Second Trimester Diagnosis of Diastematomyelia: US, CT and MRI Features

Submit Manuscript | http://medcraveonline.com A 26-year-old primigravida presented to the ultrasound unit at 21 weeks of spontaneous gestation for routine screening. 2D and 3D Ultrasound examination using Esaote (MyLabSIX) machine equipped with 7 and 10 MHz probes detected widening of the spinal canal in coronal section and additional echogenic focus in the widened portion of the vertebral column in axial, coronal and sagittal section with intact skin and soft tissues overlying the affected spinal segment (Figures 1A-1D). The spinal cord was obscured by to acoustic shadowing. We performed fetal MRI two days later. Images were obtained in three orthogonal planes by using fast spin-echo T2 weighted images (T2W) images with 3 mm slices thickness. This confirmed the abnormality, showing low signal bony spur in T2W sagittal and coronal images separating two hemicords within a single thecal sac. Both hemicords are of similar size and they are not separated by a midline sagittal septum. In the lower vertebral segments below the bony spur level, the two hemicords fused into one cord (Figure 2A-2D). There were no spinal cord tethering nor other spinal malformations. There was no evidence of additional brain anomalies. With regards to the limitation of the fetal spine evaluation in MR, an informed consent for fetal low-dose CT scan is obtained. The CT scan showed a midline thin bony septum splitting the spinal canal connecting the anterior and posterior vertebral archs in the axial plane with incomplete median sagittal partition of thoracic spine extending from T6 down to T10 level (Figure 3A, Figure 3B & Figure 3C). These findings confirmed the diagnosis of type I diastematomyelia.