title: [Epidurography: comparison with CT, spiral CT and MR epidurography].
abstract: OBJECTIVE
  The purpose of this study was to explain the origin of image patterns demonstrated by conventional epidurography, which is a controversially discussed topic in recent literature.
  
  
  METHODS
  After introduction of thoracic epidural catheters and iopamidol injection, conventional epidurography and CT-epidurography were performed on 25 preoperative patients. After injection of Gadolinium-DTPA MR-epidurography was performed in two patients treated for chronic pain with already introduced epidural catheters. Three volunteers also underwent identical imaging after introduction of thoracic epidural catheters and in addition helical-CT epidurography using twin-beam technology.
  
  
  RESULTS
  40% of the patients demonstrated the railroad track phenomenon. We were able to prove that it is a sign of a rhythmically variable filling of segments of the lateral epidural space with contrast medium 76% of the patients demonstrated no ventral epidural space at the thoracic level. 56% of the patients showed a medial area of translucence combined with a band-shaped contrasting of the epidural space in the standard ap view. This was proven in all cases to be a plica mediana dorsalis by CT. In all volunteers who underwent helical-CT and MR epidurography we observed the railroad track phenomenon and the filling defect of the anterior thoracic epidural space.
  
  
  CONCLUSIONS
  CT epidurography is well suited for obtaining new insights into the interpretation of findings obtained by conventional epidurography.
authors.affiliation: Universität Ulm, Klinik für Radiologie.
authors.forename: R
authors.initials: R
authors.lastname: Tomczak
authors.forename: W
authors.initials: W
authors.lastname: Seeling
authors.forename: A
authors.initials: A
authors.lastname: Rieber
authors.forename: R
authors.initials: R
authors.lastname: Sokiranski
authors.forename: N
authors.initials: N
authors.lastname: Rilinger
authors.forename: H J
authors.initials: HJ
authors.lastname: Brambs
mesh_terms: D015360:Analgesia, Epidural; D002908:Chronic Disease; D004824:Epidural Space / Q000000981:diagnostic imaging*; D005069:Evaluation Studies as Topic; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D059408:Pain Management; D014057:Tomography, X-Ray Computed / Q000379:methods