide was made from each digital image. Five observers scored three groups of images (the films, the displayed 1:1 digital images on the ACDSee software, and the PowerPoint slides) for the existence of proximal caries using a 5-point confidence scale, and the depth of caries on a 4-point scale. Ground sections of the teeth were used as the gold standard. Az values under the receiver operating characteristic (ROC) curve of each group of images and at different resolutions were compared using the Friedman and Wilcoxon signed rank tests. Mean different values between the lesions' depth interpreted by the observers and that of the gold standard were analysed.

RESULTS

Films showed the highest Az values. Only the 1280 x 960 images on the ACDSee software showed no significant difference of the Az value from the films (P=0.28). The digital images from three resolution settings on the PowerPoint slides showed no significant differences, either among each other or between them and the films. For caries depth, the 1280 x 960 images showed lower values of mean difference in enamel lesions compared with the other two resolution groups.

CONCLUSIONS

This study showed that in order to digitize conventional films, it was not necessary to use the highest camera resolution setting to achieve high diagnostic accuracy for proximal caries detection. The 1280 x 960 resolution setting of the digital camera demonstrated comparable diagnostic accuracy with film and was adequate for digitizing radiographs for caries detection.

COMPARISON OF DIGITIZED AND DIRECT VIEWED (ANALOG) RADIOGRAPHIC IMAGES FOR DETECTION OF PULMONARY NODULES

The purpose of this study was to compare direct (analog) viewing of thoracic radiographs with digitized images obtained with a radiographic scanner and seven digital cameras for detection of pulmonary nodules. Direct viewing of the analog radiographs was significantly better than all digitized methods (P<0.01). Significant variations exist between the radiographic scanner and the digital cameras. The scanner (Kodak LS75) was significantly better than the Kodak DC 4800 and the Sony DSC-707 cameras (P<0.05). The Nikon 995, Canon EOS-D30, and Ricoh i500 were significantly better than the Sony DSC-707 (P<0.05). There was no significant difference between the Kodak DC 3800, Kodak DC 4800, and the Sony DSC-707. For pairwise comparison of raters (when evaluating the radiographs individually compared with the consensus), the raters matched the consensus rating from 85% to 92% with no significant difference between raters.

Diagnostic accuracy of chest X-rays acquired using a digital camera for low-cost teleradiology

Store-and-forward telemedicine, using e-mail to send clinical data and digital images, offers a low-cost alternative for physicians in developing countries to obtain second opinions from specialists. To explore the potential usefulness of this technique, 91 chest X-ray images were photographed using a digital camera and a view box. Four independent readers (three radiologists and one pulmonologist) read two types of digital (JPEG and JPEG2000) and original film images and indicated their confidence in the presence of eight features known to be radiological indicators of tuberculosis (TB). The results were compared to a "gold standard" established by two different radiologists, and assessed using receiver operating characteristic (ROC) curve analysis. There was no statistical difference in the overall performance between the readings from the original films and both types of digital images. The size of JPEG2000 images was approximately 120KB, making this technique feasible for slow internet connections. Our preliminary results show the potential usefulness of this technique particularly for tuberculosis and lung disease, but further studies are required to refine its potential.

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.

Conversion of teaching file cases from film to digital format: a comparison between use of a diagnostic-quality digitizer and use of a flatbed scanner with transparency adapter

RATIONALE AND OBJECTIVES

The authors' institution had decided to convert its radiology teaching files from film to digital media. This study was performed to determine the simplest method for converting the analog film images to digital images without a subsequent loss in diagnostic accuracy.

MATERIALS AND METHODS

Twenty chest radiographs that demonstrated interstitial lung disease were randomly selected from the departmental teaching files and matched with 20 control radiographs from healthy adults. Analog film images were converted with both a diagnostic-quality film image digitizer (digitized) and a flatbed scanner equipped with a transparency adapter (scanned). Three radiology faculty members reviewed a mixed set of corresponding analog film, digitized, and scanned images. Reviewers judged whether each image depicted interstitial lung disease, indicated their level of confidence in the diagnosis, and rated each image for quality. Image quality was assessed by each reviewer subjectively at the time of viewing the individual image, without regard to other images. A one-way analysis of variance was performed to determine whether there was a statistically significant difference in diagnostic accuracy between the three image formats. Agreement in diagnosis between corresponding images in the three different formats was evaluated for each reviewer with the McNemar test.

RESULTS

There was no statistically significant difference in diagnostic accuracy between analog film and scanned images, but there was such a difference between these two groups and digitized images. Accuracy was 97% for analog film, 94% for scanned, and 89% for digitized images. Results of the McNemar test showed no statistically significant difference in agreement between the analog film images and the scanned images for any of the reviewers (P > .05).

CONCLUSION

A high-end flatbed scanner with transparency adapter provided accurate, simple, and inexpensive conversion of analog film teaching files to digital format, with no loss of the ability to detect or diagnose subtle abnormalities such as interstitial lung disease.

Pulmonary nodule detection and visual search: P45 and P104 monochrome versus color monitor displays

RATIONALE AND OBJECTIVES

The faceplate of a cathode-ray tube (CRT) display monitor is covered on the vacuum side with a phosphor screen. The different phosphors that can be used for this screen have distinctly different physical properties that can affect the noise properties of the display. Differences in noise affect the signal-to-noise ratio and, hence, may affect diagnostic performance. This study evaluated observer performance and visual search parameters in the detection of pulmonary nodules, comparing two monochrome CRT monitors with different phosphors (P45 and P104) and a color CRT monitor.

MATERIALS AND METHODS

The receiver operating characteristic paradigm was used to evaluate observer performance with a series of radiographic chest images containing solitary pulmonary nodules. Eye position was recorded as the observers searched the images on each type of monitor.

RESULTS

Observer performance, as indicated by the area under the receiver operating characteristic curve and compared by means of an analysis of variance test, was best for the P45 monitor, next best for the P104 monitor, and worst for the color monitor. All differences were statistically significant. Eye-position parameters were also affected by monitor type. The time required to fixate the lesion and overall search times were longest with the color monitor.

CONCLUSION

The type of phosphor used in the CRT monitor faceplate can affect diagnostic performance and visual search parameters. Care should be taken in the selection of monitors for use in clinical radiology.