左合 治彦¹, 林 聡¹, 湊川 靖之², 北川 道弘³, 名取 道也⁴

Haruhiko SAGO¹, Satoshi HAYASHI¹, Yasuyuki MINATOGAWA², Michihiro KITAGAWA³, Michiya NATORI⁴

¹国立成育医療センター周産期診療部胎児診療科, ²国立成育医療センター臨床検査部, ³国立成育医療センター周産期診療部, ⁴国立成育医療センター

¹Division of Fetal Medicine, Department of Perinatal Medicine and Maternal Care, National Center for Child Health and Development, ²Department of Clinical Laboratory Medicine, National Center for Child Health and Development, ³Department of Perinatal Medicine and Maternal Care, National Center for Child Health and Development, ⁴National Center for Child Health and Development

キーワード : prenatal ultrasound, ultrasound fetal screening, fetal imaging, fetal diagnosis, prenatal diagnosis

胎児超音波標準検査は，出生前や出生直後の管理・治療を必要とする胎児疾患を見出すことを目的とし，専門検査技師やトレーニングを受けた医師が一定の時間をかけて行う．検査時期は妊娠中後期の妊娠20週と30週の2回で，検査手順は胎児計測，羊水量，胎児形態観察，胎盤・臍帯の順で行う．胎児形態の見方は，頭部（脳室横断面，小脳横断面で大脳，側脳室，小脳）から胸部（四腔断面，three vessel断面，心室流出路で心臓，肺），腹部（胃，腎臓，膀胱）と胎児横断面で観察し，最後に胎児矢状断面で脊椎を観察する．これら診断の要点となる標準14画像を描出して観察する．代表的な胎児疾患として，頭部疾患では脳室拡大，水頭症，全前脳胞症，胸部疾患では先天性横隔膜ヘルニア，先天性肺嚢胞性腺腫様奇形，肺分画症，胸水，心疾患では左心低形成，心房心室中隔欠損，Ebstein奇形，内臓錯位症候群（無脾症候群，多脾症候群），腹壁疾患では腹壁破裂，臍帯ヘルニア，消化器疾患では食道閉鎖，十二指腸閉鎖，小腸閉鎖，腎疾患では水腎症，多嚢胞性異形成腎，多発性嚢胞腎，脊椎疾患では脊髄髄膜瘤，仙尾骨奇形腫を取り上げた．これらの代表的胎児疾患の画像診断の要点について正常像と比較して概説した．

Ultrasound screening of the fetus attempts to identify fetal anomalies that will require treatment either before or after birth. The standard ultrasound screening, conducted by a specially trained sonographer or a trained physician, is usually carried out at 20 and 30 weeks gestation. The ultrasound examination consists of an assessment of fetal growth, amniotic fluid, fetal morphology, and placenta and cord; and the fetus is examined at the head, chest (heart and lungs), abdomen (stomach, kidney, and bladder), and spine. Fourteen fetal ultrasound views are acquired in a standard examination. Images showing important fetal anomalies and requiring diagnosis are selected and compared with normal fetal images. Typical abnormalities include hydrocephalus, holoprocencephaly, diaphragmatic hernia, cystic adenomatoid malformation, bronchopulmonary sequestration, hydrothorax, hypoplastic left heart, atrioventricular septal defect, Ebstein anomaly, heterotaxy syndrome, gastroschisis, omphalocele, esophageal atresia, duodenal atresia, jejunal atresia, hydronephrosis, multicystic dysplastic kidney, polycystic kidney, myelomeningocele, and sacrococcygeal teratoma.