Normal anterior-posterior diameters of the spinal cord and spinal canal in healthy term newborns on sonography.

Abstract

There are no published normal values for spinal cord and canal diameters in newborns. Spinal cord and spinal canal diameters are assessed subjectively by radiologists without any objective values for the upper limit of normal. To determine normal values for anteroposterior (AP) diameters of the spinal cord and spinal canal on sonography in healthy term newborns. We performed ultrasound of the entire spine on 37 healthy newborns (23 male, 14 female). The AP diameters of the spinal canal and spinal cord were measured at representative levels of the cervical (C4, C5, C6), thoracic (T5, T6, T7, T8) and lumbar spine (lumbar enlargement and above and below the lumbar enlargement level). Statistical analysis was performed to determine the mean and standard deviation of the spinal canal and spinal cord AP diameter at each aforementioned vertebral level, and their correlations with birth weight, length and head circumference. The mean AP spinal cord diameter was 4.1±0.5mm at the cervical level, 3.3±0.3mm at the thoracic level and 4.4±0.6mm at the lumbar level. The mean AP spinal canal diameter was 7.7±0.7mm at the cervical level, 6.2±0.8mm at the thoracic level, and 8.4±0.7mm at the lumbar level. In this prospective study, we have determined normal values for AP diameters of the spinal cord and spinal canal on sonography in healthy newborns at representative cervical, thoracic and lumbar levels. This data may assist in evaluating the neonatal spine in clinical situations such as suspected spinal cord injury.