title: The value of dynamic radiographic myelography in addition to magnetic resonance imaging in detection lumbar spinal canal stenosis: A prospective study.
abstract: OBJECTIVE
  MRI is regarded as the study of choice in the diagnosis of lumbar spinal stenosis. In some cases, the supine MRI leads to a misdiagnosis in the extent of lumbar spinal stenosis. Dynamic myelography can detect lumbar spinal stenosis in these cases of where the MRI may not be as sensitive. To compare the sensitivities of dynamic radiographic myelography and supine MRI in lumbar canal stenosis (LCS) patients and to determine whether dynamic radiographic myelography is a valuable diagnostic exam in the work-up of lumbar canal stenosis.
  
  
  METHODS
  Over two years, the imaging data of 100 consecutive patients who were suspected of having LCS were prospectively analyzed. All lumbar intervertebral segments were evaluated in each patient on sagittal MR T2-weighted images and lateral plane images by myelography using a semi-quantitative scoring system. The differences in scores for 5 motion segments under 3 conditions (supine MRI, upright sitting myelography and standing myelography with extension) were analyzed statistically.
  
  
  RESULTS
  Of 100 patients with 500 analyzed intervertebral segments, 23 patients with inconclusive supine MRI results had LCS in standing myelography with extension. Compared with upright sitting myelography and supine MRI, standing myelography with extension yielded the highest score for every segment from L1/2 to L5/S1. Compared with the upright sitting myelography position, 61 more patients received a diagnosis of lumbar stenosis in the standing myelography with extension position, and 121 more stenotic segments were diagnosed. Compared with the supine MRI position, standing myelography with extension detected 64 more stenotic patients and 137 more stenotic segments.
  
  
  CONCLUSIONS
  n Based on a large patient sample, dynamic myelography is a valuable diagnostic tool in detecting lumbar spinal stenosis. Patients with lumbar spinal stenosis may have inconclusive supine MRI in 23% of cases being misdiagnosed as normal. This missed rate of LCS patients with unclear supine MRI results can be avoided with dynamic myelography. The combination of supine MRI and dynamic myelography is critical in the evaluation of LCS, especially if multisegmental findings are detected.
authors.affiliation: Department of Neurosurgery, Sankt Gertrauden Krankenhaus, Berlin, Germany; Department of Neurosurgery, University of Tübingen, Tübingen, Germany. Electronic address: martin.merkle@sankt-gertrauden.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Merkle
authors.affiliation: Department of Neurosurgery, University of Tübingen, Tübingen, Germany; Katharinenhospital Stuttgart, Stuttgart, Germany.
authors.forename: Gottlieb
authors.initials: G
authors.lastname: Maier
authors.affiliation: Department of Neuroradiology, University of Tübingen, Tübingen, Germany.
authors.forename: Sören
authors.initials: S
authors.lastname: Danz
authors.affiliation: Department of Neurosurgery, Sankt Gertrauden Krankenhaus, Berlin, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Kaminsky
authors.affiliation: Department of Neurosurgery, University of Tübingen, Tübingen, Germany.
authors.forename: Marcos S
authors.initials: MS
authors.lastname: Tatagiba
authors.affiliation: Department of Neurosurgery, Neurological Institute, Cleveland Clinic Abu Dhabi, UAE.
authors.forename: Nader M
authors.initials: NM
authors.lastname: Hebela
authors.affiliation: Department of Neurosurgery, University of Tübingen, Tübingen, Germany; Department of Neurosurgery, Neurological Institute, Cleveland Clinic Abu Dhabi, UAE. Electronic address: f.roser@gmx.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Roser
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000592:standards*; D008297:Male; D008875:Middle Aged; D009192:Myelography / Q000592:standards*; D056888:Patient Positioning / Q000592:standards*; D011446:Prospective Studies; D013130:Spinal Stenosis / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Dynamic myelography; Lumbar spinal stenosis; Supine MRI