The case of a 40-year-aid woman with a dolichoodontoid, a rare congenital a
nomaly of the cranio-cervical region, is presented. Due to summation image
and overlying bony structures, plain radiographs in two planes were inconcl
usive. MRI revealed the hyperplasia of the odontoid process, allowed a grad
ing of the subtype of this disorder and demonstrated its relationship to th
e neural structures within the foramen magnum and the upper cervical spine.
Additional inflammatory disease, suspected in this patient with long stand
ing rheumatoid arthritis could be excluded by MRI. (C) 2000 Elsevier Scienc
e ireland Ltd. All rights reserved.