PDA–Phone-Based Instant Transmission of Radiological Images over a CDMA Network by Combining the PACS Screen with a Bluetooth-Interfaced Local Wireless Link

Remote teleconsultation by specialists is important for timely, correct, and specialized emergency surgical and medical decision making. In this paper, we designed a new personal digital assistant (PDA)–phone-based emergency teleradiology system by combining cellular communication with Bluetooth-interfaced local wireless links. The mobility and portability resulting from the use of PDAs and wireless communication can provide a more effective means of emergency teleconsultation without requiring the user to be limited to a fixed location. Moreover, it enables synchronized radiological image sharing between the attending physician in the emergency room and the remote specialist on picture archiving and communication system terminals without distorted image acquisition. To enable rapid and fine-quality radiological image transmission over a cellular network in a secure manner, progressive compression and security mechanisms have been incorporated. The proposed system is tested over a code division Multiple Access 1×-Evolution Data-Only network to evaluate the performance and to demonstrate the feasibility of this system in a real-world setting.     

High-resolution digital teleradiology: A perspective

Teleradiology has come a long way, from analog transmission systems using slow-scan television over standard telephone lines, to present-day, commercially available, microcomputer-based, low-resolution teleradiology systems. However, there exists a need to address the high-resolution end of the medical imaging categories, namely chest radiographs and mammograms, to firmly establish teleradiology. The availability of high-resolution image digitizers, display units, and digital hard copiers has made high-resolution digital teleradiology a feasible concept. Although the use of satellite channels can speed up the transmission of radiographic image data, with widespread acceptance of high-resolution teleradiology systems in the foreseeable future, the sheer amount of data involved in this field will give rise to problems of data transmission and storage. Data compression schemes can bring down the amount of data handled and can have a great economic impact on future teleradiology systems. We have developed a number of compression techniques for reversible compression of medical images. Our experiments have shown that lossless compression of the order of 4:1 is possible for a class of high-resolution medical images. Use of pattern recognition techniques offers the potential to bring down these data rates even further. We plan to use these techniques in a prototype high-resolution teleradiology system being developed. In this paper, we trace some of the developments in teleradiology and image data compression, and present a perspective for teleradiology in the 1990s.     

Design of a high-speed,high-resolution teleradiology network

A teleradiology system acquires radiographic images from one location and transmits them to one or more distant sites where they are displayed and/or converted to hard-copy film recordings. The long-term goal of teleradiology research is to show that teleradiology systems can provide diagnostically equivalent results when compared with conventional radiographic film interpretation. If this hypothesis is proven, provision of the following radiology services will be improved: (1) providing for primary interpretation of radiological images for patients in underserved areas as well as in other medical facilities; (2) integration of radiological services for multihospital/clinic health care provider consortiums; (3) improving emergency service and intensive care unit coverage; (4) offering consulting-at-a-distance with subspecialty radiologists; and (5) providing radiologists in the community or in rural areas with immediate access to large academic centers for help in the interpretation of difficult and problematic cases. We are designing a high-speed, high-resolution teleradiology network that will communicate between our level 3 medical center and several outlying medical centers within the metropolitan area. Computed tomography (CT), magnetic resonance (MR), and screen-film examinations will be digitized to 2,000 x 2,000 or 4,000 x 4,000 pixels at the remote sites, transmitted to the central referral facility, and sent to a laser film printer, replicating the original film. This film may then be used for primary diagnosis, overreading/consultative purposes, or for emergency department preparation. Inherently digital modality data (eg, MR and CT) can be sent without digitization of the multiformat film if desired.     

The iPad Tablet Computer for Mobile On-Call Radiology Diagnosis? Auditing Discrepancy in CT and MRI Reporting

Tablet computers such as the iPad, which have a large format, improved graphic display resolution and a touch screen interface, may have an advantage compared to existing mobile devices such as smartphones and laptops for viewing radiological images. We assessed their potential for emergency radiology teleconsultation by reviewing multi-image CT and MRI studies on iPad tablet computers compared to Picture Archival and Communication Systems (PACS) workstations. Annonymised DICOM images of 79 CT and nine MRI studies comprising a range of common on-call conditions, reported on full-featured diagnostic PACS workstation by one Reporting Radiologist, were transferred from PACS to three iPad tablet computers running OsiriX HD v 2.02 DICOM software and viewed independently by three reviewing radiologists. Structured documentation was made of major findings (primary diagnosis or other clinically important findings), minor findings (incidental findings), and user feedback. Two hundred and sixty four readings (88 studies read by three reviewing radiologists) were compared, with 3.4 % (nine of 264) major discrepancies and 5.6 % (15 of 264) minor discrepancies. All reviewing radiologists reported favorable user experience but noted issues with software stability and limitations of image manipulation tools. Our results suggest that emergency conditions commonly encountered on CT and MRI can be diagnosed using tablet computers with good agreement with dedicated PACS workstations. Shortcomings in software and application design should be addressed if the potential of tablet computers for mobile teleradiology is to be fully realized.     

Telepathology by the Internet

A new concept for telemicroscopy has recently been introduced using the Internet and conventional web browser, with Java support for microscope remote control as well as image transfer and discussion (http://amba.charite.de/telemic/). The system has two major components: the telemicroscopy server, which is a computer with Internet access connected to the automatic microscope, and the telemicroscopy client, who remotely operates the microscope. This simplified telemicroscopy system allows any Internet user to become a consultant for telepathology without the acquisition of specialized hardware or software. For the inquirer seeking advice, however, this solution is still very expensive, since it requires a fully automated microscope. The present study describes a system that can be used for conventional microscopes. A video camera mounted on a microscope with a photo tube is connected to the frame grabber of a PC. Java-based telemicroscopy software transforms the computer into an Internet server, which automatically distributes new microscope images, after manual operations, to all connected clients. Any Internet user can access the web page of the server to become a telemicroscopy client. A Chat function allows for the online exchange of written text and a Discuss function enables the mouse button to display an arrow to all connected clients, which highlights distinct structures of the images. The system was optimized for simplicity, while presenting all features that are necessary to show and discuss difficult cases with any expert in the field who has Internet access. It offers new perspectives for telepathology and it is envisaged that many pathologists and scientists will use this facility to connect their personal microscopes to the Internet, forming a network for teleconsultation. To foster this development, the software described in this paper is being made freely available. Hopefully, this development will promote communication between pathologists and may thus increase the quality of diagnosis. Information on inquiry and installation of the software is available at the website mentioned above. Telemicroscopy sessions using the Telemic version for conventional microscopes can be scheduled by contacting the authors by e-mail (iver. petersen@charite.de).     

放疗网络与信息系统

目的:探讨目前我国放疗网络与信息系统应用的现状以及发展方向。方法:放疗网络由硬件和软件以及传输协议组成。网络硬件包括服务器、工作站、路由器和交换机、外围网络设备。网络软件包括服务器软件、客户端软件、杀毒软件以及操作系统更新。传输协议包括TCP/IP协议、DICOM协议、HL7协议等。信息系统的构成要素又包括用户,流程,新技术应用,系统管理。结果:目前我国各地医院对于放疗网络和信息系统的应用相比国际水平还有相当的差距。结论:放疗网络与信息系统作为放疗科工作开展的载体,在整个放疗科的诊疗活动中起着非常关键的作用,我国的放疗网络和信息系统的应用将更上一层楼。     

General Consumer Communication Tools for Improved Image Management and Communication in Medicine

We elected to explore new technologies emerging on the general consumer market that can improve and facilitate image and data communication in medical and clinical environment. These new technologies developed for communication and storage of data can improve the user convenience and facilitate the communication and transport of images and related data beyond the usual limits and restrictions of a traditional picture archiving and communication systems (PACS) network. We specifically tested and implemented three new technologies provided on Apple computer platforms. (1) We adopted the iPod, a MP3 portable player with a hard disk storage, to easily and quickly move large number of DICOM images. (2) We adopted iChat, a videoconference and instant-messaging software, to transmit DICOM images in real time to a distant computer for conferencing teleradiology. (3) Finally, we developed a direct secure interface to use the iDisk service, a file-sharing service based on the WebDAV technology, to send and share DICOM files between distant computers. These three technologies were integrated in a new open-source image navigation and display software called OsiriX allowing for manipulation and communication of multimodality and multidimensional DICOM image data sets. This software is freely available as an open-source project at . Our experience showed that the implementation of these technologies allowed us to significantly enhance the existing PACS with valuable new features without any additional investment or the need for complex extensions of our infrastructure. The added features such as teleradiology, secure and convenient image and data communication, and the use of external data storage services open the gate to a much broader extension of our imaging infrastructure to the outside world.     

ANTHEPROT: an integrated protein sequence analysis software with client/server capabilities

Programs devoted to the analysis of protein sequences exist either as stand-alone programs or as Web servers. However, stand-alone programs can hardly accommodate for the analysis that involves comparisons on databanks, which require regular updates. Moreover, Web servers cannot be as efficient as stand-alone programs when dealing with real-time graphic display. We describe here a stand-alone software program called ANTHEPROT, which is intended to perform protein sequence analysis with a high integration level and clients/server capabilities. It is an interactive program with a graphical user interface that allows handling of protein sequence and data in a very interactive and convenient manner. It provides many methods and tools, which are integrated into a graphical user interface. ANTHEPROT is available for Windows-based systems. It is able to connect to a Web server in order to perform large-scale sequence comparison on up-to-date databanks. ANTHEPROT is freely available to academic users and may be downloaded at http://pbil.ibcp.fr/ANTHEPROT.     

Technical considerations in planning a distributed teleradiology system.

A large-scale teleradiology project is under way to link a Florida imaging center to the UCLA Department of Radiology. The initial goal is to provide Florida patients in a routine clinical practice environment with subspecialty consultation by academic radiologists. The plan then calls for the addition of other domestic and international sites. Technical issues in planning to establish the necessary teleradiology infrastructure include wide area network design, image compression, distributed archiving, and special viewing station features. Special emphasis is placed on archive design that makes intelligent use of information, such as triggering events from the radiological information system (RIS) for image prefetching and visual cues from photo-icons for full-size image retrieval. Concepts such as teleconsultation and remote procedure monitoring are aimed at providing the same level of services at distant sites that would be available in-house. This article highlights the system design parameters that must be considered to engineer a scalable distributed teleradiology system.     

The comparative impact of video-consultation on neurosurgical health services

This study evaluated the impact of telemedicine technology on the provision of neurosurgical health services. We focused on the differences between the use of real time audio-visual teleconferencing and teleradiology versus conventional telephone consultations in the referral of neurosurgical patients from a large district general hospital. All patients requiring emergency neurosurgical consultation were included for randomization into telephone consultation only (Mode A), teleradiology and telephone consultation (Mode B) and video-consultation (Mode C). Measures of effectiveness included diagnostic accuracy and adverse events during the transfer and Glasgow Outcome Score. In a 10-month period, 327 patients were recruited and randomized into the study: the male/female ratio was 2:1 and the number of patients required to be transferred to the neurosurgical unit was 125 (38%). There was a trend towards a more favourable outcome in the video-consultation mode (44%, Mode C), versus teleradiology (31%, Mode B), versus telephone consultation (38%, Mode A). The interim data of this prospective randomized trial suggests that video-consultation may have a favourable impact on emergency neurosurgical consultations.     

Improvement and automation of artificial neural networks to estimate medical outcomes

The lengthy process of manually optimizing a feedforward backpropagation artificial neural network (ANN) provided the incentive to develop an automated system that could fine-tune the network parameters without user supervision. A new stopping criterion was introduced--the logarithmic-sensitivity index--that manages a good balance between sensitivity and specificity of the output classification. The automated network automatically monitored the classification performance to determine when was the best time to stop training-after no improvement in the performance measure (either highest correct classification rate, lowest mean squared error or highest log-sensitivity index value) occurred in the subsequent 500 epochs. Experiments were performed on three medical databases: an adult intensive care unit, a neonatal intensive care unit and a coronary surgery patient database. The optimal network parameter settings found by the automated system were similar to those found manually. The results showed that the automated networks performed equally well or better than the manually optimized ANNs, and the best classification performance was achieved using the log-sensitivity index as a stopping criterion.     

Quality assurance of picture archiving communication systems with laser film digitizers

A comprehensive quality assurance (QA) program should be implemented for all teleradiology and picture archival and communications (PACS) systems. In this report, we summarize our QA experience with a teleradiology system that includes a laser digitizer for x-ray film. A key component required for the evaluation of laser film scanners is an appropriate test pattern; digitizers should be evaluated with enhanced test patterns specifically designed for this purpose. The phantom pattern should measure high-contrast resolution, low-contrast discrimination, gray scale linearity, geometric distortion, and noise. In addition, a uniformly exposed sheet of film (approximately 0.3 optical density) serves as a good phantom for testing screen nonuniformities of viewing station monitors. It is also suggested that clinical images should be included in a QA program. Finally, it is recommended that any discrepancies in the interpretation of teleradiology images should be monitored and investigated.     

Teleradiology for remote diagnosis: A prospective multi-year evaluation

Teleradiology has been used for nearly 3 years at our institution to provide urgent radiologic interpretations for two outpatient clinics and an affiliated hospital. The purpose of this study was to evaluate the clinical reliability of the existing system. Teleradiology images were interpreted using 1600×1200 pixel display stations. The original films from the same cases were subsequently interpreted, usually by another radiologist. The initial and final interpretations were compared. Discrepancies were rated and adjudicated by another senior radiologist. These data were compared to peer review interobserver discrepancy rates. Among the 2688 teleradiology examinations evaluated, there were major discrepancies in 31 (1.15%). In three instances teleradiology rather than film interpretation was considered correct. Abnormalities missed on teleradiology were apparent in all but two at adjudication. Among the 628 peer-review cases, there were 6 (0.96%) major discrepancies. Major teleradiology diology discrepancy rates are statistically similar to film-based peer review discrepancy rates. Teleradiology is suitable for providing radiologic services to remote medical facilities.     

Network latency and operator performance in teleradiology applications

Teleradiology applications often use an interactive conferencing mode with remote control mouse pointers. When a telephone is used for voice communication, latencies of the data network can create a temporal discrepancy between the position of the mouse pointer and the verbal communication. To assess the effects of this dissociation, we examined the performance of 5 test persons carrying out simple teleradiology tasks under varying simulated network conditions. When the network latency exceeded 400 milliseconds, the performance of the test persons dropped, and an increasing number of errors were made. This effect was the same for constant latencies, which can occur on the network path, and for variable delays caused by the Nagle algorithm, an internal buffering scheme used by the TCP/IP protocol. Because the Nagle algorithm used in typical TCP/IP implementations causes a latency of about 300 milliseconds even before a data packet is sent, any additional latency in the network of 100 milliseconds or more will result in a decreased operator performance in teleradiology applications. These conditions frequently occur on the public Internet or on overseas connections. For optimal performance, the authors recommend bypassing the Nagle algorithm in teleradiology applications.     

Methods for automated concept mapping between medical databases

The retrieval and exchange of information between medical databases is often impeded by the semantic heterogeneity of concepts contained within the databases. Manual identification of equivalent database elements consumes time and resources, and may often be the rate-limiting technological step in integrating disparate data sources. By employing semantic networks as an intermediary representation of the native databases, automated mapping algorithms can identify equivalent concepts in disparate databases. The algorithms take advantage of the conceptual "context" embodied within a semantic network to produce candidate concept mappings. The performance of automated concept mapping was evaluated by creating semantic network representations for two test laboratory databases. The mapping algorithms identified all equivalent concepts that were present in the databases, and did not leave any equivalent concepts unmapped. The utilization of conceptual context to perform automated concept mapping facilitates the identification of equivalent database concepts and may help decrease the work and costs associated with retrieval and integration of information from disparate databases.     

An object-oriented design for automated navigation of semantic networks inside a medical data dictionary

In this paper we present a data dictionary server for the automated navigation of information sources. The underlying knowledge is represented within a medical data dictionary. The mapping between medical terms and information sources is based on a semantic network. The key aspect of implementing the dictionary server is how to represent the semantic network in a way that is easier to navigate and to operate, i.e. how to abstract the semantic network and to represent it in memory for various operations. This paper describes an object-oriented design based on Java that represents the semantic network in terms of a group of objects. A node and its relationships to its neighbors are encapsulated in one object. Based on such a representation model, several operations have been implemented. They comprise the extraction of parts of the semantic network which can be reached from a given node as well as finding all paths between a start node and a predefined destination node. This solution is independent of any given layout of the semantic structure. Therefore the module, called Giessen Data Dictionary Server can act independent of a specific clinical information system. The dictionary server will be used to present clinical information, e.g. treatment guidelines or drug information sources to the clinician in an appropriate working context. The server is invoked from clinical documentation applications which contain an infobutton. Automated navigation will guide the user to all the information relevant to her/his topic, which is currently available inside our closed clinical network.     

User Interface of a Teleradiology System for the MR Assessment of Multiple Sclerosis

The aim of this study was to assess the image display of a web-based teleradiology system that uses a common web browser and has no need of proprietary applets, plug-ins, or dedicated software for DICOM display. The teleradiology system (TS) is connected to the Internet by ADSL and to radiological modalities using the DICOM standard with TCP/IP. Images were displayed on a PC through Internet connection with the remote TS using a common web browser. MS lesion number and volume in T1- and T2-weighted images (T1w and T2w, respectively) of 30 brain MR studies were quantified using both the TS and a conventional software. Wilcoxon signed ranks test and intraclass correlation coefficient (ICC) were used to assess the variability and concordance between intra- and inter-observer and TS and conventional DICOM viewer, setting significance at p < 0.05. No significant differences in T1w and T2w volumes between the TS and the conventional software were found by either operator. The ICC results showed a high level of inter-operator agreement in volume estimation in T1w and T2w images using the two systems. Quantitative assessment of MS lesion volumes in T1w and T2w images with a user interface of a teleradiology system that allows the consultation by means of a common web browser, without the need for proprietary plug-ins, applets, or dedicated software for DICOM display showed no significant differences from, and almost complete agreement with, conventional DICOM viewers.     

Automated detection of a prostate Ni-Ti stent in electronic portal images

Planning target volumes (PTV) in fractionated radiotherapy still have to be outlined with wide margins to the clinical target volume due to uncertainties arising from daily shift of the prostate position. A recently proposed new method of visualization of the prostate is based on insertion of a thermo-expandable Ni-Ti stent. The current study proposes a new detection algorithm for automated detection of the Ni-Ti stent in electronic portal images. The algorithm is based on the Ni-Ti stent having a cylindrical shape with a fixed diameter, which was used as the basis for an automated detection algorithm. The automated method uses enhancement of lines combined with a grayscale morphology operation that looks for enhanced pixels separated with a distance similar to the diameter of the stent. The images in this study are all from prostate cancer patients treated with radiotherapy in a previous study. Images of a stent inserted in a humanoid phantom demonstrated a localization accuracy of 0.4-0.7 mm which equals the pixel size in the image. The automated detection of the stent was compared to manual detection in 71 pairs of orthogonal images taken in nine patients. The algorithm was successful in 67 of 71 pairs of images. The method is fast, has a high success rate, good accuracy, and has a potential for unsupervised localization of the prostate before radiotherapy, which would enable automated repositioning before treatment and allow for the use of very tight PTV margins.     

Health care providers' perceptions of telemedicine services.

OBJECTIVE: To assess the level of consensus among the administrative and health care leaders at rural Iowa hospitals regarding service gaps and priorities for developing telemedicine services. METHODS: In the summer of 1994, a survey was conducted of all rural hospital chief executive officers, chiefs of medical staffs, and directors of nursing in Iowa concerning their perceptions of telemedicine services. RESULTS: With the exception of teleradiology, few clinical specialties received high ratings as areas of need or priorities for the development of telemedicine. There was a general lack of agreement among respondents from the same hospital on such priorities. In contrast, respondents expressed higher priorities for the development of telemedicine-based educational services. CONCLUSIONS: The interest in teleradiology is consistent with the fact that teleradiology has been more thoroughly tested for medical efficacy than other telemedicine applications. Continuing medical education may represent another potential for widespread successful telemedicine application. Financial issues were reported as the greatest barriers to the development of telemedicine systems.     

Evaluation of teleradiology for interpretation of intravenous urograms

The diagnostic yield of a commercial teleradiology/picture archiving and communication system (ATT-Philips Comm View T/PACS) was evaluated for 100 urograms. A single image from each examination was digitized (2048 x 1684 x 12-bit pixels) and transmitted from a satellite hospital over a T-1 line using the T/PACS system. The video display of each digitized image was reviewed independently by four radiologists. The same four radiologists reviewed the original film images at a different time without knowledge of their T/PACS interpretation. There was no statistically significant difference in the sensitivity for clinical findings between T/PACS (86%) and film (89%). The false positive rate, however, was significantly higher with T/PACS than with film (44 versus 32 false positive findings per 100 films). We conclude that T/PACS of the type studied here demonstrates sufficient sensitivity for the detection of clinically important urographic findings in the emergency setting. A final reading of the original films is still necessary, however, to assure appropriate specificity.