title: Dynamic MR in patients affected by neurogenical claudication: technique and results from a single-center experience.
abstract: BACKGROUND
  This study aimed to determine changes in size of lumbar spinal canal and related articular structures, during dynamic MR scans acquired in symptomatic patients standing upright using a new open MR system.
  
  
  METHODS
  Forty patients (mean age 58.4 years) affected by lumbar back pain associated with claudication, referring symptoms since more than 6 months. No one underwent to previous spine surgery. MR scans were performed with a novel open 0.5-T scanner, patient supine and upright (90°). Lumbar lordotic angle, flavum ligament thickness, herniated discs, spinal canal area, spinal canal and dural sac antero-posterior diameters, and spinal alignment were measured and compared in both supine and upright positions. Mean scanning time was 43 min.
  
  
  RESULTS
  All the considered parameters showed a statistically significant difference, except for lumbar lordotic angle. Mean percentage differences moving from supine to upright were +3.9 % for lumbar lordotic angle, +15 % for flavum ligament thickness, +16.2 % for sagittal disc bulge, -10.8 % for dural sac diameter, -13.1 % for spinal canal diameter, and -15.8 % for spinal canal area. In supine position, no patient presented with spondylolisthesis; moving to upright position, four patients showed spondylolisthesis (grade I).
  
  
  CONCLUSIONS
  Dynamic MR is a valuable diagnostic exam to analyze the structures involved in lumbar back pain due to spinal canal stenosis and spondylolisthesis; in supine position, relevant factors can be underestimated or hidden, becoming appreciable only patient standing upright. In this series, flavum ligament thickening presented a role comparable to disc bulge for narrowing of lumbar spinal canal.
authors.affiliation: Neuroradiology Department, Cardarelli Hospital, Naples, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Muto
authors.affiliation: Radiology Department, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo 200, 00100, Rome, Italy. francescogiurazza@hotmail.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Giurazza
authors.affiliation: Neuroradiology Department, Cardarelli Hospital, Naples, Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Guarnieri
authors.affiliation: Emicenter European Medical Imaging, Casavatore, Naples, Italy.
authors.forename: Rossana
authors.initials: R
authors.lastname: Senese
authors.affiliation: Measurement and Biomedical Instrumentation Laboratory, Università Campus Bio-Medico di Roma, Rome, Italy.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Schena
authors.affiliation: Neuroradiology Department, Cardarelli Hospital, Naples, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Zeccolini
authors.affiliation: Neuroradiology Department, Cardarelli Hospital, Naples, Italy.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Diano
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007383:Intermittent Claudication / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000000981:diagnostic imaging*; D059906:Neuroimaging / Q000379:methods*; D056888:Patient Positioning / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013130:Spinal Stenosis / Q000000981:diagnostic imaging*; D013577:Syndrome
keywords: Disc bulge; Dynamic MR; Flavum ligaments; Neurogenical claudication; Spinal canal stenosis