Focal anterior displacement of the thoracic spinal cord without evidence of spinal cord herniation or an intradural mass on MR imaging

Abstract

Introduction: This study aimed to report MR findings on the focal anterior displacement of the thoracic spinal cord in asymptomatic patients without a spinal cord herniation or intradural mass.

Methods: Between 2007 and 2011, we collected a total of 12 patients (male: female = 6:6

mean age, 51.7

range: 15–83 years) with focal anterior displacement of the spinal cord and without evidence of an intradural mass or spinal cord herniation. Two radiologists retrospectively reviewed the MR imaging findings in consensus.

Results: In all patients, an asymmetric spinal cord deformity with a focal dented appearance was seen on the posterior surface of the spinal cord, and it involved a length of 1 or 2 vertebral segments in the upper thoracic spine (the first to 6th thoracic vertebrae). Moreover, a focal widening of the posterior subarachnoid space was also observed in all cases. None of the patients had myelopathy symptoms, and, with the exception of one patient, they showed no focal T2-hyperintensity in the spinal cord. In addition, cerebrospinal fluid flow artifacts were seen in the posterior subarachnoid space of the affected spinal cord level. CT myelography revealed a preserved CSF flow in the two available patients.

Conclusions: Focal anterior spinal cord indentation can be found in the upper thoracic level of asymptomatic patients without a spinal cord herniation or intradural mass.