The fetal spinal canal - A three-dimensional study

The size of the lumbar spinal canal was evaluated in a prospective cross-se ctional ultrasound (US) study to determine normal size values for lumbar pa rt of the vertebral canal. A total of 88 patients undergoing routine obstet ric US were studied between 16-41 weeks gestation. Structural anomalies or growth restriction were excluded. Area and volume of the vertebral canal in L1, L3 and L5 were calculated by three-dimensional (3-D) US. The size of t he spinal canal correlated well with gestational age and no major differenc es could be found between upper and lower lumbar spine. By 3-D US, in vivo assessment of the spinal canal becomes possible. Further studies are needed to confirm our findings. (C) 1999 World Federation for Ultrasound in Medic ine & Biology.