Department of Radiology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Division of Obstetrics and Gynecology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
Fetal Diagn Ther. 2023;50(2):61-69. doi: 10.1159/000528692. Epub 2023 Mar 22.
Skeletal dysplasias (SDs) are a heterogeneous group of heritable disorders that affect development of bone and cartilage. Because each SD is individually rare and because of the heterogeneity within and among disorders, prenatal diagnosis of a specific SD remains challenging. Molecular genetic diagnosis involves invasive testing, which some patients are not amenable to. Further, genetic analysis is time consuming, and results may not become available in time to make pregnancy management decisions. Low-dose fetal CT can aid in the prenatal evaluation of SDs. The main downside is the low but true risk of fetal radiation exposure. As such, fetal CT should only be performed when there is concern for a severe skeletal dysplasia and the diagnosis is in question after a detailed ultrasound or if molecular genetic testing is unavailable and when prenatal diagnosis may affect management or counseling. Fetal CT should be obtained after consultation with geneticists, maternal-fetal medicine specialists, and fetal radiologists, and sometimes orthopedic surgeons or neonatologists. The purpose of this study was to review the technique of and indications for fetal CT, as well as discuss fetal radiation risk. Illustrative cases will demonstrate when and how CT may be helpful in the diagnosis of SDs.
骨骼发育不良（SDs）是一组遗传性疾病，会影响骨骼和软骨的发育。由于每种 SD 都是罕见的，并且在疾病内部和之间存在异质性，因此对特定 SD 的产前诊断仍然具有挑战性。分子遗传学诊断涉及侵入性测试，有些患者无法接受。此外，基因分析耗时，结果可能无法及时获得，无法做出妊娠管理决策。低剂量胎儿 CT 可辅助 SD 的产前评估。主要缺点是胎儿辐射暴露的风险虽低但真实存在。因此，只有在严重骨骼发育不良存在顾虑、详细的超声检查结果有疑问或分子遗传学检测不可用时，并且产前诊断可能会影响管理或咨询时，才应进行胎儿 CT。在与遗传学家、母胎医学专家和胎儿放射科医生，有时还有骨科医生或新生儿科医生协商后，再进行胎儿 CT。本研究的目的是回顾胎儿 CT 的技术和适应证，并讨论胎儿辐射风险。通过实例说明 CT 在 SD 诊断中的应用时机和方法。
