AUTOMATIC ACQUISITION OF CT RADIATION DOSE DATA: USING THE DIAGNOSTIC REFERENCE LEVEL FOR RADIATION DOSE OPTIMIZATION.

The present work describes that we try to construct a system that collects dose information that performed CT examination from multiple facilities and unified management. The results of analysis are compared with other National diagnostic reference level (DRL), and the results are fed back to each facility and the cause of the abnormal value is investigated for dose optimization. Medical information collected 139 144 tests from 33 CT devices in 13 facilities. Although the DRL of this study is lower than that of Japan DRL, it was higher than the DRL of each country. When collecting all the examination, it is thought that the variation of the dose due to the error other than the intended imaging site is large. In future, we should continue to collect information in order to DRL renewal and we also think that it is desirable to collect information on physique and detailed scan region as well.

Construction of mammographic examination process ontology using bottom-up hierarchical task analysis.

Describing complex mammography examination processes is important for improving the quality of mammograms. It is often difficult for experienced radiologic technologists to explain the process because their techniques depend on their experience and intuition. In our previous study, we analyzed the process using a new bottom-up hierarchical task analysis and identified key components of the process. Leveraging the results of the previous study, the purpose of this study was to construct a mammographic examination process ontology to formally describe the relationships between the process and image evaluation criteria to improve the quality of mammograms. First, we identified and created root classes: task, plan, and clinical image evaluation (CIE). Second, we described an "is-a" relation referring to the result of the previous study and the structure of the CIE. Third, the procedural steps in the ontology were described using the new properties: "isPerformedBefore," "isPerformedAfter," and "isPerformedAfterIfNecessary." Finally, the relationships between tasks and CIEs were described using the "isAffectedBy" property to represent the influence of the process on image quality. In total, there were 219 classes in the ontology. By introducing new properties related to the process flow, a sophisticated mammography examination process could be visualized. In relationships between tasks and CIEs, it became clear that the tasks affecting the evaluation criteria related to positioning were greater in number than those for image quality. We developed a mammographic examination process ontology that makes knowledge explicit for a comprehensive mammography process. Our research will support education and help promote knowledge sharing about mammography examination expertise.

Development of Clinical Database System Specialized for Heavy Particle Therapy.

We have developed a data archiving system for study of charged particle therapy. We required a data-relation mechanism between electronic medical record system (EMR) and database system, because it needs to ensure the information consistency. This paper presents the investigation results of these techniques. The standards in the medical informatics field that we focus on are Integrating the Healthcare Enterprise (IHE) and 2) Health Level-7 (HL7) to archive the data. As a main cooperation function, we adapt 2 integration profiles of IHE as follows, 1) Patient Administration Management (PAM) Profile of IHE-ITI domain for patient demographic information reconciliation, 2) Enterprise Schedule Integration(ESI) profile of IHE-Radiation Oncology domain for order management between EMR and treatment management system(TMS). We also use HL7 Ver2.5 messages for exchanging the follow-up data and result of laboratory test. In the future, by implementation of this system cooperation, we will be able to ensure interoperability in the event of the EMR update.

Constructing mammography examination process ontology using affinity diagram and hierarchical task analysis.

Mammography is complex and difficult for beginner radiologic technologists (RTs) because knowledge and technical skills rely on one's experience, and it is often difficult for experienced RTs to verbally explain the process to co-workers or beginners. The purpose of this study was to construct a mammography examination process ontology for knowledge sharing among RTs and propose a new ontology construction method using an affinity diagram (AD) and hierarchical task analysis (HTA). First, tasks collected by brainstorming were clustered and connected using the AD. Subsequently, a hierarchical structure was constructed based on the clusters and relations determined in the AD. Finally, a mammography process ontology was determined based on the relations noted in the AD and HTA. As a result, the ontology contained 203 classes and 669 relations.

Development of terminology for mammographic techniques for radiological technologists.

We are developing a mammographic ontology to share knowledge of the mammographic domain for radiologic technologists, with the aim of improving mammographic techniques. As a first step in constructing the ontology, we used mammography reference books to establish mammographic terminology for identifying currently available knowledge. This study proceeded in three steps: (1) determination of the domain and scope of the terminology, (2) lexical extraction, and (3) construction of hierarchical structures. We extracted terms mainly from three reference books and constructed the hierarchical structures manually. We compared features of the terms extracted from the three reference books. We constructed a terminology consisting of 440 subclasses grouped into 19 top-level classes: anatomic entity, image quality factor, findings, material, risk, breast, histological classification of breast tumors, role, foreign body, mammographic technique, physics, purpose of mammography examination, explanation of mammography examination, image development, abbreviation, quality control, equipment, interpretation, and evaluation of clinical imaging. The number of terms that occurred in the subclasses varied depending on which reference book was used. We developed a terminology of mammographic techniques for radiologic technologists consisting of 440 terms.

Quantitative evaluation of expression difference in report assignments between nursing and radiologic technology departments.

Our purpose in this study was to investigate the expression differences in report assignments between students in nursing and radiologic technology departments. We have known that faculties could identify differences, such as word usage, through grading their students' assignments. However, there are no reports in the literature dealing with expression differences in vocabulary usage in medical informatics education based on statistical techniques or other quantitative measures. The report assignment asked for students' opinions in the event that they found a rare case of a disease in a hospital after they graduated from professional school. We processed student report data automatically, and we applied the space vector model and TF/IDF (term frequency/inverse document frequency) scoring to 129 report assignments. The similarity-score distributions among the assignments for these two departments were close to normal. We focused on the sets of terms that occurred exclusively in either department. For terms such as "radiation therapy" or "communication skills" that occurred in the radiologic technology department, the TF/IDF score was 8.01. The same score was obtained for terms such as "privacy guidelines" or "consent of patients" that occurred in the nursing department. These results will help faculties to provide a better education based on identified expression differences from students' background knowledge.