RT Journal Article SR Electronic T1 Partial Aplasia of the Posterior Arch of the Atlas with an Isolated Posterior Arch Remnant: Findings in Three Cases JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 1167 OP 1171 VO 21 IS 6 A1 Aseem Sharma A1 Shailesh B. Gaikwad A1 Parminder S. Deol A1 Nalin K. Mishra A1 Shashank S. Kale YR 2000 UL http://www.ajnr.org/content/21/6/1167.abstract AB Summary: We report the imaging findings in three symptomatic cases of partial aplasia of the posterior arch of the atlas with an isolated posterior remnant of the arch. These cases are instructive in illustrating the mechanism of cord impingement produced by the posterior arch remnant during extension of the cervical spine. Additionally, focal increased T2 signal was observed within the cord at the level of the anomaly in two of the patients.