The nerve root sedimentation sign in diagnosis of lumbar spinal stenosis

BackgroundThe nerve root sedimentation sign is a magnetic resonance (MR) sign, shown to be present in central lumbar spinal stenosis. The lack of sedimentation of the nerve roots to the dorsal part of the dural sac is consistent with the positive nerve root sedimentation sign.PurposeTo validate the reliability of the nerve root sedimentation sign in diagnosis of different grades of lumbar spinal canal stenosis.Material and MethodsThis study was a retrospective review of 101 consecutive MR imaging (MRI) studies obtained on patients with clinically suspected lumbar canal stenosis. Based on the minimum anteroposterior (AP) diameter of the dural sac the study sample was classified into two groups: a group with morphological lumbar spinal stenosis; and the group of patients free from stenosis (AP > 12 mm). Patients with stenosis were further subclassified based on its severity: severe stenosis (AP ≤ 10 mm); and moderate stenosis (AP > 10 mm to ≤ 12 mm).ResultsPositive sedimentation sign was identified in 81% o...