APPC—A new standardised coding system for trans ... - Springer Link

Eur Radiol (2010) 20: 2153–2165 DOI 10.1007/s00330-010-1780-0

COMPUTER APPLICATIONS

F. Fruehwald A. Lindner G. Mostbeck W. Hruby J. Fruehwald-Pallamar

APPC—A new standardised coding system for trans-organisational PACS retrieval

Received: 26 October 2009 Accepted: 15 February 2010 Published online: 8 April 2010 # European Society of Radiology 2010

Abstract Objectives: As part of a general strategy to integrate the health care enterprise, Austria plans to connect the Picture Archiving and Communication Systems (PACS) of all radiological institutions into a nationwide network. To facilitate the search for relevant correlative imaging data in the PACS of different organisations, a coding system was compiled for all radiological procedures and necessary anatomical details. Results: This code, called the Austrian PACS Procedure Code (APPC), was granted the status of a standard under HL7. Examples are provided of effective coding and filtering when searching for relevant imaging material using the APPC, as

F. Fruehwald : A. Lindner Diagnostic Imaging, Institut Frühwald/Steiner/Obermayer, 3100, St. Pölten, Austria G. Mostbeck Department of Radiology, Wilhelminenspital, Vienna, Austria W. Hruby Department of Radiology, Donauspital, Vienna, Austria J. Fruehwald-Pallamar ()) Department of Radiology, Medical University Vienna/ Vienna General Hospital, Vienna, Austria e-mail: [email protected]

Introduction The integration of health care enterprise (IHE) activities requires standards for further development of connectivity, not only between medical equipment and information systems, but also between the different information systems of different organisations [1–7]. Austria is a European country with a population of 8 million, with a highly developed information technology (IT) network and a very highly ranked medical system (which includes cutting-edge radiology services for all citizens [8]). In 2007, the Austrian government decided to establish a life-long electronic medical file for all inhabitants. Consequently, considerable resources will be invested in this project. To connect all the providers of medical services and collect all patient data, standards must be established in many fields. To facilitate more rapid implementation of this project, it was agreed that existing standards would be used wherever possible and

well as the planned process for future adjustments of the APPC. Discussion: The implementation and how the APPC will fit into the future electronic environment, which will include an electronic health act for all citizens in Austria, are discussed. A comparison to other nationwide electronic health record projects and coding systems is given. Limitations and possible use in physical storage media are contemplated. Keywords Medical coding . PACS . Data retrival . Automated search . DICOM

that the option to connect later to transnational structures would rely on international standards, as far as such exist. The exchange of radiological data and reports must fit in smoothly with the other forms of data exchange regarding the Austrian electronic health document (Elektronischer Gesundheitsakt, “ELGA”). The Austrian PACS Procedure Code (APPC) was developed to standardise trans-organisational image data search and retrieval. After a brief description of ELGA, we will describe the APPC, including its strengths and limitations, and discuss it in comparison to other coding systems. This paper is an attempt to further propagate the APPC as a standard for trans-organisational searching in PACS.

APPC and ELGA All health professionals in Austria will be required to use ELGA [9]. The roles of different types of health care

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providers are defined with regard to their rights and obligations to access ELGA for storage or retrieval of medical information. Whether patients should have the right to opt out entirely or to block access to certain information is currently under discussion. Indices for all health care providers are also being established (if such indices do not already exist). For example, there is already an established list of all physicians who are licensed to offer their services in Austria. Currently, demographic patient data are typically stored in administrative systems, such as Hospital Information Systems (HIS) or Radiology Information Systems (RIS). Medical images are stored in a picture archiving and communication system (PACS). Under ELGA, the administrative system will compile the final report as a clinical document architecture (CDA) document. In generating this CDA report, the administrative system will select the appropriate APPC. Thus, the document will hold all relevant demographic data, the APPC for later (internal or external) retrieval and links to the images the report references. The CDA report will be sent to a central repository. From there, the document will be registered in the central registry and will be available for further access by other parties. All information and existing data for an individual will be accessible via one single access point (virtual address). “Registries” will provide an overview about what documents are stored in which place (electronic address), so that the user (health care professional) knows the type and date of all available medical data, such as discharge reports, imaging, or laboratory data. He/she can then decide which specific data might be useful for patient treatment. Those data can then be accessed and retrieved. Each attempt to access will be logged, and any misuse of access will be punished. Currently, neither an exact definition of what constitutes “misuse” nor of what sort of consequences would follow misuse have been revealed by the Austrian government. Those topics are now Fig. 1 IHE-compliant radiology report and image communication

addressed by a special ELGA working group on privacy of medical data, ethics and civil rights, and shall be clarified before the roll out of ELGA. The repositories will be provided by the government of the nine federal states of Austria that operate the hospital chains of those federal states. There are private hospital chains that also plan to establish a repository, and Austrian radiologists are also contemplating operating a repository for all non-hospital imaging data. The end result is that each physician will have access to all existing information for all his/her patients at his/her workstation. To retrieve any given study, the administrative system sends a query to the registry. Thus, if all radiological documents are APPC-coded, all relevant previous studies can be identified automatically (Fig. 1). Working groups were established for every aspect of this enormous enterprise, and one of those groups dealt with all aspects of communicating radiological imaging data and reports. For the purposes of this paper, we will not discuss the legal, liability and privacy problems associated with such an enormous accumulation of data, and we will assume that these sorts of issues will somehow be overcome so that we radiologists can focus on our standardisation task. When ELGA is implemented and all previous studies and procedures of a particular patient are readily available for comparison, a filter that could screen relevant data would be very useful. Ideally, with such a tool, radiologists would be able to define what sort of material would contain useful information for the study they are scheduled to read. For a chest film, this might include all chest films of the last 12 or 24 months (or the last 3 days in an emergency situation where there are ICU films, for example), as well as the chest CTs from the same period. The computer would sort and display the archived material. However, the way in which the archived material would be displayed could be problematic.

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APPC and other standards In radiology systems, all the necessary parameters for display have been defined. DICOM as a standard enabled the connection of all imaging machinery of a radiological department into one system and the viewing of all material on one single workstation. DICOM defines images, and HL7 defines documents [10, 11]. ICD10 defines clinical situations and diseases, and Radlex® defines radiological vocabulary as a tool by which to index radiological teaching files [12, 13]. Until now, there has been no demand for transorganisational data mining in the PACS, and thus, no one has identified the necessity to define a new standard that would be adaptable to such data mining. As it stands now, when the PACS of another organisation is accessed, only a chronological list of all examinations in this archive will be displayed. Therefore, we needed a mathematical coding system for radiological terminology. As soon as a generally accepted code exists and is implemented into all PACS, computers could then search for old imaging data, automatically obeying the criteria the reporting radiologist has defined for this process. Presently, there is no generally accepted numeric code for radiological “modalities” and procedures, and also, no suitable coding system for regions and anatomy. A standardised code would work across different vendors, organisations and even languages, as we can easily transfer a numeric code into any language. As a first step, the APPC was transferred from German into English. (Fig. 2: Conversion of information into different languages using the APPC).

APPC requirements The code must be abstract (numbers, no words) to be unambiguous. It should be logical to support the user, and

Fig. 2 APPC can find chest films in PACS operated using different languages and even different characters

anatomically hierarchical to enable a search for larger regions rather than certain organs. For example, if a radiologist was reading an ultrasound of the liver, he/she might also be interested in a CT study of the abdomen or an MR cholangiogram. Both should be able to be found if a hierarchically organised code is used, which is not possible with a coding system using, e.g., consecutive numbering. Granularity should be adequate but not too finely detailed. For radiological anatomy, there is no need to go as far as the cellular level, but “abdomen” as the most specific entry would clearly not be deep enough. We have to keep in mind that a search for existing correlative imaging material is normally undertaken for larger regions, such as the head, neck, or abdomen, and not so much for “left suprarenal gland”. A code should be expandable in an unlimited fashion because of the rapid development of radiology, and, once established, should be “connectable” to accounting and referral code systems.

APPC development The Austrian ELGA-Radiology task force has developed a coding system for a trans-organisational data search in PACS. A draft of the proposed coding system was distributed to all leading Austrian radiologists in a ballot process. All adjustments considered necessary were incorporated. The Austrian Radiological Society (ÖRGÖsterreichische Röntgengesellschaft) adopted this code, as did the radiological representation in the Austrian Medical Association (BURA-Bundesfachgruppe Radiologie der österreichischen Ärztekammer-ÖÄK). Both organisations, which represent 100% of all Austrian radiologists, recommended the use of this code in all existing and future PACS in Austria. The approach was very similar to the implementation of appropriateness criteria for medical imaging in Austria [14, 15]. The APPC was then submitted as an application to the HL7 Committee and again was subject to a ballot procedure to become a standard under HL7; this status was recently granted [16]. This is effective for the German-speaking states of Austria, Germany and Switzerland. The radiological organisations of Austria took on the task of further developing the APPC in the future and instituting an annual update, if necessary. An English translation was provided to enable global distribution of this code. The vocabulary of the English version was matched to Radlex®. A website (www.BURA.at) was installed for downloading of the code in digital form to ease incorporation into existing PACS. Explanations addressing the code are also included. The development of new language versions is encouraged, although the recommendation is to do so in cooperation with the radiological societies and political radiological representations of a language area to avoid different, concurrent versions of the same language. A forum was established on the website for applications of new entries and for reporting of problems in coding;

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thus, consistency in solving the problems that arise can be guaranteed.

APPC structure The code was compiled using four axes: “modality”, laterality, procedure and anatomy. Clearly, for retrieval of data, the most important axis is anatomy; but to expedite workflow in the future, when all studies are readily available, the other axes are of importance as well. In all axes, 0 means “undefined”, and thus, is an “asterisk function”, such that, in a search for studies, 0 would be interpreted as “take any/all of this axis”. “Modality”

X-ray, CT, MRI, ultrasound, nuclear medicine and PET are defined as ‘Modalities’. Laterality

To cope with all possible situations, laterality defines numbers for right, left, bilateral or unpaired organs, and for an atypical situation (as in a renal transplant, for example). In the search process, for most events, we would set laterality to 0 to obtain all studies, but there are situations imaginable where we really would want to obtain only MR examinations of the left knee (if we do a follow-up study, for example). Procedure

“Procedure” was the most difficult parameter to define. Of the many possible approaches to the definition of this parameter, we chose to find a way to accomplish hierarchical research in “procedure”. Thus, we grouped procedures under an umbrella term to render procedures discoverable, even if the specific procedure is not exactly known (all procedures in any anatomical localisation are found if 0 is set as a filter). Therefore, procedures are grouped into “Imaging of preformed ducts”, “Quantitative analyses/reconstructions”, “Documentation of interventions” and “Imaging with open radioactive substances”. Anatomy

For this parameter, a good balance had to be found between too much and too little granularity. When coding one’s own procedures, deep granularity is desirable, but when retrieving data from “foreign” PACS, larger regions as entries are more desirable. We attempted to strike a good balance between these two opposites. To facilitate easy coding, adherence to the radiological tradition of anatomy is beneficial.

Anatomy was subdivided into head, neck, thorax, abdomen, the musculoskeletal system, the vascular system and the breast. Generally, all codes are meant to be implemented into the computer system without it being necessary for the physician to convert words into numbers. Rather, physicians can use the system in their native language, while the system transfers everything into numbers in the background.

APPC coding Coding is straightforward: The first axis describes the technique (fluoroscopy and angiography are coded as 1 = xray). The second axis defines laterality (here, 0 is often the best option because the search will, in most instances, not be laterality-specific). Procedures in the third axis are coded according to the best fitting category (to help in coding, a table of examples is provided on the website, www.BURA.at). Anatomy, in the fourth axis, follows the radiological tradition and is coded according to the best fitting detail. (There is, for example, no code more specific than “finger”; so, every detail of a finger, such as the distal interphalangeal joint or thumb or unguicular process, needs to be coded with the number for “finger”.) Realistically, the search for correlative imaging data will likely be performed for the term “hand” and not for “finger”. Because of the hierarchical structure of the APPC, studies of the finger will be found if the search is performed for “hand”, or even for “upper extremity”. As long as the search numbers correspond, the examination will be presented. In our example of a search with the upper extremity coded as 5.1, everything dealing with the arm will be found. If technique, laterality and procedure are set to 0, all modalities, the left and right arm, and all existing procedures will be indicated. If the anatomy code is 5.1.1 only, all details of the shoulder will be indicated, and if it is 5.1.1.1, only studies of the scapula will be indicated. Clearly, for data searching in “foreign” PACS, it is better not to over-specify because this could suppress relevant data. The code is organised in numeric “words”, divided by periods (much like IP addresses), where the “letters” of the “words” can have one or more digits to allow for unlimited expandability. Because a “letter” can contain more than one digit, the “letters” need to be hyphenated. Table 1 demonstrates the hierarchical coding of the APPC. The entire APPC is listed in Table 2. We recommend viewing the code on the website, www.bura.at Examples of APPC coding are given in Table 3; examples of search tasks and the necessary or possible filtering are given in Table 4.

APPC propagation The concept of the APPC was presented in March 2009 at the ECR in Vienna in a special session dealing with the

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Table 1 Hierachical coding of APPC Anatomy 5-1 5-1-1 5-1-1-1 5-1-1-2 5-1-1-3 5-1-1-4 5-1-2 5-1-3 5-1-4 5-1-5 5-1-6 5-1-7 5-1-7-1

5 5 5 5 5 5 5 5 5 5 5 5 5

1 1 1 1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 2 3 4 5 6 7 7

1 2 3 4

1

Upper extremity Shoulder Scapula Clavicle Sternoclavicular joint Acromio-clavicular joint Axilla Arm Elbow Forearm Wrist Hand Finger

connection of medical computer networks. The idea was warmly welcomed by the industry and by the PACS vendors who attended the conference. The consensus was that a reasonable, broadly accepted standard would ease the implementation process of PACS in any department and be beneficial in data communication between the PACS of different vendors. Providing the code free of charge was viewed as a good stimulus to establish a standard very quickly. The function of the APPC as a “translation table” between vendor-specific proprietary coding systems would protect the vendor’s investments and not interfere with future advancements and developments of all vendors. In April 2009, the APPC was presented at the “IHE Connect-a-thon” (again in Vienna, Austria) with essentially the same reception by the audience.

Discussion Standards enable smooth interaction among many different systems. This is true for normal street traffic, where millions share the streets and other infrastructure with very few accidents, and it is true for the IT world. Only with complex standards is it possible to send and receive a fax from Japan, in Europe, or to take a phone call from London on your cellular phone in New York. The same is true for medical IT. DICOM and HL7 have taken care of many interactions on a more technical basis. The retrieval of old studies from one’s own or a “foreign” PACS is a task not easily defined by technicians, but, ideally, by radiologists because they know what they need and want to obtain. APPC and other coding systems

Existing coding systems, in most cases, were developed from accounting or reimbursement points of view or for educational purposes [6, 17–28]. Others were developed based on a scientific desire to file interesting cases and find them again. There have been attempts to code

everything in all of medicine—a task that can never be completed. SNOMED CT® [22] (Systematized Nomenclature of Medicine Clinical Terms) and MeSH (Medical Subject Headings), as well as UMLS [29] (Unified Medical Language System), try to standardise medical vocabulary to support the automated retrieval of medical literature [30]. ICD 9 (10) CM [31] (International Classification of Diseases Clinical Modifiers) tries to standardise the terms used to describe diseases. LOINC® [18, 19] (Logical Observation Identifiers Names and Codes) standardises procedures primarily, but not only for laboratory work. RADLEX® [32] is a lexicon for uniform indexing and retrieval of radiology information resources. Many of these systems do, in part, include descriptions of anatomy and radiological procedures, but none of these systems ideally fits our purposes for the development of the APPC. There are already numerous projects on the way providing electronic health records for extensive populations like US Indian Health Service (USA) [33], the Veterans Health Information Systems and Technology Architecture (VistA, USA) [34], the National Health Service system (NHS, England), HealthConnect (Australia) [35], Alberta Netcare (Canada) [36] and others. Nationwide multivendor PACS generally need tools for trans-organisational image search and retrieval. Therefore, in all countries implementing such networks, the necessity of a nationwide “metacode” for all radiological procedures arises. The single vendor’s proprietary PACS codes are in a first step mapped with those national “metacodes”. In England the NHS uses a code called “NICIP” (National Interim Clinical Imaging Procedures) derived from SNOMED CT® using a six-character alphabetic code, constructed to a formula developed by the Royal College of Radiologists [37]. Others use SNOMED CT® directly or developed another national “metacode”, as Austria did with the APPC. In coding we do not see much difference between NICIP and APPC; for retrieval, we think the APPC is more practical than the NICIP because the hierarchical structure supports the identification of all previous procedures on a certain part of the body. As long as there is no widely accepted “global metacode”, mappings between different national “metacodes” can support transnational PACS access. So, for example, a mapping of the APPC with the NICIP would easily be possible if necessary. Many systems are vendor-specific and, realistically, licensing problems would arise if a vendor-specific solution were promoted as the new standard. Thus, after a long period of research to determine the most suitable code, the task force concluded that there was no coding system with the ideal granularity and developed a suitable code itself. A suitable code overcomes the problem of living language in redundantly naming procedures, like chest, thorax, heart and lung, which could all be connected to the same number and therefore be automatically found even in different languages, such as German, English, Russian or Hindi (Fig. 2).

0

Undefined

X-ray CT

MRI 3 Ultrasound 4 Nuclear medicine 5 PET

0

1 2

3 4 5 6

1 2

Code Description

Code Description

2 2 2 2 2 2 2 2 2 3 4 5 6

1-2-1-3 1 1-2-2 1 1-2-2-1 1 1-2-2-2 1 1 1 1 1 1 1 1 1 1

1 2

2 2 2 2 2

2 2 2 2 2

1-2-2-3 1-2-3 1-2-3-1 1-2-3-2 1-2-3-3 1-3 1-4 1-5 1-6

1-7 2

2-1 2-2 2-3 2-3-1 2-3-2

2-3-3 2-3-4 2-3-5 2-3-6 2-3-7

3

3 3 3 3

1 2 3 3 3

7

2

1-2-1-2 1

1

1 2 2 2

0 1

0

7

3 4 5 6

1 2

2 3 3 3 3

2

1 2 2

1

1 1

1 2 3

3

2

1

3

2

1

Conventional tomography Imaging of preformed ductal structures Enteroclysis Imaging of vessels Imaging of arteries Without contrast (colour-coded Doppler, phase contrast MRI, etc.) With contrast material (i.v. MR angio, iv. DSA, etc.) Catheter (invasive, selective, etc.) Imaging of veins Without contrast (colour-coded Doppler, phase contrast MRI , etc.) With contrast material (phlebography, etc.) Catheter (invasive, selective, etc.) Imaging of lymphatic vessels Without contrast with contrast material Catheter Fistulography Myelography Arthrography Retrograde contrast application (e.g., pyelography, urethrography, vesicography, ureterography, hysterosalpingography, ERCP, etc.) Endocavitary application Quantitative analyses/secondary reconstructions from imaging data Osteodensitometry Dental CT Recalculations from datasets Volumetry Colour-coding, flow measurements, intensity profiles, perfusion timedensity profiles in contrast enhancement, etc. MPR 3D/4D HR Recalculated images of vessels and ducts Virtual endoscopy

Undefined

L 1 L 2 L 3 L4 Description

1 1 1 1

0-1 1

0

Code

Procedures

Bilateral 1-1 Unpaired organ 1-2 Atypical situation (e.g., transplant) 1-2-1 1-2-1-1

Right Left

Undefined

Laterality

“Modality”

3-1-1

2-5 2-6 3 3-1

2 2-1 2-2 2-3 2-4

1-2-7 1-2-7-1

1-2-2 1-2-2-1 1-2-2-2 1-2-2-3 1-2-2-4 1-2-3 1-2-4 1-2-5 1-2-6

1-2-1-1

1-1-2 1-2 1-2-1

1-1-1

0-3 0-4 1 1-1

0-1 0-2

0

Code

Anatomy

3

2 2 3 3

2 2 2 2 2

1 1

1 1 1 1 1 1 1 1 1

1

1 1 1

1

0 0 1 1

0 0

0

1

1

5 6

1 2 3 4

2 2

2 2 2 2 2 2 2 2 2

2

1 2 2

1

1

3 4

1 2

1

7 7

2 2 2 2 2 3 4 5 6

1

1

2

1

1

1 2 3 4

1

Bronchi

Oesophagus (cervical) Larynx Thorax Lung

Neck Trachea Thyroid gland Parathyroid gland Pharynx

Salivary glands Duct of salivary gland

Jaws Maxilla Mandible Temporomandibular joint Tooth Paranasal sinuses Temporal bone Base of skull Nasal bone

Lacrimal canaliculus

Sella turcica Face Orbit

Cerebellum

Partial body Fetus Head Brain

Imaging without regional anatomic definition Whole body Trunk

L 1 L 2 L 3 L 4 L5 Description

Table 2 APPC. We recommend viewing the code on the Internet (www.bura.at) where a printable version is provided for downloading

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Laterality

Code Description

“Modality”

Code Description

Table 2 (continued)

2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

3-1 3-2 3-3 3-3-1 3-3-2 3-3-3 3-3-4 3-3-5 3-3-6 3-3-7 3-3-8 3-4 3-5 3-5-1 3-5-2 3-5-3 3-5-4 3-5-5 3-5-6 3-5-7 3-6 3-6-1 3-6-2 3-6-3 3-7 3-7-1 3-7-2 3-7-3 3-7-4 3-7-5 3-7-6 3-7-7 3-7-8 3-8 3-9 3-9-1 3-9-2 3-9-3

7 7 7 7 8 9 9 9 9

7

7 7 7

6 6 6 6 7

5 5 5 5 5

5 5

3 3 3 3 3 3 3 3 4 5

1 2 3

6 7

1 2 3

5 6 7 8

4

1 2 3

1 2 3

3 4 5 6 7

1 2

1 2 3 4 5 6 7 8

Measurements of angles and axes Spectroscopy Videographic assessment of movement studies Image fusion Navigation Documentation of interventions via artificial access Needle biopsy/puncture Vacuum-assisted needle biopsy (Long-term) catheter placement/ drainage/stoma Permacath Portacath Catheter-drainage TIPPS Percutaneous gastrostomy Nephrostomy Pacemaker Endovascular ultrasound Bougienage Dilatation/recanalisation/removal of calculi/foreign bodies Thrombo-fibrinolysis Embolectomy/thrombectomy / recanalisation Balloon dilatation Stent Stent-graft Filter (vena cava filter) Removal of calculi or foreign bodies Embolisation Organ Aneurysm Arterio-venous malformation Local application of drugs/energy/ local sampling Nucleolysis Blockade of ganglia (ganglia block) Facet joints [facet joint intervention (infiltration)] Radiofrequency ablation/ thermoablation Cryoablation Laser ablation Alcohol ablation Venous sampling Vertebroplasty, kyphoplasty Markers Wire Coloured particles (dye) Radioactive substances (radiopharmaceutical particles) 2-6 2-7 3

8

2 2 2

2-3-8 2-4 2-5

3 4 5

L 1 L 2 L 3 L4 Description

Procedures Code

Anatomy

4-5-5 4-5-6 4-5-7 4-6 5 5-1 5-1-1 5-1-1-1 5-1-1-2

4-5-4

4-5-1 4-5-2 4-5-3

4-4-2 4-4-3 4-4-4 4-4-5 4-5

4-2-3-2 4-3 4-4 4-4-1 4-4-1-1

4-2-3 4-2-3-1

3-5-3 4 4-1 4-1-1 4-1-1-1 4-1-2 4-1-2-1 4-2 4-2-1 4-2-2

3-5 3-5-1 3-5-2

3-3-2 3-3-3 3-4

3-2 3-3 3-3-1

Code

4 4 4 4 5 5 5 5 5

4

4 4 4

4 4 4 4 4

4 4 4 4 4

4 4

3 4 4 4 4 4 4 4 4 4

3 3 3

3 3 3

3 3 3

1 1 1 1

5 5 5 6

5

5 5 5

4 4 4 4 5

2 3 4 4 4

2 2

1 1 1 1 1 2 2 2

5

5 5 5

3 3 4

2 3 3

1 1 1

5 6 7

4

1 2 3

1 2

1

1 1 2 3 4 5

2

1

1

1

3

3 3

1 2

1 1 2 2

3

1 2

2 3

1

Prostate Scrotum/testis Penis Abdominal wall Musculoskeletal Upper extremity Shoulder Scapula Clavicle

Pregnancy

Uterus Fallopian tubes Ovary

Ureter Urinary bladder Urethra NTX (renal transplant) Lower abdomen/pelvis

Rectum Adrenal glands Urinary tract Kidney Renal pelvis

Bowel Appendix

Ribs Abdomen Upper abdomen Liver/spleen Gallbladder/bile duct Pancreas Pancreatic duct Intestinal tract Stomach/duodenum Small intestine

Chest wall Bony thorax Sternum

Valves Conduction system Oesophagus

Mediastinum Heart Myocardium

L 1 L 2 L 3 L 4 L5 Description

2159

Laterality

Code Description

“Modality”

Code Description

Table 2 (continued)

4 4 4 4 4 4

4-14 4-15 4-16 4-16-1 4-16-2 4-16-3

14 15 16 16 16 16 1 2 3

1 2 3

1 2

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4-1 4-2 4-3 4-3-1 4-3-2 4-4 4-5 4-5-1 4-5-2 4-5-3 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13

1 2 3 3 3 4 5 5 5 5 6 7 8 9 10 11 12 13

4

4 Nuclear medicine/imaging with radioactive tracers Perfusion Metabolism/organ function Bone scan Multiple phase Static Receptor scintigraphy Renal scintigraphy Dynamic (ING,CNG,DNG) Static (DMSA) Indirect radionuclide cystography Ventilation GI transit Bone marrow scintigraphy Lymph scintigraphy CSF radionuclide scintigraphy Gallium scan Meckel’s diverticulum scintigraphy Labelled blood cells (GI tract bleeding scintigraphy, leukocyte scintigraphy, platelet scintigraphy) Direct radionuclide cystography Iodine whole body scan Myocardial scintigraphy Myocardial perfusion scintigraphy Radionuclide ventriculography Gated myocardial SPECT

L 1 L 2 L 3 L4 Description

Procedures Code

Anatomy

1 1 1 1 1 1 2 2 2 3 3

1 1 1 1 1 1 1 1 1 1 1 1 1 1

6-1-3-1-1 6 6-1-3-1-2 6

3 3

5

1 2 3 4

7 7 7 7

1 2 3 4 4 5 6 7 7

1 2 3 4 5 6 7 7

1

3

5-3-5 6 6-1 6-1-1 6-1-1-1 6-1-1-2 6-1-1-3 6-1-1-4 6-1-1-5 6-1-2 6-1-2-1 6-1-2-2 6-1-3 6-1-3-1

2 2 2 2 3 3 3 3 3

1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2

1

5 6 6 6 6 6 6 6 6 6 6 6 6 6

5 5 5 5 5 5 5 5 5

5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

5

1 1

1

1 2

1 2 3 4 5

2 3 4 5

1

1

1

4

3

1 2

Heel Metatarsal Tarsal Achilles tendon Spine Cervical spine Thoracic spine Lumbar spine Sacrum/coccyx/sacroiliac joint Total spine Blood vessel Arteries Intracranial Anterior cerebral artery Middle cerebral artery Posterior cerebral artery Basilar artery Cerebral arterial circle Aorta Thoracic aorta Abdominal aorta Aortic branches Neck (carotid artery/ vertebral artery) Common carotid artery External carotid artery

Acromio-clavicular joint Axilla Arm Elbow Forearm Wrist Hand Finger Lower extremity Hip Inguinal region Thigh Knee Patella Leg Ankle Foot Toe

Sternoclavicular joint

L 1 L 2 L 3 L 4 L5 Description

5-2-7-2 5-2-7-3 5-2-7-4 5-2-7-5 5-3 5-3-1 5-3-2 5-3-3 5-3-4

5-1-1-4 5-1-2 5-1-3 5-1-4 5-1-5 5-1-6 5-1-7 5-1-7-1 5-2 5-2-1 5-2-2 5-2-3 5-2-4 5-2-4-1 5-2-5 5-2-6 5-2-7 5-2-7-1

5-1-1-3

Code

2160

Laterality

Code Description

“Modality”

Code Description

Table 2 (continued)

L 1 L 2 L 3 L4 Description

Procedures Code

1 2

1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 1 2 3 4 5 6 7

1 2 2 2 2 2 3 4 5 6 6 7 7 7 7 7

3 3 3 3 3 3 3 3 3 4

1 2 3 4

1

1 2 3 4

6 6 6 6 7 7 7 7 7 1 2 3 4

1 2 3 4

1 2 3 4

3 4

Internal carotid artery Vertebral artery Coronary arteries Pulmonary arteries Visceral arteries Celiac artery Superior mesenteric artery Inferior mesenteric artery Spinal artery Renal arteries Arteries of upper extremity Subclavian artery Arm Forearm Hand Arteries of lower extremity Iliac artery Thigh Leg Foot Dialysis shunt Veins Cerebral sinus Veins of upper extremity Subclavian vein Arm Forearm Hand Superior vena cava Inferior vena cava Hepatic vein Renal vein Spermatic/ovarian vein Veins of lower extremity Iliac vein/veins of leg Thigh Leg Foot Lymphatic vessels Whole body Head Neck Thorax Abdomen Upper extremity Lower extremity Breast Mammary duct Radiograph of specimen 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 7 7 7

1 1 2 3 4 4 4 4 4 5 6

6-1-3-6-1 6-1-3-6-2 6-1-2-6-3 6-1-2-6-4 6-1-3-7 6-1-3-7-1 6-1-3-7-2 6-1-3-7-3 6-1-3-7-4 6-1-4 6-2 6-2-1 6-2-2 6-2-2-1 6-2-2-2 6-2-2-3 6-2-2-4 6-2-3 6-2-4 6-2-5 6-2-6 6-2-6-1 6-2-7 6-2-7-1 6-2-7-2 6-2-7-3 6-2-7-4 6-3 6-3-1 6-3-2 6-3-3 6-3-4 6-3-5 6-3-6 6-3-7 7 7-1 7-2

3 3 3 3 3 3 3 3 3 3 3

6 6 6 6 6 6 6 6 6 6 6

6-1-3-1-3 6-1-3-1-4 6-1-3-2 6-1-3-3 6-1-3-4 6-1-3-4-1 6-1-3-4-2 6-1-3-4-3 6-1-3-4-4 6-1-3-5 6-1-3-6

1 1 1 1 1 1 1 1 1 1 1

L 1 L 2 L 3 L 4 L5 Description

Anatomy Code

2161

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Table 3 Coding examples Barium enema CT colonography Myocardial perfusion scintigraphy

“Modality”

Laterality

Procedure

Anatomy

1 X-ray 2 CT 5 Nuclear medicine

0 Undefined 0 Undefined 0 Undefined

1 Preformed ducts 2-3-7 Virtual endoscopy 4-16-1 Myocardial perfusion scintigraphy

4-2-3 Colon 4-2-3 Colon 3-3-1 Myocardium

At first view, this project seemed easy: we thought we could simply use DICOM and HL7. But, it quickly became apparent that, although the internal organisation of a given radiology department would work fine with DICOM and HL7, in a trans-organisational search, communication and retrieval of electronic datasets would not work. This is because the PACS of different vendors and different radiological organisations are unable to intelligently interpret the content of other PACS. While they can display a list of the whole content of a certain patient’s file, the machines do not “understand” what is behind the word in the list. Thus, the computers would not be able to understand that “chest” and “thorax” basically have the same meaning. Of course, we could live with this problem and devise different adaptations or “workarounds”, but the better solution seemed to be to provide the machines with the tools they need to intelligently interpret the content of the archives to better support radiologists’ work in the future. Task-adapted coding

In the coding of radiological procedures, a single code cannot cover all tasks. If a patient is referred for a chest Xray, the word “chest” is assigned different meanings at all stages of the process. At reception, the data are fed into the radiological system (or automatically transferred from the hospital information system). For the technical personnel, what is needed is clear: in the walking patient, “chest” means PA and lateral films, and in the patient in a wheelchair, only an AP film is required, etc. For the radiologist, it is simply “chest”, and he/she will read whatever is presented. For the accounting personnel, only the reimbursement number will be of importance, and, in many cases, not even the number of films will be relevant. Numbers are, by far, less flexible, and computers do not know the “traditions” or “habits” of an organisation. Therefore, a number unambiguously defines one thing and nothing else. We must, therefore, separate mentally the

process we perform, including all the necessary little steps, and devise systems to code these steps as accurately and completely as possible. In the case of a referral, for example, we, therefore, must specify which chest X-ray we want: PA, AP, left lateral, right lateral, decubitus or oblique; all other possibilities will have to be defined in advance, because, in a fully connected digital world, our request cannot be executed if there is no number for the task we want to perform. At the technological level, we will then have to tabulate all the radiological expositions we can imagine (both for the left and the right side of the body) to let the system know what is involved with a specific exposure. Only this allows for a predefined arrangement of “films” on a workstation (formerly known as a view box), because if the computer does not know on which film the right AP knee is displayed, or which film shows the right lateral knee, and so forth, it will not be able to display the examination to the radiologist’s satisfaction and, at the same time, expedite the workflow. For the radiologist, the APPC should handle several problems. Unambiguously numbered anatomy and procedures help to find relevant historic imaging data in one’s own and also “foreign” PACS. Ideally, our hanging protocols will work with “foreign” material as well—but, this will, again, require a standardisation procedure for all imaginable radiological expositions of all imaginable organs of the human body. Finally, at the accounting level, the assignation of numeric codes is currently covered best, by far. For all hospitals and medical insurance institutions, there are numbered codes in place, which are the basis of billing reimbursement. For radiologists, it will be of interest to connect those accounting data to the APPC in order to get a fair benchmark between different radiological institutions, as reimbursement data tend to distort the results of comparisons between different systems. National and international benchmarks would probably be fairer if based on APPC counts rather than on reimbursement data.

Table 4 Filtering to find relevant imaging data All All All All All

abdominal studies bowel images CT studies MRI arthrographies of the right knee existing material

“Modality”

Laterality

Procedure

Anatomy

0 0 2 3 0

0 0 0 1 0

0 0 0 1-5 0

4 4-2-3 0 5-2-4 0

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APPC and physical storage media

The APPC was meant to improve data exchange between the PACS of different organisations. At the moment, much data communication is implemented and stored on CD ROM or DVD [38]. This is a major obstacle in the radiologist’s daily work, as most data discs contain a proprietary viewer, which may or may not copy to the hard disc, and is not easily removed. Very often, the data cannot be opened, displayed or quickly screened, either because the foreign disk causes compatibility problems (or a real “crash”) on the workstation or because of unfamiliarity with the viewer. Several solutions to cope with this challenge were developed. Specialised software is able to read and import imaging data from multiple PACS vendors’ CDs into the user’s own PACS and to display those images with the user’s own viewer [39, 40]. If those discs contained a reference to the APPC of the imaged organ, the handling inside one’s own PACS would be greatly eased, as the data could simply be copied into the PACS. The images could be viewed fully integrated in a customised environment. Furthermore, this imported material would be found later by intelligent, automated search when requested under the appropriate APPC. Without APPC in most cases the studies would be labelled as “foreign material” inside the PACS. APPC implementation

Implementation of the APPC is a task for the vendors, and it is a relatively easy task to accomplish. The code must be incorporated into the RIS/HIS system, and a reference must be set to the APPC number for all proprietary entries. Thus, the communication with “foreign” systems is handled on the RIS/HIS APPC level, and the work on the workstation as before according to the proprietary nomenclature. Perhaps, in the future, PACS codes will primarily use the APPC as the “proprietary code” and therefore waive the translation process between codes. The current target for the APPC is the header of a CDA document and thus needs to be implemented by the RIS vendors. In the long run, it is desirable to have the coding in the DICOM header on the PACS as well. But this would need definition on a global level. Radiologists should become involved in this implementation process to ensure that every proprietary anatomical detail and radiological procedure is correctly correlated with an APPC number, as technicians very often lack the knowledge to perform this. As soon as this coding is completed, the radiologist will never be in direct contact with the APPC. Although there will be references of more than one detail to the same APPC number, this is not a problem and means only that all those details will be indicated in the search for that specific APPC number. For the developers of radiological workstations, much work remains to be done. The winner of this development process will be the vendor who provides us with the most

versatile and efficient search tools for “foreign” PACS. Of course, all other features for efficient workstation reading remain on the agenda, such as optimal hanging protocols, tools for image analysis and so forth. One major tool will be the predefinition of which other APPC codes should be searched if there is an examination that falls under a specific APPC coding. Ideally, there should be defaults set for the beginner, but with options to redefine the search according to each radiologist’s needs. APPC limitations

The inner logic of any code is not entirely sustainable; every code has holes and inconsistencies, and must be assessed pragmatically. In our case, the limitation to four axes requires dealing with entries that were not agreed upon by everyone, but that were the result of the Austrian ballot process. In addition, in the radiological tradition, Angiography and Fluoroscopy might normally be considered separate “modalities”—we viewed those as “radiological procedures”, but granted CT the status of a specific “modality”. We did so to keep the code as simple as possible with the main goal being to enable an automated search in “foreign” PACS. We are aware that the inner logic of this code is not 100% perfect, but we think it works well. Some hospital chains in Austria have already incorporated the APPC into their computer networks to spark image transfer between hospitals and private offices, and, in this way, reduce or eliminate redundant imaging, which is not cost-effective and increases radiation exposure. It might be argued to even go further in the coding and include whether the result of a study is positive or negative or inconclusive. Although this sounds reasonable, it cannot be done since, at least under Austrian privacy law, the metadata information of the CDA document header must not contain any relevant medical information. For Austria as for all other countries implementing an electronic health record, a national patient index will be established providing a unique ID number for all residents. A “global” ID number for transnational retrieval seems not realistic at the moment. So at this time only name and date of birth seem to be a working option since most systems would tolerate being accessed by name and date of birth as an alternative approach substituting the unique ID.

Outlook One point seems of paramount importance: The APPC must be unambiguously used in all systems. It is mandatory that the users not have to key in any numbers, because this will lead to mistyping and studies in the PACS that no one can find again. The APPC ideally works in the background, providing the user with pull-down

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menus in his/her normal language and vocabulary for all searches that need to be done in modern workstation reading. New tools must be developed to cope with the challenges of a totally cross-linked medical environment with an enormous volume of data for each individual. With an awareness of these systems that will make a large amount of data readily accessible in the future, it is mandatory that radiology leaders try to discover ways to deal with the flood of information and imaging data that will occur when every single X-ray of every patient is available. For example, we want to avoid the situation where radiologists could be held accountable for every misinterpretation that might have been avoided if only one had had a look at the 3-year-old CT study from another hospital.

The workload in radiology is ever increasing, and we face an international shortage of radiologists. Thus, we need every bit of help we can get to expedite our reading on workstations. The electronic patient record may improve that problem, and will almost certainly improve patient care if the imaging data from every patient’s life are available at the moment of reading the actual study. We hope the radiological community in other countries will find our work useful and that industry will incorporate it into their systems to enable trans-organisational data retrieval. Our hope is to ignite a spark for a global coding system developed by radiologists for radiologists. Acknowledgements We thank Mrs. Mary McAllister for proof reading and editing the manuscript.

References 1. Mosser H, Urban M, Durr M, Ruger W, Hruby W (1992) Integration of radiology and hospital information systems (RIS, HIS) with PACS: requirements of the radiologist. Eur J Radiol 16:69–73 2. Oosterwijk H (1998) DICOM versus HL7 for modality interfacing. J Digit Imaging 11:39–41 3. Pelikan E, Kotter E, Jager D, Langer M, Timmermann U (1999) Modern network technologies for data communication in the hospital. Radiologe 39:292–297 4. Pelikan E, Kotter E, Timmermann U (2001) Networks in the radiology department and the hospital. Eur Radiol 11:337–345 5. Schrader U, Kotter E, Pelikan E, Zaiss A, Timmermann U, Klar R (1997) Critical success factors for a hospitalwide PACS. Proc AMIA Annu Fall Symp 439–443 6. Blazona B, Koncar M (2007) HL7 and DICOM based integration of radiology departments with healthcare enterprise information systems. Int J Med Inform 76:S425–S432 7. Hruby W, Mosser H, Urban M et al (1994) Clinical experiences with PACS: digital radiology. Radiologe 34:291– 299 8. Developement OfEC-Oa (2009) OECD Health Data 9. ARGE AEG (2009) ARGE ELGAArbeitsgemeinschaft Elektronische Gesundheitsakte. Available via http:// www.arge-elga.at. Accessed 3 Sept 2009 10. Board H (2008) Store-Health Level Seven. Available via HL7 Home. https://www.hl7.org/store/index.cfm. Accessed 22 Aug 2009

11. Committee CaS (2007) NEMA-2007DICOM-FULLSET. Available via NEMA-National Electrical Manufacturers Association. http://www. nema.org/stds/2007-DICOMFULLSET.cfm. Accessed 3 Sept 2009 12. Langlotz CP (2006) RadLex: a new method for indexing online educational materials. Radiographics 26:1595–1597 13. Marwede D, Daumke P, Marko K, Lobsien D, Schulz S, Kahn T (2009) RadLex-German version: a radiological lexicon for indexing image and report information. Rofo 181:38–44. doi:10.1055/s-2008-1027895 14. Partan G, Kainberger F, Fruhwald F (2008) Referral guidelines in diagnostic imaging. Radiologe 48:268–271. doi:10.1007/s00117-008-1618-9 15. Frühwald F, Imhof H, Kletter K, Stiskal M (2006) Orientierungshilfe Radiologie-Anleitung zum optimalen Einsatz der klinischen Radiologie. Verlagshaus der Ärzte, Vienna 16. Sabutsch S (2009) Health-IT Standardisierungsorganisationen in Österreich vereinbaren Kooperation. HL7-Mitteilungen 25:21–23 17. ACR ((2004–2009)) The ACR Radiology Coding Source™. Available via The official Web Site of the American College of Radiology. http:// acr.org/SecondaryMainMenuCategories/ ACRStore/FeaturedCategories/econ/ TheACRRadiologyCodingSource.aspx. Accessed 22 Aug 2009 18. Committee L (2009) LOINC 2.27. Available via Logical Observation Identifiers Names and Codes. www. loinc.org. Accessed 22 Aug 2009 19. Dugas M, Thun S, Frankewitsch T, Heitmann KU (2009) LOINC codes for hospital information systems documents: a case study. J Am Med Inform Assoc 16:400–403

20. Edelberg C (2004) Emergency department coding and billing. Emerg Med Clin North Am 22:131–151. doi:10.1016/S0733-8627(03)00098-1 21. Miller J, Lineberry J (2004) Coding for effective denial management. Radiol Manage 26:18–21 22. NLM USNLoM (2008) SNOMED Clinical Terms® (SNOMED CT®). Available via United States Library of Medicine, National Institutes of Health. http://www.nlm.nih.gov/research/umls/ Snomed/snomed_main.html. Accessed 3 Sept 2009 23. Phillips CD, Hillman BJ (2001) Coding and reimbursement issues for the radiologist. Radiology 220:7–11 24. Price P (2002) Fundamentals of coding and reimbursement. Radiol Technol 74:123–129 quiz 130–124 25. Renfrew DL, Bass SH, Albanese MA, Whitis BM (1992) Hypercard coding system for the ACR Index for Radiological Diagnoses. AJR Am J Roentgenol 158:669–672 26. Rosenbloom ST, Brown SH, Froehling D et al (2009) Using SNOMED CT to represent two interface terminologies. J Am Med Inform Assoc 16:81–88 27. Yam CS, Kruskal J, Sitek A, Larson M (2004) A Web-based ACR index for radiological diagnoses. AJR Am J Roentgenol 183:1517–1521 28. Rosenbloom ST, Miller RA, Johnson KB, Elkin PL, Brown SH (2006) Interface terminologies: facilitating direct entry of clinical data into electronic health record systems. J Am Med Inform Assoc 13:277–288 29. NLM USNLoM (2008) Unified Medical language System. Available via United States Library of Medicine, National Institutes of Health. http://www.nlm.nih. gov/research/umls/. Accessed 3 Sept 2009

2165

30. Lindberg DA, Humphreys BL, McCray AT (1993) The unified medical language system. Methods Inf Med 32:281–291 31. CDC CfDCaP (2009) ICD-10-CM Classification of Diseases, Functioning, and Disability. Available via Classification of Diseases, Functioning, and Disability. http://www.cdc.gov/ nchs/icd/icd10cm.htm#09update. Accessed 3 Sept 2009 32. Committee RS (2008) Radlex: A Lexicon for Uniform Indexing and Retrieval of Radiology Information Resources. In: Radiological Society of North America. http://rsna.org/radlex. Accessed 3 Sept 2009 33. Services USDoHaH (2009) Indian Health Service. Available via www.ihs. gov/cio/EHR/index.cfm. Accessed 15 Dec 2009

34. Affairs USDoV (2009) Profiles for the VistA Imaging and Commercial PACS DICOM Interface. Available via www1. va.gov/imaging/docs/ VistA_PACS_DICOM_Profile_1_00. pdf. Accessed 15 Dec 2009 35. Department of Health and Ageing CG (2009) Health Connect. Available via http://www.healthyactive.gov.au/ internet/main/publishing.nsf/Content/ eHealth. Accessed 15 Dec 2009 36. Alberta Go (2009) Alberta Netcare. Available via http://www.albertanetcare. ca/212.htm. Accessed 15 Dec 2009 37. Arrowsmith I, Braithwaite M (2009) National Interim Clinical Imaging Procedures to support PACS/RIS implementations. Available via http:// www.connectingforhealth.nhs.uk/ systemsandservices/data/terminology/ imaging/interim.pdf. Accessed 25 Dec 2009

38. Mildenberger P, Kotter E, Riesmeier J et al (2007) The DICOM-CD-Project of the German Radiology Association—an overview of the content and results of a pilot study in 2006. Rofo 179:676–682. doi:10.1055/s-2007-963122 39. van Ooijen PM, Guignot J, Mevel G, Oudkerk M (2005) Incorporating outpatient data from CD-R into the local PACS using DICOM worklist features. J Digit Imaging 18:196–202. doi:10.1007/s10278-005-5158-9 40. van Ooijen PM, Roosjen R, de Blecourt MJ, van Dam R, Broekema A, Oudkerk M (2006) Evaluation of the use of CDROM upload into the PACS or institutional web server. J Digit Imaging 19(Suppl 1):72–77. doi:10.1007/ s10278-006-0932-x