Method and system for detecting a portable direct radiographic
panel in a multi- stand radiographic exposure room.
[DESCRIPTION]
Field of the invention :
The present invention relates to a method and a system for
detecting a portable direct radiographic panel in a medical
imaging system comprising multiple radiographic exposure
units .
The portable direct radiographic panel will hereinafter
often be referred to as DR Panel.
More in particular the invention relates to a method and
system for conveniently and operator- friendly detecting the
position of the direct radiographic panel in the multiple
exposure units of the medical imaging system and to perform a
check whether that position corresponds with the position as
set forth in the worklist for the forthcoming radiographic
exposure .
Background of the invention.
It is known that radiographic illumination or exposure has
important applications in medical imaging, whereby the medical
advantages for the patient largely exceed the small risk of
damage resulting from such radiographic illumination.
In earlier days radiographic exposures mostly made use of
film based on silver halide technology as image capturing
medium.
Since a number of years the so-called computed radiography
technique has gained wide market acceptance. This technology
makes use of a radiographic panel that does not use silver
halide technology as the light capturing medium, but uses
stimulable phosphors.
This method is described amongst others in detail in the
Handbook of Medical Imaging, (ed. R.V. Matter et al ., SPIE
Press, Bellingham, 2000) .
During recent years, radiographic exposures increasingly
make use of direct digital radiographic techniques, known as
DR (Direct Radiography) .
This method is increasingly used as alternative for film-based
imaging techniques, as well as for the panels based on the use
of stimulable phosphor- technologies , as described supra.
In this digital radiographic method the radiographic
exposure energy is captured pixelwise in a radiographycally
sensitive panel, and hereupon is converted to electronic image
data by means of electronic components. Hereupon the
information is read out imagewise and displayed on a suitable
monitor for diagnostic purposes by a radiologist.
One of the driving forces behind the success of direct
digital radiography is the ability to rapidly visualise the
radiographic images and to efficiently and simply communicate
over datanetworks to one or more sites for analysis and remote
diagnosis by a radiologist or other medical expert. The
delays that are characteristic for the development, packaging
and physical transport of radiographic films are avoided by
the above methods. Also the difficulties arising from the
scanning of developed films and the corresponding loss in
resolution is avoided by the above techniques.
The advantage of direct radiographic systems over computed
radiographic systems, based on stimulable phosphors, is that
no read-out (in a digitizer) of the latently captured
radiographic image needs to take place. On the contrary, the
digital radiographic image promptly or directly can be read
for the purpose of evaluating the image from a diagnostic
point of view. This diagnosis can take place at a local or
remote workstation.
At the beginning the first direct radiographic panels were
integrated in the overall radiographic imaging system. The
wiring was designed such that minimal trouble to the
radiographic operator was caused hereby when the radiographic
direct panel was placed for exposure of a body part of a
patient .
More recently portable direct radiographic panels have been
introduced to the market place. These panels make use of an
on-board battery and communicate with the radiographic control
panel or workstation, as well as with the datacapturing
apparatus and the display components in a tethered or wireless
manner .
The latter aspects resulted in a wide acceptance of such
portable wireless panels by the marketplace and ensures their
practical use in a fully digital radiographic exposure system.
In a hospital or medical diagnosis center, these panels
can be used as well in a completely newly installed
radiographic imaging system or in a so-called retrofit
situation. The term retrofit should be understood as directed
to an existing radiographic system, that previously made use
of radiographic films or stimulable phosphor plates, and
whereby the latter registration media have been replaced by a
direct radiographic capturing medium, a so-called direct
radiographic or DR panel, without the need to replace the
workstation or the radiographic source itself.
The advantage of such a retrofit radiographic system as
compared to a completely newly installed radiographic system,
is its lower investment cost, as part of the already installed
radiographic system can be re-used.
Although portability and wireless communication of the
radiographic registration medium clearly is an advantage when
portable and wireless DR panels are used, these features also
are characterized by the occurrence of problems under
practical circumstances of use.
In particular problems occur when such DR Panels are used in a
medical imaging system comprising multiple radiographic
exposure units or stands .
Such system will hereinafter be referred to as a multistand
radiographic exposure room or as a medical imaging
system comprising one or more radiographic exposure stands.
A medical imaging system comprising multiple radiographic
exposure units or stands may comprise for example on the one
hand a mobile radiographic exposure unit, and on the other
hand a fixed-position exposure unit. The latter exposure unit
may further comprise for example a wall and/or a table stand.
The same DR panel may be used in any of these exposure
units .
The problem arises when multiple radiographic exposure
units are comprised in a medical imgaging system.
It that case it is of vital importance that for each
radiographic exposure the DR Panel is correctly positioned,
this means that it is positioned in that specific radiographic
exposure unit of the medical imaging system where the patient
is positioned and that such position corresponds to the
positions as set forth for the patient and the DR panel in the
radiological worklist.
In such a multi- stand radiographic exposure room, it may
happen that by accident the DR panel is placed in one exposure
stand, e.g. the wall stand, whereas the patient is positioned
in the table stand, or that both the panel and patient are
positioned in the same stand, but that such stand is not in
conformity with the stand as set forth in the radiological
worklist prescribed for the radiological exposure.
Clearly in such a case, the patient might be exposed to
radiographic illumination, but no radiographic image will be
detected by the DR Panel, as it is ill-positioned.
This then results in a re-take of the radiographic exposure,
resulting not only in waste of time and effort, but also in
needless harmfull double radiographic exposure for the
patient .
Without a specific method that enables to reduce to an
absolute minimum the probability of ill-positioning the DR
Panel, there remains an enhanced risk for an incorrect
exposure of a patient, resulting in retakes. On its turn,
this results in a number of complaints, confusion, and a loss
of time and efforts.
Problem to be solved
The aim and purpose of the invention is to avoid the
abovementioned problems by providing a convenient, automated
and user- friendly method and system for the detection of the
correct position of a DR Panel in a multi -stand radiographic
exposure room.
Summary of the invention
The abovementioned aspects are realised by means of the
method and the medical imaging system as described in the
independent claims .
Specific features of preferred embodiments of the
invention are set forth in the dependent claims.
Further advantages and embodiments of the present
invention are clarified in the description that follows.
Description of the invention
The present invention relates to a method for detecting
the presence of a portable direct radiographic panel in a
medical imaging system comprising one or more radiographic
exposure stands. In such medical imaging system, each
radiographic exposure stand and each radiographic panel are
provided with an NFC tag. The method then comprises the
following steps :
° positioning the radiographic panel in the radiographic
exposure stand such that the NFC tags of the panel and the
stand are in each other's operating range;
° detecting the presence of the radiographic panel in the
radiographic exposure stand by a communication between the NFC
tag of the panel and the NFC tag of the radiographic exposure
stand;
° communicating the presence of the radiographic panel in the
radiographic exposure stand to the medical imaging system.
Also, the invention relates to a medical imaging system
comprising one or more radiographic exposure stands and one or
more portable direct radiographic panels, comprising :
° NFC tags provided on each radiographic exposure stand and on
each portable direct radiographic panel;
0 means for positioning the radiographic panel in the
radiographic exposure stand such that the NFC tag of the panel
and the NFC tag of the stand are in each other's operating
range ;
means for detecting the presence of the panel in the
radiographic exposure stand by a communication between the NFC
tag of the panel and the NFC tag of the radiographic exposure;
° means for communicating the presence of the radiographic
panel in the radiographic exposure stand to the medical
imaging system.
Description of preferred embodiments :
A preferred embodiment of the invention comprises the step
of controlling whether for a radiographic exposure for which
the exposure conditions are set forth in a radiological
worklist, the radiographic exposure stand wherein the presence
of the radiographic panel is detected, conforms to the
radiographic exposure stand specified in said radiological
worklist .
A further preferred embodiment of the invention comprises
the step of selecting for a radiographic exposure, when the
presence of a radiographic panel in more than one radiographic
exposure stand has been detected and the radiological exposure
conditions are set forth in a radiological worklist, the
radiographic exposure stand specified in said radiological
worklist for the radiographic exposure, provided the presence
of a radiographic panel in the selected exposure stand has
been detected.
Preferably the presence of the radiographic panel in the
radiographic exposure stand is communicated to a radiographic
workstation of the medical imaging system. An example of such
radiographic workstation is the apparatus marketed by Agfa
Healthcare N.V. under the brand name NX.
According to a further preferred embodiment of the
invention the NFC tag provided on each portable direct
radiographic panel is an active NFC tag, and the NFC tag
provided on each radiographic exposure stand of the medical
imaging system is a passive NFC tag, the communication between
the NFC tags being triggered by moving the active NFC tag
towards the passive NFC tag such that the latter is within the
operational range of the former. In a still further preferred
embodiment of the invention, the communication is triggered by
the active NFC tag pulling a response to occur from the
passive NFC tag provided on the radiographic exposure stand.
The presence of the portable direct radiographic panel in
the radiographic exposure stand may be communicated to the
medical imaging system by the portable panel by means of a
wired ethernet or a wireless short-range radio-wave
transmission.
According to a further preferred embodiment of the
invention, when the conformity between the presence of the
portable direct radiographic panel in the radiographic
exposure stand with the radiographic exposure stand as
specified in the radiographic worklist is not established, a
warning is given to the radiographic operator.
Further, upon the radiographic exposure having taken
place, the radiographic image and metadata stored in the
direct radiographic panel are transmitted to the medical
imaging system.
Further, the medical imaging system according to the
invention Defurther comprises means for controlling whether
for a radiographic exposure for which the exposure conditions
are set forth in a radiological worklist, the radiographic
exposure stand wherein the presence of the radiographic panel
is detected, conforms to the radiographic exposure stand
specified in said radiological worklist.
According to a further preferred embodiment, the medical
imaging system further comprises means for selecting, when the
presence of a radiographic panel in more than one radiographic
exposure stand is detected and the radiological exposure
conditions are set forth in a radiological worklist, the
radiographic exposure stand specified in said radiological
worklist for the radiographic exposure, provided the presence
of a radiographic panel in the selected exposure stand has
been detected.
In a further preferred embodiment, in the medical imaging
system according to the invention, the NFC tag provided on
each portable direct radiographic panel is an active tag, and
the NFC tag provided on each radiographic exposure unit is a
passive tag.
The medical imaging system according to the invention
further preferably comprises a radiographic workstation, such
as Agfa Healthcare's NX apparatus, and wherein the portable
direct radiographic panel and the workstation further comprise
means for wireless communication by means of short-range radio
waves, preferably through IFI .
The medical imaging system further may be provided with a
radiological workstation provided with means for receiving
the communication of the presence of the radiographic panel in
a radiographic exposure stand, and
for performing the control or selection as set forth supra.
In a still further preferred embodiment of the medical
imaging system according to the invention, each radiographic
exposure unit comprises at least two NFC tags for determining,
apart from the presence, the orientation of the radiographic
panel in the radiographic exposure unit.
Detailed description of the invention
Retrofit system
The method of the present invention is applicable as well
in a radiographic exposure system that is newly installed in a
medical care centre such as a hospital, or it may be applied
in a retrofit situation as described earlier in this text.
Communication between DR panel and medical imaging system
Once the presence of the radiographic panel in one of the
radiographic exposure units has been detected, this should be
communicated to the medical imaging system.
Such communication may be performed by transmitting the
presence in a given exposure stand to a radiological
workstation, comprised in the medical imaging system.
This workstation may be connected wirelessly or through a
wired connection with the portable radiographic panel. A
wireless connection is preferred, provided the radiographic
panel is a wireless-enabled panel. In that case the
radiological workstation and the panel are provided with means
for wireless communication, such as a wireless communication
processor .
The wireless communication preferably is performed by
means of short-range radio waves.
The wireless communication module or processor of the
radiographic panel can be used for wirelessly transmitting the
spatial positon of the radiographic panel to the radiological
workstation, but is may also be used to wirelessly transmit
the radiographic image and meta-data stored in the direct
radiographic panel to the medical imaging system, more in
particular to the radiological workstation comprised in such
system.
Such wireless communication module is a means known for
the person skilled in the art. Such module has been described
e.g. in the US patents of Fuji Photo Film, Inc., Japan, Nr. US
7 829 859 and US 8 116 599. The patent first mentioned
describes how the portable radiographic panel transmits the
digital image data stored therein over such wireless
communication processor to the radiological workstation or
radiographic console by means of a transceiver of the
radiographic Panel. The U B (Ultra Wide Band) protocol is
mentioned as an example of such wireless communication
protocol. Such UWB Protocol is characterised by a substantial
reduction of energy- consumption, and by enhanced communication
speed, as compared to other wireless communication techniques.
The other US patent, US 8 116 599, describes the
conversion to wireless communication signals of the image data
by the wireless communication unit according to one of the
following existing wireless communciation protocols : UWB,
Bluetooth, Zigbee, HiSWANa (High Speed Wireless Access Network
type a), HiperLAN, Wireless 1394, Wireless USB, and finally
Wireless LAN, infrared (irDA) , NFC (Near Field Communication) ,
IO-Homecontrol .
Preferably use is made of a wireless communication
protocol working according to the IEEE 802.11 standard.
In such a case, the direct radiographic panel communicates
by means of a short-range radio or infrared connection over
the wireless network with the radiographic workstation by
means of any of the above communication protocols.
Generally a short-range radioconnection is preferred over
an infrared connection, as the first mentioned connection
operates in an omnidirectional manner, whereas for an infrared
connection, as it is an optical connection method, a direct
optical path should be created between the transmitter and the
receiver of the signals.
The wireless LAN Network can make use of a number of
various wireless network protocols and mechanisms. Preferably
use is made of the wireless IEEE 802.11 g or IEEE 802.11 n
interface ( IF ) standard.
One can also make use of the IEEE 802.11 b standard,
whereby in a point-to-point configuration (1 point to various
points) , one acces point (the wireless entry point) through a
multidirectional antenna communicates with other clients that
are within the range of the central access point.
The one access point may be the modality or radiological
workstation, and the other clients are the various portable
radiographic panels.
So as to realise such wireless connection, preferably such
WIFI connection, with the workstation, the processor has at
its disposal on the direct radiographic panel an antenna
driver and a chip technology that enables such short-range
radio -connect ion.
NFC Tag
The term NFC tag as used in the present description should
be understood as an electronic chip, designed specifically for
being used according to the NFC set of standards . More in
particular an NFC tag is essentially a small microchip
containing a small amount of memory attached to an
antenna/aerial which can store a small amount of information
for transfer to another electronic device according to the NFC
standard.
The information on the NFC tag is usually stored in a
specific data format (NDEF - NFC data exchange format) so that
it can be reliably read by electronic, e.g. mobile devices.
The NFC tags to be used in the method and system of the
present invention preferably are no standard tags, as those
won't work directly onto metal surface.
To that end on-metal NFC tags should be selected, which
are available e.g. from RapidNFC, London, U.K.
The NFC tags of the radiographic exposure unit may be
installed on the bucky of such unit, either the wall or the
table stand.
As set forth supra in a preferred embodiment of the method
according to the invention, the exposure stands, e.g. the
table and wall bucky may be provided with a passive NFC tag.
The advantage of using such passive NFC tag at this position,
is that no charging by a battery is required, and that these
tags can be quite easily installed.
Given the fact that the range of an NFC tag is quite
limited, there also is no risk for false positive detections.
So the situation of a panel being detected as present in the
bucky whereas in reality the panel is not present there,
cannot arise.
On the DR Panel on the contrary, an active NFC tag is
used. This has the advantage that the wireless ( IFI )
settings of the radiological workstation may be transmitted to
the panel through such active NFC tag.
This aspect is described in a co-pending patent
application of the same applicant, filed on even date
herewith.
NFC
The term NFC as used in the present description should be
understood as a set of standards for mobile devices such a
smartphones and similar devices to establish radio
communication with each other by touching them together or
bringing them into close proximity, usually no more than a few
inches .
NFC standards cover communication protocols and data
exchange formats, and are based on existing radio- frequencyidentification
(RFID) standards.
Link to the HIS/RIS/ Radiological Worklist
According to a preferred embodiment of the present
invention as set forth above, the method further comprises
the step of controlling whether for a radiographic exposure
for which the exposure conditions are set forth in a
radiological worklist, the radiographic exposure stand wherein
the presence of the radiographic panel is detected, conforms
to the radiographic exposure stand specified in said
radiological worklist.
If the result of this conformity check is OK, the operator
will proceed to the radiographic exposure.
According to a still further preferred embodiment, in case
the conformity between the so identified direct radiographic
panel and the direct radiographic panel as set forth in the
worklist of the radiographic work station has not been
established, a warning is given to the operator. Such warning
may comprise a pop-up on the display of the radiographic
workstation, optionally including an acoustic or other form of
alarm .
In such a case, a manual intervention of the operator is
required : he can either adapt the worklist by selecting
another DR Panel and/or another exposure unit for the
forthcoming exposure or he may reposition the DR panel in the
exposure unit designated in the radiological work list for the
forthcoming radiographic exposure .
The worklist of the planned radiographic exposures is
usually displayed on the screen of the workstation during the
various radiographic exposures that are planned for a given
time-frame and for a given radiographic exposure room or unit.
Such worklist is part of or comprised within the
Radiological Information System (RIS) of the hospital or
medical care organisation and is communicated to the work
station. Such communication may e.g. comprise the radiographic
operator of the radiographic exposure unit concerned to
navigate in the Hospital Information System (HIS) to the
specific RIS data, and visualising on the screen or display of
the radiographic work station such worklist.
The radiographic worklist usually comprises one or more of
the following information :
• identity of the patients to be radiographed (name or other
personal attributes) ,
• object to be radiographed (arm, knee, hand, or other body
part) ,
• stand (wall or bucky) , as well as
• the digital radiographic panel to be used for the
radiographic exposure, and - optionally - the exposure
parameters .
Unique Identification of DR Panel
Each direct radiographic panel has a unique identification
number or other form of identification. Such identification is
allocated to the panel at the time of manufacturing the panel
or at the time of marketing of the direct radiographic panel.
The abovementioned unique identification code or number of
the direct radiographic panel may comprise or consist of a
unique serial- or manufacturing-number, or, in an alternate
embodiment, may comprise or consist of the fixed or variable
IP address, MAC addres or some sort of Unique Identifier
allocated to the DR Panel .
The wireless communication module of the direct
radiographic panel uses through the wireless communication
protocol with the radiographic workstation this unique
identification code to distinguish this DR Panel in an
unambiguous manner from the other DR panels, and to identify
same as such.
Transmission of image data to the workstation
In a next step, namely after the radiographic exposure has
taken place, the radiographic image data are sent to the
radiographic workstation from the DR Panel for visualisation
and diagnostic evaluation on the monitor by a radiologist.
DR Panel in its docking station
In a radiographic exposure room the various direct
radiographic panels mostly are placed in their respective
docking stations. The docking station is the place where the
direct radiographic panel is positioned when it is not used
for a radiographic exposure : through such docking station the
DR Panel recharges its on-board battery.

Claims
1 . A method for detecting presence of a portable direct
radiographic panel in a medical imaging system comprising
at least one radiographic exposure stand, said
radiographic exposure stand and radiographic panel being
provided with an NFC tag, comprising the following steps :
° positioning said radiographic panel in a radiographic
exposure stand such that the NFC tag of said panel and the
NFC tags of said stand are in each other' s operating
range ;
° detecting presence of said radiographic panel in said
radiographic exposure stand by a communication between
the NFC tag of the panel and the NFC tag of the
radiographic exposure stand;
° communicating presence of the radiographic panel in
said radiographic exposure stand to the medical imaging
system .
2 . Method according to claim 1 , further comprising the step
of controlling whether for a radiographic exposure for
which exposure conditions are set forth in a radiological
worklist, a radiographic exposure stand wherein presence
of the radiographic panel is detected, conforms to a
radiographic exposure stand specified in said radiological
worklist .
3 . Method according to claim 1 , further comprising the step
of selecting for a radiographic exposure, when presence of
a radiographic panel in more than one radiographic
exposure stand has been detected and radiological exposure
conditions are set forth in a radiological worklist, a
radiographic exposure stand specified in said radiological
worklist for a radiographic exposure, provided presence of
a radiographic panel in the selected exposure stand has
been detected.
4 . Method according to claim 1 , wherein presence of the
radiographic panel in a radiographic exposure stand is
communicated to a radiographic workstation of the medical
imaging system.
5 .Method according to claim 1 , wherein the NFC tag provided
on each portable direct radiographic panel is an active
NFC tag, and the NFC tag provided on each radiographic
exposure stand of the medical imaging system is a passive
NFC tag, communication between the NFC tags being
triggered by moving said active NFC tag towards said
passive NFC tag such that the latter is within the
operational range of the former.
6 . Method according to claim 5 , wherein communication is
triggered by the active NFC tag pulling a response to
occur from the passive NFC tag provided on the
radiographic exposure stand.
7 . Method according to claim 1 , wherein the presence of the
portable direct radiographic panel in the radiographic
exposure stand is communicated to the medical imaging
system by the portable panel by means of a wired ethernet
or a wireless short-range radio-wave transmission.
8 . Method according to claim 2 , wherein when conformity
between presence of the portable direct radiographic panel
in the radiographic exposure stand and a specified
radiographic exposure stand in a radiological worklist is
not established, a warning is given to the radiographic
operator .
9 .Method according to claim 1 , wherein upon radiographic
exposure, a radiographic image and metadata stored in the
direct radiographic panel are transmitted to the medical
imaging system.
Medical imaging system comprising one or more radiographic
exposure stands and one or more portable direct
radiographic panels, comprising :
NFC tags provided on each radiographic exposure stand
and on each portable direct radiographic panel;
° means for positioning the radiographic panel in the
radiographic exposure stand such that the NFC tag of the
panel and the NFC tag of the stand are in each other's
operating range;
° means for detecting the presence of the panel in the
radiographic exposure stand by a communication between the
NFC tag of the panel and the NFC tag of the radiographic
exposure ;
means for communicating the presence of the radiographic
panel in the radiographic exposure stand to the medical
imaging system.