Usha D Nagaraj1, Karin S Bierbrauer2, Charles B Stevenson2, Jose L Peiro3, Foong-Yen Lim3, Bin Zhang4, Beth M Kline-Fath1. 1. 1 Department of Radiology and Medical Imaging, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3026. 2. 2 Department of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH. 3. 3 Department of Pediatric Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH. 4. 4 Department of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH.
Abstract
OBJECTIVE: The purpose of this study was to examine differences between patients with myelomeningocele and those with myelocele with respect to brain imaging findings at fetal MRI. MATERIALS AND METHODS: A single-center retrospective analysis was performed of fetal MRI examinations revealing open spinal dysraphism from 2004 through 2016 with available diagnostic postnatal spinal MR images in conjunction with neurosurgical follow-up findings. Images were reviewed by two board-certified fellowship-trained pediatric neuroradiologists. Relevant clinical data were recorded. RESULTS: The study included 119 fetal MRI examinations of patients with open spinal dysraphism. Myeloceles were found in 29.4% (35/119) of these examinations and myelomeningoceles in the others. All (35/35) myeloceles showed grade 3 (severe) Chiari II malformations. Only 73.8% (62/84) of myelomeningoceles showed grade 3 Chiari II malformation. Clinically significant spinal kyphosis was found in 5.0% (6/119) of fetuses, and all of these fetuses had grade 3 Chiari II malformations. The size of the spinal dysraphic defect had significant positive correlation with lateral (p < 0.0001) and third (p = 0.006) ventricular size. Mean volume of the myelomeningocele sac was significantly different among Chiari II grades and inversely proportional to Chiari II grade (p = 0.0009). CONCLUSION: Larger spinal dysraphic defects correlated with increased ventricular size at fetal MRI. All of the fetuses with myelocele or kyphosis had severe Chiari II malformations. Larger myelomeningocele sac size was associated with lower grade of Chiari II malformation, suggesting that myelomeningocele sac formation may be protective against hindbrain herniation.
OBJECTIVE: The purpose of this study was to examine differences between patients with myelomeningocele and those with myelocele with respect to brain imaging findings at fetal MRI. MATERIALS AND METHODS: A single-center retrospective analysis was performed of fetal MRI examinations revealing open spinal dysraphism from 2004 through 2016 with available diagnostic postnatal spinal MR images in conjunction with neurosurgical follow-up findings. Images were reviewed by two board-certified fellowship-trained pediatric neuroradiologists. Relevant clinical data were recorded. RESULTS: The study included 119 fetal MRI examinations of patients with open spinal dysraphism. Myeloceles were found in 29.4% (35/119) of these examinations and myelomeningoceles in the others. All (35/35) myeloceles showed grade 3 (severe) Chiari II malformations. Only 73.8% (62/84) of myelomeningoceles showed grade 3 Chiari II malformation. Clinically significant spinal kyphosis was found in 5.0% (6/119) of fetuses, and all of these fetuses had grade 3 Chiari II malformations. The size of the spinal dysraphic defect had significant positive correlation with lateral (p < 0.0001) and third (p = 0.006) ventricular size. Mean volume of the myelomeningocele sac was significantly different among Chiari II grades and inversely proportional to Chiari II grade (p = 0.0009). CONCLUSION: Larger spinal dysraphic defects correlated with increased ventricular size at fetal MRI. All of the fetuses with myelocele or kyphosis had severe Chiari II malformations. Larger myelomeningocele sac size was associated with lower grade of Chiari II malformation, suggesting that myelomeningocele sac formation may be protective against hindbrain herniation.