[Usefulness of nuclear medicine extension code keeping the integrity with JJ1017].

OBJECTIVE: Working group on JJ1017 nuclear medicine domain extension code in the Japanese Society of Nuclear Medicine has created nuclear medicine extension codes keeping the integrity with JJ1017. The objective of this study was to investigate the usefulness of nuclear medicine extension codes in real clinical settings. METHOD: Nuclear medicine examinations of each institution were extracted from the examination master table and then the target subset of examinations to be coded with JJ1017 were identified. For this subset, working process was conducted, during which the followings compared conformity rate, application rate of representative frequently code set and compliance rate of nuclear medicine extension codes. RESULTS: Without using representative frequently code set, it was difficult to invent the same code for the same examination. By using the representative frequently code set, the same code expression could be invented for the same examination. Furthermore, using nuclear medicine extension codes additionally, these which could not be appropriately coded with representative frequently code set alone. CONCLUSION: Nuclear medicine extension codes keeping the integrity with JJ1017, was proved to be useful to improve the accuracy of coding.

SUBOPTIMAL MODULATION OF RADIATION DOSE IN THE COMPUTED TOMOGRAPHY COMPONENT OF WHOLE-BODY POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY.

Radiation exposure in computed tomography (CT) is automatically modulated by automatic exposure control (AEC) mainly based on scout images. To simulate the whole-body positron emission tomography/CT, CT images of a phantom were obtained using the posteroanterior scout image alone (PA scout) or the posteroanterior and lateral images (PA + Lat scout). Old and new versions of the AEC software were compared. Using the old version of the software and the PA scout, a markedly high dose at the top of the head was observed, which varied depending on the position of the phantom. This issue was resolved in the new version of the software. Radiation dose in the shoulder region was much higher using the PA scout than using the PA + Lat scout, even with the new version of the software. AEC may cause unreasonably high radiation exposure locally, and the appropriateness of the dose modulation pattern should be examined at each facility.