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BACKGROUND: Development of deep convolutional neural networks for breast cancer classification has taken significant steps towards clinical adoption. It is though unclear how the models perform for unseen data, and what is required to adapt them to different demographic populations. In this retrospective study, we adopt an openly available pre-trained mammography breast cancer multi-view classification model and evaluate it by utilizing an independent Finnish dataset. METHODS: Transfer learning was used, and the pre-trained model was finetuned with 8,829 examinations from the Finnish dataset (4,321 normal, 362 malignant and 4,146 benign examinations). Holdout dataset with 2,208 examinations from the Finnish dataset (1,082 normal, 70 malignant and 1,056 benign examinations) was used in the evaluation. The performance was also evaluated on a manually annotated malignant suspect subset. Receiver Operating Characteristic (ROC) and Precision-Recall curves were used to performance measures. RESULTS: The Area Under ROC [95%CI] values for malignancy classification obtained with the finetuned model for the entire holdout set were 0.82 [0.76, 0.87], 0.84 [0.77, 0.89], 0.85 [0.79, 0.90], and 0.83 [0.76, 0.89] for R-MLO, L-MLO, R-CC and L-CC views respectively. Performance on the malignant suspect subset was slightly better. On the auxiliary benign classification task performance remained low. CONCLUSIONS: The results indicate that the model performs well also in an out-of-distribution setting. Finetuning allowed the model to adapt to some of the underlying local demographics. Future research should concentrate to identify breast cancer subgroups adversely affecting performance, as it is a requirement for increasing the model's readiness level for a clinical setting.

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UNLABELLED: Dental evidence, especially from radiographs, has been found to be an effective method in personal identification. Previously, it has been shown that wireless personal digital assistants (PDA) can be used to transfer digitized radiographs. The purpose of this study was to set up a secure and reliable mobile connection for transferring dental digital images for disaster victim identification, and to test this new way of working in Phuket, Thailand, following the December 2004 Asian Tsunami disaster. MATERIAL AND METHODS: Digital dental radiographs and clinical images were transferred in two separate sets using secured data transmission from a server in Finland to PDA terminals in Thailand. The mean size of the images in test 1 and test 2 were 90.7 kB and 88.1 kB, respectively. RESULTS: The mean speed of the transmission was 3.7 kB/s with the Nokia 9500 and 3.4 kB/ s with the Qtek 2020i. The quality of all the pictures was found to be good enough for dental identification purposes. CONCLUSIONS: Wireless personal digital assistants (PDA) together with data secure transmission of digital clinical information could be used in order to assist in disaster victim identification in areas where GSM cellular networks are available.

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Oulu University Hospital has a Web-based multimedia medical record in use. One key element in the creation of regional e-health networks is an electronic referral letter and discharge letter service. In Oulu an XML messaging system is used for an integral part of the medical record. The service has now been extended to primary care centres and hospitals in the Oulu region. Using a secure Web link, primary care physicians have direct remote access to the original hospital's electronic patient record, including medical images and laboratory results. According to the users, e-referral saves time and improves the quality of documentation. On the other hand, workflow development is still immature. Our experience suggests that the implementation of e-referrals is a process which requires careful handling, in relation to the technology as well as organizational changes and communication.

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Three different, well established systems for e-referral were examined. They ranged from a system in a single country handling a large number of cases (60,000 per year) to a global system covering many countries which handled fewer cases (150 per year). Nonetheless, there appeared to be a number of common features. Whether the purpose is e-transfer or e-consultation, the underlying model of the e-referral process is: the referrer initiates an e-request; the organization managing the process receives it; the organization allocates it for reply; the responder replies to the initiator. Various things can go wrong and the organization managing the e-referral process needs to be able to track requests through the system; this requires various performance metrics. E-referral can be conducted using email, or as messages passed either directly between computer systems or via a Web-link to a server. The experience of the three systems studied shows that significant changes in work practice are needed to launch an e-referral service successfully. The use of e-referral between primary and secondary care improves access to services and can be shown to be cost-effective.

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Telemedicine widens the access to sensitive data and therefore data security development is an essential part of telemedicine projects. Publicly available security evaluation methods provide a good starting point for security work. We built a mobile teleradiology consultation system that is integrated into hospital information system and systematically evaluated possible security threats that may endanger it. Based on the analysis, a security model was designed and implemented. We conclude that systematic approach to data security development facilitates the process but does not give all answers to the practical questions.

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In vivo dose measurements with diodes are easy to perform. The first aim of our study was to show whether diode measurements of the patient exit doses are precise enough for verifying inhomogeneity corrections used for treatment planning. The second aim was to assess the precision of the modified Batho Law inhomogeneity correction of the CadPlan treatment planning system. For this purpose, entrance and lait doses were measured in the thoracic region of 115 patients. Diode measurements were sufficiently precise to verify the density corrections predicted by the treatment planning system (< 0.5% of ICRU dose). The measured doses were compared with calculations of the CadPlan treatment planning system. The mean deviation of the exit dose calculations within the measurements error was zero. The present results show that measurements of exit dose even in a small number of patients are sufficient to identify systematic errors in the dose calculation.

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A new type of terminal device, a wireless personal digital assistant (PDA) based on a GSM digital cellular phone, was used to transmit computerized tomography scans of 21 patients to a neuroradiologist. All transmitted images were suitable for a preliminary consultation and in one case a final report could be made. In 18 cases the findings were compatible with the reference film reading performed later and in three cases there were minor differences of no clinical importance. Transmission of a single image lasted 1 min 30 s and the transmission of a complete brain scan (14 images) took on average 21 min. The total process of transmission and interpretation of a brain examination series took on average 40 min. In this pilot study the neuroradiologist gained essential information in 24% of the cases and beneficial information in 62%. The neuroradiologist considered that the image consultation saved a hospital visit in 15 cases (71%). Although PDA technology is at an early stage of development and has numerous limitations, it is likely that future technical improvements will allow easier clinical consultations for neurosurgeons and neurologists.

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The new concept of teleradiology is centered on the consideration that it involves management of medical information rather than the simple transmission of diagnostic images from one location to another. Teleradiology must therefore be able to contribute to the seamless integration of the digital environment in which medical data are managed throughout and beyond the hospital, generating value added services for the patients as well as prospective economical benefits for the institution. In this perspective the evolution of telecommunication with the spectacular success of mobile telephony and Internet will play and increasingly important role, by allowing further development in the exchange of multimedia medical information on a regional as well as international level. However, new responsibilities are being given to the radiologists, who must take all necessary technical and organizational actions in order to avoid that the digital management of data may endanger the confidentiality and the integrity of patients' data.

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After the design and development of the teleradiology system, a work practice oriented approach was used to gain a more holistic understanding of the relationship between the emerging work practice and the newly implemented technology, and to provide information for redesigning the system. The approach which utilized ethnographically informed fieldwork and cooperative workshops was introduced. Cooperation, the chain of tasks, and articulation work of teleradiology work practice were described, with the focus on image interpretation in particular. From the point of view of radiologists image interpretation work, a report was made on how these findings influenced the evaluation and redesign of the system. Furthermore, the problematics of distributed collaboration, reorganization of work, and education are emphasized.

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The authors present four cases where foreign bodies within the central nervous system had spontaneously migrated. Two of these were surgical clips and two were bullets. The clips seemed to pass intradurally into the lumbar region with minor or no symptoms. Possible explanations for the migration are the circulation of CSF and the gravity. A new observation was that an infection may develop at the site where the foreign body had been situated before migration. From the clinical point of view, the removal of foreign bodies from the intradural space is not indicated, if the patient has no connected symptoms.

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A wireless system for radiological subspecialist consultation based on a portable personal computer and a GSM cellular phone was tested. A link with secure access to the hospital image network was built. A total of 68 emergency computerized tomography (CT) examinations were transmitted. Transmission time via GSM for a single CT image was 1 min and for a complete head scan was 18 min. The transmitted images were acceptable for final diagnosis in 72% of the cases, the rest being acceptable for preliminary diagnosis. The diagnosis from the transmitted images did not change after a later review of the original images in 97% of cases. The wireless link saved a hospital visit by the senior radiologist in 24% of cases. The results show that a remote consultation link can be built with readily available technology and that the technique is useful in radiological subspecialist consultations for CT images.

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We present four patients with uncommon encapsulated intracerebral haematomas (ICH). Because of ring enhancement, three were incorrectly diagnosed as gliomas and operated upon. In one case the diagnosis of chronic ICH was made on MRI. MRI can be used to demonstrate that a lesion is only a haematoma and is valuable in follow-up and in differentiating these haematomas from neoplasms. Angiography may reveal a vascular malformation which may be the reason for repeated bleeding, which may lead to encapsulation. The mechanism, however, remains unclear in most cases.

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A teleradiology link based on standard personal computers and a flat-bed CCD scanner was tested. A 64 kbit/s dial-up digital ISDN telephone line was used for transmission. A total of 254 films (174 uncompressed, 80 compressed) were sent. Ninety-six per cent of the uncompressed images and 98% of the compressed images were considered technically acceptable. The total diagnostic agreement between the acceptable transmitted images and the original films was 98%. Image quality was sufficient for diagnosis in CT and conventional chest and bone radiographs. However, a 256-step gray scale of the scanner was not sufficient for demanding situations, such as overexposed images with a high contrast gradient. The average speed of transmission was 60 kbit/s, which was considered adequate. The tested system suggests that a teleradiology link based on standard personal computers and programs works in situations where instant consultation is needed. However, the image digitization time with the prototype system was quite long, and a better user interface is under development.

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The dust concentrations of different work phases in iron foundries of different sizes were studied. The results of the total dust measurements made during the Finnish Foundry Project were considered according to the eight main work phases, and the 51 iron foundries were divided into four groups according to the number of foundry workers. The division between the groups at 25, 50, and 100 workers is related to the degree of mechanization in Finnish foundries. The total dust concentration clearly increased in sand making and melting as the size of the foundry increased. The concentration decreased in molding, coremaking, knock-out, and cleaning as the number of workers increased. No significant differences between the foundry groups could be found during casting. The factors affecting the differences in dust concentrations are discussed.

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Dust measurements were made in 51 iron, 9 steel, and 8 nonferrous foundries, at which 4,316 foundrymen were working. The sampling lasted at least two entire shifts or work days continuously during various operations in each foundry. The dust samples were collected at fixed sites or in the breathing zones of the workers. The mass concentration was determined by weighing and the respirable dust fraction was separated by liquid sedimentation. The free silica content was determined by X-ray diffraction. In the study a total of 3,188 samples were collected in the foundries and 6,505 determinations were made in the laboratory. The results indicated a definite difference in the dust exposure during various operations. The highest dust exposures were found during furnace, cupola, and pouring ladle repair. During cleaning work, sand mixing, and shake-out operations excessive silica dust concentrations were also measured. The lowest dust concentrations were measured during melting and pouring operations. Moderate dust concentrations were measured during coremaking and molding operations. The results obtained during the same operations of iron and steel foundries were similar. The distribution of the workers into various exposure categories, the content of respirable dust and quartz, the correlation between respirable dust and total dust, and the correlation between respirable silica and total dust concentrations are discussed. Observations concerning dust suppression and control methods are briefly considered.

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