[Development of the method for the similarity detection of descriptions in radiology reports using structuring technology].

Radiologists often spend much time for re-reading some of the past free-text radiology reports and determining interval changes in the physical findings when creating a report for long term cases. The aim of this study was to propose the method to detect semantic similar descriptions in the free-text reports using the structuring method based on text-mining technology. In a previous study, we had developed the structuring method that can semantically analyze the free-text reports and convert them into the description unit consisting of five items: finding/diagnosis, modifier, region, regional modifier, and confidence. Our developed prototype system extracted similar descriptions from the free-text reports by calculating the similarity index between description units. We confirmed similar descriptions extracted by the system applied to free-text reports of cases which had more than one chest CT examination written in actual clinical situation. As a result, it became available to identify candidates of similar descriptions from free-text reports. In some cases regarding practical use, the similar descriptions could not be identified in the sentences which used paraphrasing or where the findings had status changes. A solution of identifying similarity in these cases was necessary to improve the method. With the presented method here, it is expected that interval changes in the findings can be visualized and applied it to support diagnosis.

Vessel wall temperature estimation for novel short term thermal balloon angioplasty: study of thermal environment.

We have been proposing novel thermal balloon angioplasty, photo-thermo dynamic balloon angioplasty (PT-DBA). PTDBA realized <10s short term heating that can prevent surrounding tissue thermal injury and low pressure dilatation that can prevent restenosis in chronic phase. We aim to determine the most efficient heating condition suit to individual symptom with pre-operation thermal simulation. We analyzed the flow dynamics and heat convection inside the balloon, and investigated heat conduction of balloon film to establish the temperature estimation method among vessel wall. Compared with ex vivo temperature measurement experiment, we concluded that the factors need to be considered for the establishment would be the heat conduction of the flow inside PTDB, heat conduction at the balloon film, and contact thermal resistance between the balloon film and vessel wall.