title: Postoperative MR Imaging of Spontaneous Transdural Spinal Cord Herniation: Expected Findings and Complications.
abstract: OBJECTIVE
  Spontaneous transdural spinal cord herniation is no longer a rare cause of myelopathy. The high frequency of diagnoses has led to an increase in the number of surgical procedures. The purpose of this study was to describe the spectrum of postoperative MR imaging findings concerning spontaneous transdural spinal cord herniation and to provide a practical imaging approach for differentiating expected changes and complications after an operation.
  
  
  METHODS
  We retrospectively reviewed MR images from 12 patients surgically treated for spontaneous transdural spinal cord herniation. Surgery comprised either dural defect enlargement or duraplasty procedures. Postoperative follow-ups included at least 3 (early, intermediate, late) MR imaging studies. MR images were analyzed with respect to 3 spinal compartments: intradural intramedullary, intradural extramedullary, and extradural. The meaning and reliability of changes detected on MR images were related to their radiologic and clinical evolution with time.
  
  
  RESULTS
  Spinal cord realignment has been stable since the early study, whereas spinal cord signal and thickness evolved during the following scans. Most extramedullary and extradural changes gradually reduced in later MR images. Three patients treated with dural defect enlargements experienced the onset of new neurologic symptoms. In those patients, late MR images showed extradural fluid collection and the development of pial siderosis.
  
  
  CONCLUSIONS
  Our findings demonstrate the spectrum of postoperative imaging findings in spontaneous transdural spinal cord herniation. Spinal cord thickness and signal intensity continued to evolve with time; most extramedullary postsurgical changes became stable. Changes observed in later images may be suggestive of complications.
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.) simona.gaudino@rm.unicatt.it.
authors.forename: S
authors.identifier: http://orcid.org/0000-0003-1681-4343
authors.initials: S
authors.lastname: Gaudino
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: R
authors.identifier: http://orcid.org/0000-0002-1242-296X
authors.initials: R
authors.lastname: Colantonio
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-6328-2987
authors.initials: C
authors.lastname: Schiarelli
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-0801-0380
authors.initials: M
authors.lastname: Martucci
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: R
authors.identifier: http://orcid.org/0000-0003-4517-3477
authors.initials: R
authors.lastname: Calandrelli
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-2219-6484
authors.initials: A
authors.lastname: Botto
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-7691-8999
authors.initials: M
authors.lastname: Pileggi
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: E
authors.identifier: http://orcid.org/0000-0003-1041-2888
authors.initials: E
authors.lastname: Gangemi
authors.affiliation: Institute of Neurosurgery (G.M.), Catholic University of Rome, Rome, Italy.
authors.forename: G
authors.identifier: http://orcid.org/0000-0001-9214-3911
authors.initials: G
authors.lastname: Maira
authors.affiliation: From the Institute of Radiology (S.G., R. Colantonio, C.S., M.M., R. Calandrelli, A.B., M.P., E.G., C.C.).
authors.forename: C
authors.identifier: http://orcid.org/0000-0003-3800-3648
authors.initials: C
authors.lastname: Colosimo
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D059685:Herniorrhaphy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008591:Meningomyelocele / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D019635:Neurosurgical Procedures; D011184:Postoperative Period; D012189:Retrospective Studies