Abstract: Objective To assess the practicability and reliability of lumbar MRM and analyze the clinical value of lumbar MRM for degenerative lumbar spine disorders.Methods One lumbar intervertebral disc(L₃₄,L₄₅,L₅S₁) as well as two nether lumbar nerve roots make up an investigative unit. One hundred and eight investigative units of 36 patients with degenerative lumbar spine disorders were examined with computed tomography(CT) and magnetic resonance imaging(MRI) and MRM.All patients were treated surgically.The evaluation of the practicability included the quality of image,security and cost.On the basis of clinical diagnosis,we compared the sensitivity and specificity of CT,MRI and MRM by χ² test in order to assess the facticity of lumbar MRM.Results Thirty-four(94.4%) of the patients' images were excellent.All were examined without injury or side-effect.The average examination time is eighteen minutes and the cost is 1 080 RMB.Statistical results showed that MRM as a whole appears to be as sensitive as MRI or CT but more specific than MRI or CT in diagnosing degenerative lumbar spine disorders.Conclusion MR myelography has many technical characters:(1) Technical improvements make the operation simple and more convenient.(2) The quality of images is excellent.(3) The security is good.(4) The integrative cost is no higher than other means.(5) MRM not only has an obvious advantage in locating the lesion of degenerative lumbar spine disorders,but also helps to distinguish the kind of degeneration.(6) The specificity is higher and so is the sensitivity.Therefore,MRM has important clinical value in the diagnosis and operative planning of degenerative lumbar spine disorders,but it has not been regarded as a conventional examination now.

Key words: lumbar degenerative spine disorders, magnetic resonance myelography, sensitivity, specificity, clinical value