title: Thyroid ultrasound findings in children from three Japanese prefectures: Aomori, Yamanashi and Nagasaki.
abstract: Due to the likelihood of physical and mental health impacts following the unprecedented accident at the Fukushima Dai-ichi Nuclear Power Plant, the Fukushima prefectural government decided to conduct the Fukushima Health Management Survey to assist in the long-term health management of residents. This included thyroid ultrasound examination for all children in Fukushima. For appropriate evaluation of ultrasound screening of the thyroid, it is important to understand its reference data of thyroid findings in children in general. In order to analyze the frequencies of specific thyroid findings, we conducted ultrasound screening of the thyroid by the same procedures as used in Fukushima in 4,365 children, aged 3 to 18 years, from three Japanese prefectures. Overall, thyroid cysts were identified in 56.88% and thyroid nodules in 1.65% of the participants. Thyroid cysts and nodules with a maximum diameter of more than 5 mm were identified in 4.58% and 1.01%, respectively, and age-adjusted prevalences were 3.82% and 0.99%, respectively. Although the prevalence of cysts and nodules varied among the examination areas, no significant differences were observed among the three examination areas in the prevalence of cysts and nodules with a maximum diameter of more than 5 mm. Also, the prevalence of thyroid cysts and nodules, especially those with a maximum diameter of more than 5 mm, significantly increased with age, and showed a female predominance. We also identified ectopic thymus (1.95%), diffuse goiter (1.40%), ultimobranchial body (0.73%), lymph node swelling (0.21%) and thyroid agenesis (0.05%). This is the first ultrasound description of the age-adjusted prevalence of thyroid cysts and nodules, or of the prevalence of abnormalities other than cysts and nodules, such as ectopic thymus, in relation to age, in the general Japanese child population. We contend that this can provide relevant information for the Fukushima Health Management Survey and future population studies.
authors.affiliation: Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Hayashida
authors.affiliation: Department of Clinical Studies, Radiation Effects Research Foundation, Nagasaki, Japan.
authors.forename: Misa
authors.initials: M
authors.lastname: Imaizumi
authors.affiliation: Department of Laboratory Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shimura
authors.affiliation: Department of Social Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Okubo
authors.affiliation: Department of Emergency and Disaster Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Asari
authors.affiliation: Department of Endocrinology and Metabolism, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nigawara
authors.affiliation: Department of Radiation Health Management, Fukushima Medical University, Fukushima, Japan.
authors.forename: Sanae
authors.initials: S
authors.lastname: Midorikawa
authors.affiliation: Department of Clinical Laboratory Medicine, Jichi Medical University, Tochigi, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kotani
authors.affiliation: Department of Social Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Nakaji
authors.affiliation: Department of Radiation Health Management, Fukushima Medical University, Fukushima, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Otsuru
authors.affiliation: The First Department of Medicine, Wakayama Medical University, Wakayama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Akamizu
authors.affiliation: Division of Endocrinology and Metabolism, Showa General Hospital, Tokyo, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kitaoka
authors.affiliation: Department of Thyroid and Endocrinology, Fukushima Medical University, Fukushima, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Department of Clinical Laboratory Medicine, Jichi Medical University, Tochigi, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Taniguchi
authors.affiliation: Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan ; Radiation Medical Science Center for the Fukushima Health Management Survey, Fukushima Medical University, Fukushima, Japan.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Yamashita
authors.affiliation: Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Takamura
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003560:Cysts / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D062406:Fukushima Nuclear Accident; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D055848:Nuclear Power Plants; D015995:Prevalence; D011834:Radiation Monitoring; D012737:Sex Factors; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D014463:Ultrasonography