PITFALLS IN ASSESSING THE NORMAL SPINE

1. Apparent splaying of the spine in the thoracic region created by imaging a portion of the fetal ribs in the parasagittal plane (1). This artifact is avoided by imaging in the true sagittal plane.
2. "Pseudodysraphism" (2) - The curvature of the fetal spine must be considered when imaging the spine transversely to avoid too much craniocaudal angulation, which may give one the appearance of splaying.

REFERENCES

1. Russ PD, Pretorius DH, Manco-Johnson ML et.al. The fetal spine. Neuroradiology 1986;28:398-407.
2. Dennis MA, Drose JA, Pretorius DH et.al. Normal fetal sacrum simulating spina bifida: "pseudodysraphism". Radiology 1985;155:751-754.