Teleradiology in Europe
Content
European Journal of Radiology 33 (2000) 2 – 7
www.elsevier.nl/locate/ejrad
Teleradiology in Europe
Davide Caramella a,*, Jarmo Reponen b, Fabrizio Fabbrini c, Carlo Bartolozzi a
a
Department of Radiology, Diagnostic and Inter6entional Radiology, Uni6ersity of Pisa, Via Roma 67, 56100 Pisa, Italy
b
Department of Radiology, Uni6ersity of Oulu, Oulu, Finland
c
Istituto di Elaborazione dell’Informazione, CNR, Pisa, Italy
Received 21 July 1999; accepted 22 July 1999
Abstract
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. © 2000 Elsevier Science Ireland Ltd. All rights reserved.
Keywords: Teleradiology; Images transmission; Internet; Computers multimedia
1. Introduction
Teleradiology is evolving from the present capability
of moving images from one place to the other to the
capability of managing medical information within an
integrated environment stretching from the hospital
towards affiliated institutions and medical partners distributed in large geographical areas [1,2].
The consolidation of many health institutions is an
ongoing process in most European countries. This is
mainly due to the need to reduce costs by making more
efficient use of human as well as technological
resources.
Also the approach to PACS implementation has been
influenced by this process: it is now well understood by
the industry and the users alike that PACS can not be
modeled after the paradigm of office automation. The
aim of replacing the traditional film-based system by
deploying technologically advanced equipment for the
display, archiving, and transmission of diagnostic im-
* Corresponding author. Tel.: +39-050-992509; fax: + 39-050551461.
E-mail address: [email protected] (D. Caramella)
ages is no longer sufficient.
The new concept is centered on the consideration
that PACS and teleradiology must contribute to the
seamless integration of the digital environment in which
information is managed throughout and beyond the
hospital, and have to be able to generate value added
services for the patients as well as prospective economical benefits for the institution [3].
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 have to ensure that the digital management of data does not endanger the confidentiality
and the integrity of patients’ data, and that the radiological workplace remains ergonomically (and not only
economically) appropriate [4,5].
The way radiologists will be able to cope with these
issues will be crucial for the future development of
teleradiology applications.
0720-048X/99/$ - see front matter © 2000 Elsevier Science Ireland Ltd. All rights reserved.
PII: S 0 7 2 0 - 0 4 8 X ( 9 9 ) 0 0 1 0 4 - 7
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
2. Clinical applications
2.1. Primary interpretation
Teleradiology for primary diagnosis aims at providing the remote interpretation of imaging examinations
that can not be appropriately interpreted in the location
where the images are acquired [6]. This may due to the
absence of a radiologist on site or to the recognition
that the local radiologists may lack of specific expertise
(for instance in interpreting neuroradiological cases) [7].
In such circumstances, the images together with additional clinical information are transmitted to and
viewed by a remote radiologist who takes full legal
responsibility for the diagnostic report. For its distinctive features this teleradiology application requires
maximum reliability and optimal image quality [8].
Typical examples of teleradiology for primary interpretation include military applications, rural teleradiology, on-call situations, vacation coverage, etc [9,10].
2.2. Intrainstitutional teleradiology
Image communication among remote units of the
same hospital or between a leading institution and its
affiliated hospitals allows to create the functional integration of radiological services. This type of intrainstitutional teleradiology is aimed at building what has
also been termed a ‘regional PACS’ [11,12].
At the Pisa University Hospital since 1992 intrainstitutional teleradiology is operational and allows the
transmission of data and images between two radiological units that are about 5 km apart [13]. In each of the
two units an Ethernet local area network (LAN) for the
acquisition and local management of diagnostic images
was implemented. The two LANs have been connected
since June 1992 by means of a 64 Kbit/s link. But only
starting with September 1994 intrainstitutional teleradiology was routinely used when the interconnection was
provided by a broadband metropolitan area network
(MAN) compliant with the IEEE 802.6 standard. In
fact this type of teleradiology application requires the
availability of high-speed telecommunication links, in
order to reduce the waiting time for an image to appear
on the screen within the limits that are considered
‘tolerable’ in clinical routine [11,14]. In practice there
should not be a perceivable difference between the time
required to retrieve images that are stored on local and
on remote archives.
2.3. Teleconsultation with subspecialists
Remote subspecialty consultation enables the access
to the ‘second opinion’ of a distantly located radiologist
[6]. In this teleradiology application the consulted radiologist acts as an advisor to the requesting radiologist
3
who in turn has to decide whether or not to accept the
opinion of the colleague, therefore keeping the final
responsibility of the diagnosis. This special relationship
has been compared, from a legal point of view, to the
one existing in the UK between solicitor (in many
aspects similar to the radiologist requesting advice) and
barrister (corresponding to the consulted radiologist).
The latter will bear responsibility for the advice given,
although the responsibility does not pass from the
former even when the advice has been taken and acted
upon [15].
The service of subspecialty consultation is presently
the object of commercial offerings through high-performance links or via the Internet. These consultation
services are aimed at providing second opinions, image
over-reading for radiologists getting started in a new
imaging technique, recommendations for improving
exam quality, and quality control of image
interpretation.
2.4. Training and education
Teleradiology can also be used for educational purposes since it allows students to take advantage of
distant teachers, with minimal logistical disadvantages.
When a ‘live’ lecture is replaced by the access to
interactive textbooks and image databases, the ability
of the user to customize his or her training is significantly enhanced.
Internet is ideally suited for these educational applications, due to the user-friendliness, platform independence, ease of support and the large existent user base
[1]. Moreover, the reference material can be constantly
updated after publication. There are a few initiatives
however, that assure the scientific and educational quality of radiological material published on the Internet.
Among these, the EURORAD Project created a radiological database to be used in the domains of routine
practice, training and research that can be accessed at
the address: www.eurorad.org [16].
EURORAD is based on a collection of multimedia
case records. Each anonymous case record contains
radiological images and a text file for case comment
with keywords and codes. The European Association of
Radiology coordinates the EURORAD Project and
intends to build a strategic tool for the world-wide
recognition of European radiology scientific achievements. Compliance with established academic quality
assurance standards will be fulfilled since each submitted case report will be anonymously peer-reviewed as to
guarantee the relevance and quality of the material
included in the database. The reviewing process follows
a three levels system with one Editor-in-Chief and
several section editors and reviewers covering 14 subspecialties. All exchanges between authors and section
editors and between the three categories of reviewers
are done on Internet [16].
4
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
Another particular application of teleradiology is the
remote processing of diagnostic images. In fact the
images to be processed are sent to centers were the
processing is actually performed and from were the
outcome is sent back for clinical evaluation. An example is provided by the EU funded project NOVICE that
provides extensible Web-based visualization tools for
medical applications that works within a high-performance computing environment (http://www.man.ac.uk/
MVC/research/NOVICE/). Access to such environment
is provided through a simple user interface, which can
be supported on affordable desktop, such that the need
for high-end graphics workstations is removed. This
will reduce costs dramatically and make advanced medical image processing available without the large capital
investment currently required. A primary charter of
NOVICE is to help the European hospitals to advance
the state-of-the-art in medical care, by providing remote processing services to European hospitals.
3. Mobile teleradiology
A new field of teleradiology applications is currently
being experimented in Finland, where mobile telephone
technology has been used in parallel to terrestrial lines
[17,18]. In 1993 at the Oulu University Hospital a
laptop computer was connected to a Nokia DC 560
portable NMT-450 (Nordic Mobile Telephone) cellular
system car phone with a modem adapter. This system
was connected to an image server at the University
Hospital, where digitized and JPEG compressed CT
images were available. The transfer speed was as slow
as 2400 bit/s and the system weighed over 9 kg. The
laptop computer used as a remote terminal could only
show 16 grey levels on the screen. Despite its limitations, the system could be used for image reception all
over Scandinavia and showed the potentialities of mobile teleradiology.
Since 1994 a smaller NMT-900 standard handheld
cellular phone and a compatible NMT PCMCIA data
card were tested. A more advanced laptop computer
was capable of showing 256 colors. Packed in a suitcase, this system weighed less than 5 kg, and could
serve as a portable terminal. The limitations were short
operation time and slow effective speed due to transmission errors in the analogue transmission.
After the development of GSM digital networks the
problems in establishing a secure and stable transmission have largely been solved. This new technology
enabled a clinical trial. A neuroradiologist was supplied
with a portable terminal which was capable of receiving
and viewing images. The terminal consisted of a notebook computer whose display had 640× 480 pixel resolution and 256 colors. The notebook computer was
equipped with a PCMCIA digital cellular data card,
that was used to interface the computer to a GSM
telephone. The data transmission rate was 9600 bit/s.
The CT images were captured from the screen of a
workstation using a public domain software. To reduce
the bandwidth required for transmission, the images
were compressed with a JPEG algorithm and stored in
8 bit/pixel grayscale format. The images were than
automatically transferred in patient folders to the
server. The consultant then accessed the images from
the server.
In the trial, two series of scans were examined: in the
first series, a neuroradiologist interpreted the CT scans
during normal working hours on a portable computer,
later the same neuroradiologist reviewed the images on
film. In the second series, the images were sent by a
junior radiologist for a neuroradiologist consultation
after normal working hours. Three senior neuroradiologist gave their advice in turn. These results were also
compared to the film interpretation the next morning.
In the re-evaluation, the images of all patients were
viewed in the manner used by the radiologists to interpret CT images in daily work. A written report was
made both for transmitted a comparison images.
A total of 68 emergency CT examinations were transmitted. Transmission time via GSM for a single CT
image was one minute and for a complete head scan 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 later review of the
original images in 97% of the cases. The wireless link
saved the senior radiologist a hospital visit in 24% of
the cases. The results showed that the remote consultation link can be built with readily available technology
and that the technique is useful in radiological subspecialist consultations of CT images.
4. Security issues
The transmission of radiological data over open networks inherently put at risk the confidentiality and the
integrity of alphanumeric data and images sent during a
teleradiology session.
Therefore, well defined policies need to be established
to reduce the risk that information exchanged during a
teleradiology session might be used for purposes that
may harm (physically, emotionally or economically) the
patient [19]. As a result, data protection measures are
to be taken to safeguard the confidentiality as well as
the completeness, accuracy and correctness of
information.
Interconnectivity of imaging equipments, archives
and information systems, although desirable from a
clinical and managerial point of view, adds new complexity to data protection initiatives. In fact, the in-
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
creased use of teleradiology could expose sensitive data
to a variety of threats that will have to be appropriately
addressed.
Although security threats may have different aspects,
any attempt at breaking the security of an information
system can be considered to meet one of the following
objectives:
4.1. To obtain information
Stealing information from a computer is conceptually
similar to stealing information from an office (where
the thief sneaks in, breaks a safe open and copies
sensitive documents). However, larger data volumes can
be easily obtained with the use of computers, faster
copying is possible and there is less likelihood of finding
out the offender.
4.2. To depri6e others of the use of the system
A legitimate user may be deprived of the total or
partial use of the system in different ways, for instance
by introducing programs able to reduce the system
performance. The most common example is that of
6iruses, that are programs designed to replicate themselves and to ‘infect’ other programs in a computer or
network.
4.3. To alter information
This kind of security incident, leading to a loss of
accuracy or completeness of information, may concern
local as well as transmitted data, and its origin can be
classified as natural (when the security incident is due
to physical failures of natural origin: e.g. the ageing
process of materials and devices); negligent (when the
security damage is due to unintentional human errors,
like those which may occur during the design and
programming of the information system, or while operating the system); malicious (when the attempts at
altering data are intentional and their objective is sabotage – a willful damage to render a system useless – or
fraud – a criminal deception to obtain unlawful
benefits-).
5. Security management
Teleradiology systems have the contradictory task of
both protecting the transmitted radiological information and of making it accessible by a number of users
[20]. Security management should provide an enabling
mechanism for information sharing, while ensuring the
protection of data and computing assets, rejecting every
access that does not result in accordance with the
established security scheme.
5
A variety of mechanisms exist for protecting electronic information [21]. These include both technical
actions for improving computer and network security
as well as organizational actions for ensuring that all
co-workers understand their responsibility to protect
information and realize that security processes are in
place for detecting and reporting violations.
From a technical point of view, the security elements
needed to meet the desired protection level and to
realize the defined sharing scheme may be implemented
by means of two main tools. The first tool is the
identification of the user, that is any mechanism able to
verify the identity of a user requesting information in a
computing environment. Identification of the user may
be implemented:
(1) by location, that identifies the user on the basis of
where the user is located (e.g. a terminal connected by
hardwired line, a phone number used in a callback
scheme, a network address). To prevent illegal access,
security precautions have often to be taken (such as
surveillance personnel, locked doors, passwords) in order to guarantee the physical security of the terminal as
well as the communication line.
(2) by characteristics, that is based on the identification of something that the user has (a key, a magnetic
card, etc.) or something related to who the user is
(signature, fingerprints, voiceprints, etc.).
(3) by knowledge, that is based on the use of something the user knows (a password, a personal ID number? etc).
The degree of success of all these methods depends,
of course, on users’ willingness not to share the key,
information or characteristic that allows to uniquely
identify them. The classical method for identification in
computing environments is to assign each user a unique
identifier and to associate a secret personal password
with it. Nevertheless, the realization of a protecting
Mechanism based on the use of IDs and passwords
presents many weak points, fundamentally related to
the vulnerability of the handling process (selection,
assignment, conservation).
The second security tool to help secure exchange of
information is encryption, that is coding information
into unintelligible data. Cryptography is a technique
that has been used for centuries, however in the computer era it has reached new levels of complexity and
sophistication [22,23]. The basic encryption process encodes text material, converting it into scrambled data
that must be decoded to be understood. The process is
based on algorithms able to translate the original information into a data stream absolutely incomprehensible
to the person who does not know the decoding
algorithm.
Encryption is used most often for sensitive data that
is transmitted over networks or public communication
systems. When the encrypted material reaches its desti-
6
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
nation, a user with a decryption key can convert it
back to its readable form.
At present, two kinds of cryptography are used:
symmetric (or secret-key) cryptography, a system in
which the same key is used for encryption and decryption, and asymmetric (or public-key) cryptography, a system in which two different keys are used,
one for encryption and one for decryption.
Encryption addresses two completely different security needs. The most obvious is to keep information
secret. An equally important use is to keep data from
being altered [24]. Radiological information, in its alphanumeric and pictorial form, might require both
kinds of protection.
In fact, encryption technologies can be successfully
used to implement an authentication method, provided
that the terminal is able to perform cryptographic
functions using a key supplied by the user.
For ensuring the authenticity of images, also ‘digital watermarking’ techniques can be usefully employed [25,26]. These methods allow to uniquely
identify the image by encoding information as slight
changes to the luminance of the pixels or as changes
in the frequency domain. Since these changes are
known only by the author of the image any altered
version or any illegitimate copy can be easily recognized.
has to be accurate, because additional information is
not as easily available as in a local hospital environment: one has to be prepared for different working
culture in various organizations.
The process of image interpretation within teleradiology is different from the traditional way of film
reading. Teleconsultations are mostly read on screen,
so a radiologist has to be familiar with a computer.
Many of the tasks performed earlier by a secretary
like image fetching and hanging the films are now
performed by the radiologist himself at the workstation. Image processing like zooming and windowing
has now become an inherent part of the work.
In separate teleradiology workstations image interpretation is still two to three times slower than with
films, mostly due to an extra preparation work. If the
teleradiology workstation is connected to a PACS environment, the tasks can be performed in the same
manner as in normal routine. The PACS workstations
nowadays have viewing protocols and preset working
environments to support a more fluent work. If a
radiologist already works daily with a PACS workstation, there is technically no difference if images are
coming from a local archive or form another hospital.
The basic problem still remains: teleradiological consultations are answered without all that comparison
material that is available for local images at the hospital.
6. Organizational issues
7. Conclusions
Teleradiology greatly influences the way radiologists
do their work. The changes are seen at an organizational level and also in how primary image interpretation is performed [27].
A typical teleradiology scenario is the one in which
is a remote site sends images for second opinion. The
straightforward output of this service is the opinion
given by the subspecialist to the requesting physician.
However, the process of giving this information is
rather complex, and involves a requesting physician, a
technician digitizing the images, a radiologist interpreting the images, a secretary typing the report, and
once again the original physician reading the answer.
There are two kinds of supporting work or articulation work to enable this process: articulation work
of cooperation and articulation work of individual
tasks. The first group of supporting work makes
workflow possible by delivering information to the
next performer and the latter group of supporting
work prepares and organizes materials for each task.
In practice, each step has great influence to the quality and to the speed of the service. For instance the
order and quality how a technician at the remote site
digitized images influences the performance of the radiologist. Also the information in the written request
Teleradiology is rapidly evolving: remote consultations may become a reality in the near future for
many radiologists. Since a few years Internet has already been enabling professionals to update their
knowledge by means of on-line publications and image databases.
However, security issues and workflow adjustments
still have to be fully analyzed in order to avoid that
the potential advantages for the organization may
bring unacceptable damage to both patients and radiologists. In particular, the protection of electronic information transmitted from a radiological department
requires a combination of technical and organizational practices, whose selection involves trade-offs
among cost, complexity, and degree of privacy provided. Organizational practices are at least as important as technical practices: although technical
mechanisms can be used to validate the identity of
computer users, establish controls on the information
they can access, and encrypt information transmitted
between locations, organizational policies have to establish the objectives of technical measures, determining who is allowed access to information and how
tightly the access will be controlled.
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
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www.elsevier.nl/locate/ejrad
Teleradiology in Europe
Davide Caramella a,*, Jarmo Reponen b, Fabrizio Fabbrini c, Carlo Bartolozzi a
a
Department of Radiology, Diagnostic and Inter6entional Radiology, Uni6ersity of Pisa, Via Roma 67, 56100 Pisa, Italy
b
Department of Radiology, Uni6ersity of Oulu, Oulu, Finland
c
Istituto di Elaborazione dell’Informazione, CNR, Pisa, Italy
Received 21 July 1999; accepted 22 July 1999
Abstract
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. © 2000 Elsevier Science Ireland Ltd. All rights reserved.
Keywords: Teleradiology; Images transmission; Internet; Computers multimedia
1. Introduction
Teleradiology is evolving from the present capability
of moving images from one place to the other to the
capability of managing medical information within an
integrated environment stretching from the hospital
towards affiliated institutions and medical partners distributed in large geographical areas [1,2].
The consolidation of many health institutions is an
ongoing process in most European countries. This is
mainly due to the need to reduce costs by making more
efficient use of human as well as technological
resources.
Also the approach to PACS implementation has been
influenced by this process: it is now well understood by
the industry and the users alike that PACS can not be
modeled after the paradigm of office automation. The
aim of replacing the traditional film-based system by
deploying technologically advanced equipment for the
display, archiving, and transmission of diagnostic im-
* Corresponding author. Tel.: +39-050-992509; fax: + 39-050551461.
E-mail address: [email protected] (D. Caramella)
ages is no longer sufficient.
The new concept is centered on the consideration
that PACS and teleradiology must contribute to the
seamless integration of the digital environment in which
information is managed throughout and beyond the
hospital, and have to be able to generate value added
services for the patients as well as prospective economical benefits for the institution [3].
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 have to ensure that the digital management of data does not endanger the confidentiality
and the integrity of patients’ data, and that the radiological workplace remains ergonomically (and not only
economically) appropriate [4,5].
The way radiologists will be able to cope with these
issues will be crucial for the future development of
teleradiology applications.
0720-048X/99/$ - see front matter © 2000 Elsevier Science Ireland Ltd. All rights reserved.
PII: S 0 7 2 0 - 0 4 8 X ( 9 9 ) 0 0 1 0 4 - 7
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
2. Clinical applications
2.1. Primary interpretation
Teleradiology for primary diagnosis aims at providing the remote interpretation of imaging examinations
that can not be appropriately interpreted in the location
where the images are acquired [6]. This may due to the
absence of a radiologist on site or to the recognition
that the local radiologists may lack of specific expertise
(for instance in interpreting neuroradiological cases) [7].
In such circumstances, the images together with additional clinical information are transmitted to and
viewed by a remote radiologist who takes full legal
responsibility for the diagnostic report. For its distinctive features this teleradiology application requires
maximum reliability and optimal image quality [8].
Typical examples of teleradiology for primary interpretation include military applications, rural teleradiology, on-call situations, vacation coverage, etc [9,10].
2.2. Intrainstitutional teleradiology
Image communication among remote units of the
same hospital or between a leading institution and its
affiliated hospitals allows to create the functional integration of radiological services. This type of intrainstitutional teleradiology is aimed at building what has
also been termed a ‘regional PACS’ [11,12].
At the Pisa University Hospital since 1992 intrainstitutional teleradiology is operational and allows the
transmission of data and images between two radiological units that are about 5 km apart [13]. In each of the
two units an Ethernet local area network (LAN) for the
acquisition and local management of diagnostic images
was implemented. The two LANs have been connected
since June 1992 by means of a 64 Kbit/s link. But only
starting with September 1994 intrainstitutional teleradiology was routinely used when the interconnection was
provided by a broadband metropolitan area network
(MAN) compliant with the IEEE 802.6 standard. In
fact this type of teleradiology application requires the
availability of high-speed telecommunication links, in
order to reduce the waiting time for an image to appear
on the screen within the limits that are considered
‘tolerable’ in clinical routine [11,14]. In practice there
should not be a perceivable difference between the time
required to retrieve images that are stored on local and
on remote archives.
2.3. Teleconsultation with subspecialists
Remote subspecialty consultation enables the access
to the ‘second opinion’ of a distantly located radiologist
[6]. In this teleradiology application the consulted radiologist acts as an advisor to the requesting radiologist
3
who in turn has to decide whether or not to accept the
opinion of the colleague, therefore keeping the final
responsibility of the diagnosis. This special relationship
has been compared, from a legal point of view, to the
one existing in the UK between solicitor (in many
aspects similar to the radiologist requesting advice) and
barrister (corresponding to the consulted radiologist).
The latter will bear responsibility for the advice given,
although the responsibility does not pass from the
former even when the advice has been taken and acted
upon [15].
The service of subspecialty consultation is presently
the object of commercial offerings through high-performance links or via the Internet. These consultation
services are aimed at providing second opinions, image
over-reading for radiologists getting started in a new
imaging technique, recommendations for improving
exam quality, and quality control of image
interpretation.
2.4. Training and education
Teleradiology can also be used for educational purposes since it allows students to take advantage of
distant teachers, with minimal logistical disadvantages.
When a ‘live’ lecture is replaced by the access to
interactive textbooks and image databases, the ability
of the user to customize his or her training is significantly enhanced.
Internet is ideally suited for these educational applications, due to the user-friendliness, platform independence, ease of support and the large existent user base
[1]. Moreover, the reference material can be constantly
updated after publication. There are a few initiatives
however, that assure the scientific and educational quality of radiological material published on the Internet.
Among these, the EURORAD Project created a radiological database to be used in the domains of routine
practice, training and research that can be accessed at
the address: www.eurorad.org [16].
EURORAD is based on a collection of multimedia
case records. Each anonymous case record contains
radiological images and a text file for case comment
with keywords and codes. The European Association of
Radiology coordinates the EURORAD Project and
intends to build a strategic tool for the world-wide
recognition of European radiology scientific achievements. Compliance with established academic quality
assurance standards will be fulfilled since each submitted case report will be anonymously peer-reviewed as to
guarantee the relevance and quality of the material
included in the database. The reviewing process follows
a three levels system with one Editor-in-Chief and
several section editors and reviewers covering 14 subspecialties. All exchanges between authors and section
editors and between the three categories of reviewers
are done on Internet [16].
4
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
Another particular application of teleradiology is the
remote processing of diagnostic images. In fact the
images to be processed are sent to centers were the
processing is actually performed and from were the
outcome is sent back for clinical evaluation. An example is provided by the EU funded project NOVICE that
provides extensible Web-based visualization tools for
medical applications that works within a high-performance computing environment (http://www.man.ac.uk/
MVC/research/NOVICE/). Access to such environment
is provided through a simple user interface, which can
be supported on affordable desktop, such that the need
for high-end graphics workstations is removed. This
will reduce costs dramatically and make advanced medical image processing available without the large capital
investment currently required. A primary charter of
NOVICE is to help the European hospitals to advance
the state-of-the-art in medical care, by providing remote processing services to European hospitals.
3. Mobile teleradiology
A new field of teleradiology applications is currently
being experimented in Finland, where mobile telephone
technology has been used in parallel to terrestrial lines
[17,18]. In 1993 at the Oulu University Hospital a
laptop computer was connected to a Nokia DC 560
portable NMT-450 (Nordic Mobile Telephone) cellular
system car phone with a modem adapter. This system
was connected to an image server at the University
Hospital, where digitized and JPEG compressed CT
images were available. The transfer speed was as slow
as 2400 bit/s and the system weighed over 9 kg. The
laptop computer used as a remote terminal could only
show 16 grey levels on the screen. Despite its limitations, the system could be used for image reception all
over Scandinavia and showed the potentialities of mobile teleradiology.
Since 1994 a smaller NMT-900 standard handheld
cellular phone and a compatible NMT PCMCIA data
card were tested. A more advanced laptop computer
was capable of showing 256 colors. Packed in a suitcase, this system weighed less than 5 kg, and could
serve as a portable terminal. The limitations were short
operation time and slow effective speed due to transmission errors in the analogue transmission.
After the development of GSM digital networks the
problems in establishing a secure and stable transmission have largely been solved. This new technology
enabled a clinical trial. A neuroradiologist was supplied
with a portable terminal which was capable of receiving
and viewing images. The terminal consisted of a notebook computer whose display had 640× 480 pixel resolution and 256 colors. The notebook computer was
equipped with a PCMCIA digital cellular data card,
that was used to interface the computer to a GSM
telephone. The data transmission rate was 9600 bit/s.
The CT images were captured from the screen of a
workstation using a public domain software. To reduce
the bandwidth required for transmission, the images
were compressed with a JPEG algorithm and stored in
8 bit/pixel grayscale format. The images were than
automatically transferred in patient folders to the
server. The consultant then accessed the images from
the server.
In the trial, two series of scans were examined: in the
first series, a neuroradiologist interpreted the CT scans
during normal working hours on a portable computer,
later the same neuroradiologist reviewed the images on
film. In the second series, the images were sent by a
junior radiologist for a neuroradiologist consultation
after normal working hours. Three senior neuroradiologist gave their advice in turn. These results were also
compared to the film interpretation the next morning.
In the re-evaluation, the images of all patients were
viewed in the manner used by the radiologists to interpret CT images in daily work. A written report was
made both for transmitted a comparison images.
A total of 68 emergency CT examinations were transmitted. Transmission time via GSM for a single CT
image was one minute and for a complete head scan 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 later review of the
original images in 97% of the cases. The wireless link
saved the senior radiologist a hospital visit in 24% of
the cases. The results showed that the remote consultation link can be built with readily available technology
and that the technique is useful in radiological subspecialist consultations of CT images.
4. Security issues
The transmission of radiological data over open networks inherently put at risk the confidentiality and the
integrity of alphanumeric data and images sent during a
teleradiology session.
Therefore, well defined policies need to be established
to reduce the risk that information exchanged during a
teleradiology session might be used for purposes that
may harm (physically, emotionally or economically) the
patient [19]. As a result, data protection measures are
to be taken to safeguard the confidentiality as well as
the completeness, accuracy and correctness of
information.
Interconnectivity of imaging equipments, archives
and information systems, although desirable from a
clinical and managerial point of view, adds new complexity to data protection initiatives. In fact, the in-
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
creased use of teleradiology could expose sensitive data
to a variety of threats that will have to be appropriately
addressed.
Although security threats may have different aspects,
any attempt at breaking the security of an information
system can be considered to meet one of the following
objectives:
4.1. To obtain information
Stealing information from a computer is conceptually
similar to stealing information from an office (where
the thief sneaks in, breaks a safe open and copies
sensitive documents). However, larger data volumes can
be easily obtained with the use of computers, faster
copying is possible and there is less likelihood of finding
out the offender.
4.2. To depri6e others of the use of the system
A legitimate user may be deprived of the total or
partial use of the system in different ways, for instance
by introducing programs able to reduce the system
performance. The most common example is that of
6iruses, that are programs designed to replicate themselves and to ‘infect’ other programs in a computer or
network.
4.3. To alter information
This kind of security incident, leading to a loss of
accuracy or completeness of information, may concern
local as well as transmitted data, and its origin can be
classified as natural (when the security incident is due
to physical failures of natural origin: e.g. the ageing
process of materials and devices); negligent (when the
security damage is due to unintentional human errors,
like those which may occur during the design and
programming of the information system, or while operating the system); malicious (when the attempts at
altering data are intentional and their objective is sabotage – a willful damage to render a system useless – or
fraud – a criminal deception to obtain unlawful
benefits-).
5. Security management
Teleradiology systems have the contradictory task of
both protecting the transmitted radiological information and of making it accessible by a number of users
[20]. Security management should provide an enabling
mechanism for information sharing, while ensuring the
protection of data and computing assets, rejecting every
access that does not result in accordance with the
established security scheme.
5
A variety of mechanisms exist for protecting electronic information [21]. These include both technical
actions for improving computer and network security
as well as organizational actions for ensuring that all
co-workers understand their responsibility to protect
information and realize that security processes are in
place for detecting and reporting violations.
From a technical point of view, the security elements
needed to meet the desired protection level and to
realize the defined sharing scheme may be implemented
by means of two main tools. The first tool is the
identification of the user, that is any mechanism able to
verify the identity of a user requesting information in a
computing environment. Identification of the user may
be implemented:
(1) by location, that identifies the user on the basis of
where the user is located (e.g. a terminal connected by
hardwired line, a phone number used in a callback
scheme, a network address). To prevent illegal access,
security precautions have often to be taken (such as
surveillance personnel, locked doors, passwords) in order to guarantee the physical security of the terminal as
well as the communication line.
(2) by characteristics, that is based on the identification of something that the user has (a key, a magnetic
card, etc.) or something related to who the user is
(signature, fingerprints, voiceprints, etc.).
(3) by knowledge, that is based on the use of something the user knows (a password, a personal ID number? etc).
The degree of success of all these methods depends,
of course, on users’ willingness not to share the key,
information or characteristic that allows to uniquely
identify them. The classical method for identification in
computing environments is to assign each user a unique
identifier and to associate a secret personal password
with it. Nevertheless, the realization of a protecting
Mechanism based on the use of IDs and passwords
presents many weak points, fundamentally related to
the vulnerability of the handling process (selection,
assignment, conservation).
The second security tool to help secure exchange of
information is encryption, that is coding information
into unintelligible data. Cryptography is a technique
that has been used for centuries, however in the computer era it has reached new levels of complexity and
sophistication [22,23]. The basic encryption process encodes text material, converting it into scrambled data
that must be decoded to be understood. The process is
based on algorithms able to translate the original information into a data stream absolutely incomprehensible
to the person who does not know the decoding
algorithm.
Encryption is used most often for sensitive data that
is transmitted over networks or public communication
systems. When the encrypted material reaches its desti-
6
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
nation, a user with a decryption key can convert it
back to its readable form.
At present, two kinds of cryptography are used:
symmetric (or secret-key) cryptography, a system in
which the same key is used for encryption and decryption, and asymmetric (or public-key) cryptography, a system in which two different keys are used,
one for encryption and one for decryption.
Encryption addresses two completely different security needs. The most obvious is to keep information
secret. An equally important use is to keep data from
being altered [24]. Radiological information, in its alphanumeric and pictorial form, might require both
kinds of protection.
In fact, encryption technologies can be successfully
used to implement an authentication method, provided
that the terminal is able to perform cryptographic
functions using a key supplied by the user.
For ensuring the authenticity of images, also ‘digital watermarking’ techniques can be usefully employed [25,26]. These methods allow to uniquely
identify the image by encoding information as slight
changes to the luminance of the pixels or as changes
in the frequency domain. Since these changes are
known only by the author of the image any altered
version or any illegitimate copy can be easily recognized.
has to be accurate, because additional information is
not as easily available as in a local hospital environment: one has to be prepared for different working
culture in various organizations.
The process of image interpretation within teleradiology is different from the traditional way of film
reading. Teleconsultations are mostly read on screen,
so a radiologist has to be familiar with a computer.
Many of the tasks performed earlier by a secretary
like image fetching and hanging the films are now
performed by the radiologist himself at the workstation. Image processing like zooming and windowing
has now become an inherent part of the work.
In separate teleradiology workstations image interpretation is still two to three times slower than with
films, mostly due to an extra preparation work. If the
teleradiology workstation is connected to a PACS environment, the tasks can be performed in the same
manner as in normal routine. The PACS workstations
nowadays have viewing protocols and preset working
environments to support a more fluent work. If a
radiologist already works daily with a PACS workstation, there is technically no difference if images are
coming from a local archive or form another hospital.
The basic problem still remains: teleradiological consultations are answered without all that comparison
material that is available for local images at the hospital.
6. Organizational issues
7. Conclusions
Teleradiology greatly influences the way radiologists
do their work. The changes are seen at an organizational level and also in how primary image interpretation is performed [27].
A typical teleradiology scenario is the one in which
is a remote site sends images for second opinion. The
straightforward output of this service is the opinion
given by the subspecialist to the requesting physician.
However, the process of giving this information is
rather complex, and involves a requesting physician, a
technician digitizing the images, a radiologist interpreting the images, a secretary typing the report, and
once again the original physician reading the answer.
There are two kinds of supporting work or articulation work to enable this process: articulation work
of cooperation and articulation work of individual
tasks. The first group of supporting work makes
workflow possible by delivering information to the
next performer and the latter group of supporting
work prepares and organizes materials for each task.
In practice, each step has great influence to the quality and to the speed of the service. For instance the
order and quality how a technician at the remote site
digitized images influences the performance of the radiologist. Also the information in the written request
Teleradiology is rapidly evolving: remote consultations may become a reality in the near future for
many radiologists. Since a few years Internet has already been enabling professionals to update their
knowledge by means of on-line publications and image databases.
However, security issues and workflow adjustments
still have to be fully analyzed in order to avoid that
the potential advantages for the organization may
bring unacceptable damage to both patients and radiologists. In particular, the protection of electronic information transmitted from a radiological department
requires a combination of technical and organizational practices, whose selection involves trade-offs
among cost, complexity, and degree of privacy provided. Organizational practices are at least as important as technical practices: although technical
mechanisms can be used to validate the identity of
computer users, establish controls on the information
they can access, and encrypt information transmitted
between locations, organizational policies have to establish the objectives of technical measures, determining who is allowed access to information and how
tightly the access will be controlled.
D. Caramella et al. / European Journal of Radiology 33 (2000) 2–7
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