title: Spinal MR findings in continuous epidural analgesia without infection.
abstract: OBJECTIVE
  Spinal epidural abscesses are major complications of epidural anesthesia, and their MR features have been reported. In patients receiving continuous infusion via an epidural catheter, MR findings may mimic those of spinal epidural abscess in the absence of infection. The purpose of this study was to assess the spinal MR findings associated with continuous epidural anesthesia.
  
  
  METHODS
  Spinal MR findings in five consecutive patients receiving continuous epidural anesthesia were retrospectively evaluated. Axial and sagittal T1- and T2-weighted spin-echo and contrast-enhanced fat-suppressed T1-weighted spin-echo images were obtained. Infection was ruled out on microbiologic analysis three patients and on follow-up in two. Each lesion was evaluated for its MR signal intensity, location, extent, delineation, and enhancement pattern. In three patients, follow-up MR imaging was performed within 5-150 days, and the images were compared.
  
  
  RESULTS
  Posterior epidural lesions were identified in all five patients. The lesions were isointense to hypointense relative to the spinal cord on T1-weighted images, isointense relative to CSF on T2-weighted images, and well enhanced on enhanced T1-weighted images. The anomalous enhancement involved two to seven vertebral bodies. In one patient, the enhanced lesion slightly compressed the spinal cord. On follow-up MR imaging, the epidural lesions decreased in two patients and did not change in one.
  
  
  CONCLUSIONS
  Continuous epidural anesthesia can result in MR findings similar to those of epidural abscess, even in the absence of infection.
authors.affiliation: Department of Radiology, Miyakonojo Medical Association Hospital, Kitakyushu, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ikushima
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.forename: Yukunori
authors.initials: Y
authors.lastname: Korogi
authors.forename: Maeda
authors.initials: M
authors.lastname: Norio
authors.forename: Mikako
authors.initials: M
authors.lastname: Koganemaru
authors.forename: Ryoko
authors.initials: R
authors.lastname: Suga
authors.forename: Shoji
authors.initials: S
authors.lastname: Morishita
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D015360:Analgesia, Epidural; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013116:Spinal Cord / Q000473:pathology*