A Practical Approach to Store DICOM-conform Prentations of
Radiological Images
Lutz Vorwerk,Christoph Meinel
Institut fuer Telematik,Trier,RP,Germany,D-54292,Bahnhofstras30-32
童子鸡英文>新东方国际游学ABSTRACT
Engrane is a system which is ud to prepare and show prentations of radiological images as well as the reports which belong to the images.The prentations with Engrane will be performed by displaying DICOM(digital imaging and communication in medicine)1images and an interpretation of the images prented as text.A databa is ud to manage DICOM-objects like images and reports.Images are transferred using the DICOM protocol enhanced by TLS (transport layer curity)2protocol.Correlating images and reports is necessary as well as a log mechanism which is ud to reconstruct a prentation.The correlation and the log mechanism lead to SR(structured reporting).An order is needed for quences of elements.A new supplement called“hanging protocol”3define arrangements of elements.It has to be examined if SR or“hanging protocol”is sufficient
in order to store prentation files of radiological images. Neither SR nor“hanging protocols”fulfil all requirements.
英语试卷讲评课教案Engrane was developed in order to improve the prentation and the communication of radiological images.An appropriate standard to store tho prentations has to be defined.Therefore,we suppo a combination of hanging protocols and SR in order to meet technical and organizational requirements.
Keywords:DICOM,prentation,image management,hanging protocols,curity.
1.INTRODUCTION
Currently,we are developing a system called Engrane.Engrane is a system which can be ud to prepare and show prentations of radiological images,as well as reports which belong to the images.The prentations of Engrane consist of DICOM images and interpretations of the images reprented as text.The Engrane system itlf consists of three modules:a primary module to prepare the prentation,a module for actual prentation and a third module to organize the prentations.Additionally,a databa is ud to manage patient information data which is part of the DICOM images being prented.Several operations can be performed on the images during prepara
tion and prentation,such as windowing and annotation.It is also possible to realize slideshows of ries of images.Java is ud to develop the ur interface of Engrane in order to obtain a system independent interface.Methods for processing image data are written in programming language C in order to increa processing large amounts of data.Engrane retrieves images via using the DICOM protocol.To increa the performance of the image management,an algorithm of adaptive compression may be ud.The system needs a practical approach in order to store DICOM conform prentations of radiological images.
1.1PRESENTATION OF THE SYSTEM
The Engrane system integrates a DICOM-rver and a ur interface of different programming languages.Engrane displays patient data in accordance to DICOM Patient,Study,Series,Image object hierarchy.Important values of attributes for each level are listed.At the ries level it is possible to choo two ries and compare them.This feature is important to compare ries of patient images that are made at different times.Image operations integrated at ries level and image level are rotation,zooming,flipping,annotation,adjustment of brightness,and contrast,and windowing.The cond module is developed in order to manage prentations and to arrange them into a calendar via drag and drop as shown in Fig.1.Every prentation is prented as an icon cont
training the patient’s name and date of birth.The third module contains the prentation rvice.The prentation can be started simply by a click on the corresponding icon.Afterwards,a walk through the prentation can be realized simply by pressing a button.
Fig.1:A calendar for managing prentations六级听力mp3
1.2INCREASING PERFORMANCE BY USING BEST FEATURES OF TWO PROGRAMMING LANGUAGES
The JNI(Java Native Interface)is included in the standard JDK(Java Development Kit),and allows interaction between native code and Java objects.The main advantage is the possibility to implement time-critical process in a low-level programming-language,without renouncing the easy-to-do GUI-Development and the broad class library of Java.After tting up this development environment,the development of a Java application with JNI functionality (here,native language is C)takes veral steps.First step is the implementation of a Java-Application with an interface to the desired dynamic library and the cond step is the JNI-method invocation.Accomplishing the steps,you will have to consider,that the JNI maps data types to special JNI-data types when interacting between the VM(Virtual Machine)and the native method.While this procedure is not critical using primitive data types,the usage of arrays might lead into problems.Returning an array from C to Java,requires a duplication of the whole array,which might result in a lack of performance for your application.But there is a much more effective way of returning C-arrays to Java.First you need to hand a JNI-array of identical size and type to the C-routine.Within the C-routine,you copy the head of this array,which
contains lengths and structure information,to a new C-array.Casting the pointer to the C-
Array to a JNI-Array-pointer and returning this pointer to the invoking Java object before termination of the JNI-
method,completes the process.This approach is applied in order to transfer image data between Java and C within Engrane.
1.3EASE THE USER INTERFACE
tenorFor managing prentation files Engrane us drag and drop(Fig.1).The package Swing from Java1.3gives the opportunity to implement this feature as a part of Java programs.The Idea was to implement a date book.The ur should be able to fill in dates,to move them and to delete them.For the integration of drag and drop into Engrane were ud some ready-made class that have been expanded.Displayed objects were constructed by using predefined elements and patient related information which is retrieved from DICOM image documents.rerveage
2.REQUEST FOR A PRESENTATION SYSTEM
One major task in every day’s work is the transfer of knowledge into text,pictures or alternative types
of communication.The method knowledge is prented must be comprehensible for an audience who are not familiar with this kind of specific knowledge.However they need this knowledge as a part of the work they have to perform.The easiest way to communicate and transfer knowledge can realized by using images,gestures and words.The communication of knowledge is therefore usually performed as a prentation containing text and/or images in order to explain a solution or a result.In order to explain the images,the prenter us his or her hands,a lar pointer or a stick to focus attention on special features of the image.Meanwhile,the image is explained using‘spoken word’.If the audience has questions relating to the prentation,there might be the possibility to ask questions.For other kinds of prentations it is very important to understand the prentation’s tenor immediately.Additionally,there is less time to po questions.Such a type of prentation,which can be ud in meetings between radiologists and other members of medical staff in a hospital or other medical institution will be discusd below.
Regarding the procedure of knowledge transfer between the scope of radiology and other fields of application in healthcare,results in the problem how to reprent the interpretation of radiological images.The way of reprentation must be clear and plain.
In cas of emergency,there is no spare time to discuss results of the interpretations of radiological i
mages.Reports are written in a hurry.In many cas,images are added to a report but without a little knowledge in radiology it is time consuming,to relate the reports to the images.Therefore,the prentations are performed in order to avoid difficulties resulting from report-image-association.The prentations are performed in a special room.An alternator rves as a helping tool to show the images in a convenient order.The radiologist explains the findings of an image and after finishing the comment he proceeds further on to the next ca.Nowadays,this traditional form of prentation can be replaced by computers,ud to facilitate the interpretation of radiological images.The computer is connected to a beamer in order to display the image on a silver screen.The management and transfer of images are done by using the standard of DICOM.
The internet offers a wide choice of free-,share-and commercial software of DICOM applications.Most of the applications are DICOM viewers to display and manage images.A simple way to develop a prentation system is to get such a DICOM viewer,install it on a book)and copy the images for prentation on the computer’s hard disc.However,after careful consideration of all features of the offered viewers it is quite obvious,that the viewers are not suitable for every kind of prentation.A further problem is the way of organizing and preparing prentations.
3.TAKE CARE WITH COMPLEXITY OF DICOM
67是什么意思 The u of computers in medical imaging and the development of applications that process images,which have been produced by imaging devices,creates the problem of how to exchange images with related patient data between devices of different manufacturers.A common interface has to be specified for the devices and applications.This interface, called DICOM,makes it possible to connect devices,PACS and databas that contain diagnostic data.The DICOM-standard is accepted and ud by many manufacturers.
The status of the standard is reprented by the core.This core consists of parts which specify the required elements needed to develop and to understand a DICOM-conform application.The required elements are:the definitions of attributes,the reprentation of the attributes,the transfer of a t of attributes and the storing of the attributes in a file.A statement declaring which attributes defined in the DICOM-standard have been ud and how they are being reprented,as well as additionally defined attributes that do not occur in the DICOM-standard,has to be written.The statement is important for a ur who wants to buy a DICOM application or hardware with a DICOM interface.The statement may rves as information about the interoperability of two DICOM interfaces.Interoperability may not be guaranteed if the statement is vague,incomplete,not preci or
incorrect.Developers of DICOM-conform applications, as well as manufacturers of DICOM-conform devices,must be sure to describe the features of their products thoroughly in order to increa the interoperability and acceptance of products that conform to the DICOM-standard.
The core of the DICOM-standard may be extended by correction-proposals or supplements.The evolution of DICOM is achieved by the integration of accepted supplements that have reached a final status and by the acceptance of correction proposals.
An SOP is a combination of a t of modules reprenting a DICOM document,called‘Information Object Definition’(IOD)and a rvice that allows to work on the attributes of the modules and therefore,on the IOD.Operations that move data from one point to another are an example of such a rvice.
4.DICOM CONFORMS RADIOLOGICAL REPORTS
The DICOM-standard was enhanced by a supplement called Structured Reporting(SR).This supplement is now part of the core.The SR defines a way to produce medical reports of radiological image interpretations.In practice,the production of a report is achieved by using a dictaphone.The report recorded on tape is transcribed by a cretary.The cretary shows the transcribed report to t
he physician who recorded the tape.The physician verifies the report and signs it.To reduce the amount of text,the physician us a medical code.The code is often a standard-code like logical obrvation identifier names and codes(LOINC)or systemized nomenclature of human medicine(SNOMED). Additionally,private codes of physicians who want their code to be understood only by themlves or by a group of people they trust is also ud.The supplement SR us the supplements for coding medical data which are integrated in the core now in a pre-defined scheme.In the definition of SR,there are three pre-defined kinds of reports.The basic-text,the enhanced,and the comprehensive Information Object Definition(IOD).
The structure of a SR report is complex4,5.This structure is reprented in DICOM as an IOD.In1,there are three definitions for a report IOD.The three definitions will be described in the following.The simplest definition is the SR-Basic-Text-IOD.This definition posss the features of reference images and other reports.The structure of a report in this definition consists of the following elements:a document content that contains information about the examiner,as well as information pertaining to the time the report was created and why the report was created.Medical Codes may be integrated.An obrvation context may be integrated by using relationships between predefined class defined for the creation of a report.
The SR-enhanced-IOD provides additional class like coordinates to reference an area in an image.The coding scheme defined for the three IOD is the SNOMED DICOM micro glossary(SDM).This coding scheme is a medical coding scheme that assigns medical code words to their descriptions.
The comprehensive IOD allows the specification of relationships by reference instead of using values like in the other two IODs.
There are some implementations of SR which u SR to relate text to images.Currently,SR is regarded as very complex.The complexity can let applications run into difficulties when interpreting SRs becau too many variations of ways to construct a report exist.
Nevertheless,we decided to u SR becau it provides the best way to relate images and reports.In order to reduce the complexity and resulting problems and due to our aim of constructing a prentation,we cho not to u medical coding schemes.
5.DICOM DEFINES HANGING PROTOCOLS法文歌曲
The“Hanging Protocol”contains information about physician viewing preferences,related to display c
apabilities.The goal is for physicians to be able to conveniently define their preferred methods of prentation and interaction for different types of viewing circumstances once,and then to have image ts automatically hung according to the ur’s preferences on display systems of similar capability.The main expectation is to facilitate the automatic and consistent hanging of images according to definitions provided by the physicians,sites or vendors of the display systems.
Specifically,
• save defined hanging protocols,and arch for them by id(urname,site,manufacturer),exam type,and display characteristics.
• allow automatic hanging of primary and comparison image ts to occur for all exams on defined displays,or similar displays by matching against ur or site defined hanging protocols.This includes supporting automatic hanging when the ur reads from different locations,or on different but similar display types.Allow shared u of hanging protocols to facilitate consulting on shared ,two physicians reviewing the same ca from remote locations).quantico
Further,it is anticipated that vendors will make it easy for urs to point to a graphical reprentation of what they want (like4x1versus12x1format with a horizontal alternator scroll mechanism)and lect
what they want.Obtaining the images for comparison image ts is outside the scope of the Hanging Protocol IOD,and left up to vendor specific implementation.The following rvices are considered to be beyond the scope of the Hanging Protocol IOD and SOP Class:
• the rvices required to retrieve the ,image ts)that is to be prented by an instance of a Hanging Protocol IOD.
6.HANGING PROTOCOLS USES PRESENTATION STATES
Softcopy Prentation states are ud to store viewing preferences.A workstation that supports this rvice memorizes how the image was viewed initially,stores this in a"Softcopy Prentation State"object and is able to nd image with this information to other devices that support the interpretation of this DICOM object.The receiving device interprets the Prentation State and knows exactly how to recreate the initial image appearance.Prentation States makes u of the Grayscale Standard Display Function,which defines how displays can prent images in a consistent manner.This consistency is achieved by defining how the input values to the display should be converted into the luminance values, measured at the screen surface.If the two displays at the earlier scenario both support this Grayscale Function,their prentation in luminance would be defin
ed,and identical.According to hanging protocols prentation states are either referenced or inrted values.
6.1EXAMPLE SCENARIO ADAPTED TO ENGRANE
A Physician sits down at workstation and brings up a chest CT study.He reads his first ca.The workstation queries the DICOM rver.It finds nothing for this specific ur,but matches a site default,which was tup when the workstation was installed at the site.It us the site default,and the physician reads the ca.He decides to customize and configure the application.He tells the application to save this hanging protocol for him,which caus the DICOM HP IOD defining his preferences to be stored to the DICOM rver.He has chon to define a2columns by1rows tiled prentation(Fig.2)with a“vertical alternator”interaction,and a default scroll amount of one row of images.In this ca the best match returned is with the urid matching his urid,the study type matched to the study type of the image t he is bringing up for viewing,and the display type matching the display system he’s using now.A list of matches is produced,with the defined HP IOD the ur defined yesterday for chest CT matching the best,and the study is automatically brought up on the monitor with that hanging protocol.Alternative next best matches are available to him via the application interface’s pull-down menu list of all cloly matching hanging protocols.Also,becau thi
s hanging protocol defines a comparison image t,the year prior chest CT for the same patient is automatically displayed next to the current image t on the right monitor.The next week,the same radiologist reads chest CT at the Ambulatory Care Center one mile away on a similar type workstation,workstation Y,from a different vendor.
Fig.2:Example for comparing two ries of images by indicating areas of interest
