ORIGINAL ARTICLE Fetal magnetic resonance imaging of skeletal dysplasias Leah A. Gilligan 1 & Maria A. Calvo-Garcia 1,2 & K. Nicole Weaver 3,4 & Beth M. Kline-Fath 1,2 Received: 14 June 2019 /Revised: 19 August 2019 /Accepted: 16 September 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Background Fetal magnetic resonance imaging (MRI) is obtained for prenatal diagnosis and prognostication of skeletal dyspla- sias; however, related literature is limited. Objective The purpose of this study was to define the utility of fetal MRI for skeletal dysplasias and to report MRI findings associated with specific diagnoses. Materials and methods This retrospective study was approved by the institutional review board; informed consent was waived. Women referred for suspected fetal skeletal dysplasia who underwent MRI between January 2003 and December 2018 were included. Definitive diagnoses were determined by genetic testing, autopsy, physical examination and/or postnatal/postmortem imaging. Fetal MRI examinations and reports were reviewed. Descriptive statistics were used to summarize imaging findings. Results Eighty-nine women were referred for fetal MRI for possible skeletal dysplasia. Forty-three (48%) were determined to have a diagnosis other than skeletal dysplasia and nine were excluded for lack of specific skeletal dysplasia diagnosis. Thirty-seven cases of skeletal dysplasia with available fetal MRI and specific diagnosis were included for analysis. Diagnoses included achondrogenesis (n=2), achondroplasia (n=5), Boomerang dysplasia (n=1), campomelic dysplasia (n=2), Jeune syndrome (n=1), Kniest dysplasia (n=1), osteogenesis imperfecta (n=15) and thanatophoric dysplasia (n=10). A specific skeletal dysplasia diagnosis was mentioned in 17/37 (46%) of MRI imaging reports and correct for 14/17 (82%). MRI findings were reported for each specific skeletal dysplasia diagnosis. Conclusion Fetal MRI is a useful diagnostic tool for skeletal dyplasias and excluded the diagnosis in nearly half of referred pregnancies. In addition to providing fetal lung volumes, fetal MRI demonstrates findings of the brain in achondroplasia and thanatophoric dysplasia, of the spine in achondroplasia and achondrogenesis, of the calvarium in osteogenesis imperfecta and thanatophoric dysplasia, and of the cartilage in Kniest dysplasia. Keywords Achondroplasia . Fetus . Magnetic resonance imaging . Osteogenesis imperfecta . Skeletal dysplasia . Thanatophoric dysplasia Introduction Skeletal dysplasias are a large, heterogeneous group of osteochondrodysplasias, or disorders of the skeleton. Skeletal dysplasias manifest with one or more bone findings including abnormal length, shape, number and/or density. They encompass more than 400 specific diagnoses, for which associated mutations in more than 300 genes have been iden- tified and for which phenotypes and outcomes vary, respec- tively, from mild and good to severe and lethal [1]. Grouped together, skeletal dysplasias occur at a rate of 1 in 3,000 to 5,000 live births [2]. Severe skeletal dysplasias are often de- tected by routine prenatal ultrasound (US) examination around 20 weeks’ gestation. Furthermore, antenatal sonogra- phy is highly accurate for predicting the lethality of skeletal * Leah A. Gilligan leah.gilligan@mchs.com 1 Department of Radiology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave., MLC 5031, Cincinnati, OH 45229, USA 2 Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA 3 Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA 4 Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA Pediatric Radiology https://doi.org/10.1007/s00247-019-04537-8