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Structured reporting in gastrointestinal endoscopy:
International Journal of Medical Informatics 48 (1998) 201 – 206
Structured reporting in gastrointestinal endoscopy: Integration with DICOM and minimal standard terminology L.Y. Korman a,*, M. Delvaux b, Dean Bidgood c a
American Society for Gastrointestinal Endoscopy, Veterans Administration Medical Center, Washington, DC, USA b European Society for Gastrointestinal Endoscopy, CHU Rangeuil, Toulouse, France c American College of Radiology, Duke Uni6ersity School of Medicine, Durham, NC, USA
Abstract The interest of the international gastrointestinal endoscopy community in developing standards for endoscopic reporting resulted in a standard lexicon for describing endoscopic findings. It became clear that in order to facilitate the widespread use of this lexicon, a messaging standard which could link images to text had to be adopted. The DICOM 3.0 Standard (digital imaging and communication in medicine) was extended by the introduction of the Visible Light Supplement and the SNOMED-DICOM microglossary. These two standards should expand the ability of DICOM to accomodate endoscopic images and the clinical description of these images. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Endoscopy; Computers; Standards; Images; Terminology; DICOM
1. Introduction The advent of the videoendoscope has revolutionized the practice of gastrointestinal endoscopy [1]. The substitution of the charge-coupled transfer device for fiberoptic image acquisition permits high quality video
* Corresponding author. Present address. Department of Veterans Affairs Medical Center, 50 Irving Street NW, Washington, DC 20422. Tel.: + 1 202 7458151; fax: +1 202 2969122; e-mail: [email protected]
images to be transmitted, captured and stored by modern, high speed integrated circuits. This advance in technology was not accompanied by advances in image documentation or reporting. Rather, the goal of the international endoscopy community has been to create a common lexicon for endoscopy and a common structure for reporting that would facilitate data exchange, database development and outcomes research. Images are critical components of the clinical record. Since the 1970s, when digital images first became widely used in clinical
1386-5056/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S 1 3 8 6 - 5 0 5 6 ( 9 7 ) 0 0 1 2 6 - 3
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L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
Fig. 1. Endoscopy record model.
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
203
Fig. 2. Elements of an endoscopic report organized by object (concept).
practice (with routine use of computerized tomography), there has been an ever-increasing need for a generic image-file format and exchange protocol to enable interchange of diagnostic images and related information in electronic form. The Digital Imaging and Communications in Medicine (DICOM) standard [2] was developed by the American College of Radiology and the National Electrical Manufacturers Association to meet this need [3]. DICOM is a set of engineering specifications for a generic image file format,
a network image-interchange protocol and an explicit semantic data model for images and related information [4]. The DICOM standard has been very favorably received by industry and by professional organizations. Since publication of DICOM in 1993, digital image management systems enabled by DICOM interfaces have been widely implemented in radiology. The task of assembling a digital image management system is less complex but still faces the challenge of indexing and managing the complex information
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L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
that is contained in, or associated with, images. Indexing implies the need for controlled terminology describing the salient properties of the indexed material. In biomedical imaging, this requires controlled terminology for clinically-relevant description of image-acquisition procedures and diagnostic findings. The concept of indexing images can be considered as a subset of endoscopic reporting. It is essential to note that a medical image is of little clinical value without associated data, such as description of the image-acquiTable 1 Elements of an endoscopic report Patient name Address Date of birth Sex SSN Patient ID (internal) Telephone no. (home) Telephone no. (work) Study date (date of procedure) Study time Study type (type of procedure) Referring physician Endoscopist (procedure MD) Endoscopic instrument ASA status Medication Reason for examination Indication Anatomic extent of examination Limitation of examination Complication Finding Site Term Attribute Attribute value Therapeutic procedure Diagnostic impression Diagnostic impression IC9-CM code Pathologic result Final diagnosis Final diagnosis ICD9-CM code Recommendation
sition procedure and identification of the patient, parameters of image acquisition, physical examination findings, laboratory values and past medical history. It is the integration of reporting with images that is the essential goal of the multimedia electronic record. In endoscopy this goal will not be reached unless there is broad international concensus on standards for data exchange, the structure of the report and the lexicon used.
2. The endoscopy model Several international societies in gastrointestinal endoscopy have collaborated with standards development groups to develop a common model for endoscopy and a lexicon which can be readily implemented by existing standards. A model for endoscopy begins with a general drawing of part of the endoscopic process (Figs. 1 and 2; Table 1). Although this modeling may not conform to the formal object modeling process, it represents a clinically logical model which may then be translated through a more formal process into an object model. The strength of this clinically logical model is that it enables specialty groups with little or no formal informatics training to build a clinical concensus around the elements of the report and facilitate the creation and integration of existing data dictionaries. It is important to recognize the arbitrary nature of the grouping. A useful rule is to consider what is fundamental to that concept and is not included in any other concept. The Endoscopy Record Model is under development by the ASGE Informatics Committee as an experiment in the development of an open standard to facilitate data exchange in medical information systems. It builds on existing practice guidelines and in-
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
205
Table 2 Mapping of the Minimal Standard Terminology structural elements into the SNOMED DICOM microglossary MST structural element
SDM structural element
Site: anatomic region
Template for the hierarchy of anatomic descriptors: (region+site+epicenter+locus). Anatomic concepts are represented in SDM context groups for regions (e.g. stomach, colon), sites (e.g. antrum, fundus), epicenters (e.g. extrinsic, intralumenal, wall), and loci (e.g. lumen, contents, mucosa). Surface lesion class: Taxonomy of lesion morphology as viewed from the intralumenal-imaging perspective of endoscopy (i.e. raised, flat, excavated). Note: some MST© classes are represented in the SDM as anatomic observations, or as chemical or biological-product observations (in context groups) at the ‘locus’ level of the anatomic-site hierarchy (e.g. lumen, contents, mucosa) or as clinical diagnosis concepts (e.g. normal). Context groups for morphological, functional, or clinical diagnosis observations. Templates for observation-description. SDM Context groups of properties of morphological or functional observations. Note: some MST© attributes are represented in the SDM as functional, morphological, or clinical diagnosis observations. Context groups for morphological or functional observations. Context groups for names of diagnostic or therapeutic procedures from SNOMED7 or Clinical LOINC8 databases.
Class: logical grouping of terms according to a morphological relationship
Term: observation or concept Attribute: characteristic of a term which is significant in further defining the term.
Attribute value: modifying concept. Therapy: intervention related to observation.
corporates concept modeling from DICOM and HL-7 standards. The goal is to use the resources of the ASGE web site to build a list of all the data elements that can be incorporated into an endoscopic report. An endoscopy record can be thought of as a file which contains a series of documents defined both by national and local standards. The goal is to identify all the possible data elements associated with a record and create a coherent grouping of these elements to facilitate implementation in medical information systems. Initial work by a specialty standards committee defined in a list formulation
those data elements believed to be a minimal part of the standard report of a gastrointestinal endoscopy.
3. Role of the SNOMED DICOM microglossary The integration of gastrointestinal endoscopy into the patient imaging record is facilitated by the introduction of the SNOMED DICOM Microglossary (SDM). The SDM is a database of value sets for DICOM data elements. It supports DICOM
206
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
[5] Supplement 15: Visible Light (VL) and Supplement 23: Structured Reporting (SR), as well as other data-interchange specifications that utilize a similar interdependent message/terminology architecture. In brief, the SDM enables specialists to create templates for the content of specialized reports and suggest value-sets (pick-lists) for the coded-entry fields of the report. Table 2 depicts the schema used for mapping one of the Findings Concepts of the Gastrointestinal Endoscopy Report (Fig. 1) into the SNOMED DICOM microglossary. For representation of terms content in the SDM, the structural elements of the Minimal Standard Technology (MST) are transformed into properties of SDM templates, (i.e. concept-names for which context-dependent value-sets may be defined), SDM context groups, (i.e. context-dependent value sets for coded-entry data elements) or observational concepts (i.e. terms or phrases that are members of a Context Group). The content of the MST [6,7] is fully preserved in the transformation. Relationships defined by the semantic MST network (Fig. 1) may be implemented by defining appropriate relationships between observations in DICOM structured-interpretation messages.
4. Conclusion The cooperation of multiple groups within
.
the medical specialty and between technical and clinical groups holds promise for developing a concensus around an international standard for endoscopic reporting. This endoscopic standard can be used to improve the quality of endoscopic reporting by integrating images and text, create large image bases and facilitate clinical research by use of a common lexicon.
References [1] M.V. Sivak, Video endoscopy, Clin. Gastroenterol. 15 (1986) 205 – 234. [2] Digital imaging and communications in medicine (DICOM), NEMA PS 3 Supplement 15: Visible light image for endoscopy, microscopy and photography, The National Electrical Manufacturers Association, Rosslyn, VA, USA, 1997. [3] Digital imaging and communications in medicine (DICOM). NEMA PS 3 Supplement 23: Structured reporting, The National Electrical Manufacturers Association. Rosslyn, VA, USA, 1997. [4] Digital imaging and communications in medicine (DICOM). NEMA PS 3.1 – PS 3.12. The National Electrical Manufacturers Association, Rosslyn, VA, USA, 1992, 1993, 1995, 1997. [5] W.D. Bidgood Jr., S.C. Horii, Extension of the DICOM standard to new imaging modalities and services, J. Digital Imaging 9 (1996) 67 – 77. [6] Z. Maratka, Terminology, Definitions and Diagnostic Criteria in Digestive Endoscopy, 3rd ed., Normed Verlag, Bad Homburg, 1994. [7] M. Crespi, M. Delvaux, M. Schapiro, C. Venables, F. Zweibel, Minimal standards for a computerized endoscopic database, Am. J. Gastro. 89 (1994) S144 – S153.
Structured reporting in gastrointestinal endoscopy: Integration with DICOM and minimal standard terminology L.Y. Korman a,*, M. Delvaux b, Dean Bidgood c a
American Society for Gastrointestinal Endoscopy, Veterans Administration Medical Center, Washington, DC, USA b European Society for Gastrointestinal Endoscopy, CHU Rangeuil, Toulouse, France c American College of Radiology, Duke Uni6ersity School of Medicine, Durham, NC, USA
Abstract The interest of the international gastrointestinal endoscopy community in developing standards for endoscopic reporting resulted in a standard lexicon for describing endoscopic findings. It became clear that in order to facilitate the widespread use of this lexicon, a messaging standard which could link images to text had to be adopted. The DICOM 3.0 Standard (digital imaging and communication in medicine) was extended by the introduction of the Visible Light Supplement and the SNOMED-DICOM microglossary. These two standards should expand the ability of DICOM to accomodate endoscopic images and the clinical description of these images. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Endoscopy; Computers; Standards; Images; Terminology; DICOM
1. Introduction The advent of the videoendoscope has revolutionized the practice of gastrointestinal endoscopy [1]. The substitution of the charge-coupled transfer device for fiberoptic image acquisition permits high quality video
* Corresponding author. Present address. Department of Veterans Affairs Medical Center, 50 Irving Street NW, Washington, DC 20422. Tel.: + 1 202 7458151; fax: +1 202 2969122; e-mail: [email protected]
images to be transmitted, captured and stored by modern, high speed integrated circuits. This advance in technology was not accompanied by advances in image documentation or reporting. Rather, the goal of the international endoscopy community has been to create a common lexicon for endoscopy and a common structure for reporting that would facilitate data exchange, database development and outcomes research. Images are critical components of the clinical record. Since the 1970s, when digital images first became widely used in clinical
1386-5056/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S 1 3 8 6 - 5 0 5 6 ( 9 7 ) 0 0 1 2 6 - 3
202
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
Fig. 1. Endoscopy record model.
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
203
Fig. 2. Elements of an endoscopic report organized by object (concept).
practice (with routine use of computerized tomography), there has been an ever-increasing need for a generic image-file format and exchange protocol to enable interchange of diagnostic images and related information in electronic form. The Digital Imaging and Communications in Medicine (DICOM) standard [2] was developed by the American College of Radiology and the National Electrical Manufacturers Association to meet this need [3]. DICOM is a set of engineering specifications for a generic image file format,
a network image-interchange protocol and an explicit semantic data model for images and related information [4]. The DICOM standard has been very favorably received by industry and by professional organizations. Since publication of DICOM in 1993, digital image management systems enabled by DICOM interfaces have been widely implemented in radiology. The task of assembling a digital image management system is less complex but still faces the challenge of indexing and managing the complex information
204
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
that is contained in, or associated with, images. Indexing implies the need for controlled terminology describing the salient properties of the indexed material. In biomedical imaging, this requires controlled terminology for clinically-relevant description of image-acquisition procedures and diagnostic findings. The concept of indexing images can be considered as a subset of endoscopic reporting. It is essential to note that a medical image is of little clinical value without associated data, such as description of the image-acquiTable 1 Elements of an endoscopic report Patient name Address Date of birth Sex SSN Patient ID (internal) Telephone no. (home) Telephone no. (work) Study date (date of procedure) Study time Study type (type of procedure) Referring physician Endoscopist (procedure MD) Endoscopic instrument ASA status Medication Reason for examination Indication Anatomic extent of examination Limitation of examination Complication Finding Site Term Attribute Attribute value Therapeutic procedure Diagnostic impression Diagnostic impression IC9-CM code Pathologic result Final diagnosis Final diagnosis ICD9-CM code Recommendation
sition procedure and identification of the patient, parameters of image acquisition, physical examination findings, laboratory values and past medical history. It is the integration of reporting with images that is the essential goal of the multimedia electronic record. In endoscopy this goal will not be reached unless there is broad international concensus on standards for data exchange, the structure of the report and the lexicon used.
2. The endoscopy model Several international societies in gastrointestinal endoscopy have collaborated with standards development groups to develop a common model for endoscopy and a lexicon which can be readily implemented by existing standards. A model for endoscopy begins with a general drawing of part of the endoscopic process (Figs. 1 and 2; Table 1). Although this modeling may not conform to the formal object modeling process, it represents a clinically logical model which may then be translated through a more formal process into an object model. The strength of this clinically logical model is that it enables specialty groups with little or no formal informatics training to build a clinical concensus around the elements of the report and facilitate the creation and integration of existing data dictionaries. It is important to recognize the arbitrary nature of the grouping. A useful rule is to consider what is fundamental to that concept and is not included in any other concept. The Endoscopy Record Model is under development by the ASGE Informatics Committee as an experiment in the development of an open standard to facilitate data exchange in medical information systems. It builds on existing practice guidelines and in-
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
205
Table 2 Mapping of the Minimal Standard Terminology structural elements into the SNOMED DICOM microglossary MST structural element
SDM structural element
Site: anatomic region
Template for the hierarchy of anatomic descriptors: (region+site+epicenter+locus). Anatomic concepts are represented in SDM context groups for regions (e.g. stomach, colon), sites (e.g. antrum, fundus), epicenters (e.g. extrinsic, intralumenal, wall), and loci (e.g. lumen, contents, mucosa). Surface lesion class: Taxonomy of lesion morphology as viewed from the intralumenal-imaging perspective of endoscopy (i.e. raised, flat, excavated). Note: some MST© classes are represented in the SDM as anatomic observations, or as chemical or biological-product observations (in context groups) at the ‘locus’ level of the anatomic-site hierarchy (e.g. lumen, contents, mucosa) or as clinical diagnosis concepts (e.g. normal). Context groups for morphological, functional, or clinical diagnosis observations. Templates for observation-description. SDM Context groups of properties of morphological or functional observations. Note: some MST© attributes are represented in the SDM as functional, morphological, or clinical diagnosis observations. Context groups for morphological or functional observations. Context groups for names of diagnostic or therapeutic procedures from SNOMED7 or Clinical LOINC8 databases.
Class: logical grouping of terms according to a morphological relationship
Term: observation or concept Attribute: characteristic of a term which is significant in further defining the term.
Attribute value: modifying concept. Therapy: intervention related to observation.
corporates concept modeling from DICOM and HL-7 standards. The goal is to use the resources of the ASGE web site to build a list of all the data elements that can be incorporated into an endoscopic report. An endoscopy record can be thought of as a file which contains a series of documents defined both by national and local standards. The goal is to identify all the possible data elements associated with a record and create a coherent grouping of these elements to facilitate implementation in medical information systems. Initial work by a specialty standards committee defined in a list formulation
those data elements believed to be a minimal part of the standard report of a gastrointestinal endoscopy.
3. Role of the SNOMED DICOM microglossary The integration of gastrointestinal endoscopy into the patient imaging record is facilitated by the introduction of the SNOMED DICOM Microglossary (SDM). The SDM is a database of value sets for DICOM data elements. It supports DICOM
206
L.Y. Korman et al. / International Journal of Medical Informatics 48 (1998) 201–206
[5] Supplement 15: Visible Light (VL) and Supplement 23: Structured Reporting (SR), as well as other data-interchange specifications that utilize a similar interdependent message/terminology architecture. In brief, the SDM enables specialists to create templates for the content of specialized reports and suggest value-sets (pick-lists) for the coded-entry fields of the report. Table 2 depicts the schema used for mapping one of the Findings Concepts of the Gastrointestinal Endoscopy Report (Fig. 1) into the SNOMED DICOM microglossary. For representation of terms content in the SDM, the structural elements of the Minimal Standard Technology (MST) are transformed into properties of SDM templates, (i.e. concept-names for which context-dependent value-sets may be defined), SDM context groups, (i.e. context-dependent value sets for coded-entry data elements) or observational concepts (i.e. terms or phrases that are members of a Context Group). The content of the MST [6,7] is fully preserved in the transformation. Relationships defined by the semantic MST network (Fig. 1) may be implemented by defining appropriate relationships between observations in DICOM structured-interpretation messages.
4. Conclusion The cooperation of multiple groups within
.
the medical specialty and between technical and clinical groups holds promise for developing a concensus around an international standard for endoscopic reporting. This endoscopic standard can be used to improve the quality of endoscopic reporting by integrating images and text, create large image bases and facilitate clinical research by use of a common lexicon.
References [1] M.V. Sivak, Video endoscopy, Clin. Gastroenterol. 15 (1986) 205 – 234. [2] Digital imaging and communications in medicine (DICOM), NEMA PS 3 Supplement 15: Visible light image for endoscopy, microscopy and photography, The National Electrical Manufacturers Association, Rosslyn, VA, USA, 1997. [3] Digital imaging and communications in medicine (DICOM). NEMA PS 3 Supplement 23: Structured reporting, The National Electrical Manufacturers Association. Rosslyn, VA, USA, 1997. [4] Digital imaging and communications in medicine (DICOM). NEMA PS 3.1 – PS 3.12. The National Electrical Manufacturers Association, Rosslyn, VA, USA, 1992, 1993, 1995, 1997. [5] W.D. Bidgood Jr., S.C. Horii, Extension of the DICOM standard to new imaging modalities and services, J. Digital Imaging 9 (1996) 67 – 77. [6] Z. Maratka, Terminology, Definitions and Diagnostic Criteria in Digestive Endoscopy, 3rd ed., Normed Verlag, Bad Homburg, 1994. [7] M. Crespi, M. Delvaux, M. Schapiro, C. Venables, F. Zweibel, Minimal standards for a computerized endoscopic database, Am. J. Gastro. 89 (1994) S144 – S153.