Proposed Workitem: Display mapping and viewing solution for intraoral radiography

Proposed Workitem: Display mapping and viewing solution for intraoral radiography

• Proposal Editor: Akitoshi Katsumata on behalf of the Special Study/Research Project of the Japanese Association for Dental Science and Informatics Committee, the Japanese Society of Oral and Maxillofacial Radiology
• Editor: Yoshihiko Hayakawa
• Date: N/A (Wiki keeps history)
• Version: N/A (Wiki keeps history)
• Domain: Radiology

2. The Problem

Intra-oral radiography has been specifically mentioned in the DICOM Standard since Supplement 32 introduced the intraoral radiograph Io subtype of Dx. Intra-oral radiography is the examination of teeth and their supporting alveolar bone. Multiple teeth, usually from one to four teeth, are depicted on each periapical image, while six to eight tooth crowns are present on most bitewing radiographs. Impacted, or supernumerary teeth are sometimes found, and teeth may be missing congenitally or due to extraction. Hence, there is not a one to one relationship between each tooth and each intra-oral radiographic image.

Full mouth series of intra-oral radiography have a limited number of variations among and within diverse countries. Such a representative series is shown on Page 4, DICOM Suppl. 123: Structured Display, “Figure Use Case-1 Intra-oral Full Mouth Series Structured Display” is but one of many possible image-series for the adult full–mouth survey, and others, such as 1, 2, 4, 6, 8, 10, 12, 14, 20, and 21 image-series as well as the 18 image-series that was shown as but one example. Further there are also series designed for the child dentition and for the edentulous adult. Specific series are ordinarily reflected in a display format solution. The DICOM definition of the relationship between each display disposition and the tooth/teeth group is of value for dental professionals. DICOM Supplement 123 (Structured Display) is flexible for definition of any number of image display boxes for multiple disciplines, rather than specifically predicated on specific dental anatomic sequence.

To define the standards of display formats for intraoral radiography has the capability to reduce cost for PACS systems integrating the dental medicine (dentistry/dental surgery).

3. Key Use Case

As limitations of the current standard, there is no method currently to denote precisely which teeth are present in a given intra-oral radiograph in a given position within a structured display. There is no present method to provide query-retrieve of images containing specific teeth. This is very common procedure during dental treatment. To utilize the coding of teeth to create x-ray charts is necessary for mapping and viewing intraoral radiographs. An interoperable solution is necessary for dental practice.

4. Standards and Systems

This proposal is to define the examination codes for intraoral radiography techniques and the relationship between tooth/teeth group and display disposition and to provide a solution to tooth specific Query-Retrieve for intra-oral radiographic images.

1. Examination codes for intra-oral radiography techniques Developing a new examination code is thought to be convenient to differentiate various techniques in the intraoral radiography examination, such as paralleling, bisecting-angle, bitewing, occlusal and periapical projection.
2. Display format templates A means to specify specific display format templates within DICOM Structured Display is proposed. A finite number of templates are required by certain users and might be achieved by adding a DICOM tag or tags for designation of specific displaying templates. A means of defining the relationship between tooth number (or tooth group) and the display within templates would be sought. This would be a basis for achieving dental query-retrieve for intraoral radiographic images within any given template. This solution would be primarily for intraoral radiographic images, but could also be used for dental photographs, and all other images including teeth and tooth sequence.

5. Discussion

"Dental Mapping and Query-Retrieve” is approved work item by the DICOM Standards Committee, and WG22 (Dentistry) is supportive of this work item for a new DICOM Supplement.

This project would be directed by the Informatics Committee, the Japanese Society for Oral and Maxillofacial Radiology. There is support from several dental companies in Japan and discussions have been made with JIRA (Japan Industries Association of Radiological Systems) and JAMI (Japan Association for Medical Informatics). They have committed to contribute to this standardization actively. Now this is the special research/study project of the Japanese Association for Dental Science.

The Japanese Task Group of the Japanese Society for Oral and Maxillofacial Radiology (JSOMR) carried out a survey of display mapping and viewing solutions for intraoral radiographs in university dental hospitals in Japan. The survey showed the display mapping and format patterns of intraoral radiographs that were used in dental school hospitals in Japan, in Dec. 2010. A finite number of templates were used in university dental hospitals in Japan. To define specific examination codes (DICOM tags) for intraoral radiography techniques and to add tags for designation of specific displaying templates will provide a solution for the dental query-retrieve for intraoral radiographs on any given template by achieving a definition of the relationship between tooth/teeth groups and display disposition.

Should at least consult with IHE Dental, or maybe refer this to them to handle on their own.