[Current practice of pediatric MDCT in Japan: survey results of demographics and age-based dose reduction].

Purpose: To assess the current practice of pediatric MDCT in Japan, with particular reference to age-related dose adjustment.

Materials and methods: During the first three months of 2004, a questionnaire was mailed to 996 institutions, among which listed MDCT users ranged from private hospitals to large university-based hospitals.

Results: We received responses from 348 (34.9%) institutions. Fifty-three percent of the respondents had four-detector MDCT units. Approximately 70% of examinations were head and 22% were body. Scanning parameters were determined by full-time radiologists in 40%, and by CT technologists in 28% of respondents. Eighty-nine percent (head CT) and 85% (abdominal CT) of respondents indicated that they changed parameters for children. More than 90% changed tube current for optimization. Change was based on the technologist's experience (56%, head CT; 43%, abdominal CT), and automatic exposure control has been used as a basis of mAs control in 17% of respondents for head CT and in 34% for abdominal CT. Age-related mAs settings for abdominal CT were almost the same as those published in a United States survey.

Conclusion: Although Japan has approximately 40% of the world's CT units, optimized pediatric MDCT settings might be moved away from a fixed mA protocol as recommended by the FDA and in conformity with the ALARA (as low as reasonably achievable) concept.